Crustacea Glossary Complete List

Introduction

Joel Martin

jmartin@nhm.org

Because crustaceans are the most morphologically diverse group of animals on the planet, it comes as no surprise that there exists a huge number of morphological terms that are being used, or that have been used in the past, to describe them. As far as I have been able to determine, there is no single, standard glossary that is widely accepted. This is in part because different terms may mean different things for different groups of crustaceans, and in part because many existing glossaries tend to deal with selected subgroups or local faunas rather than with the taxon as a whole. More general glossaries do exist, and include McLaughlin's (1980) book on crustacean morphology and the glossary in the Treatise on Invertebrate Paleontology (Moore and McCormick, 1969), upon which McLaughlin's glossary seems to have been largely based.

The following glossary includes terms and their definitions taken verbatim from a variety of sources. In all cases, the reference is given in brackets [ ] following the definition. In cases where the same term is defined in slightly different ways, both definitions are given and both references are listed. If the definitions are identical, I have simply cited both references after the definition. The references also include the name of the group or groups of crustaceans with which that reference primarily deals. For example, the terms taken from Williams (1984) deal only with the Decapoda, specifically those of the east coast of the United States, and this is so indicated. In some publications, the glossary also contains more adjectival terms and non-morphological entries, in addition to the strictly descriptive terms. I have opted to list everything found in the original publication, so that you will occasionally find unusual entries that seem to deal not with crustacean morphology in general but with descriptive terms or even more specialized topics (e.g., "Moult to puberty").

References to figures refer to original illustrations in the original publications, and not to any figures in this computer file. Perhaps some day we will be able to add appropriate figures to this file as well, as in some cases the figures are much more clear than the verbal definitions given.

Please be sure to cite the original source of the definition, and not this electronic file, as your source for these definitions.

I have not made any attempt to correct definitions, grammar, or spelling, preferring instead to list each entry as it originally appeared without inserting my own biases or judgment. An obvious exception with regard to biases is that my specialty is the Decapoda, and so initially most terms will have been taken from publications on this group. I hope that as time goes by and more definitions are received by other workers in the field, this bias will correct itself.

Some descriptive adjectival terms are included here as well, and definitions for some of these have been taken from the American Heritage Dictionary of the English Language, third edition [AHD].

If you are aware of other publications that contain good glossaries for crustaceans, please let us know so we can add them to our list.

Corrections? Additions? Comments? Please send them to me. I promise to at least consider them.

Joel Martin
jmartin@nhm.org

Definitions

Current as of 7 November 2009

Note that this is a web reference, and hence may change over time.
Please send us corrections using the online comment form.

This resource is found at: http://crustacea.nhm.org//glossary

Abdomen

Posterior part of body, of six segments or somites, sometimes including tailfan. [Poore, 2004]
Region of the body posterior to cephalothorax, consisting of six body segments and telson (see Fig. 13). [Hobbs and Jass, 1988]
That part of the body posterior to the cephalothorax, consisting of six body segments or somites plus the telson (Fig. 1).
(syn. Tail) [Perez Farfante and Kensley, 1997]
That portion of the body posterior to the cephalothorax, consisting of the telson and six body segments ot somites; the "tail". [Hobbs, Hobbs, and Daniel 1977]
The "tail or that part of the body posterior to the cephalothorax, consisting of six body segments or somites and the telson. [Chace and Hobbs, 1969]
The part of the body posterior to cephalothorax, the 'tail." [Butler, T. H.]
The posterior region of the trunk (body). [Brusca and Brusca, 2002]
The segmented hindmost part of the body held flexed forward beneath the thorax. Composed of six segments and a telson, referred to here as seven-segment. [Ingle, 1983]
Trunk somites (tagma) between thorax and telson; somites with or without limbs.
(syn. pleon) [McLaughlin, 1980]
Trunk tagma following thorax and including telson; somites either without limbs or (in Malacostraca) bearing pleopods or uropods or both; in crabs bent sharply forward under thorax and much wider in females than in males.
(syn. pleon)
See: Metasome, Urosome [Moore and McCormick, 1969]
(Taxon-specific: Order Cladocera) Trunk. [Stachowitsch, 1992]
(Taxon-specific: Order Notostraca) Posterior division (tagma) of body (head, thorax, abdomen), Consists of large and variable number of segments (body rings), the anterior abdominal rings each bearing several appendages. [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) Trunk. [Stachowitsch, 1992]
(Taxon-specific: Order Anostraca) Posterior division (tagma) of body (head, thorax, abdomen). Consists of eight segments (somites) and bears terminal telson with caudal rami. lacks appendages except for anterior two somites, which are fused (genital somite) and bear reproductive structures. [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) Posterior division (tagma) of body (cephalon, thorax, abdomen). Consists of 11 segments (somites) and bears terminal telson (anal somite) with caudal furca, With the exception of a reduced pair of appendages ("genital appendages"), abdomen lacks limbs. Thorax and abdomen together occasionally termed trunk. [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) Pleon. [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) Pleon. [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Posterior division (tagma) of body (cephalothorax, abdomen). Consists of six somites (pleomeres), each bearing pair of appendages (pleopods). Sixth pleomere (with uropods) bears posterior telson. (extended, bent upon itself, folded under cephalothorax, spirally coiled; symmetrical, asymmetrical; compressed, depressed; acutely triangular, broadly triangular, broadly oval, subcircular, T-shaped; smooth, sculptured).
(syn. pleon) [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Pleon. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) Pleon. [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Posterior of three basic divisions (tagmata) of body (head, thorax, abdomen). Consists of six somites (pleomeres) bearing posterior telson.
(syn. pleon) [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Posterior division (tagma) of body (cephalon, thorax, abdomen). Consists of six somites (pleomeres), each bearing pair of appendages (pleopods). Sixth pleomere (with uropods) bears or is fused with telson. (compressed, depressed).
(syn. pleon) [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Posterior division (tagma) of body (cephalon, thorax, abdomen). Consists of seven segments (somites), the first six each bearing pair of pleopods; bears telson and caudal furca posteriorly. Anterior region of abdomen covered, along with thorax and posterior part of head (cephalon), by carapace.
(syn. pleon) [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) Unsegmented posterior division (tagma) of body (cephalothorax, abdomen, or cephalon, pereon, abdomen). Relatively small, dorsoventrally flattened, and drawn out posteriorly into two lobes; bears pair of caudal rami and anus in cleft (sinus) between two lobes. (acorn-shaped, broadly elliptical, cordate, obcordate, obovate, spindle-shaped; lobes: acutely pointed, bluntly pointed, rounded).
(syn. pleon) [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) In ascothoracican, posteriormost division (tagma) of body (head, thorax, abdomen). Consists of four or five segments (somites), the last bearing caudal furca. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Posterior and typically narrowest of three basic divisions of body (cephalon, thorax, abdomen). Consists of five somites (pleomeres), the first often being termed genital somite, the last termed anal somite (posterior to caudal rami). Typically lacks appendages. (symmetrical, asymmetrical; segmented, unsegmented).
(syn. pleon) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) That part of the body of a copepod posterior to the somite bearing the genital opening. The abdomen includes four somites, three of which do not bear a paired appendage; the posterior somite bears the caudal rami and is the first abdominal somite to appear during development. [Ferrari and Dahms, in press]
(Taxon-specific: Subclass Mystacocarida) According to interpretation dividing body into cephalon, thorax, and abdomen, last five somites of body. Lacks appendages yet bears telson and caudal furca. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Rudimentary region of body bearing caudal rami; indistinguishably fused to thorax. [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) Posterior of three divisions (tagmata) of body (head, throrax, abdomen). Consists basically of six somites (pleomeres) bearing posterior telson, although in bathynellacean, last pleomere is fused with telson to form pleotelson. Bears varying number of pleopods.
(syn. pleon) [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) Posterior of three divisions (tagmata) of body (cephalon, thorax, abdomen). Consists basically of six somites (pleomeres) bearing posterior telson. (See also pleotelson).
(syn. pleon) [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Posterior division (tagma) of body (cephalo-thorax, abdomen); consists of six somites (pleomeres), the first first five bearing pleopods, the sixth bearing uropods. Bears posterior telson. [Stachowitsch, 1992]

Abdominal aorta

(Taxon-specific: Order Mysida) Posterior aorta. [Stachowitsch, 1992]

Abdominal appendage

(Taxon-specific: Order Stomatopoda) Pleopod. [Stachowitsch, 1992]

Abdominal ganglion

(Taxon-specific: Subclass Branchiura) Ganglion adjoining last thoracic ganglion in anterior region of thorax (forming last lobe of six-lobe ganglion mass). May bear smaller pair of lobes; gives rise to two pairs of nerves extending into abdomen. [Stachowitsch, 1992]

Abdominal limb

See: Pleopod, Uropod [Martin, 2005]

Abdominal process

Finger-like projection ( one to several ) on dorsal surface of cladoceran abdomen; may help to retain eggs in brood chamber. [Moore and McCormick, 1969]
(Taxon-specific: Order Cladocera) Finger-like projection(s) on dorsal surface of abdomen. [McLaughlin, 1980]
(Taxon-specific: Order Cladocera) One of typically two dorsal processes projecting from border of trunk and postabdomen. Considered to serve in closing off brood chamber posteriorly.
(syn. abdominal outgrowth) [Stachowitsch, 1992]

Abdominal segment

Entire animal, right appendages omitted, dorsal view, based on Munida. [Baba, 2005]
(Figure only.) [Baba, 2005]

Abdominal seta

(Taxon-specific: Order Cladocera) One of two elaborate setae located on small protuberance on dorsal surface of postabdomen.
(syn. setae natatoriae) [Stachowitsch, 1992]

Abdominal somite

Any single division of body behind thorax.
(syn. pleomere, pleonite) [Moore and McCormick, 1969]
Any single division of body between thorax and telson.
(syn. pleomere, pleonite) [McLaughlin, 1980]
(Taxon-specific: Class Cephalocarida) One of 11 segments of abdomen. First abdominal somite ( = 9th postcephalic segment) bears reduced pair of appendages ("genital appendages"). Last abdominal somite (19th postcephalic segment) bears telson. [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Pleomere. [Stachowitsch, 1992]

Abdominal spine

(Taxon-specific: Order Anostraca) Spine-shaped projection on each side of abdominal somite. [Stachowitsch, 1992]

Abreptor

Postabdomen of cladocerans, bent forward from junction with body and terminating in 2 claws with spines and teeth on their concave sides. [Moore and McCormick, 1969]
(Taxon-specific: Order Cladocera) Postabdomen, bent forward from junction with body, terminating in 2 claws. [McLaughlin, 1980]
(Taxon-specific: Order Cladocera) Postabdomen. [Stachowitsch, 1992]

Acanthopod

In Cirripedia (Thoracica), appendage where rami of cirrus have setae along lesser curvature much reduced; setae of greater curvature arranged in transverse row, as strong sharp spines at each articulation (cf., ctenopod, lasiopod). [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Appendage (cirrus) with short row of strong sharp spines distally at each articulation of greater curvature and few or no spines along lesser curvature. [McLaughlin, 1980]

Acanthosoma

(Taxon-specific: Order Decapoda) Zoea. [Stachowitsch, 1992]

Accessory Antennule

(Taxon-specific: Subclass Copepoda) The atrophied and offset terminal segment of the antennary endopod. [Boxshall and Halsey, 2004]

Accessory flagellum

(Taxon-specific: Order Amphipoda) Small inner flagellum of antennule (as opposed to larger primary flagellum). Number of articles is of taxonomic importance. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) In antenna of certain isopods, small, many-segmented flagellum projecting from fourth segment of peduncle. [Stachowitsch, 1992]

Accessory flexor muscle

A small muscle which flexes the leg at the MC joint. It is in two parts, proximal and distal, and inserts on a long thin apodeme in the merus (Fig. 19). [Warner, 1977]

Accessory gill

(Taxon-specific: Order Amphipoda) One in a series of I small respiratory structures projecting from bases of coxal gills. [Stachowitsch, 1992]

Accessory gland

(Taxon-specific: Order Stomatopoda) In male reproductive system, pair of slender glands in thorax under heart; fused anteriorly and opening at tips of penes (via ducts running parallel to sperm ducts). [Stachowitsch, 1992]

Accessory heart

(Taxon-specific: Order Decapoda) Cor frontale. [Stachowitsch, 1992]

Accessory lobe

Small lobe at base of median lobe, on anterior surface of petasma in the genus Gennadas. [Perez Farfante and Kensley, 1997]
(Taxon-specific: Order Cumacea) One posteriorly directed part of epipod of first maxilliped pair, single respiratory projection set apart from series of remaining branchial lobules. [Stachowitsch, 1992]

Accomodation groove

(Taxon-specific: Class Ostracoda) Hinge structure; longitudinal groove above median hinge element. Receives dorsal edge of opposite valve. [Stachowitsch, 1992]

Acicle

Antennal scale reduced to a spine. [Williams, 1984]
Small scaphocerite or antennal scale. [Poore, 2004]
(Taxon-specific: Order Decapoda) Spine-shaped outer branch (exopod) of antenna; represents reduced antennal scale (scaphocerite). May also refer to spine-like ophthalmic scale on eyestalk. (unarmed, spinose). [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Ocular scale. [Stachowitsch, 1992]

Acron

Anteriormost part of body carrying eyes, not considered to be true cephalic somite.
(syn. ophthalmic somite, presegmental region. [Some authors recognize as protocephalon anterior part of h) [Moore and McCormick, 1969]
Anteriormost part of the body carrying the eyes; not considered true cephalic somite.
(syn. opthalmic somite, presegmental region) [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) Anterior segment of body (although not considered to be a true somite); bears eyestalks (ocular peduncles). Acron and first cephalic somite occasionally interpreted as representing protocephalon.
(syn. ophthalmic somite, pre-segmental region) [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Anteriormost segment of body (although not considered to be a true somite); divided into three plates-fastigial, ocular, and postocular- of which the median ocular plate bears the eyestalks (ocular peduncles). Not covered by carapace, although rostrum may partially or entirely extend across acron.
(syn. opthalmic somite) [Stachowitsch, 1992]

Acumen

Pointed apical part (tip) of rostrum, frequently delineated basally by marginal spines (see Fig. 14). [Hobbs and Jass, 1988]
The apical part of the rostrum frequently delimited basally by marginal spines. [Hobbs, Hobbs, and Daniel 1977]

Acute

Tapering to sharp point. [Butler, T. H.]

Adductor muscle (of carapace)

Muscle attached to carapace for pulling it to the body (thorax) or connecting halves of bivalve shell (e.g. Conchostraca, Ostracoda, Leptostraca) or valves of cirriped capitulum for closure of them. In Cirripedia, any transverse muscles, particularly that of maxillary segment, for closure of aperture; in Thoracica, adductor (adductor scutorum) acts upon scutal plates or valves. [Moore and McCormick, 1969]
(Taxon-specific: Order Diplostraca) Well-developed muscle attaching each side of head region to carapace. (See also ligament). [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Carapace adductor muscle. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Conspicuous transverse muscle joining both scuta and serving to close aperture. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Muscle attached to carapace for pulling it to body or connecting halves of bivalve carapace. [McLaughlin, 1980]
(Taxon-specific: Class Ostracoda) Well-developed transverse muscle extending from body to inner surface of each valve. Forms characteristic muscle scars on valves and serves to close carapace. [Stachowitsch, 1992]

Adductor muscle scar pattern

(Taxon-specific: Class Ostracoda) Rather central pattern of scars (raised or depressed) indicating where central adductor muscles attach to valves; not always clearly visible. [Cohen, Peterson, and Maddocks, in press]

Adductor pit

In cirripeds, depression on interior of scutum for attachment of adductor muscle, located between adductor ridge and occludent margin. [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature: on inner surface of scutum, depression marking attachment point of adductor muscle. In unstalked barnacle, located between adductor ridge and occludent margin. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Depression on inner surface of scutum between adductor ridge and occludent margin for attachment of adductor muscle (thoracic Cirripedia). [McLaughlin, 1980]

Adductor ridge

In cirripeds (Balanomorpha), linear elevation on interior of scutum between adductor pit and tergal margin. [Moore and McCormick, 1969]
Linear elevation on inner surface bounding adductor pit on tergal pit in sessile barnacles. [McLaughlin, 1980]
Balanus trigonus: wall plates, exploded; and interior of operculum. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature: on inner surface of scutum in unstalked form, linear elevation between adductor muscle pit and tergal margin. [Stachowitsch, 1992]

Adhesion pads

(Taxon-specific: Subclass Copepoda) Raised areas of specialised integument, ornamented with fine ridges, found in some siphonostomatoids parasitic on fish. [Boxshall and Halsey, 2004]

Adhesive gland

(Taxon-specific: Subclass Cirripedia) Cement gland. [Stachowitsch, 1992]

Adont hinge

(Taxon-specific: Class Ostracoda) Single element hinge, bar on one valve fits into groove of other valve. [Cohen, Peterson, and Maddocks, in press]

Adrostal carina

Ridge flanking the rostrum, sometimes nearly reaching the posterior margin of the carapace (Fig. 2B). [Perez Farfante and Kensley, 1997]

Adrostral ridge

Ridge parallel to and separated by narrow groove from rostrum (Penaeoidea). [Poore, 2004]

Adrostral sulcus

Groove flanking the rostrum mesial to the adrostral carina, sometimes nearly reaching the posterior margin of the carapace (Fig. 2B). [Perez Farfante and Kensley, 1997]

Aesthetasc seta

Confined to antennule; thin-walled, smooth, non-tapering seta, rounded tip; without pore; annulus not evident. [Ingle, 1992]

Aesthetascs

See: Esthetasc [Martin, 2005]
A long, tubular, sensory seta having thin cuticle, found on the antennula or antenna. Aesthetascs may have a chemosensory function, because males generally have more of these structures than females. [Wilson, 1989]
Sensory seta covered by delicate cuticle, often projecting from antenna or antennule.
(syn. olfactory hair, esthetasc, esthete...) [McLaughlin, 1980]
Simple, tubular, thin-walled, chemosensory seta often found on the antennular flagellum. [Holdich and Jones, 1983]
Spinelike cuticular processes often occurring in clumps or rows and functioning in chemoreception, usually located on the antennules. [Brusca and Brusca, 2002]
(Taxon-specific: Order Cladocera) One in a tuft of sensory projections at tip of each antennule.
(syn. esthete, olfactory seta) [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) Elongate sensory projection at tip of each antennule.
(syn. esthete) [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) One in a series of sensory projections on main flagellum of antennule. [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) One in a series of sensory projections on flagella of antennules. [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) One in a series of small sensory projections on outer flagellum of antennule.
(syn. esthetasc, esthete, olfactory hair) [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) One in a series of thin-walled sensory projections on antennule.
See: Calceolus [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) One in a series of sensory projections on antennules. (uniramous, biramous, triramous). [Stachowitsch, 1992]
Nomenclature of isopod cephalon (A). Examples of isopod mouth appendages: Idoteidae (B, C, F, H); Cirolanidae (D, E, G, I). [Wetzer et al. 1997]
(Taxon-specific: Order Isopoda) Thin-walled chemosensory seta usually found on antennular flagellum. [Wetzer et al. 1997]
(Taxon-specific: Order Isopoda) Thin-walled sensory seta usually on flagellum of antennule. [Kensley and Schotte, 1989]
(Taxon-specific: Order Leptostraca) One in a series of sensory projections on antennules and ocasionally also on antennae. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) A thin-walled, sensory element with putative chemoreceptive function, found on the antennules. [Boxshall and Halsey, 2004]
(Taxon-specific: Subclass Copepoda) A transformed seta of antenna 1 or another oral appendage of copepodids. An aesthetasc usually has a sclerotized base but otherwise is poorly sclerotized; it often is considered to have a chemosensory function. [Ferrari and Dahms, in press]
(Taxon-specific: Subclass Copepoda) One in a series of small sensory projections along antennule.
(syn. esthetasc, esthete) [Stachowitsch, 1992]
(Taxon-specific: Subclass Mystacocarida) Small sensory projection at tip of each antennule.
(syn. aesthete) [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) One in a series of small sensory projections along antennule or antenna; considered to be modified setae. [Stachowitsch, 1992]
(Taxon-specific: Class Remipedia) One of numerous robust, long sensory projections aggregated in several dense rows at base of antennules (on pad on first article of peduncle); directed posteriorly and partially covering antennae.
(syn. esthetasc, esthete, olfactory hair) [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) One of several senory projections on larger of two flagellaf antennule. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) One in a series of small sensory projections on each antennule. [Stachowitsch, 1992]

Afferent branchial channels

Pair of channels between ridges, supplying water to branchial cavity and opening in front of chelipeds or alongside epistome (some Brachyura). [Poore, 2004]

Afferent channels

Opening through which water passes to gills. [McLaughlin, 1980]
Openings through which water passes to gills, in brachyuran crabs generally located in front of bases of chelipeds. [Moore and McCormick, 1969]
Openings through which water passes to gills. In brachyuran crabs, usually opening behind pterygostomian regions and in front of chelipeds except in certain Oxystomata in which they open at anterolateral angles of palate or endostome. [Williams, 1984]

Afferent respiratory channels

Channels through which water passes to the gills, that open in front of the chelipeds and behind the pterygostomial region except in some oxystomata where they open at the sides of the endostome.
(syn. afferent branchial channels) [Ingle, 1980]
(Taxon-specific: Order Decapoda) Opening through which water enters branchial chamber under carapace. Typically applied to more restricted opening in crab-like (brachyuran) decapod; located anteroventrally on each side of body, either behind pterygostomial regions or in front of chelipeds.
(syn. afferent branchial channel)
See: Efferent respiratory channels [Stachowitsch, 1992]

Ala

One of pair of posteriorly directed cephalic-shield extensions; in cirripeds (Balanomorpha), triangular lateral part of compartment plate delimited from paries, which is overlapped by adjacent compartment plate with or without radius.
(pl. alae) [Moore and McCormick, 1969]
(Taxon-specific: Subclass Branchiura) One of two posterolateral extensions of carapace. (broad, broadly rounded, narrowly rounded, elongate and coiled behind thorax, greatly elongated; extending to second, third, or fourth thoracomere, to abdomen, beyond abdomen). [Stachowitsch, 1992]
Balanus trigonus: wall plates, exploded; and interior of operculum. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature: in unstalked form, triangular lateral part of compartmental plate. Delimited from median part (paries) and overlapped by lateral part (radius) of adjoining compartmental plate. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) One of pair of posteriorly directed cephalic-shield extensions (Branchiura and some parasitic Copepoda); triangular lateral part of compartmental plate, with or without radii, overlapped by adjacent compartmental plate (balanomorph Cirripedia).
(pl. alae) [McLaughlin, 1980]
(Taxon-specific: Subclass Copepoda) In parasitic copepod, one of two posterolateral extensions of cephalic shield. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Wing-like extension of valve, typically located ventrally and directed posteriorly. (simple, carinate). [Stachowitsch, 1992]

Aliform apophyses

Incurved anterior and posterior extremities of growth lines (e.g., Conchostraca, characteristic of Ipsilonia). [Moore and McCormick, 1969]
(Taxon-specific: Order Diplostraca) Incurved anterior and posterior extremities of growth lines. [McLaughlin, 1980]

Alimentary tract

Tubular organ comprising the oesophagus, foregut, hepatopancreas, and hindgut. [Holdich and Jones, 1983]

Allometric growth

Growth of one part of the body relative to another part in which there is a change in relationships of proportions and/or shape. [Ingle, 1983]

Ambulatory leg

See: Pereiopod [Moore and McCormick, 1969]
See pereopod. [McLaughlin, 1980]
(Taxon-specific: Order Isopoda) (as applied to pereopods). Used for walking. [Kensley and Schotte, 1989]

Ambulosome

The part of the thorax of munnopsid isopods that bears the walking legs. It consists of pereonites 1-4. [Wilson, 1989]

Ambulosomite

A body segment of the ambulosome. [Wilson, 1989]

Amphidont hinge

(Taxon-specific: Class Ostracoda) A modified entomodont hinge in which the four elements are well differentiated (Families Hemicytheridae, Trachyleberididae). [Cohen, Peterson, and Maddocks, in press]

Ampulla

(Taxon-specific: Order Amphipoda) One in a series of spinose and setose ridges surrounding border between esophagus and stomach. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) One of two spinose or setose internal ridges on each side of foregut. Serves in crushing food. [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) In digestive tract, diverticulum at junction of posterior (pyloric) stomach, digestive ceca, and midgut.
(syn. pars ampullaris) [Stachowitsch, 1992]

Anal flap

(Taxon-specific: Class Remipedia) Small lobe covering anus at posterior end of anal segment. [Stachowitsch, 1992]

Anal furca

(Taxon-specific: Subclass Branchiura) Caudal ramus. [Stachowitsch, 1992]

Anal operculum

(Taxon-specific: Subclass Copepoda) A small median process on dorsal surface of the anal somite protecting the anus. [Boxshall and Halsey, 2004]
(Taxon-specific: Subclass Copepoda) Lid-like structure covering anus. (smooth, toothed). [Stachowitsch, 1992]

Anal papilla

(Taxon-specific: Subclass Branchiura) Caudal ramus. [Stachowitsch, 1992]

Anal segment

(Taxon-specific: Order Diplostraca) Telson.
(syn. anal somite) [Stachowitsch, 1992]
(Taxon-specific: Order Anostraca) Telson.
(syn. anal somite) [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) Telson.
(syn. anal somite) [Stachowitsch, 1992]
(Taxon-specific: Class Remipedia) Posteriormost segment of body; partially fused to reduced last trunk segment and bearing both anus and caudal rami. Occasionally also referred to as telson. (Length longer than, equal to, or shorter than width). [Stachowitsch, 1992]

Anal somite

Postsegmental plate or lobe bearing anus. [Brusca and Brusca, 2002]
(Taxon-specific: Order Leptostraca) Telson.
(syn. anal segment) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Last (fifth) segment of abdomen; bears anus dorsally and pair of caudal rami posteriorly. Occasionally termed telson. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) The posterior somite and abdominal somite onto which the anus opens. The anal somite bears a paired appendage called the caudal rami. The anal somite is considered the first abdominal somite, despite its posterior position, because it is the first abdominal somite to appear during post-embryonic development. [Ferrari and Dahms, in press]
(Taxon-specific: Subclass Mystacocarida) Telson. [Stachowitsch, 1992]

Anal spines

Single row of spines on either side of cladoceran postabdomen (e.g., Sididae, Holopedidae, Daphniidae). [In addition, some cladocerans possess lateral spines (e.g., Macrothricidae, Chydoridae).]. [Moore and McCormick, 1969]
Single row of spines on either side of postabdomen (cladocera) or prominent telsonal spines (Conchostraca). [McLaughlin, 1980]
(Taxon-specific: Order Cladocera) One in a series of spines along (morphological) dorsal surface of postabdomen.
(syn. anal tooth) [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) One of two blade-like, serrate spines projecting from posterodorsal end of telson. [Stachowitsch, 1992]

Anameric

The addition of only one somite to the body at each molt during development. [Ferrari and Dahms, in press]

Anamorphic development

In which a series of similar larval stages are passed through after hatching. [Ingle, 1992]
Indirect development in which the embryo hatches as a nauplius larva and the adult form is achieved via a series of gradual changes in body morphology as new segments and appendages are added. [Brusca and Brusca, 2002]

Androdioecy

Rare type of mixed mating system in which males coexist with hermaphrodytes but there are no true females. [Brusca and Brusca, 2002]

Androgenic gland

(Taxon-specific: Order Decapoda) In male, small gland associated with terminal end of each vas deferens. Secretes hormones stimulating spermatogenesis and development of secondary sex characteristics. [Stachowitsch, 1992]

Anecdysis

A prolonged period without ecdysis; occurs in crustaceans that molt seasonally. [Bliss, 1982]
An intermoult stage in which all tissue growth has been completed. [Ingle, 1983]

Angulate

(Taxon-specific: Order Isopoda) Having an angle or an angular shape. [Kensley and Schotte, 1989]

Annulate seta, with setules

These are always mechanoreceptors; they always form in invaginated pockets, may be of a variety of sizes and shapes, may have the setules distributed along the shaft in many kinds of patterns, and may have denticules distally along the shaft. [Watling, 1989]

Annulate seta, without setules

These usually are chemoreceptive, but may be mechanoreceptive in large groups; they always form in invaginated pockets and may be smooth or denticulate, elongate and stiff, or short and robust. [Watling, 1989]

Annulations

Spaced rings on a segment of appendage, not articulated, yet wth flexability. [Butler, T. H.]

Annulus

A faint ring circumscribing the shaft; may be located near the base or well along the shaft. [Watling, 1989]

Annulus ventralis

Crayfish seminal receptacle, consisting of median sclerite between fourth and fifth pereiopods; the spermatophore receptacle on sternum of female (see Fig. 23d). [Hobbs and Jass, 1988]
Seminal receptacle of cambarids, consisting of a median sclerite between the fourth and fifth pereiopods. [Hobbs, Hobbs, and Daniel 1977]
Seminal receptacle of female crayfish. [McLaughlin, 1980]

Anomura

A suborder of decapod crustaceans in which the fifth pair of pereiopods are extremely reduced and often concealed beneath the carapace; the antennae are placed to the outside of the eyestalks and the sub-hepatic regions of the carapace are not fused with the endostome. (Hermit crabs, Porcelain crabs, Lithodid crabs). [Ingle, 1980]

Anomuran crabs

Hermit crabs; coconut crab; also crab-like members of the infraorder Anomura, in which the last (fifth) pair of thoracic legs is very small and often kept hidden within the branchial chambers. [Bliss, 1982]

Anomuran seta

A small (pappose-type seta in species studied) occuring on or near the outermost part of the telson posterior margin in anomuran larvae (and also Dromia), and distinct from all other types of telson setae. [Ingle, 1992]

Antenna

Antennal peduncle consisting of 5 articles, based on Uroptychus. [Baba, 2005]
(Figure only.) [Baba, 2005]
Mobile sensory appendages arising below the eyes at the front of the head. There are two pairs of these appendages, the first and second antennae. The first antennae are uniramous and may have two or three flagellae each. The second antennae are biramous, one branch being similar in gross form to the first antenna, the other being flattened and scale-like (referred to as a scale). [Mauchline, 1984]
More lateral of the two paired, usually flagellate appendages projecting distally from the anterior end of the cephalothorax (Fig. 1).
(pl. antennae) [Perez Farfante and Kensley, 1997]
One of pair of anterior appendages of head region placed morphologically next behind antennule, uniramous in some crustaceans but biramous in all nauplii and in adults of most classes; may be extremely long and composed of multitudinous small segments or reduced to mere rudiment or lacking.
(syn. second antenna) [Moore and McCormick, 1969]
One of pair of appendages of second cephalic somite.
(syn. 2nd antenna) [McLaughlin, 1980]
Second cephalic appendage, usually with peduncle of five articles and multiarticulate flagellum (sometimes antenna 2); plural sometimes used to refer to both antennules and antennae.
(pl. antennae) [Poore, 2004]
Second pair of cephalic appendages (antenna 2). [Holdich and Jones, 1983]
The appendages of the second and third head segments are the first and second pairs of antennae respectively. The first antennae are secondarily biramous (Fig. 3) Both pairs of antennae are sensory. [Warner, 1977]
The more lateral of the the two paired flagellate appendages projecting anteriorly from anterior end of the body.
(pl. antennae) [Butler, T. H.]
The more lateral of the two paired flagellate appendages projecting anteriorly from the anterior end of the body.
(pl. antennae) [Chace and Hobbs, 1969]
The second pair of appendages situated between the antennules and the orbits, sometimes referred to as second antennae. [Ingle, 1983]
The second, paired, cephalic appendage. It consists of four short, robust, proximal segments, two long, intermediate segments, and a long series of tapering annuli, called the flagellum. The third basal segment bears a smaller, lateral appendage called the antennular scale that is homologous to the exopod in other Crustacea.
(syn. second antenna) [Wilson, 1989]
Whiplike, generally long sensory organ arising from anterior region of cephalothorax (see Figs. 13, 14). [Hobbs and Jass, 1988]
(Taxon-specific: Order Cladocera) Second and much larger pair of antennae; located laterally near posterior margin of head. Biramous, consisting of relatively large basal part (peduncle) bearing two- to four-segmented dorsal and ventral branches (rami). Serves as principle locomotory organ and moved by relatively large muscles (antennal muscles). (biramous and flattened, simple and cylindrical, branched, not branched).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Notostraca) Second and smaller pair of antennae; uniramous, extending from each side of labrum on underside of head. (very small, vestigial, absent).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) Second and much larger pair of antennae on head; biramous, consisting of long, terminally annulate basal part (protopod, with basal lobe) and pair of segmented branches (flagella, rami).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Anostraca) Second and larger of two pairs of antennae; uniramous, projecting ventrally from head. In female, typically unsegmented and reduced. In male, forms clasper generally consisting of exapanded basal segment (with antennal appendage) and more slender distal segment. (fused at base, not fused at base; basal segment: with/without hand; with/without finger-like process on median surface near midlength; with prominent, dorsally directed, peg-like process on median surface just below mid-length; with row of spines along median margin; with spinous pad, median protuberance, and many small distal spines; distal segment: laminate, not laminate, with/without calcar) (See also clypeus, hand).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) Second pair of antennae. Biramous, consisting of two-segmented protopod, relatively short, two-segmented endopod, and longer, multi-segmented exopod. Serves in locomotion and feeding.
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) Second pair of antennae; uiramous. If fully developed, consisting of proximal five-segmented peduncle and distal flagellum.
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) Second, relatively small pair of antennae.
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Second and typically larger pair of antennae. Originates from second (antennal) somite of head. Biramous, consisting of basal peduncle (typically composed of protopod, endopod, and scaphocerite) and distal flagellum. Bears pore of antennal gland. (elongate, spatulate, squamiform).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Second pair of antennae. Uniramous, consisting of proximal five-segmented peduncle and distal flagellum. May bear sensory structures (aesthetascs, calceoli). (short, long; slender, robust; naked, setose, spinose; similar, sexually dimporphic; pediform).
(syn. second antenna) [Stachowitsch, 1992]
Nomenclature of isopod cephalon (A). Examples of isopod mouth appendages: Idoteidae (B, C, F, H); Cirolanidae (D, E, G, I). [Wetzer et al. 1997]
(Taxon-specific: Order Isopoda) (pl. antennae) [Wetzer et al. 1997]
Schematic representation of an isopod illustrating morphological terms. [Kensley and Schotte, 1989]
(Taxon-specific: Order Isopoda) Paired appendage of the third cephalon segment; sometimes referred to as antenna 2. [Kensley and Schotte, 1989]
(Taxon-specific: Order Isopoda) Second, usually longer appendage of cephalon. Uniramous, consisting of basal peduncle and distal lagellum. (pediform).
See: Accessory flagellum, Antennal scale [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Second pair of antennae. Biramous, consisting of peduncle bearing scale-like outer branch (antennal scale, squama, exopod) and elongate inner branch (flagellum).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Second and smaller pair of antennae; originating from second somite of head (cephalon). Biramous, consisting of basal, two-segmented peduncle, two-segmented exopod (distal segment = antennal scale), and three-segmented endopod (with distal flagellum). (See also antennule).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Second pair of antennae. Uniramous, relatively long, and consisting of three- or four-segmented peduncle and variously shaped endopod (flagellum). (peduncle: three-/four-segmented; flagellum: long with many small joints, small with few large joints).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) Second pair of appendages on underside of head. Relatively short, uniramous, and consisting of four to six segments. Armed basally with large spines/hooks, terminally with smaller spines. Serves in attachment to host.
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Biramous second pair of antennae. Present, with the exception of certain ascothoracicans, only in early larval stages (nauplius).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Second and typically shorter pair of antennae on underside of head. Highly setose and serving in suspension feeding or, in certain parasitic copepods, with terminal claw and serving in attachment to host. If uniramous, outer branch (exopod) is missing. The term second antenna is often preferentially applied. (biramous, uniramous; prehensile).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) The limb of the cephalon posterior to antenna 1; on most naupliar stages, it bears a distinct protopodal masticatory arthrite which is not present on copepodid stages or on non-feeding naupliar stages, especially those of species with lecithotrophic embryos.
(syn. antenna 1) [Ferrari and Dahms, in press]
(Taxon-specific: Subclass Copepoda) The second cephalic appendage. [Boxshall and Halsey, 2004]
(Taxon-specific: Subclass Mystacocarida) Second and smaller pair of antennae. Biramous, consisting of basal protopod bearing nine-segmented exopod and four-segmented endopod. Serves in locomotion and feeding.
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Second pair of antennae on head. Basically biramous, consisting of basal protopod and distal endopod and exopod (the latter often being reduced). Serves, along with antennules, as chief locomotory appendage. Carapace margin may be indented (rostral notch) for antenna. (biramous, uniramous).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Class Remipedia) Second and smaller, more paddle-shaped pair of antennae on underside of head (cephalon); biramous and consisting of protopod (with two articles) bearing scale-like exopod and three-segment endopod. Endopod articles arc around anterior aspect of exopod. Setae on antenna are plumose.
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) Second pair of antennae. Consists of basal peduncle and either single flagellum (stygocaridacean), single or paired (flagellum and small exopod) branches (bathynellacean), or flagellum and scaphocerite (anaspidacean). (uniramous, biramous).
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) Second, relatively small pair of antennae. Uniramous, consisting of peduncle and flagellum.
(syn. second antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Second pair of antennae. Biramous, consisting of proximal single-segmented peduncle, scale-shaped outer branch (exopod = scaphocerite), and inner branch (endopod) consisting of three larger segments and multiarticulate flagellum. Peduncle bears opening of antennal gland.
(syn. second antenna) [Stachowitsch, 1992]

Antennae

The second pair of antennae. [Brusca and Brusca, 2002]

Antennal acicle

(Taxon-specific: Order Decapoda) Acicle. [Stachowitsch, 1992]

Antennal appendage

(Taxon-specific: Order Anostraca) Variously shaped process extending from basal segment of each antenna; more common in male. (conical, lamelliform, robust, slim; extending/not extending beyond basal segment of antenna; with small teeth, with large teeth; with teeth longer on one side, with teeth not greatly different in size; with/without conical processes).
(syn. basal antennal appendage) [Stachowitsch, 1992]

Antennal artery

(Taxon-specific: Order Decapoda) Artery.
(syn. antennary artery) [Stachowitsch, 1992]

Antennal carina

See: Carapace carina a [Martin, 2005]
Ridge extending posteriorly along dorsal extremity of antennal region, often continuous with antennal spine (Fig. 2B). [Perez Farfante and Kensley, 1997]
(Taxon-specific: Order Decapoda) On each side of carapace, narrow, longitudinal ridge extending posteriorly from antennal spine.
(syn. postannular crest) [Stachowitsch, 1992]

Antennal flagellum

Multiarticulate, whiplike terminal part of the antenna (Fig. 1).
(pl. antennal flagella) [Perez Farfante and Kensley, 1997]

Antennal gland

See: Green glands [Martin, 2005]
Excretory gland situated in the basal article of the antennal peduncle. [Holdich and Jones, 1983]
Nephridial excretory organs exiting via a pore at the base of the antennae. [Brusca and Brusca, 2002]
One of pair of complex excretory glands in many malacostracans with duct opening on antenna.
(syn. green gland) [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) One of two glands located in anterior region of head and consisting basically of end sac (divided into saccule and labyrinth), bladder, and excretory duct. Opens via excretory pore on basal segment (coxa) of each antenna. Functions in excretion and controls internal fluid pressure as well as ion concentration.
(syn. green gland, excretory organ) [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Pair of excretory glands in head, one opening to exterior at base (peduncle) of each antenna.
See: Gland cone [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) Pair of poorly developed excretory organs in head of certain isopods, one opening at base of each antenna. [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Excretory gland located in head; consists of long, coiled excretory canal and bladder. Opens to exterior on basal segment of either antenna. (See also maxillary gland). [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Pair of excretory glands in head, one opening to exterior at base of each antenna. (See also maxillary gland). [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Excretory organ, one opening at each base of antenna. Characteristic for larval stages and cetain parasitic copepods. (See also maxillary gland). [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) One of two excretory glands opening at base of antennae (See also maxillar gland). [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Pair of excretory glands in head, one opening to exterior at base (peduncle) of each antenna. [Stachowitsch, 1992]

Antennal groove

See: Carapace groove a [Martin, 2005]
See: Carapace grooves a [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) On each side of carapace, longitudinal groove extending posteriorly from vicinity of antennal spine. [Stachowitsch, 1992]

Antennal muscle

(Taxon-specific: Order Cladocera) One of several well-developed muscles spanning from antenna to dorsal part of head. According to position and function one may distinguish, e.g., antennal levator muscle and antennal adductor muscle. [Stachowitsch, 1992]

Antennal notch

(Taxon-specific: Order Cumacea) On each side of carapace, notch in anterior border below pseudorostrum. Antennules and occasionally antennae project through antennal notch. Lower extension of notch termed anterolateral angle or corner. (deep, shallow).
(syn. antennal sinus) [Stachowitsch, 1992]

Antennal peduncle

Basal segments of antennule from which the flagella arise. [Butler, T. H.]
Five basal segments of the antenna, from which the antenna arises distally. [Perez Farfante and Kensley, 1997]
The basal segments of the antenna, from which the flagellum arises. [Chace and Hobbs, 1969]

Antennal region

See: Carapace region a [Martin, 2005]
See: Carapace regions a [McLaughlin, 1980]
Area on lateral surface of the carapace posterior to and encompassing antennal spine. [Butler, T. H.]
Area on the lateral face of the carapace posterior to and encompasing the antennal spine. [Perez Farfante and Kensley, 1997]
The area on the lateral surface of the carapace of shrimps posterior to and encompassing the antennal spine. [Chace and Hobbs, 1969]
(Taxon-specific: Order Decapoda) In shrimp-like (natantian) decapod, one of two relatively small regions along anterolateral margin of carapace; corresponds to position of antenna. Adjoining regions include orbital, hepatic, and pterygostomial regions. [Stachowitsch, 1992]

Antennal scale

See: Stylocerite, Scaphocerite [Martin, 2005]
Bladelike exopod of antenna situated at base of antenna (see Figs. 13, 14). [Hobbs and Jass, 1988]
See scaphocerite. [McLaughlin, 1980]
See scaphocerite.
See: Scaphocerite [Poore, 2004]
The laterally ragid lamellar exopod of the antenna. [Butler, T. H.]
The laterally rigid lamellate exopod of the antenna of shrimps and crayfishes. [Chace and Hobbs, 1969]
The plate-like exopod of the antenna. [Hobbs, Hobbs, and Daniel 1977]
(Taxon-specific: Order Tanaidacea) Scale-like structure projecting from second segment of peduncle of antenna. Considered to represent outer branch (exopod). [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Scaphocerite. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) Projection extending from base (peduncle) of antenna; considered to represent reduced outer branch (exopod).
(syn. squama) [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Scale-shaped outer branch (exopod) of antenna, frequently with terminal articulation. (Scale-shaped, spine-shaped).
(syn. exopod, scaphocerite, squama) [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) On each (second) antenna, large, flattened terminal segment of exopod; bears setae.
(syn. scaphocerite) [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) Scaphocerite. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Scaphocerite. [Stachowitsch, 1992]

Antennal setae formula

(Taxon-specific: Order Cladocera) Notation specifying number of segments and number of setae per segment in dorsal and ventral branches (rami) of antenna. Example: 0-0-1-3/1-1-3.
(syn. setation formula) [Stachowitsch, 1992]

Antennal spine

See: Carapace spine a [Martin, 2005]
See: Carapace spines a [McLaughlin, 1980]
Anterior part of carapace, including ocular peduncles, based on Munidopsis. [Baba, 2005]
(Figure only.) [Baba, 2005]
A short spine usually present on or near the anterior margin of the carapace of shrimps just ventral to the orbit. [Chace and Hobbs, 1969]
A spine on, or adjacent to, the anterior margin of the carapace, immediately ventral to the orbit. [Hobbs, Hobbs, and Daniel 1977]
Short spine usually present on or near anterior margin of carapace just ventral to orbit. [Butler, T. H.]
Spine on anterior edge of carapace immediately below orbit adjacent to base of antenna (fig. 2). [Williams, 1984]
Spine on anterior margin of carapace ventral or lateral to orbit (antennal angle if spine absent). [Poore, 2004]
Spine on, or adjacent to, anterior margin of carapace and ventral to orbit (see Fig. 13). [Hobbs and Jass, 1988]
Spine situated on the anterior margin of the carapace just ventral to the orbital margin (Fig. 2A). [Perez Farfante and Kensley, 1997]
(Taxon-specific: Order Decapoda) Anteriorly directed, spine-like projection on anterior region on each side of carapace; located below orbit, adjacent to base of antenna, and may extend beyond carapace margin. [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Spine. [Stachowitsch, 1992]

Antennary nerves

Nerves extending from the tritocerebrum to the antennae. [Brusca and Brusca, 2002]

Antennula

The first paired cephalic appendage. In munnopsids, it consists of a wide, flattened basal segment, two segments of intermediate thickness, and distal annular segments of varying lengths. The most distal segments generally bear aesthetascs.
(syn. first antenna, antennule) [Wilson, 1989]

Antennular artery

(Taxon-specific: Order Decapoda) Artery. [Stachowitsch, 1992]

Antennular flagellum

Multiarticulate paired filaments (sometimes flattened and lamellate) of the antennule (Fig. 3B).
(pl. antennular flagella) [Perez Farfante and Kensley, 1997]

Antennular fossette

(Taxon-specific: Order Decapoda) On each side of carapace, anteroventral depression containing basal portion of antennule.
See: Orbito-antennulary pits [Stachowitsch, 1992]

Antennular lamella

(Taxon-specific: Order Mysida) In antennule of certain mysidaceans, term occasionally applied to scale-like process projecting from last (third) peduncular segment. [Stachowitsch, 1992]

Antennular lappet

(Taxon-specific: Order Euphausiacea) On each antennule, small lobe extending dorsally from end of first peduncular segment. (bifid, laminar, obtuse, triangular).
(syn. leaflet) [Stachowitsch, 1992]

Antennular peduncle

Proximal segments of antennule, from which flagella arise. [Hobbs and Jass, 1988]
The basal segments of the antennule, from which the flagella arise. [Chace and Hobbs, 1969]
The proximal segments of the antennule, from which the flagella arise. [Hobbs, Hobbs, and Daniel 1977]
Three basal segments of the antennule, from which the flagella arise distally (Fig. 3B). [Perez Farfante and Kensley, 1997]

Antennular process

(Taxon-specific: Order Stomatopoda) Tapering dorsolateral extension on each side of first head somite (antennular somite). [Stachowitsch, 1992]

Antennular scale

See: Stylocerite [Martin, 2005]
See stylocerite. [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) Stylocerite. [Stachowitsch, 1992]

Antennular somite

(Taxon-specific: Order Stomatopoda) First true somite of head (cephalon); located between acron and second (antenna-bearing) somite. Bears pair of anteriorly directed antennules as well as dorsolateral antennular processes. Not covered by carapace, although rostrum may partially or entirely extend across it.
(syn. posterior dorsal plate) [Stachowitsch, 1992]

Antennular spine

(Taxon-specific: Order Decapoda) Stylocerite. [Stachowitsch, 1992]

Antennulary nerves

Nerves that innervate the antennules and connect them to the deuterocerebrum. [Brusca and Brusca, 2002]

Antennulary part

(Taxon-specific: Subclass Mystacocarida) Region of head (cephalon) anterior to cephalic constriction. Bears antennules, four ocelli, two anteromedian lobes (rostral plate), and two anterolateral (lateral) lobes. (posterolateral corner: obtuse, right-angled). [Stachowitsch, 1992]

Antennule

First cephalic appendage, usually with peduncle of three articles and two multiarticulate flagella (sometimes antenna 1). [Poore, 2004]
First pair of cephalic appendages (antenna 1). [Holdich and Jones, 1983]
First pair of feelers, or antennae. [Bliss, 1982]
Inner of two paired flagelate appendages projecting from anterior end of body. [Butler, T. H.]
More mesial of the two paired, usually flagellate appendages projecting from the anterior end of the cephalothorax (Fig. 1, 3B). [Perez Farfante and Kensley, 1997]
One of a pair of appendages of the first cephalic somite.
(syn. 1st antenna) [McLaughlin, 1980]
One of pair of appendages of the first cephalic somite; "first antenna" (Figs. 13, 14). [Hobbs and Jass, 1988]
One pair of morphologically frontmost appendages of head region, usually filiform and multiarticulate, uniramous except in Malacostraca where it is generally biramous or even triramous; may be larger or smaller than morphologically next following appendages named antennae.
(syn. antennula, first antenna) [Moore and McCormick, 1969]
The first pair of antennae. [Brusca and Brusca, 2002]
The first pair of appendages situated medially close together under the frontal region. [Ingle, 1983]
The more mesial of the two paired flagellate appendages projecting from the anterior end of the body. [Chace and Hobbs, 1969]
(Taxon-specific: Order Cladocera) First and typically much smaller pair of antennae; located ventrally near posterior margin of head. Uniramous, unsegmented, with tuft of terminal aesthetascs. (movable, immovable = fixed; fused/ not fused with rostrum; insterted/ not inserted at anterior end of ventral edge of head).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Notostraca) First and larger pair of antennae; relatively short, uniramous and slender. Extends from each side of labrum anterior to antennae. (simple, obscurely segmented).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) First and much smaller pair of antennae; uniramous, typically with series of dorsal sensory papillae. (short, long; unsegmented = unjointed, with two segments, multijointed).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Anostraca) First and smaller of two pairs of antennae, projecting from anterior end of head. Uniramous, either unsegmented or only superficially segmented. (with/without tuft of terminal setae).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) First pair of antennae. Uniramous, consisting of six segments; bears terminal aesthetasc. With locmomotory and sensory functions.
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) First pair of antennae. Basically biramous, consisting of proximal three-segmented peduncle bearing larger outer (main) and smaller inner (accessory) flagellum. May bear aesthetascs. (uniramous, biramous; geniculate).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) First, relatively large pair of antennae. If fully developed, biramous, consisting of proximal four-segmented peduncle and two flagella. (uniramous, biramous).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) First and typically smaller pair of antennae. Originates from first (antennular) somite of head, each consisting of basal peduncle and one or more distal flagella. Peduncle bear statocysts and stylocerites, flagella bear aesthetascs. In crab-like (brachyuran) decapod, may be folded into orbitoantennulary pit of carapace. (biramous, triramous).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) First pair of antennae. Basically biramous, consisting of proximal three-segmented peduncle bearing large outer (primary) and smaller inner (accessory) flagella. (short, long; slender, robust; naked, setose, spinose; geniculate; with/without accessory flagellum = biramous/uniramous).
(syn. first antenna) [Stachowitsch, 1992]
Nomenclature of isopod cephalon (A). Examples of isopod mouth appendages: Idoteidae (B, C, F, H); Cirolanidae (D, E, G, I). [Wetzer et al. 1997]
(Taxon-specific: Order Isopoda) Antennae 1 or first antennae; anteriormost paired appendages of head (= antennula). [Wetzer et al. 1997]
(Taxon-specific: Order Isopoda) First, usually shorter appendage of cephalon; typically uniramous,
consisting of basal peduncle and distal flagellum. (uniramous, biramous).
(syn. first antenna) [Stachowitsch, 1992]
Schematic representation of an isopod illustrating morphological terms. [Kensley and Schotte, 1989]
(Taxon-specific: Order Isopoda) Paired appendage of the second cephalon segment; sometimes referred to as antenna 1. [Kensley and Schotte, 1989]
(Taxon-specific: Order Mysida) First pair of antennae. Biramous, consisting of three-segmented peduncle and pair of flagella. Antennule of male may bear processes masculinus and, rarely, an additional unsegmented accessory process.
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) First and larger pair of antennae; originating from first (antennular) somite of head. Consists of slender, three-segmented peduncle and three short flagella.
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) First pair of antennae. Relatively long, basically biramous, typically consisting of four-segmented peduncle with flagelliform inner branch (endopod) and scale-like outer branch (exopod). (biramous, uniramous; fourth segment of peduncle: with/without process, with tuft of bristles). [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) First pair of appendages on underside of head. Relatively short and basically four-segmented. Bears palp and several large spines/hooks; anterior antennular spine/hook is associated with gland or sensory organ. Serves in attachment to host.
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) First pair of antennae. Present in larval (nauplius, cyprid) stages, yet typically reduced or absent in adults. Used in attachment by barnacle larvae and associated with cement glands. Well developed in adult acrothoracican and ascothoracican. (prehensile, raptorial, subchelate, uniramous).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) First and typically larger pair of antennae on underside of head. Uniramous, consisting of up to 26 articles. In male, one or both may be equipped with hinge joint for grasping female during copulation. Bears aesthetascs. Number of articles is of systematic importance. The term first antenna is often preferentially applied. (geniculate).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) The anterior limb of the cephalon; it is uniramous in copepods.
(syn. antenna 1) [Ferrari and Dahms, in press]
(Taxon-specific: Subclass Copepoda) The first cephalic appendage. [Boxshall and Halsey, 2004]
(Taxon-specific: Subclass Mystacocarida) First and larger pair of antennae. Uniramous, consisting of eight setose segments and occasionally bearing terminal aesthetasc.
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) First pair of antennae on head. Uniramous, typically consisting of five to eight segments. Bears setae and claws for swimming, digging, and copulation; bears one or more aesthetascs. Carpace margin may be indented (rostral notch) for antennules.
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Class Remipedia) First and larger pair of antennae on underside of head (cephalon); biramous and consisting of basal peduncle (with two articles and bearing aesthetasc pad) and distal (dorsal and ventral) flagella. Setae on antennae are simple.
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) First pair of antennae. Consists of basal peduncle and distal flagellum (or flagella). Biramous, with tiny lappet in bathynellacean interpreted as representing second branch. (with/without statocyst).
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) First, relatively large pair of antennae. Uniramous, consisting of peduncle and flagellum.
(syn. first antenna) [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) First pair of antennae. Biramous, consisting of proximal three-segmented peduncle and two distal flagella. Antennules joined to each other by setae on first peduncular segment. (with/ without antennular lappet).
(syn. first antenna) [Stachowitsch, 1992]

Antepenultimate

Second from the last; third from the end in a series. [AHD]
Third from last, as a segment of appendage. [Butler, T. H.]

Anterioposterior axis

(Taxon-specific: Subclass Copepoda) An imaginary line through the rostral area of the head and the anal segment. [Ferrari and Dahms, in press]

Front end of organism "head end." [Hobbs and Jass, 1988]
Of, pertaining to, or toward the front. [Butler, T. H.]

Anterior aorta

(Taxon-specific: Order Cumacea) Aorta. [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) Aorta.
(syn. cephalic aorta) [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Major unpaired blood vessel arising from anterior end of heart and extending into head. May bear accessory heart (cor frontale); gives rise to series of smaller arteries supplying brain and eyestalks.
(syn. ophthalmic artery) [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Aorta. [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Major unpaired blood vessel arising from anterior end of heart and extending over stomach into head. Bears accessory pumping organ (cor frontale). [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) Aorta.
(syn. anterior dorsal aorta) [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Major unpaired blood vessel arising from anterior end of heart and extending over stomach into head. Bears accessory pumping organ (cor frontale) and gives rise to series of smaller arteries supplying brain and eyes.
(syn. first antenna) [Stachowitsch, 1992]

Anterior chamber

Second portion (after the esophagus) of the chitin-lined foregut; has often been called the cardiac stomach. [Bliss, 1982]

Anterior element

(Taxon-specific: Class Ostracoda) Hinge. [Stachowitsch, 1992]

Anterior head lobe

(Taxon-specific: Order Amphipoda) Lateral lobe. [Stachowitsch, 1992]

Anterior lappet

(Taxon-specific: Order Mysida) Pleura. [Stachowitsch, 1992]

Anterior process

Anterior part of an elongate median protuberance lying on the penultimate (XIII) thoracic sternite (Fig. 4A). [Perez Farfante and Kensley, 1997]

Anterior tubercle

Swelling or small protuberance in anterior region of carapace of Archaeostraca; polygenetic, includes the "optic tubercle" of some authors. [Moore and McCormick, 1969]

Antero-lateral teeth

Teeth situated on the antero-lateral margin of the carapace; i.e., the margin between the outer region of the orbit and the widest part of the carapace. [Ingle, 1983]

Anterolateral

Front side of a structure. [Butler, T. H.]

Anterolateral angle

(Taxon-specific: Order Cumacea) On each anterolateral margin of carapace, lower extension of antennal notch. (acute, rounded; armed, unarmed).
(syn. anterolateral corner) [Stachowitsch, 1992]

Anterolateral carina

Longitudinal ridge extending along the anterior part of carapace, ventral to gastro-orbital carina. [Perez Farfante and Kensley, 1997]

Anterolateral margin

Margin of carapace between orbit and lateral angle or spine. [Poore, 2004]

Anterolateral region

See: Carapace region a [Martin, 2005]
See: Carapace regions b [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) In crab-like (brachyuran) decapod, relatively small region along each anterolateral margin of carapace. Adjoining regions include hepatic or subhepatic regions.
See: Posterolateral region [Stachowitsch, 1992]

Anterolateral spine

Anterior part of carapace, including ocular peduncles, based on Munidopsis. [Baba, 2005]
(Figure only.) [Baba, 2005]

Anterolateral tooth

(Taxon-specific: Order Decapoda) On carapace of crab-like (brachyuran) decapod, one (or one in a series of) projection(s) along each anterolateral margin. (acute, conical, obtuse, quadrangular, spiniform, subtriangular; ciliated, denticulate, spiny; tip: acuminate, rounded). [Stachowitsch, 1992]

Antimerodont hinge

(Taxon-specific: Class Ostracoda) A median bar or groove differentiated, usually with all elements crenulate. [Cohen, Peterson, and Maddocks, in press]

Antizoea

A modified zoeal stage exhibited by some stomatopods. [Brusca and Brusca, 2002]
(Taxon-specific: Order Stomatopoda) Early larval stage of certain stomatopods; characterized by uniramous antennules, five pairs of biramous thoracopods, and no pleopods. (See also pseudozoea). [Stachowitsch, 1992]

Antorbital spine

The spine at the postero-lateral corner of the supraorbital eave in Majidae. [Ingle, 1983]

Antrum

(Taxon-specific: Subclass Copepoda) Atrium. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) In female reproductive system, invagination of ventral surface (sternite) of first abdominal segment (genital somite). Recieves common opening of both oviducts and openings of seminal receptacles.
(syn. atrium, genital atrium) [Stachowitsch, 1992]

Anus

(Taxon-specific: Order Cladocera) Posterior opening of digestive tract at end of postabdomen. (terminal, on dorsal margin). [Stachowitsch, 1992]
(Taxon-specific: Order Notostraca) Posterior opening of digestive tract at end of telson; located between caudal rami and may be covered dorsally by supra-anal plate. [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) Posterior opening of digestive tract at end of telson. [Stachowitsch, 1992]
(Taxon-specific: Order Anostraca) Posterior opening of digestive tract; located terminally on telson (between caudal rami). [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) Posterior opening of digestive tract. Located at end of last (sixth) pleonite or on ventral surface of telson (in the latter case occasionally divided telson into preanal and postanal parts). Flanked by pair of anal valves. [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) Posterior opening of digestive tract to exterior. Located on ventral surface of telson. [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Posterior opening of digestive tract; located on ventral surface of telson. [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Posterior opening of digestive tract to exterior; located ventrally at base of telson. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) Posterior opening of digestive tract to exterior; located ventrally at base of telson. [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Posterior opening of digestive tract; located on ventral surface of telson. [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Posterior opening of digestive tract; located anteroventrally on telson. [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Posterior opening of digestive tract; located ventrally on telson between caudal rami. [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) Posterior opening of digestive tract. Located at posterior end between two lobes of abdomen; typically flanked on each side by minute caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Posterior opening of digestive tract. Located near posteriormost thoracic appendages. i.e., between sixth pair of cirri; in ascothoracican at end of abdomen. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Posterior opening of digestive tract. Located terminally, on dorsal surface of last abdominal segment (anal somite); covered by anal operculum. [Stachowitsch, 1992]
(Taxon-specific: Subclass Mystacocarida) Posterior opening of digestive tract; located on ventral surface of telson (anal somite). [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Posterior opening of digestive tract at end of body (thorax/abdomen). May be located either dorsal or ventral to caudal rami. [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) Posterior opening of digestive tract. Located on telson. (terminal, ventral). [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) Posterior opening of digestive tract to exterior; apparently terminal. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Posterior opening of digestive tract; located ventrally at posterior margin of last (sixth) abdominal somite (pleomere). [Stachowitsch, 1992]

Aorta

(Taxon-specific: Order Cladocera) Heart. [Stachowitsch, 1992]
(Taxon-specific: Order Cladocera) Unpaired blood vessel extending ventroposteriorly from heart. Separated from heart by anteroventral aortic valve and splits distally into several branches. [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) In circulatory system, major blood vessel exending from end of heart. One may distinguish 1) an unpaired anterior aorta extending into head and bearing a cor frontale and 2) paired posterior aortas extending to end of abdomen. [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) In circulatory system, major blood vessel extending from end of heart. One may distinguish an anterior aorta extending into head and paired posterior aortas. Anterior aorta bears cor frontale.
See: Lateral artery [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Anterior aorta, dorsal aorta. [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) In circulatory system, major blood vessel extending from end of heart. One may distinguish an anterior aorta extending into head and a paired or unpaired posterior aorta extending to end of abdomen. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) In circulatory system, major unpaired blood vessel extending from anterior end of heart. Extends into head and bears small accessory heart (corfrontale). [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) In circulatory system, major blood vessel extending from heart. According to position one may distinguish an anterior aorta (bearing cor frontale), a posterior aorta, and a descending aorta. [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Major blood vessel leading from heart. According to position one may distinguish an anterior aorta (giving rise to antennal, antennular, opthalmic, and other cephalic arteries) and a posterior aorta. [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) In circulatory system, major unpaired blood vessel extending from end of heart. One may distinguish an anterior aorta extending into head and a posterior aorta extending into abdomen; each is branched distally. [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) Unpaired dorsal blood vessel extending anteriorly from heart. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Unpaired dorsal blood vessel extending anteriorly from heart.
(syn. anterior aorta) [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) In circulatory system of anaspidacean, major blood vessel extending from heart. According to position one may distinguish an anterior aorta extending into head, a posterior aorta extending into abdomen, and a descending aorta at level of eighth thoracic somite. (See also artery). [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) In circulatory system, blood vessel extending from end of heart. One may distinguish short anterior and posterior aortas. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Anterior aorta, descending aorta, posterior aorta. [Stachowitsch, 1992]

Aortic valve

(Taxon-specific: Order Cladocera) Anteroventral opening in heart through which blood is pumped into aorta. (See also hepatic valve). [Stachowitsch, 1992]

Apertural hook

(Taxon-specific: Subclass Cirripedia) In acrothoracican, hook-like structure protecting aperture. (See also apertural spine). [Stachowitsch, 1992]

Apertural spine

(Taxon-specific: Subclass Cirripedia) In acrothoracican, spine-like structure protecting aperture. (See also apertural hook). [Stachowitsch, 1992]

Aperture

Posteroventral opening into cirriped mantle cavity. [Moore and McCormick, 1969]
Lepas anatifera: rostral view; and left valve and cirri removed. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) In barnacle, opening through which thoracic appendages (cirri) are protruded. In stalked barnacle, bordered on each side by scutum and tergum; bordered in unstalked barnacle by operculum (paired scuta and terga in symmetrical forms, single scutum and tergum in asymmetrical forms). (See also occludent margin).
(syn. orifice) [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Posteroventral opening into mantle cavity. [McLaughlin, 1980]

Apex

Upper angle of scutum or tergum of cirripeds. [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature; uppermost point (angle) of plate. Typically refers to scutum, tergum, or carina. (beaked). [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Upper angle of scutum or tergum (thoracic Cirripedia). [McLaughlin, 1980]

Apical

Apex; tip. [Hobbs and Jass, 1988]
At the distal end. [Butler, T. H.]
(Taxon-specific: Order Isopoda) Relating to the apex or tip. [Kensley and Schotte, 1989]

Apicobasal ridge

In cirripeds longitudinal feature which divides tergal slip (tergum) from rest of valve.
(syn. apicobasal furrow) [Moore and McCormick, 1969]

Apicoumbonal ridge

(Taxon-specific: Subclass Cirripedia) Barnacle plate feature; in scutum of stalked form, ridge extending from upper point (apex) to umbo. [Stachowitsch, 1992]

Apodemal pit

Any of several often unpigmented depressions on the carapace of many crabs indicating the origin of an invaginated element that forms part of the internal thoracic skeleton. [Chace and Hobbs, 1969]

Apodeme

A cuticular, usually calcified invagination upon which muscles insert and which, itself, inserts by means of tough flexible cuticle onto that part of the skeleton which is moved by its muscles (Figs. 12, 13). [Warner, 1977]
Any cuticular ingrowth of body wall. [Williams, 1984]
Infold of exoskeleton for attachment of muscles. [McLaughlin, 1980]
Infold of exoskeleton serving for attachment of muscles. [Moore and McCormick, 1969]
(Taxon-specific: Order Decapoda) Any one of numerous infolds of exoskeleton serving for attachment of muscles (e.g., head apodeme). May be highly developed as endopleurites and endosternites to form endoskeleton. [Stachowitsch, 1992]

Apophysis

(Taxon-specific: Subclass Copepoda) A spinous process on a swimming leg segment, typically sexually dimorphic (present in male only); ma y originate as produced segmental margin, or may be derived by modification of setal element present in female. [Boxshall and Halsey, 2004]
(Taxon-specific: Class Ostracoda) Type of valve sculpture: extension of wall (murus) in reticulate pattern. May lead to pore. [Stachowitsch, 1992]

Appendage

Schematic drawing of a thoracic leg. [Holthuis, 1993]
(Figure only.) [Holthuis, 1993]
(Taxon-specific: Order Isopoda) An articulated structure used for feeding, locomotion, sensory reception, e.g., mouthparts, antennae, pereopods, pleopods, uropods. [Kensley and Schotte, 1989]
(Taxon-specific: Subclass Copepoda) Paired extensions of a somite along a proximodistal axis and usually composed of serially repeated elements. Appendages of copepods include the limb of the five cephalic somites, the limb of the seven thoracic somites plus the caudal ramus of the anal segment (see also limb and swimming leg). [Ferrari and Dahms, in press]

Appendix interna

A slender rodlike lappet on the mesial ,argin of the endopod of the second through fifth pleopods of shrimps; it is provided with terminal hooked setae by which the two pleopods of a pair must be joined mesially.
(pl. appendices internae) [Chace and Hobbs, 1969]
A slender rodlike structure on the mesial border of the endopod of the second through fifth pleopods of shrimps; terminal and/or subterminal hooked setae allow the mesial joining of two pleopods of a pair. [Hobbs, Hobbs, and Daniel 1977]
Medial projection stemming from pleopodal endopods, serving to unite members of each pair of pleopods.
(syn. stylamblys) [Moore and McCormick, 1969]
Median process of pleopodal endopod uniting members of each pair.
(syn. stylamblys) [McLaughlin, 1980]
Slender lappet, sometimes rodlike, at the mesial base of the endopod of the second pleopod (dorsal to the appendix masculina) of many males.
(pl. appendices internae) [Perez Farfante and Kensley, 1997]
Slender rodlike flap on inner margin of endopod of the second to fifth pleopods of shrimp.
(pl. appendices internae) [Butler, T. H.]
Slender, rodlike structure on mesial border of endopod of second through fifth pleopods of shrimp. [Hobbs and Jass, 1988]
Small branch on inner margin of pleopod 2, triangular or rod-like, usually with clusters of hooks to attach to its pair.
(pl. appendices internae) [Poore, 2004]
Small separate branch on mesial side of pleopodal endopodite, usually tipped with hooks which interlock with opposite member in swimming. [Williams, 1984]
(Taxon-specific: Order Decapoda) Projection of inner branch (endopod) of each pleopod; serves to hook pleopod to its opposite member (for swimming).
(syn. stylamblys) [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Projection of inner branch (endopod) of each pleopod. Bears hooks (retinacula) and, in first pleopod pair of male, hook-shaped and tubular processes (petasma).
(syn. stylamblys) [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) In each of the four well-developed anterior pairs of pleopods, medially (inwardly) directed process at base of endopod. Serves to link pleopods together for swimming. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Medially (inwardly) directed process of each pleopod. Serves to link pleopods of each somite together for swimming. [Stachowitsch, 1992]

Appendix masculina

A lappet inserted between the appendix interna and the mesial margin of the second pleopod of most male shrimps. The presence or absence of an appendix masculina is the easiest way to distinguish males and females in most caridean shrimps, and in some families, such as the Atyidae, it is greatly enlarged, dwarfing the superimposed appendix interna, and it offers important taxonomic characters.
(pl. appendices masculinae) [Chace and Hobbs, 1969]
A setiferous lobe or rodlike structure situated between the appendix interna and the mesial margin of the mesial ramus (endopod) of the second pleopod of male shrimps. Often an important taxonomic character, the presence or absence of an appendix masculina is the easiest means of distinguishing males and females of most freshwater shrimps. [Hobbs, Hobbs, and Daniel 1977]
Accessory male organ located mesially on second pair of pleopods between endopodite and appendix interna. [Williams, 1984]
An alternative name for a stylet-like copulatory structure on the male pleopod II. This structure is not homologous to similarly named structures found in non-isopod Eumalacostraca. [Wilson, 1989]
Complex median process of 2nd ploepodal endopod of male Caridea and some other Eucarida used in copulation or spermatophore transfer. [McLaughlin, 1980]
Complex median process of endopod of second pleopods of male Caridea and some isopods; serves in copulation. [Moore and McCormick, 1969]
Flap inserted between appendix interna and inner margin of endopod of the second pleopod in most male shrimps.
(syn. appendices musculinae) [Butler, T. H.]
Lappet, sometimes scalelike, at the mesial base of the endopod of the second pleopod (ventral to the appendix interna if latter present) in some males.
(pl. appendices masculinae) [Perez Farfante and Kensley, 1997]
Lobe or rodlike structure, bearing setae, situated between appendix interna and mesial margin of endoopod of second pleopod of male shrimps. The presence or absence of this structure provides easiest means of distinguishing males from females; an important taxonomic character for palaemonids (see Fig. 73j,k). [Hobbs and Jass, 1988]
Small branch on inner margin of pleopod 2 of males, usually rod-like, proximal to appendix interna.
(pl. appendices masculinae) [Poore, 2004]
(Taxon-specific: Order Decapoda) Median process of inner branch (endopod) of second pleopod in male; serves in copulation or spermatophore transfer. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) Copulatory stylet arising from medial margin of male pleopod 2 endopod, used for transfer of spermatophores in at least some species.
(pl. appendices masculinae) [Wetzer et al. 1997]
(Taxon-specific: Order Isopoda) Rod-shaped median process on endopod of second pleo-pod in male; serves in sperm transfer.
(syn. male stylet) [Stachowitsch, 1992]

Aquaculture

Large-scale cultivation of aquatic organisms under controlled conditions, for use of food or for other economic purposes. [Bliss, 1982]

Area

(Taxon-specific: Order Cladocera) One in a number of somewhat arbitrarily delimited regions on lateral surface of valve. According to position one may distinguish anterior, anterodorsal, anteromedian, anteroventral, dorsal, dorsomedian, median, midanterior, middorsal, midposterior, posterior, posterodorsal, posteromedian, posteroventral, ventral, and ventromedian areas. [Stachowitsch, 1992]

Areola

Area between branchiocardiac grooves and posterior to cervical groove on dorsal surface of carapace (Astacidea and Austroastacidea). [McLaughlin, 1980]
Dorsomedial area (usually hourglass-shaped) of thoracic region of carapace of crayfishes, bounded laterally by paired arched (branchiocardiac) grooves delineating dorsomedial limits of gill chamber (see Fig. 14). [Hobbs and Jass, 1988]
See "Cardiac region". [Chace and Hobbs, 1969]
The dorsomedian area of the thoracic part of the carapace of crayfishes, bound laterally by paired arched (branchiocardiac) grooves. [Hobbs, Hobbs, and Daniel 1977]
(Taxon-specific: Order Decapoda) On dorsal surface of carapace, area between two longitudinal branchiocardiac grooves and posterior to transverse cervical groove. [Stachowitsch, 1992]

Areolation

Demarcated and usually elevated regions of the brachyuran carapace. [Martin, 2005]

Armature

(Taxon-specific: Subclass Copepoda) The setae and spines carried on the paired limbs and caudal rami. [Boxshall and Halsey, 2004]

Artery

(Taxon-specific: Order Decapoda) One of numerous blood vessels originating from aorta or directly from heart. According to position or body region/appendages supplied, one may distinguish, among others, antennal, antennular, hepatic, lateral cephalic, ophthalmic, optic, pleopodal, rostral, segmental, sternal, and subneural arteries. [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) One of numerous blood vessels originating from heart or aortas. According to position one may distinguish anterior lateral or facial artery as well as three pairs of lateral arteries. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) One of numerous blood vessels originating from heart or aorta. According to position one may distinguish anterior and posterior arteries as well as a subneural artery. [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) One of numerous blood vessels originating from aorta or directly from heart. According to position and mysidacean group, one may distinguish hepatic, (anterior and posterior) lateral, sternal, subneural, and ventral arteries. [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) One of numerous blood vessels originating from heart or aorta. According to position or appendages supplied, one may distinguish antennal, antennular, opthalmic, lateral, and subneural arteries. [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) One of numerous blood vessels originating from heart or aortas. According to position or organ supplied, one may distinguish dorsal, labral, median, and segmental arteries, the latter with podial and visceral branches. [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) In anaspidacean, one of numerous blood vessels originating from heart or aorta. According to position one may distinguish seven pairs of lateral arteries and a subneural artery (arising from descending aorta). [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) One of numerous blood vessels originating from aorta or directly from heart. According to position or body region/appendages supplied, one may distinguish, among others, abdominal, antennal, antennular, anterior lateral, mandibular-maxillary, ophthalmic, posterior lateral, and sternal arteries. [Stachowitsch, 1992]

Arthribranch

Arthrite

(Taxon-specific: Subclass Copepoda) A movable endite, used for the praecoxal endite of maxillule. [Boxshall and Halsey, 2004]
(Taxon-specific: Subclass Copepoda) A ventrally articulating, sclerotized extension of a protopodal segment that is moved by muscles. [Ferrari and Dahms, in press]

Arthrobranch

Schematic drawing of a thoracic leg. [Holthuis, 1993]
(Figure only.) [Holthuis, 1993]
A decapod gill associated with the articular membrane between the coxa and the body wall; "joint gills." [Brusca and Brusca, 2002]
A gill arising from the articular membrane at the proximal base of the coxa of an appendage. [Hobbs, Hobbs, and Daniel 1977]
A gill arising from the junction of the limb with the body. [Ingle, 1983]
Gill attached to the articular membrane between body wall and coxa of an appendage. [Butler, T. H.]
Gill attaching to membrane between coxa and side of body, 1 or 2 pairs per somite and usually pointing upwards. [Poore, 2004]
Gill of decapods attached to articular membrane between limb and body.
(syn. arthrobranchia) [Moore and McCormick, 1969]
(Taxon-specific: Order Decapoda) Gill attached to articular membrane between appendage and body.
(syn. arthrobranchiata) [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) Type of gill attached to point of articulation (articular membrane) between thoracopod and body wall. If full complement is developed, may be found associated with first through seventh thoracopods (i.e., all except last pereopods).
(syn. arthrobranchia)
See: Pleurobranch, Podobranch [Stachowitsch, 1992]

Arthrobranchia

Branchia (gill) attached to the joint area between the body and the first podomere of the leg (Fig. 3C).
(pl. arthrobranchiae) [Perez Farfante and Kensley, 1997]

Arthrobranchiae

Gills attached to articular membrane between coxa of appendage and body wall. [Williams, 1984]

Arthrobranchiata

Arthrodial membrane

Tough flexible cuticle occurring between skeletal elements and allowing relative movement. [Warner, 1977]
(Taxon-specific: Subclass Copepoda) An unsclerotized, flexible section of the exoskeleton between the sclerotized parts of two somites or two segments. [Ferrari and Dahms, in press]

Arthrophragm

See: Endophragm [Martin, 2005]
A cuticular calcified invagination, usually in the form of a plate, which provides a rigid orgin for muscles. [Warner, 1977]
See endophragm. [McLaughlin, 1980]

Article

A segment of any limb, but usually applied to the antennula or antenna. [Wilson, 1989]
Any of the segments of a limb or appendage.
See: Coxa, Basis, Ischium, Merus, Carpus, Propodus, Dactylus [Poore, 2004]
Any one of the subdivisions of an appendage segment. [Perez Farfante and Kensley, 1997]
Individual element of crustacean appendage.
(syn. joint, segment) [Moore and McCormick, 1969]
Subdivision of antennal or antennular flagella or appendage.
See: Segment [McLaughlin, 1980]
(Taxon-specific: Order Diplostraca) One of up to 25 segments of antennal branches (rami, flagella). May also refer to segment of other appendages. [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) Segment of appendage. [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) Any segment of appendage, although often applied to segment of flagellum of antennule or antenna.
(syn. joint, segment) [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) One in a series of numerous segments of flagellum at end of antenna or antennule. May also refer to segment of pereopod.
(syn. joint, segment) [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Any segment of an appendage, although often applied to segments of flagella of antennules or antennae.
(syn. joint, segment) [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) A single section of an appendage, with an articulation at one or both ends. [Kensley and Schotte, 1989]
(Taxon-specific: Order Isopoda) Any segment of an appendage, although often applied to segments of flagellum of antennae or antennules.
(syn. joint, segment) [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) One in a series of numerous segments of flagellum at end of antennule or antenna. [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) One in a series of segments of flagellum of antennule or antenna. May also refer to segment of other appendages.
(syn. joint, segment) [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) One in a series of segments of thoracic appendage (cirrus) or other appendage.
(syn. joint segment) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) One in a series of up to 26 segments of flagellum of antennule (few in antenna). Number of articles is of systematic importance. May also be used to refer to segments of other appendages.
(syn. segment, joint) [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) See podomere.
See: Podomere [Cohen, Peterson, and Maddocks, in press]
(Taxon-specific: Class Remipedia) In antennule, one of 11 or 12 segments of larger dorsal flagellum or 3 or 8 segments of smaller ventral flagellum. Each article bears tuft of several setae at distoventral end as well as scattered setae along shaft. Last article bears terminal tuft of setae . Also synonymous with any appendage segment.
(syn. joint, segment) [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) Any segment of appendage, although often applied to segment of flagella of antennules and antennae.
(syn. joint, segment) [Stachowitsch, 1992]

Articular furrow

In cirripeds, groove on tergal margin of scutum or scutal margin of tergum forming part of articulation between the plates. [Moore and McCormick, 1969]
Balanus trigonus: wall plates, exploded; and interior of operculum. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature: in unstalked form, linear elevation on tergal margin of scutum or scutal margin of tergum. Ridge and furrow of scutum (or tergum) articulate with corresponding structures in tergum (or scutum). [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Groove near tergal margin of scutum or scutal margin of tergum forming part of articulation between the two valves (balanomorph Cirripedia). [McLaughlin, 1980]

Articular knob

A swelling or irregularity in the integument at a joint, as on either side of a chela at the base of the movable finger or between the abdominal somites at the juncture of the terga and the pleura. [Chace and Hobbs, 1969]
Swelling or irregularity in the shell at a joint of an appendage, or between abdominal somites at the juncture of pleuron and tergum. [Butler, T. H.]

Articular membrane

The uncalcified integument at a joint, permitting movement of the exoskeleton, as between the podomeres of a pereiopod. [Chace and Hobbs, 1969]
The uncalcified integument, permitting movement of the shell, as between segments of a periopod, or between abdominal somites. [Butler, T. H.]
Uncalcified integument of a joint, permitting movement of the exoskeleton, as between the segments of a pereopod. [Perez Farfante and Kensley, 1997]

Articular ridge

In cirripeds (Balanomorpha), linear elevation on tergal margin of scutum or scutal margin of tergum close to articular furrow and with it forming articulation between these plates. [Moore and McCormick, 1969]
Balanus trigonus: wall plates, exploded; and interior of operculum. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) Linear elevation on scutum or tergum bordering articular furrow and with it forming articulation between with two valves (balanomorph Cirripedia). [McLaughlin, 1980]

Ascending

Growing or directed upward. [Butler, T. H.]

Atrium oris

Preoral cavity, bounded ventrally by posteriorly directed labrum, dorsally by ventral surface of cephalon just behind mouth, and laterally by paragnaths and mandibles. [Moore and McCormick, 1969]
Preoral cavity, bounded ventrally by posteriorly directed labrum, dorsally by ventral surface of cephalon just behind mouth, and laterally by paragnaths and mandibles. [McLaughlin, 1980]
(Taxon-specific: Order Diplostraca) Large preoral cavity formed by upper lip (labrum) extending over mouth. Tips (molar processes) of mandibles extend into atrium oris. [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) Large preoral cavity formed by labrum extending over mouth. Mandibles (and to a lesser extent the endites or gnathobases of maxillules) extend into atrium oris. [Stachowitsch, 1992]
(Taxon-specific: Class Remipedia) Cavity around mouth formed by projecting posterior margin of labrum and paragnaths; masticatory ends (incisor process, lacinia mobilis, molar process) of mandible project into atrium oris. [Stachowitsch, 1992]

Attachment disc

(Taxon-specific: Subclass Cirripedia) In female acrothoracican, anteroventral horny structure used in attachment to burrow. If somewhat elevated, referred to as attachment knob. [Stachowitsch, 1992]

Attractor epimeralis muscle

Important muscle in many decapods, inserted along line of branchiocardiac groove in carapace. [Moore and McCormick, 1969]
Prominent muscle in many decapods, inserting along line of branchiocardiac groove. [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) In each side of cephalothorax, prominent muscle extending from epimeral fold to carapace, where it inserts along branchiocardiac groove (or lateral gastrocardiac marking).
(syn. tergoepimeral muscle) [Stachowitsch, 1992]

Autotomy

The voluntary shedding of a limb by snapping it off the base. [Ingle, 1983]

Bar

(Taxon-specific: Order Cladocera) Hing structure: Ridge-like projection extending along and set off from dorsal margin of one valve. Fits into accommodation groove of opposite valve. (smooth, crenulate).
(syn. hinge bar) [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) One in a series of chitinous skeletal elements supporting distal end of proboscis. According to position on may distinguish groove, lateral, lateral marginal, anterior and posterior lateral oblique, and inner and outer mandibular bars. [Stachowitsch, 1992]

Basal margin

In cirripeds, lower edge of scutum or tergum or other plate. [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature: lower edge of plate. Typically refers to lower edge of scutum or tergum. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Lower edge of scutum or tergum or other plate (thoracic Cirripedia). [McLaughlin, 1980]

Basal plate

(Taxon-specific: Subclass Branchiura) Spine-studded, plate-like structure on basal segment of each maxilla. (spines: alike, unlike; close together, well-separated; blunt, curved, scale-like, sharp).
(syn. maxillary plate) [Stachowitsch, 1992]

Baseoendopod

(Taxon-specific: Subclass Copepoda) The fused basis and endopod, particularly of the fifth leg in harpacticoids. [Boxshall and Halsey, 2004]

Basi-ischium

The second podomere from the base of a limb, formed from the fusion of the basis and the ischium of the primitive appendage (Figs. 1, 2). [Warner, 1977]
(Taxon-specific: Order Decapoda) Ischiobasis. [Stachowitsch, 1992]

Basial spine

Spine projecting from basis of a thoracic appendage. [Perez Farfante and Kensley, 1997]

Basicarinal angle

Intersection of basal and carinal margins of cirriped tergum. [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature: corner of tergum formed by junction of basal and carinal margins. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Intersection of basal and carinal margins of tergum (thoracic Cirripedia). [McLaughlin, 1980]

Basicerite

Second or distal segment of the protopodite of antenna, to which are attached the scale and peduncle. [Butler, T. H.]
Second segment of antennal peduncle (in Caridea bearing scaphocerite). [Moore and McCormick, 1969]
Second segment of antennal peduncle, bearing scaphocerite (Caridea). [McLaughlin, 1980]
Spine on dorsal side of basis of antenna; sometimes more lateral than dorsal. [Martin, 2005]
(Taxon-specific: Order Decapoda) In antenna, term applied to second of two segments (coxicerite, basicerite) of peduncle; may bear antennal scale (scaphocerite).
See: Carpocerite, Ischiocerite, Merocerite [Stachowitsch, 1992]

Basidorsal point

(Taxon-specific: Subclass Cirripedia) In certain unstalked barnacles, cone-shaped projection at base of penis. [Stachowitsch, 1992]

Basilateral angle

In cirripeds, intersection of lateral and tergal margins of scutum.
(syn. basitergal angle) [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Basitergal angle. [Stachowitsch, 1992]

Basioccludent angle

Intersection of basal and occludent margins of cirriped scutum. [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature: corner of scutum formed by junction of basal and occludent margins. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Intersection of basal and occludent margins of scutum (thoracic Cirripedia). [McLaughlin, 1980]

Basiophthalmite

Proximal segment of eyestalk, articulating with distal segment (podophthalmite) which bears corneal surface of eye. [Moore and McCormick, 1969]
Proximal segment of eyestalk, articulating with distal segment (podopthalmite) bearing corneal surface of eye. [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) Proximal of typically two segments (basiophthalmite, podophthalmite) of eyestalk. [Stachowitsch, 1992]

Basipod

See: Basis [Martin, 2005]
See basis. [McLaughlin, 1980]

Basis

Schematic drawing of a thoracic leg. [Holthuis, 1993]
(Figure only.) [Holthuis, 1993]
Article 2 of thoracic and abdominal appendages. [Holdich and Jones, 1983]
Limb segments adjoining coxa on its distal side and commonly bearing endopod and exopod; in nonpedunculate cirripeds comprises basal calcareous or membranous plate which furnishes anchorage to foreign body or substrate.
(syn. basipod(ite)) [Moore and McCormick, 1969]
Second article (from body) of leg or maxilliped. Sixth segment from distal end of limb.
(syn. basipodite) [Williams, 1984]
Second article of limb.
(pl. bases) [Poore, 2004]
Second podomere or segment, from the proximal end of a typically 7-segmented appendage (Fig. 3C).
(pl. bases) [Perez Farfante and Kensley, 1997]
Second segment (from proximal end) of segmented appendage. [Hobbs and Jass, 1988]
Second segment from the proximal end of a typically 7-segmented appendage.
(pl. bases) [Butler, T. H.]
Second segment of a pereiopod or maxilliped counted from the proximal end, immovably united with the ischium. [Ingle, 1983]
Segment of protopod adjoining coxa and carrying exopod and endopod distally; also basal calcareous or membranous plate furnishing anchorage to substrate in sessile cirripeds.
(pl. bases) [McLaughlin, 1980]
The second segment from the proximal end of a segmented appendage. [Hobbs, Hobbs, and Daniel 1977]
The second segment from the proximal end of a typically 7-segmented appendage.
(pl. bases) [Chace and Hobbs, 1969]
The second segment of a thoracic limb.
See: Pereopod [Wilson, 1989]
(Taxon-specific: Order Cladocera) Second segment of appendage; from distal segment of protopod (coax, basis). Often fused and indistinguishable.
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) Protopod. [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) Elongate second segment of thoracopod (maxillipeds and pereopods) or pleopods. May bear five-segmented endopod and smaller exopod. (See also epipod). [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) Second of seven segments (coxa, basis, ischium, merus, carpus, propodus, dactylus) of thoracopod. Bears endite in maxillae and maxillipeds.
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Second segment of appendage (thoracopod); forms distal segment of protopod (coxa, basis) and bears variously developed branches (endopod, exopod). May be fused to following segment (ischium) to form ischiobasis.
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Second of seven segments of thoracopod (coxa, basis, ischium, merus, carpus, propodus, dactylus); represents first movable (free) segment.
(syn. basipodite) [Stachowitsch, 1992]
Nomenclature of isopod cephalon (A). Examples of isopod mouth appendages: Idoteidae (B, C, F, H); Cirolanidae (D, E, G, I). [Wetzer et al. 1997]
(Taxon-specific: Order Isopoda) (Figure only.) [Wetzer et al. 1997]
Schematic representation of an isopod illustrating morphological terms. [Kensley and Schotte, 1989]
(Taxon-specific: Order Isopoda) Article of appendage adjoining coxa proximally, and carrying endopod distally, i.e., article 2 of pereopod. [Kensley and Schotte, 1989]
(Taxon-specific: Order Isopoda) Second segment of pereopod; located between coxa and ischium.
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Second of two segments (coxa, basis) of proximal part (protopod) of appendage.
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Third segment of thoracic appendage (thoracopod); located between coxa and merus. Also interpreted as being second segment (between coxa and ischium).
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) In thoracopod, third of three segments (precoxa, coax, basis) of protopod; may also be applied to segment of antennule.
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Basal element by which unstalked barnacle is attached to substratum. (calcareous = solid, membranous). [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Second segment of appendage; forms distal segment of protopod (coxa, basis).
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) The distal segment of the protopod of postantennulary appendages, bearing the rami. [Boxshall and Halsey, 2004]
(Taxon-specific: Subclass Copepoda) The distal segment of the protopod; it bears no more than two ventral, setose endites. The rami, exopod and endopod of a limb, originate on the basis (see coxa and praecoxa). [Ferrari and Dahms, in press]
(Taxon-specific: Subclass Mystacocarida) Protopod. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Distal part of divided protopod (separated from coxa by suture). [Cohen, Peterson, and Maddocks, in press]
(Taxon-specific: Superorder Syncarida) Second of two segments (coxa, basis) of proximal part (protopod) of appendage.
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) Second of two segments (coxa, basis) of proximal part (protopod) of appendage. Frequently interpreted as being fused with following segment (ischium) in maxilliped endopod.
(syn. basipodite) [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Second segment of appendage; forms distal segment of protopod (coxa, basis) and bears variously developed branches (endopod, exopod). Typically specified only when referring to thoracopods.
(syn. basipodite) [Stachowitsch, 1992]

Basiscutal angle

Intersection of basal and scutal margins of cirriped tergum. [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature; corner of tergum formed by junction of basal and scutal margins. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Intersection of basal and scutal margins of tergum (thoracic Cirripedia). [McLaughlin, 1980]

Basitergal angle

Intersection of basal and tergal margins of cirriped scutum. [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Barnacle plate feature; corner of scutum formed by junction of basal and tergal margins.
(syn. basilateral angle) [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Intersection of basal and tergal margins of scutum (thoracic Cirripedia). [McLaughlin, 1980]

Bathypelagic

Zone in the ocean deeper than 1000 m below the surface, or pertaining to its inhabitants. [Butler, T. H.]

Beak

(Taxon-specific: Class Ostracoda) Downwardly directed (anteroventral) projection of carapace margin. Not equivalent to rostrum and not associated with rostral notch. [Stachowitsch, 1992]

Beaked apex

In cirripeds (Balanomorpha), upper angle of tergum produced into long narrow point. [Moore and McCormick, 1969]

Bellonci organ

(Taxon-specific: Class Ostracoda) Organ projecting from forehead or naupliar (medial) eye of most Myodocopa. [Cohen, Peterson, and Maddocks, in press]

Bender muscle

The muscle which bends the leg forward at the CP joint.
See: Abdominal spine, Cephalothorax [Warner, 1977]

Benthos

Biarticulate

Consisting of two articles or segments. [Wilson, 1989]
(Taxon-specific: Order Isopoda) Composed of two articles. [Kensley and Schotte, 1989]

Bidentate

(Taxon-specific: Order Isopoda) Having two teeth. [Kensley and Schotte, 1989]

Bifid

A structure with two distal tips, as in unequally bifid seta. [Wilson, 1989]
Split in two, as in spines. [Butler, T. H.]
(Taxon-specific: Order Isopoda) Divided into two lobes or parts by a cleft. [Kensley and Schotte, 1989]

Biformes

Carapaces reflecting sexual dimorphism (e.g., Conchostraca), marked by differing valve proportions for each sex of same species (DADAY); a given species may have carapaces that are "biformes.". [Moore and McCormick, 1969]
Carapaces reflecting sexual dimorphism (e.g., Conchostraca), marked by differing valve proportions for each sex of the same species. [McLaughlin, 1980]

Bifurcate

Forked, divided into two branches. [Butler, T. H.]

Bilobed

(Taxon-specific: Order Isopoda) Composed of two lobes. [Kensley and Schotte, 1989]

Bioluminescene

Production of light by living organisms; occurs in several genera of shrimps. [Butler, T. H.]

Biramous

Having two branches or rami (exopodite and endopodite). [Holdich and Jones, 1983]
Having two branches, a typical condition for most primitive crustacean appendages. [Wilson, 1989]
Having two branches, as a pleopod. [Butler, T. H.]
Having two branches, as in the basic appendage (Fig. 2). [Warner, 1977]
Having two branches. Crustacean appendage with two rami; also antennule or antenna with two flagellar elements. [McLaughlin, 1980]
Two-branched; crustacean limb in which basis bears both exopod and endopod. [Moore and McCormick, 1969]
(Taxon-specific: Order Isopoda) Composed of two rami or branches. [Kensley and Schotte, 1989]
(Taxon-specific: Order Isopoda) Composed of two rami or branches. [Wetzer et al. 1997]
(Taxon-specific: Subclass Copepoda) Two-branched, used of limbs possessing both endopod and exopod. [Boxshall and Halsey, 2004]

Biserial branch

Primary branch of dendrobranchiate gill subdivided into two rows or series. [McLaughlin, 1980]

Biunguiculate

(Taxon-specific: Order Isopoda) Having two claws, as in a bifid dactylus. [Kensley and Schotte, 1989]

Bladder

(Taxon-specific: Order Decapoda) Expanded section of antennal gland between end sac and excretory pore. Consists of simple vesicle or is subdivided into a number of lobes or elongate diverticula extending into different regions of body. [Stachowitsch, 1992]

Blind capsule

(Taxon-specific: Subclass Branchiura) In male reproductive system, pair of glands in anterior region of thorax. Duct from each blind capsule connects to vas deferens and leads to common ejaculatory duct and gonopore.
(syn. blind gland) [Stachowitsch, 1992]

Blood pump

(Taxon-specific: Subclass Cirripedia) Rostral sinus. [Stachowitsch, 1992]

Blood rooms

Network of anastomosing cavities in body of conchostracans which provide for circulation of blood (SARS). [Moore and McCormick, 1969]

Body articulation

(Taxon-specific: Subclass Copepoda) Point at which body is capable of bending to greatest extent. Region of body anterior to flexure point is termed prosome, that posterior to it, urosome. According to group, it is located either between third/fourth, fourth/fifth, fifth/sixth thoracic somites or between sixth thoracomere and genital somite.
(syn. body flexure, flexure point) [Stachowitsch, 1992]

Body chamber

In cirripeds, interior of shell contaning soft parts of animal. [Moore and McCormick, 1969]

Body of mandible

See: Mandible body [Martin, 2005]

Body ring

Combined tergite and sternite of single somite, bearing legs or legless (as used by some specialists on Notostraca, not equivalent to somite). [Moore and McCormick, 1969]
(Taxon-specific: Order Notostraca) One in a series of divisions of thorax and abdomen. Posterior body rings may bear more than one pair of appendages each and are therefore considered to consist of several fused segments. May be modified to form half rings or spiral rings. (with leg, apodous).
(syn. ring) [Stachowitsch, 1992]

Body somite

Generally refers to unit division of thorax + abdomen in contrast to cephalic somite. [Moore and McCormick, 1969]

Boletate

A tubercle with a thick stem that is expanded distally into a convex or flat-topped surface with a circumference broader than the stem and that is usually punctate or marginally striate. [Ingle, 1980]

Bopyridum

Postlarva of epicaridean isopod that is attached to permanent host. [McLaughlin, 1980]

Boss

A globular, often polished, protrusion from the carapace surface. [Ingle, 1983]
An expanded portion (rounded protuberance) on mesial surface of coxa of fourth pereiopod of male crayfish (see Fig. 14). [Hobbs and Jass, 1988]

Brachium

(Taxon-specific: Subclass Copepoda) The digital segment of the maxilla of some siphonostomatoid copepods, corresponding to the basis plus basal endite. [Boxshall and Halsey, 2004]

Brachyura

An infra-order of decapod crustaceans. Used by Latrielle (1802) for the 'short tail' decapods, and now having the following restricted definition. Epistome always fused laterally with carapace and usually also medioanteriorly, pereiopod 1 chelate, 2-4 alike, abdomen reduced in size, bent under thorax. [Ingle, 1992]

Brachyuran crabs

Members of the infraorder Brachyura, in which all five pairs of thoracic legs are well developed.
(syn. true crabs) [Bliss, 1982]

Brain

(Taxon-specific: Order Notostraca) Main concentration of nreve tissue in head; consists of supraesophagael ganglion (protocerebrum and deutocerebrum) and, posterior to mouth, tritocerebrum (ganglion of antennal somite). Continues posteriorly as ladder-like ventral nerve cords. [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) Main concentration of nerve tissue in head. Consists basically of ganglion (supraesophageal ganglion = protocereberum + deutocerebrum) anterior to esophagus and ganglion (tritocerebrum) to side of or posterior to esophagus. Continues posteriorly as ladder-like ventral nerve cord. [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) main concentration of nerve tissue in head. Consists basically of ganglion (supraesophageal ganglion = protocerebrum and deuterocerebrum) anterior to esophagus and ganglion (tritocerebrum = circumesophageal ganglion = ganglion of antennal somite) to each side of or posterior to esophagus. Continues posteriorly as ladder-like ventral nerve cord. [Stachowitsch, 1992]
(Taxon-specific: Order Anostraca) Main concentration of nerve tissue; consists of supraesophageal ganglion (protocerebrum, deuterocerebrum) and, posterior to mouth, tritocerebrum (ganglion of antennal somite). [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) Main concentration of nerve tissue in cephalon. Connected with "eyes" by optic nerves and continues posteriorly to form subesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) Supraesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Supraesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Supraesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) Supraesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Supraesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) Supraesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Supraesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Supraesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Subclass Mystacocarida) Main concentration of nerve tissue in cephalon. Consists of anterior protocerebrum, median deutocerebrum (ganglion of antennular somite), and, at some distance posterior to deutocerebrum, a tritocerebrum (ganglion of antennal somite). Surrounds esophagus and gives rise to pair of ventral nerve cords. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Supraesophageal ganglion. [Stachowitsch, 1992]
(Taxon-specific: Class Remipedia) Main concentration of nerve tissue located above foregut in anterior region of head (cephalon); connected to ventral nerve cord by pair of circumesophageal commissures.
(syn. supraesophageal ganglion) [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) Main concentration of nerve tissue above (anterior to) esophagus. Continues posterior to esophagus as ventral nerve cord.
(syn. supraesophageal ganglion) [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Supraesophageal ganglion. [Stachowitsch, 1992]

Branchia

Gills, usually thoracic. [Poore, 2004]
Respiratory organ (gill) associated with an appendage or with the body wall.
(pl. branchiae) [Perez Farfante and Kensley, 1997]
Thin-walled finger-like or leaf-like structure extending outward from limb or secondarily from side of body, functioning for respiration.
(syn. gill. [Special types are termed arthrobranchs, pleurobranchs, and podobranchs, depending on their pl) [Moore and McCormick, 1969]
Thin-walled, fingerlike or leaflike structure extending outward from appendage or secondarily from side of body, functioning in respiration.
(pl. branchiae) (syn. gill) [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) Gill. [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Coxal gill. [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) Respiratory structure on or modification (thin cuticle, folding, etc.) of pleopod for gas exchange. [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Gill. [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Gill. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Branchial plate, gill. [Stachowitsch, 1992]

Branchial

Pertaining to the gills. [Butler, T. H.]

Branchial apparatus

(Taxon-specific: Order Cumacea) Term applied to epipods of first maxilliped pair (or, in an alternate interpretation, to epipods and exopods). Modified for respiration, the posteriorly directed part extending into branchial cavity and bearing branchial lobules, the anteriorly directed part ("exopod") forming part of exhalant cephalon. [Stachowitsch, 1992]

Branchial carina

See: Carapace carina b [Martin, 2005]
See: Carapace carina b [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) On each side of carapace in shrimp-like (natantian) decapod, narrow, longitudinal ridge extending posteriorly from orbit over branchial region. [Stachowitsch, 1992]

Branchial cavity

See: Branchial chamber [Martin, 2005]
Space between thorax and lateral flap of carapace (branchiostegite) enclosing branchia or gills. [Poore, 2004]

Branchial chamber

A chamber limited primarily by the lateral folds of the carapace, the inner surface of which performs a respiratory function. [Holdich and Jones, 1983]
Area between body and carapace enclosing branchiae.
(syn. gill chamber) [McLaughlin, 1980]
Chamber between carapace and body wall (pleura) that contains gills in most decapods. [Brusca and Brusca, 2002]
On either side of the cephalothorax of shrimps, lobsters, crabs and certain other crustaceans; formed from a deep lateral fold of the carapace; house the gills. [Bliss, 1982]
Space between body and wall of carapace enclosing branchiae.
(syn. gill chamber) [Moore and McCormick, 1969]
The chamber formed by the lateral region of the carapace enclosing the gills. [Ingle, 1983]
(Taxon-specific: Order Cumacea) Space on each side of cephalothorax between body and inner wall of carapace. Contains posteriorly directed part of epipods of first maxillipeds. Closed posteriorly, with water entering anteriorly and exiting frontmedially via siphon. [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) Space on each side of head between body and inner wall of carapace. Epipods of maxillipeds extend into branchial chamber. Water enters chamber primarily at posteroventral margins of carapace and exits ventrally at bases of maxillipeds.
(syn. branchial cavity) [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Lateral or dorsolateral space on each side of cephalothorax between body wall and carapace; encloses gills. In shrimp-like (natantian) decapod, water enters branchial chamber along posterior or ventral edges of carapace; in crab-like (brachyuran) decapod, it typically enters via afferent respiratory channels near bases of chelipeds.
(syn. gill chamber)
See: Epibranchial space, Hypobranchial space [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) Area on ventral surface of abdomen (pleon) containing branchiae; may be covered by expanded pleopods or uropods. [Stachowitsch, 1992]

Branchial count

The number of gills and epipodites present on one side of the cephalothorax. [Hobbs, Hobbs, and Daniel 1977]

Branchial filament

(Taxon-specific: Subclass Copepoda) In parasitic copepod, one element in tuft-like aggregations of slender processes of abdomen. [Stachowitsch, 1992]

Branchial glands

masses of connective-tissue cells surrounding venous channels in branchiae and devoid of ducts. [Moore and McCormick, 1969]
Masses of connective-tissue cells without ducts surrounding venous channels in branchiae. [McLaughlin, 1980]

Branchial lobe

A boss located at the anteriomesial angle of the mesobranchial region on the carapace of certain crabs. [Chace and Hobbs, 1969]
(Taxon-specific: Order Cumacea) One in a series of respiratory projections along posteriorly directed part of epipods of first maxillipeds. Located in branchial chamber. (finger-like, lamelliform) (See also accessory lobule). [Stachowitsch, 1992]

Branchial plate

(Taxon-specific: Class Ostracoda) Enlarged, flattened modification of outer branch (exopod) of either mandible, maxillule, maxilla, or first thoracic limb. Bears long setae along margin and maintains water circulation within carapace.
(syn. vibratory plate, respiratory plate) [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Flat setose epipod, used to circulate water through the domicilium.
(syn. vibratory plate) [Cohen, Peterson, and Maddocks, in press]

Branchial region

See: Carapace region c [Martin, 2005]
See: Carapace regions c [McLaughlin, 1980]
Area of the carapace overlying the branchial cavity. [Perez Farfante and Kensley, 1997]
Paired regions of dorsal carapace between hepatic regions in front posterior margin behind, sometimes bearing branchial spine(s), defined laterally in crabs by posterolateral margin. [Poore, 2004]
Portion of the carapace overlying the branchial cavity. [Butler, T. H.]
The portion of the carapace overlying the branchial cavity, in the true crabs comprising the epibranchial, mesobranchial, and metabranchial regions and the branchial lobe. [Chace and Hobbs, 1969]
(Taxon-specific: Order Cumacea) One of two relatively larger lateral regions of carapace overlying branchial chamber.
(syn. branchial area) [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) One of two relatively large, lateral regions of carapace overlying gills (branchiae). May be subdivided (from anterior to posterior) into epibranchial, mesobranchial, and metabranchial regions/ lobes/areas. [Stachowitsch, 1992]

Branchiocardiac carina

See: Carapace carina c [Martin, 2005]
See: Carapace carinae c [McLaughlin, 1980]
Ridge extending along posterodorsal limit of branchiostegite (Fig. 2A). [Perez Farfante and Kensley, 1997]
(Taxon-specific: Order Decapoda) On each side of carapace, narrow ridge separating branchial region from cardiac region. [Stachowitsch, 1992]

Branchiocardiac groove

See: Carapace groove b [Martin, 2005]
See: Carapace grooves b [McLaughlin, 1980]
Groove separating branchial and cardiac regions. [Williams, 1984]
Line along dorsal limit of branchiostegite.
(syn. branchiocardiac ridge) [Poore, 2004]
(Taxon-specific: Order Decapoda) On each side of carapace, oblique groove separating branchial and cardiac regions. Considered to represent former transverse border between two cephalic somites. May also refer to pair of grooves connecting cervical and postcervical grooves or extending posteriorly from post-cervical groove. [Stachowitsch, 1992]

Branchiocardiac sulcus

Groove extending along dorsal limit of branchiostegite, running parallel to branchiocardiac carina. [Perez Farfante and Kensley, 1997]

Branchiostegal area

Part of carapace extending laterally and downward over branchiae. [Moore and McCormick, 1969]
Part of carapace extending laterally and ventrally over branchiae. [McLaughlin, 1980]

Branchiostegal carina

Longitudinal ridge extending along anteroventral part of carapace, usually continuous with branchiostegal spine. [Perez Farfante and Kensley, 1997]

Branchiostegal spine

See: Carapace spine b [Martin, 2005]
See: Carapace spines b [McLaughlin, 1980]
A short spine located on or near the anterior margin of the carapace, ventral to the antennal spine in the shrimps; in crayfishes, immediately ventral to the anterior extremity of the cervical groove. [Hobbs, Hobbs, and Daniel 1977]
A short spine on or near the anterior margin of the carapace of some shrimps ventral to the antennal spine and dorsal to the anterolateral angle of the carapace. [Chace and Hobbs, 1969]
Short spine on or near the anterior margin of the carapace ventral to the antennal spine and dorsal to the anteroventral angle of the carapace (Fig. 2A). [Perez Farfante and Kensley, 1997]
Short spine situated on or near anterior margin of carapace, ventral to antennal spine in shrimps; in crayfishes, located immediately ventral to anterior extremity of cervical groove (see Fig. 13). [Hobbs and Jass, 1988]
Spine on anterior edge of carapace, or near it, immediately below branchiostegal groove (Fig. 2). [Williams, 1984]
Spine on or near anterolateral margin of the carapace of some shrimps, ventral to antennal spine and dorsal to pterygostomian spine. [Butler, T. H.]
(Taxon-specific: Order Decapoda) Anteriorly directed, spine-like projection on branchial region on each side of carapace in shrimp-like (natantian) decapod; located at anterior margin, below branchiostegal groove and between antennal and pterygostomial spines. [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Spine. [Stachowitsch, 1992]

Branchiostegal sulcus

Groove often accompanying branchiostegal carina, located on the anteroventral part of the carapace. [Perez Farfante and Kensley, 1997]

Branchiostegal-hepatic carina

Longitudinal ridge consisting of the fusion of the branchiostegal and hepatic carinae. [Perez Farfante and Kensley, 1997]

Branchiostegite

Expanded dorsal and lateral branchial region of carapace. [McLaughlin, 1980]
Expanded ventro-lateral part of the carapace covering the gills (Fig. 2A). [Perez Farfante and Kensley, 1997]
Expanded ventrolateral part of carapace covering gills. [Poore, 2004]
Part of carapace extending over top and side of branchial chamber. [Moore and McCormick, 1969]
Part of carapace not coalesced ventrally with thoracic somites, but overhanging on each side as covering for gill chamber. [Williams, 1984]
The anterior and lateral margins of the carapace extending ventrally on either side. [Ingle, 1983]
(Taxon-specific: Order Decapoda) Lateral or dorsolateral part of carapace extending over gills and forming outer wall of branchial chamber. [Stachowitsch, 1992]

Branchiostegites

The anterior and lateral margins of the carapace extend ventrally on either side forming the walls of the cephalothorax and enclosing the branchial chambers (Fig. 1). [Warner, 1977]

Bristle

Indefinite term for short, stiff seta or spinule. [Butler, T. H.]

Brood chamber

(Taxon-specific: Order Cumacea) In female, chamber formed on ventral surface of pereon by oostegites on last (third) maxillipeds and on first three pereopod pairs.
(syn. brood pouch, marsupium) [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) In female, space between thoracopods and carapace in which eggs are brooded. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) In female rhizocephalan, pouch-like structure projecting from body of host; contains eggs and seminal receptacle and serves as site of attachment of male. May also refer to brood pouch of ascothoracican.
(syn. externa) [Stachowitsch, 1992]

Brood plate

(Taxon-specific: Order Amphipoda) Oostegite. [Stachowitsch, 1992]

Brood pouch

(Taxon-specific: Order Tanaidacea) Marsupium. [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) In female, chamber formed on ventral surface of pereon by oostegites on second to fifth pereopods.
(syn. marsupium) [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) Chamber formed on ventral surface of pereon in female by three to five pairs of oostegites.
(syn. brood chamber, marsupium) [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Marsupium. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) An expanded region of the female domicilium, usually posterior, for protecting developing eggs and instars. [Cohen, Peterson, and Maddocks, in press]
(Taxon-specific: Order Thermosbaenacea) In female, dorsal chamber between thorax and carapace. Serves to brood eggs.
(syn. marsupium) [Stachowitsch, 1992]

Brood sac

A pouch formed from either one or two oostegites. [Holdich and Jones, 1983]

Brooding female

An adult female with fully extended oostegites on the coxae. In specimens from deep-sea samples, the developing embryos are often lost during sample processing, so it is generally not possible to tell whether the female was in fact brooding embryos, or whether she released the young before sampling. [Wilson, 1989]

Broom seta

A sensory seta that has a distinctly articulated pedestal, and two distal rows of long, extremely thin setules. It may be found on the antennulae or any of the pereopods. [Wilson, 1989]

Brush

Clump or band of setae or spinules, usually on distal flexor margin of propodus of fifth pereiopod; used by shrimp for grooming. [Butler, T. H.]

Brush-shaped organ

(Taxon-specific: Class Ostracoda) Rudimentary third pair of thoracopods (ninth paired appendage of body). Consists of basal part (stem) bearing distal cluster of hairs. Typically restricted to male and considered to be sensory.
(syn. brush-like structure) [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Small pair of lobes bearing numerous fine setae; found between the fifth limbs in males of most Cytherocopina and some Cypridocopina; might represent vestigial appendages. [Cohen, Peterson, and Maddocks, in press]

Buccal cavern

Space, especially in crabs, enclosing the mouthparts and more or less covered by third maxillipeds, defined anteriorly by epistome and laterally by pterygostomial region, sometimes by ridges.
(syn. buccal frame) [Poore, 2004]

Buccal cavity

Cavity on ventral surface of body in which mouth parts are situated; bounded anteriorly by epistome, laterally by free edges of carapace. Within this "frame" lie the mouth parts, which in most Brachyura are covered by operculiform third maxillipeds. [Williams, 1984]
Hollow space on ventral side of body containing mouth parts, in Malacostraca bounded by epistome in front and free edges of carapace on sides. [Moore and McCormick, 1969]
The area on the ventral surface of the carapace in which the mouth parts are situated. Bounded anteriorly by the epistome, laterally by the inner margin of the pterygostomial region and posteriorly by the anterior margin of the first thoracic sternite. [Ingle, 1983]
(Taxon-specific: Class Malacostraca) Area of cephalon containing mouthparts; bounded by epistome anteriorly and free margins of carapace laterally. [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) On underside of head, cavity in which mouthparts (labrum, mandibles, maxillules, maxillae, maxillipeds, labium) are located. [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) In front of mouth, chamber formed by lip-like extensions of proboscis margins. Contains mandibles. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) In parasitic copepod, term applied to space formed around mouth by prolonged upper lip (labrum) and lower lip (labium). (See also mouth cone). [Stachowitsch, 1992]

Buccal frame

structure of brachyuran decapods enclosing mouth parts, its sides formed by free anterolateral edges of carapace, its front delimited by epistome, and commonly closed by operculiform third maxillipeds. [Moore and McCormick, 1969]
(Taxon-specific: Order Decapoda) In crab-like (brachyuran) decapod, well-defined, frame-like depression on underside of head; contains mouthparts (labrum, mandibles, maxillules, maxillae, maxillipeds, labium) and may be covered by expanded (operculiform) maxillipeds. (quadrate, triangular).
See: Endostome [Stachowitsch, 1992]
(Taxon-specific: Infraorder Brachyura) Structural region of cephalon enclosing mouthparts. [McLaughlin, 1980]

Buccal groove

(Taxon-specific: Order Decapoda) See: Carapace grooves c [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) On each side of carapace, transverse groove behind antennal spine; connects gastroorbital and antennal grooves. [Stachowitsch, 1992]

Bud

(Taxon-specific: Subclass Copepoda) The earliest step of a developing limb; a limb bud does not articulate with its somite and bear setae including at least the crown group of terminal setae. A limb bud often is considered functionless on immature stages although limb 6 of podopleans is a bud which covers the genital opening of the adult male (see transformed limb and secondary bud). [Ferrari and Dahms, in press]

Bulb

(Taxon-specific: Class Ostracoda) Type of valve sculpture: relatively large, subspherical projection. [Stachowitsch, 1992]

Bulla

(Taxon-specific: Subclass Copepoda) A small, chitinous anchor-like structure fused to the tips of the maxillary arms in lernaeopodid copepods, that is embedded in the surface of the host fish to serve as an anchor. [Boxshall and Halsey, 2004]
(Taxon-specific: Subclass Copepoda) In parasitic copepod, attachment disc formed at fused end of both arm-like maxillae. (club-shaped, elliptical, spherical).
(syn. button) [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Type of valve sculpture: tubercle-like projection whose summit is elongated into a transverse or radial direction. May be considered to be type of verruca. [Stachowitsch, 1992]

CB

The junction between the coxa and the basi-ischium (Fig. 12). [Warner, 1977]

CP

The junction between the carpus and the propodus (Fig. 12). [Warner, 1977]

Calamus

(Taxon-specific: Subclass Copepoda) The main claw on the apex of the basis of the maxilla of some siphonostomatoids. [Boxshall and Halsey, 2004]

Calathus

See Optic Calathus. [Perez Farfante and Kensley, 1997]

Calcar

(Taxon-specific: Order Anostraca) Spur-like process on distal segment of antenna. (one-half as long/one-eighth or less as long as basal segment of antenna). [Stachowitsch, 1992]

Calceolus

Complex sensory filaments on antennules of some amphipods. [Moore and McCormick, 1969]
(Taxon-specific: Order Amphipoda) Complex sensory filaments on antennules.
(pl. calceoli) [McLaughlin, 1980]
(Taxon-specific: Order Amphipoda) One in a series of club-shaped sensory projections on antennules and antennae. More common in male.
See: Aesthetascs [Stachowitsch, 1992]

Calcified inner lamella

(Taxon-specific: Class Ostracoda) Calcified part of the inner (medial) lamella of valve margin. [Cohen, Peterson, and Maddocks, in press]

Calyptopis

First larval stage following the nauplius stage in euphausids, corresponding roughly to the the protozoea stage. [Brusca and Brusca, 2002]
Larval stage of euphausiids. There are three successive calyptopes, distinguished by the increasing degree of development of the abdomen. [Mauchline, 1984]
Third larval stage in euphausiaceans, characterized by differentiation of abdomen and appearance of compound eyes. [Moore and McCormick, 1969]
Third larval stage, characterized by differentiation of abdomen and appearance of compound eyes (Euphausiacea); see also zoea. [McLaughlin, 1980]
(Taxon-specific: Order Euphausiacea) Third of several larval stages (nauplius, metanauplius, calyptopis, furcilia). Characterized by development of carapace, elongation of abdomen, differentiation of somites, and development of eyes under carapace.
See: Cyrtopia [Stachowitsch, 1992]

Canna

(Taxon-specific: Subclass Copepoda) The armature element representing the basal endite of the maxilla of some siphonostomatoids. [Boxshall and Halsey, 2004]

Caperation

(Taxon-specific: Class Ostracoda) Type of valve sculpture: fine wrinkle. [Stachowitsch, 1992]

Capitate

Enlarged or globular at end. [AHD]

Capitulum

In pedunculate cirripeds portion of carapace enclosing trophic structures, commonly armored by calcareous plates. [Moore and McCormick, 1969]
Portion of carapace enclosing body, commonly protected by calcareous plates (lepadomorph cirripeds); or anterior prominence in complex tooth and socket hingement (Ostracoda). [McLaughlin, 1980]
(Taxon-specific: Subclass Cirripedia) In stalked barnacle, one of two external divisions of body (capitulum, peduncle). Consists of mantle and associated plates enclosing body. [Stachowitsch, 1992]

Carapace

Entire animal, right appendages omitted, dorsal view, based on Munida. [Baba, 2005]
(Figure only.) [Baba, 2005]
Carapace, spines, based on Munida. [Baba, 2005]
(Figure only.) [Baba, 2005]
"Head Shield" cuticular structure arising from posterior margin of cephalon, extending anteriorly and posteriorly, and covering the cephalothoracic somites of the body (Fig. 1). [Perez Farfante and Kensley, 1997]
"Shield" (exoskeleton) overlying cephalothoracic somites of body (see Figs. 13,14) [Hobbs and Jass, 1988]
'Head shield" covering the cephalothoracic somites of the body. [Butler, T. H.]
A more expansive structure than the head shield (cephalic shield) , comprising the head shield and a large fold of the exoskeleton that probably arises (primitively) from the maxillary somite. [Brusca and Brusca, 2002]
A sheet of cuticle extending back from the head to enclose the dorsal and lateral parts of the thorax; the 'shell' of a crab (Fig. 1). [Warner, 1977]
A shield that covers the head and thorax. [Mauchline, 1984]
an extension of the exoskeleton which covers and fuses with the head and the first two thoracic somites. [Holdich and Jones, 1983]
Cuticular, usually calcified, structure arising from posterior margin of cephalon, extending anteriorly and posteriorly, often covering head and thorax (cf. Eucarida); also fold of integument extending from maxillary segment, forming bivalved shell of cyprid larvae and of ascothoracicans and mantle of other cirripedia; mantle usually with calcified plates in thoracicans. [McLaughlin, 1980]
Cuticular, varyingly calcified structure comprising cephalic shield and fold of integument arising from posterior border of maxillary somite extending over trunk, usually covering it laterally as well as dorsally; commonly fused to one or more thoracic somites and in may forms having mid-dorsal hinge. [Moore and McCormick, 1969]
Shield arising from posterior margin of head and comprising lateral extensions of thoracic somites covering all or most of cephalothorax. [Poore, 2004]
The "head shield" covering the cephalothoracic somites of the body. [Chace and Hobbs, 1969]
The "head shield" overlying the cephalothoracic somites of the body. [Hobbs, Hobbs, and Daniel 1977]
The exoskeleton that covers the dorsal and ventro-lateral portions of the cephalothorax. [Ingle, 1980]
The portion of the hard exoskeleton, or shell, that covers all or part of the body of many crustaceans; in shrimps, lobsters, and crabs, the carapace covers the head and thorax. [Bliss, 1982]
(Taxon-specific: Order Cladocera) Single-piece (univalved) shield which, if fully developed, covers only posterior part of body (trunk). Laterally compressed, with ventral gape, and therefore occasionally described as bivalved (i.e., consisting of two "valves" ). (angular, circular, elongate, oval, ovate, ovoid, spherical, subcircular, subquadrate; laterally compressed, thick-bodied; with/without carapace spine, with/without crest, narrowed and prolonged/not narrowed and prolonged posteriorly into short tube, anterior portion swollen/not swollen, with/without projection on anteroventral margin, ventral margin smooth/with fine spines, dorsal margin smooth/serrate; sculpture: reticulated, smooth; longitudinally, obliquely, transversely striated; with/without hairs, with polygonal or rhomboid markings).
(syn. shell) [Stachowitsch, 1992]
(Taxon-specific: Order Notostraca) Large broad shield covering dorsal surface of head, thorax, and anterior part of abdomen. Consists of single element (univalve) and is emarginated (notch, sinus) posteriorly. Bears median eye, compound eyes, and dorsal organ anteriorly and is sculptured by median keel and transverse mandibular and cervical grooves.
(syn. dorsal shield) [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) Bivalved, laterally compressed shield typically enclosed entire body; consists of two valves with dorsal hinge line, although occasionally interpreted as representing a single continuous element. Joined to body by ligament and pair of adductor muscles in head region. (broadly oval, compressed, globose = globular, oblong, ovate, subovate, subrectangular, subspherical, swollen, thick and globose, thin and pellucid; with/without growth lines; with/without umbones; with/without keel; sculpture: polygonal, punctate, reticulate, with dendritic or radial grooves, with striae).
(syn. shell) [Stachowitsch, 1992]
(Taxon-specific: Order Cumacea) Large, shield-like structure covering head and three to six thoracic somites. Extends laterally to enclose branchial chamber. Regionated to form anterior pseudorostrum, frontal lobe, ocular lobe, as well as branchial and cardiac regions. (inflated, laterally compressed; dorsal outline: straight, arched, with slight undulations; with/without lateral horns; smooth, sculptured: hairy, rugose, with denticles, with median/lateral carina, with longitudinal depressions, with dorsal crest: serrate, smooth, with teeth). [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) Shield-like structure covering head and first two thoracic segments (thoracomeres). Extends laterally to enclose branchial chamber.
See: Cephalothorax [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Large, shield-like cuticular structure covering cephalothorax; bears rostrum anteriorly and is typically regionated and sculptured with various carinae, grooves, spines, and teeth. Encloses gill-bearing bases of thoracopods and thus forms branchial chambers. (general form: cylindrical, compressed, depressed; shape: convex, circular, globular, hemispherical, hexagonal, octagonal, orbicular, oval, ovate triangular, pentagonal, polygonal, pyriform, quadrilateral, rectangular, subcircular, subcylindrical, subglobose, subhexagonal, suborbicular, subovoid, subpenta-gonal, subquadrate, subquadrilateral, sub-triangular, transversely oval, tumid; surface: areolated, carinate, eroded, glabrous, granulate, nodular, nodulose, plicate, polished, pubescent, punctuate, with rugae, smooth, squamose, tuberculate, wrinkled). [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Shield-like structure coving head and most of thorax. Typically fused to first three thoracic segments (thoracomeres) and typically bearing rostrum. (with/without rostrum; undecorated, ornamented: spinose, with keels; posterior margin: indented, produced into spines, with lobes) (See also cervical sulcus). [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Shield-like cuticular structure covering cephalon (except for anterior acron and antennular somite) as well as first four thoracic somites (thoracomeres); overlaps but does not enclose bases of first five thoracopods. Broad, flattened, and typically sculptured with various carinae and grooves. Bears rostrum anteriorly. (with/without carinae; anterolateral corners: armed, unarmed, rounded). [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Large shield covering thorax, posterior part of head, and anterior part of abdomen. Laterally compressed and therefore often described as being bivalved (although no dorsal hinge is present). Two halves of carapace can be drawn toward each other by carapace adductor muscle. Bears rostral plate anteriorly. (elliptical and posterodorsally truncate, subtriangular and posteriorly acuminate; smooth, with polygonal ornamentation). [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) Dorsoventrally flattened, shield-like structure covering head and first thoracic somite (thoracomere); characterized by pair of posterolateral wing-like extensions (alae). Bears pair of compound eyes dorsolaterally and set of median nauplius eyes. (circular, cordate, elliptical, trifoliate). [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Mantle. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Lateral outfolds of dorsal epithelium and cuticle, bivalved and enveloping the entire body. [Cohen, Peterson, and Maddocks, in press]
(Taxon-specific: Class Ostracoda) Shell-like outer covering; consists of pair of valves joined dorsally by hinge and entirely enclosing body. (calcareous, uncalcified; ornate, smooth; amplete, postplete, preplete). [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) Shield-like structure fused to and covering head and first thoracic somite (thoracomere). Extends posteriorly and laterally to cover additional thoracomeres. Serves in respiration and forms brood pouch in female. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Shield-like, relatively thin structure fused to thoracic somites and covering cephalothorax. Does not enclose gill-bearing bases of thoracopods. Typically bears cervical groove. (with/without rostrum). [Stachowitsch, 1992]

Carapace angles

In Leaiidae (Conchostraca), angle made by straight dorsal margin with anterior rib (a) and with posterior rib (b); these angles may have utility in tracing evolutionary development and in stratigraphic zonation. [Moore and McCormick, 1969]
(Taxon-specific: Order Diplostraca) Intersection of straight and dorsal margin by anterior rib (alpha) and posterior rib (beta). [McLaughlin, 1980]

Carapace carina

Narrow ridge on surface of carapace (cf. decapod carapace and stomatopod integumental ornamentation). [McLaughlin, 1980]
Narrow ridge variously located on surface of decapoda carapace — named types:
a) antennal. Narrow ridge extending backward from antennal spine.
b) branchial. Narrow ridge extending backward from orbit over branchial region.
c) branchialcardiac. Narrow ridge marking off branchial from cardiac regions of carapace.
d) gastroorbital. Narrow ridge extending backward from supraorbital spine.
e) lateral. Narrow ridge on side margin of carapace.
f) orbital. Narrow ridge on margin of orbit.
g) posterior. Transverse narrow ridge in front of carapace marginal groove.
h) postorbital. Narrow ridge slightly behind orbital margin and parallel to it.
i) postrostral. Narrow ridge behind rostrum extending along dorsal mid-line of carapace.
j) rostral. Longitudinal narrow ridge continuous with lateral margin of rostrum.
k) subhepatic. Narrow ridge extending backward from branchiostegal spine.
l) submedian. Narrow ridge on either side of postrostral carina and parallel to it; may join rostral carina.
m) supraorbital.
See: Gastroorbital carina [Moore and McCormick, 1969]

Carapace carinae

(Taxon-specific: Order Decapoda) (a) antennal. Extending posteriorly from antennal spine.
(b) branchial. Extending posteriorly from orbit over branchial region.
(c) branchiocardiac. Dividing branchial from cardiac region.
(d) gastroorbital. Extending posteriorly from supraorbital spine; syn., supraorbital.
(e) lateral. On lateral margin of carapace.
(f) orbital. On margin of orbit.
(g) posterior. Transverse ridge anterior to marginal groove.
(h) postorbital. Slightly posterior and parallel to orbital margin.
(i) postrostral. Posterior to rostrum along dorsal midline.
(j) rostral. Continuous with lateral margin of rostrum.
(k) subhepatic. Extending posteriorly from branchiostegal spine.
(l) submedian. On either side of, and parallel to, postrostral carina, sometimes joining rostral carina.
(m) supraorbital. See gastroorbital. [McLaughlin, 1980]

Carapace costae

Closely spaced radial ridges, grading from fine to coarse, that become obsolete near umbo and do not cross it (=radial lirae, radial riblets, accessory ribs) (e.g., Conchostraca, especially Estheriellidae, in which valves generally have more than 5 costae). [Moore and McCormick, 1969]
(Taxon-specific: Order Diplostraca) Closely spaced radial ridges, grading from fine to coarse, not crossing to umbo.
(syn. radial lirae) [McLaughlin, 1980]

Carapace costellae

Fine radial ridges that run from ventral margin to and across umbo, and are usually numerous on any given valve (e.g. Conchostraca). [Moore and McCormick, 1969]
(Taxon-specific: Order Diplostraca) Fine radial ridges extending from ventral margin across umbo. [McLaughlin, 1980]

Carapace groove

Furrow on surface of decapod, generally dorsal — named types:
a) antennal. Furrow on carapace extending backward from vicinity of antennal spine.
b) branchiocardiac. Oblique furrow approximately in middle of posterior half of each side of carapace, separating branchial and cardiac regions and reaching dorsomedian part of carapace well behind cervical or postcervical grooves; may be longitudinal, connecting cervical and postcervical grooves, or extending backward from submedian point on postcervical groove.
c) cervical. Transverse furrow in median part of carapace between gastric and cardiac regions, curving forward toward antennal spine.
d) gastroorbital. Short longitudinal furrow branching from cervical groove at level of orbit and running toward it.
e) hepatic. Short longitudinal furrow connecting cervical with postcervical and branchiocardiac grooves, more or less continuing antennal groove.
f) inferior. Transverse furrow extending from junction or hepatic and cervical grooves toward side margin of carapace, more or less continuous with cervical groove.
g) marginal. Furrow close to posterior edge of carapace and parallel to it.
h) postcephalic. one of three transverse furrows on carapace of many fossil decapods.
i) postcervical. Furrow located behind cervical groove and parallel to it, dividing cardiac region into two parts.
j) submedian. Longitudinal furrow in submedian dorsal part of carapace closely adjacent to post-rostral carina. [Moore and McCormick, 1969]

Carapace grooves

(Taxon-specific: Order Decapoda) (a) antennal. Extending posteriorly from vicinity of antennal spine.
(b) branchiocardiac. Oblique groove approximately in middle of posterior half on each side of carapace, separating branchial and cardiac regions and reaching dorsomedian part well posterior to cervical or postcervical grooves; sometimes longitudinal, connecting cervical and postvcervical grooves or extending posteriorly from submedian point on postcervical groove.
(c) buccal. Transverse groove crossing mandibular elevation behind antennal spine, connecting gastroorbital and antennal grooves.
(d) cervical. Transverse groove medially between gastric and cardiac regions, curving toward antennal spine; syn., cervical suture, cervical furrow.
(e) dorsomedian. Longitudinal groove extending from tip of rostrum to posterior carapace margin dorsomedially.
(f) gastroorbital. Short, longitudinal groove branching from cervical groove at level of orbit and directed toward it.
(g) hepatic. Short, longitudinal groove connecting cervical with postcervical and branchiocardiac grooves, more or less continuous with antennal groove.
(h) inferior. Extending from junction of hepatic and cervical grooves toward lateral margin, more or less continuous with cervical groove.
(i) intercervical. Oblique groove connecting postcervical and cervical grooves.
(j) intestinal. Short, transverse groove in median part of posterior carapace, interrupted by intestinal tubercle.
(k) marginal. Close to, and parallel with, posterior margin.
(l) parabranchial. Groove below, behind and almost parallel with branchiocardiac and postcervical grooves, joining latter in lower part.
(m) postcephalic. One of three transverse furrows on carapace of many fossils.
(n) postcervical. Posterior to, and parallel with, cervical groove, bisecting cardiac region.
(o) sellar. Short transverse groove dorsally anterior tp cervical groove.
(p) submedian. Longitudinal groove in submedian dorsal part, contiguous with postrostal carina.
(q) urogastric. Short transverse groove in median or submedian region posterior to postcervical groove, sometimes joining upper part of postcervical groove. [McLaughlin, 1980]

Carapace growth line

(Taxon-specific: Order Diplostraca) Peripheral margin of successive membranes added to shell during each molt. [Moore and McCormick, 1969]

Carapace horn

Anterodorsal termination of carapace valves in some Archaeostraca; may be indurated (e.g., Ceratiocaris) or produced into long process (e.g., Caryocaris). [Moore and McCormick, 1969]

Carapace length

In shrimps, distance from the posterior margin of orbit to midcaudodorsal margin of carapace; in crayfishes, distance from tip of rostrum to midcaudodorsal margin of carapace (see Fig. 14). [Hobbs and Jass, 1988]
In shrimps, the distance from the posterior margin of the orbit to the mid-caudodorsal margin of the carapace; in crayfishes, the distance from the tip of the rostrum to the mid-caudodorsal margin of the carapace. [Hobbs, Hobbs, and Daniel 1977]

Carapace lirae

(Taxon-specific: Order Diplostraca) Linear concentric edges parallel to and between growth lines. [McLaughlin, 1980]
(Taxon-specific: Order Diplostraca) Raised, linear, fine concentric ridges parallel to growth lines and occupying an interspace. [Moore and McCormick, 1969]

Carapace region

Differentiated portion of decapod carapace surface distinguished in descriptions and used in classification — named types:
a) antennal. Anterior marginal part of carapace bordering orbital region laterally and also touching hepatic, pterygostomial, and, in some forms, frontal region.
b) anterolateral. Lateral part of carapace bordering subhepatic or hepatic regions.
c) branchial. Lateral part of carapace behind pterygostomial region and overlying branchiae, divided by some authors into epibranchial, mesobranchial, and metabranchial subregions.
d) cardiac. Median part of carapace behind cervical groove or suture, between urogastric and intestinal areas.
e) frontal. Anteromedian part of carapace including rostrum and area behind it.
f) gastric. Median part of carapace in front of cervical groove and behind frontal region; divided by some authors into epigastric, mesogastric, metagastric, protogastric, and urogastric subregions.
g) hepatic. Part of carapace which may touch antennal, cardiac, and pterygostomial regions.
h) intestinal. Short transverse part of carapace behind cardiac region, designated by some as posterior cardiac lobe.
i) jugal. See: Pterygostomial region
j) orbital. Part of carapace behind eyes, bordered by frontal and antennal regions.
k) pterygostomial. Anterolateral part of carapace on ventral surface located on opposite sides of buccal cavity.
l) subhepatic. Part of carapace below hepatic region and extending below lateral edge of latter.
(syn. carapace area) [Moore and McCormick, 1969]
(Taxon-specific: Order Decapoda) Differentiated portion of carapace surface.
See: Carapace regions [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) One of numerous, more or less clearly delimited and elevated subdivisions of carapace. According to position or underlying internal organs, as well as according to group, one may distinguish antennal, anterolateral, branchial, cardiac, epibranchial, epigastric, frontal, gastric, hepatic, intestinal, mesobranchial, mesogas-tric metabranchial, metagastric, orbital, pos-terolateral, protogastric, pterygostomial, subhepatic, and urogastric regions. [Stachowitsch, 1992]

Carapace regions

(Taxon-specific: Order Decapoda) (a) antennal. Anterior marginal part bordering orbital region laterally, adjoining hepatic, pterygostomial, and occasionally also frontal regions.
(b) anterolateral. Lateral part bordering subhepatic or hepatic regions.
(c) branchial. Lateral part posterior to ptergostomial region, overlying branchiae; epibranchial, mesobranchial, and metabranchial lobes or areas sometimes distinguished.
(d) cardiac. Median part posterior to cervical groove between urogastric and intestinal regions.
(e) frontal. Anteromedian part including rostrum and region behind it.
(f) gastric. Median part posterior to cervical groove and posterior to frontal region; sometimes epigastric, mesogastric, metagastric, protogastric, and urogastric (genital) areas distinguished.
(g) hepatic. Part adjoining antennal, cardiac, and pterygostomial regions.
(h) intestinal. Short traverse part posterior to cardiac region; sometimes referred to as posterior cardiac lobe.
(i) jugal. See pterygostomial region.
(j) orbital. Part posterior to eyes bordered by frontal and antennal regions.
(k) pterygostomial. Anterolateral part on ventral surface located on opposite sides of buccal cavity; syn., jugal region, pterygostome.
(l) subhepatic. Part on ventral surface below hepatic region, bounded by pterygostomial and suborbital regions.
(m) suborbital. Part on anteroventral surface beneath orbit. [McLaughlin, 1980]

Carapace spine

Sharp projection of carapace important for classification — chief types:
a) antennal. Spine on front margin of carapace slightly below orbit.
b) branchiostegal. Spine on front margin of carapace or slightly behind it about halfway between antennal and pterygostomial spines.
c) hepatic. Spine in hepatic region of carapace below lower branch of cervical groove and behind it.
d) infraorbital. Spine on lower angle of orbit.
e) postorbital. Spine at moderate distance behind middle of orbit.
f) postrostral. Dorsomedian spine immediately behind rostrum.
g) pterygostomial. Spine on anterolateral angle of carapace.
h) suborbital. Spine at moderate distance below middle of orbit and slightly beneath it.
i) supraorbital. Spine at moderate distance obliquely behind and above orbit (may be placed at postorbital carina). [Moore and McCormick, 1969]
(Taxon-specific: Order Cladocera) Large, posteriorly directed, spine-like structure formed by posterodorsal extension of carapace. Relative length may be of taxonomic importance.
(syn. apical spine, posterior spine, shell spine) [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Sharp projection from carapace.
See: Carapace spines [McLaughlin, 1980]

Carapace spines

(Taxon-specific: Order Decapoda) (a) antennal. On anterior margin slightly below orbit.
(b) branchiostegal. On or clsoe to anterior margin medially between antennal and pterygostomial spines.
(c) hepatic. Below and posterior to lower branch of cervical groove.
(d) infraorbital. On lower angle of orbit.
(e) postorbital. At moderate distance posterior to middle of orbit.
(f) postrostral. Immediately posterior to rostrum.
(g) pterygostomial. On anterolateral angle.
(h) suborbital. Slightly below and posterior to middle of orbit.
(i) supraorbital. At moderate distance obliquely behind and above orbit; somtimes on postorbital carina. [McLaughlin, 1980]

Carapace teeth

(Taxon-specific: Order Decapoda) (a) cardiac. On midline of carapace just posterior to cervical groove.
(b) gastric. On midline of carapace immediately anterior to cervical groove.
(c) lateral. On lateral margin of carapace; anterolateral, mediolateral, and posterolateral teeth distinguished.
(d) orbital. On orbital margin.
(e) posterior. On midline of carapace between posterior margin and marginal groove.
(f) pregastric. On midline of carapace between gastric tooth and rostrum.
(g) rostral. On rostrum, either single or multiple; upper, lower, and lateral teeth distinguished. [McLaughlin, 1980]

Carapace tooth

Generally blunt projection of carapace, often broader than spine.
See: Carapace teeth, Stomatopod integumental ornamentation [McLaughlin, 1980]
Small sharp spinous projection in varied locations — named types:
a) cardiac. Tooth on mid-line of carapace just behind cervical groove.
b) gastric. Tooth on mid-line of carapace just in front of cervical groove.
c) lateral. Tooth placed on lateral margin of carapace (includes anterolateral, mediolateral, posterolateral teeth).
d) orbital. Tooth on orbital margin.
e) posterior. Tooth on mid-line of carapace just in front of posterior margin between it and marginal groove.
f) pregastric. Tooth on mid-line of carapace between gastric tooth and rostrum.
g) rostral. Tooth on rostrum; may be single (e.g., scyllarid palinurans) or multiple and classified as upper, lower or lateral (e.g., nephropid astacideans and natantian crabs). [Moore and McCormick, 1969]

Carcinisation

Tendency for decapods to evolve towards a crab-like form. [Poore, 2004]

Cardiac

A median region of the carapace, between the gastric and intestinal regions. [Poore, 2004]

Cardiac notch

Indentation on posterior margin of carapace (e.g., some Alpheidae).
(syn. cardiac incision) [Moore and McCormick, 1969]
Indentation on posterior margin of carapace. [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) In shrimp-like (natantian) decapod, notch on posterior margin of carapace. [Stachowitsch, 1992]

Cardiac region

See: Carapace region d [Martin, 2005]
See: Carapace regions d [McLaughlin, 1980]
Dorsolateral region of carapace bounded anteriorly by gastric region and laterally by branchial regions. [Butler, T. H.]
The dorsomedian area on the carapace bounded anteriorly by the gastric region, laterally by the branchial regions, and (in the crabs) posteriorly by the intestinal region. This area is often very narrow in the crayfishes and commonly called the areola. [Chace and Hobbs, 1969]
The region on the dorsal surface of the carapace bounded by parts or the margins of the urogastric, mesobranchial, metabranchial and intestinal regions. [Ingle, 1983]
(Taxon-specific: Order Cumacea) Unpaired median region in posterior half of carapace; overlies anterior region of heart. (See also branchial region). [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Relatively large, unpaired median region in posterior half of carapace; overlies heart. Adjoined anteriorly by gastric, posteriorly by intestinal, and laterally by branchial regions. [Stachowitsch, 1992]

Cardiac stomach

Anterior region of the decapod foregut. [Brusca and Brusca, 2002]
(Taxon-specific: Order Decapoda) Anterior and larger cuticle-lined division of stomach; separated from smaller posterior pyloric stomach by cardiopyloric valve and characterized by variously developed grinding apparatus (gastric mill). [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Stomach. [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Anterior and larger division of stomach occupying most of head (cephalon). Separated from smaller posterior pyloric stomach by filtering apparatus; contains only small pairs of plates (ossicles). [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Stomach. [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) Stomach. [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) Stomach. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Anterior and larger division of stomach; separated from smaller posterior pyloric stomach by cardiopyloric valve. Serves to grind food. (with/without denticles). [Stachowitsch, 1992]

Cardiac tooth

See: Carapace tooth a [Martin, 2005]
See: Carapace teeth a [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) On midline of carapace, tooth-like projection in cardiac region just posterior to cervical groove. [Stachowitsch, 1992]

Cardial sulcus

(Taxon-specific: Order Mysida) Transverse groove across posterior region of carapace at level of heart. (See also cervical sulcus). [Stachowitsch, 1992]

Cardiopyloric valve

(Taxon-specific: Order Decapoda) In digestive tract, valve-like structure between anterior cardiac stomach and posterior pyloric stomach. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) In digestive tract, valve-like structure between anterior cardiac stomach and posterior pyloric stomach. [Stachowitsch, 1992]

Cardo

Basal segment of maxillula articulating with head. [Moore and McCormick, 1969]
Basal segment of maxillule articulating with cephalon. [McLaughlin, 1980]

Caridean lobe

External rounded projection on basal part of exopod of 1st maxilliped (Caridea). [McLaughlin, 1980]
External rounded projection on basal part of exopod of first maxilliped (e.g., Caridea). [Moore and McCormick, 1969]
(Taxon-specific: Order Decapoda) In first maxilliped, setose broadening or lobe at base of outer branch (exopod). [Stachowitsch, 1992]

Caridean shrimps

Higher shrimps, members of the infraorder Caridea; include the majority of shrimps and prawns. [Bliss, 1982]

Caridoid escape reaction

"Tail-flip" behavior resulting from rapid contraction of the ventral abdominal (flexor) muscles, causing the animal to shoot quickly backward from the force of water displaced by the large propulsive surface provided by the tail fan. [Brusca and Brusca, 2002]

Caridoid facies

Aspect of primitive Eumalacostraca distinguished by enclosure of thorax by carapace, movably stalked eyes, biramous antennules, scaphocerite-bearing antennae, thoracopods with natatory exopods, elongate abdomen ventrally flexed and powerfully muscled, and caudal fan. [Moore and McCormick, 1969]
Basic group of characters distinguishing eumalacostracan crustaceans: enclosure of thorax by carapce, movable stalked eye, biramous antennules, antennae with scaphocerites, thoracopods with natatory exopods, ventrally flexed abdomen, and tailfan. [McLaughlin, 1980]

Carina

A raised ridge on the surface of the exoskeleton. [Ingle, 1980]
A ridge or keel of the exoskeleton (Fig. 1, 2).
(pl. carinae) [Perez Farfante and Kensley, 1997]
Any keel-like structure, as on dorsum of pleon on some amphipods; in cirripeds, single compartment plate at end of shell where cirri are protruded, or adjacent to tergum, possessing alae only.
See: Carapace carina [Moore and McCormick, 1969]
Any keellike structure; any well-defined projecting ridge on outer surface of carapace (podocopan Ostracoda); unpaired posterodorsal plate of thoracic Cirripedia (in lepadomorphs 1 of up to 4 unpaired plates of capitulum; in verrucomorphs compartmental plate between rostrum and fixed tergum; in balanomorphs compartmental plate, with alae on each side, opposite rostrum). [McLaughlin, 1980]
Keel, acute ridge, crest. [Poore, 2004]
Keel, or ridge.
(pl. carinae) [Butler, T. H.]
Keel-like ridge or prominence. [Williams, 1984]
Median middorsal ridge on rostrum; oriented parallel to lateral margins of rostrum (see Figs. 37,47). [Hobbs and Jass, 1988]
(Taxon-specific: Order Notostraca) Median keel. [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) One of a number of narrow, elevated ridges along carapace or abdomen. According to position and according to group, those on carapace may be termed antennal, branchial, branchiocardiac, gastroorbital, lateral, orbital, posterior, postorbital, postrostral, rostral, subhepatic, submedian, and supraorbital carinae.
(syn. ridge, keel) [Stachowitsch, 1992]
(Taxon-specific: Order Isopoda) A keel, or acute ridge. [Wetzer et al. 1997]
(Taxon-specific: Order Isopoda) A keel, or an acute ridge. [Kensley and Schotte, 1989]
(Taxon-specific: Order Stomatopoda) One in a series of longitudinal, keel-like elevations on dorsal surface of either carapace, thoracic somites (thoracomeres), abdominal somites (pleomeres) or telson. According to position (from midline outward) one may distinguish median, submedian, intermediate, lateral, marginal, and various accessory carinae or secondary ridges. Refers also to ventral elevations (e.g., postanal carina). (sharp, swollen/rounded; posteriorly spined, posteriorly rounded; straight, curved; median carina: bifurcate, not bifurcate). [Stachowitsch, 1992]
Lepas anatifera: left valve removed. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
Balanus trigonus: apical view; left lateral view; and operculum, body, and branchiae. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
Balanus trigonus: wall plates, exploded; and interior of operculum. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) One of five primary plates (carina, two scuta, two terga) on outer surface of barnacle: unpaired posterior plate. In stalked form, posterior plate on capitulum. In unstalked barnacle, compartmental plate between rostrum and fixed tergum (asymmetrical form) or plate opposite rostrum (symmetrical form); consists of median paries and lateral alae. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Type of valve sculpture: prominent ridge or keel. (disconnected, excavate, ponticulate = perforate, simple, undercut; dorsal, marginal, median, ventral). [Stachowitsch, 1992]

Carinal

In cirripeds (Thoracica), toward or adjacent to compartment plate termed carina. [Moore and McCormick, 1969]

Carinal latus

See: Latus (carinal) a [Martin, 2005]
See latus. [McLaughlin, 1980]
(Taxon-specific: Subclass Cirripedia) Barnacle shell plate: in stalked form, paired plates (latera), one on each side of carina. Homologous with carinolateral of unstalked form.
(syn. carinolatus) [Stachowitsch, 1992]

Carinal margin

In cirripeds (Thoracica) , edge of tergum adjacent to carina, occluding with carinal margin of opposed tergum. [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) Edge of any plate adjacent to carina; occluding with carinal margin of opposed tergum (thoracic Cirripedia). [McLaughlin, 1980]

Carinate

Conchostracan valve bearing rib(s), chiefly applicable to Leaiidae. [Moore and McCormick, 1969]
Having a carina, keeled. [Butler, T. H.]
(Taxon-specific: Order Diplostraca) Valve bearing rib(s). [McLaughlin, 1980]
(Taxon-specific: Order Isopoda) Having one or more carinae or acute ridges. [Kensley and Schotte, 1989]

Carinolateral

Compartment plate of cirripeds located on either side of carina, with radii on cardinal side and alae on rostral side.
(syn. latus (cardinal)) [Moore and McCormick, 1969]
Balanus trigonus: apical view; left lateral view; and operculum, body, and branchiae. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
Balanus trigonus: wall plates, exploded; and interior of operculum. [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) (Figure only.) [Anderson, 1980]
(Taxon-specific: Subclass Cirripedia) Barnacle shell plate: in unstalked form, paired posterolateral plate, one between carina and each lateral plate. Consists of median paries with radius on one (carinal) side, ala on other (lateral) side.
(syn. carinolatus) [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) One of pair of compartmental plates typically overlapping carina on each side, with radius on carinal side and ala on lateral side, sometimes absent; homologous with lepadomorph carinal latus (balanomorph Cirripedia). [McLaughlin, 1980]

Carpace

Carpocerite

Distal (5th) segment of antennal peduncle. [Moore and McCormick, 1969]
Distal (5th) segment of antennal peduncle. [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) In antenna, term applied to last of three segments (ischiocerite, merocerite, carpocerite) of endopod (alternate interpretation: fifth segment of peduncle). [Stachowitsch, 1992]

Carpochelate

(Taxon-specific: Order Isopoda) Having a chela or pincerlike structure formed by the seventh (dactylus) and fifth (carpus) articles of an appendage. [Kensley and Schotte, 1989]

Carpopod

See: Carpus [Martin, 2005]
See carpus [McLaughlin, 1980]

Carpoprodus

(Taxon-specific: Order Mysida) On inner branch (endopod) of thoracopod, multisegmented unit formed by carpus and propodus. [Stachowitsch, 1992]

Carpus

Schematic drawing of a thoracic leg. [Holthuis, 1993]
(Figure only.) [Holthuis, 1993]
Entire animal, right appendages omitted, dorsal view, based on Munida. [Baba, 2005]
(Figure only.) [Baba, 2005]
Endopod of Mxp 3, lateral; and endopod of Mxp 3, including basal 2 articles, distal articles omitted, central. Based on Munidopsis. [Baba, 2005]
(Figure only.) [Baba, 2005]
Antepenultimate segment of thoracopod or pereopod.
(syn. carpopod) [McLaughlin, 1980]
Article 5 of pereopod (article 4 of cheliped). [Holdich and Jones, 1983]
Fifth article of limb (first article of palp in maxilliped 3). [Poore, 2004]
Fifth podomere from the proximal end of a typically 7-segmented appendage (Fig. 3C).
(pl. carpi) [Perez Farfante and Kensley, 1997]
Fifth segment from proximal end of a typically 7-segmented appendage.
(pl. carpi) [Butler, T. H.]
Fifth segment from proximal end of segmented appendage. [Hobbs and Jass, 1988]
Segment of limb located next distally from merus and joined to propodus proximally.
(syn. carpopod(ite), wrist) [Moore and McCormick, 1969]
The fifth segment from the proximal end of a segmented appendage; in some shrimps, consisting of several articles (that of the second pereiopod of alpheids and hippolytids consisting of a number of articles). [Hobbs, Hobbs, and Daniel 1977]
The fifth segment from the proximal end of a typically 7-segmented appendage.
(pl. carpi) [Chace and Hobbs, 1969]
The fifth segment of a thoracic limb.
(syn. carpopodite)
See: Pereopod [Wilson, 1989]
The third podomere from the tip of the endopod of a limb (Figs. 1, 2). [Warner, 1977]
Third article from distal end of leg.
(syn. carpopodite) [Williams, 1984]
Third segment of a pereiopod or maxilliped, counted from the distal end. [Ingle, 1983]
(Taxon-specific: Order Cumacea) Third of five segments (ischium, merus, carpus, propodus, dactylus) of endopod of thoracopod (maxillipeds and pereopods).
(syn. carpopodite) [Stachowitsch, 1992]
(Taxon-specific: Order Tanaidacea) Fifth of basically seven segments (coxa, basis, ischium, merus, carpus, propodus, dactylus) of thoracopod.
(syn. carpopodite) [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Fifth segment of thoracopod; located between merus and propodus. (simple, multiar-ticulated = subdivided).
(syn. carpopod, carpopodite, wrist) [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Fifth of basically seven segments (coxa, basis, ischium, merus, carpus, propodus, dactylus) of thoracopod; represents fourth movable (free) segment. In certain amphipods, may form part of subchela (i.e., dactyl and propodus bearing down on carpus).
(syn. carpopodite) [Stachowitsch, 1992]
Schematic representation of an isopod illustrating morphological terms. [Kensley and Schotte, 1989]
(Taxon-specific: Order Isopoda) Article 5 or pereopod. [Kensley and Schotte, 1989]
(Taxon-specific: Order Isopoda) Fifth segment of pereopod; located between merus and propodus.
(syn. carpopodite) [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Fourth of basically six segments (preischium, ischium, merus, carpus, propodus dactylus) of inner branch (endopod) of thoracopod, May form a multiarticulate unit with propodus (carpopropodus). (multiarticulate, one-segmented).
(syn. carpopodite) [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Fifth segment of thoracic appendage (thoracopod); located between merus and propodus.
(syn. carpopodite) [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) Fourth of basically six segments (preischium, ischium, merus, carpus, propodus, dactylus) of inner branch (endopod) of thoracopod. Main bend (knee) of thoracopod typically occurs between carpus and propodus.
(syn. carpopodite) [Stachowitsch, 1992]
(Taxon-specific: Order Thermosbaenacea) Third of basically five segments (ischium, merus, carpus, propodus, dactylus) of inner branch (endopod) of thoracopod.
(syn. carpopodite) [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Fifth segment of thoracopod (third segment of five-segmented endopod); positioned between merus and propodus.
(syn. carpopodite) [Stachowitsch, 1992]

Catalepsis

Bridging of the dorsal surface of the shrimp, as if telson is about to touch rostrum; a defensive position. [Butler, T. H.]

Caudal

Posterior (rear,tail) end of organism. [Hobbs and Jass, 1988]

Caudal appendage

In cirripeds, one of terminal, multiarticulate or uniarticulate, uniramous paired appendages, homologous with caudal furca of other crustaceans. [Moore and McCormick, 1969]
(Taxon-specific: Subclass Cirripedia) One of terminal, multiarticulate or simple, uniramous paired appendages homologous with caudal furca. [McLaughlin, 1980]

Caudal fan

Combination of laterally expanded uropods and telson turned backwards to form powerful swimming structure or means of steering and balancing.
(syn. tail fan, rhipidura) [Moore and McCormick, 1969]
Powerful swimming structure formed of laterally expanded uropods and telson.
(syn. tailfan) [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) Tailfan. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Tailfan. [Stachowitsch, 1992]

Caudal filament

See: Caudal ramus [Martin, 2005]

Caudal furca

Pair of caudal rami. [Moore and McCormick, 1969]
Paired caudal rami of terminal abdominal segment or telson.
(syn. furca) [McLaughlin, 1980]
(Taxon-specific: Order Cladocera) Caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Order Notostraca) Caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) Caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Order Anostraca) Caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) Caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Subclass Mystacocarida) Caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Caudal ramus. [Stachowitsch, 1992]
(Taxon-specific: Order Euphausiacea) Subapical spine. [Stachowitsch, 1992]

Caudal process

(Taxon-specific: Class Ostracoda) Posterior extension of carapace.
(syn. keel) [Cohen, Peterson, and Maddocks, in press]
(Taxon-specific: Class Ostracoda) Posterior projection of valve border generally above midheight, or posteroventral, directed upward. [McLaughlin, 1980]
(Taxon-specific: Class Ostracoda) Posterior projection of valve margin. (posterodorsal, posteroventral and upwardly directed). [Stachowitsch, 1992]

Caudal rami

Pair of appendage-like or spine-like processes borne on anal somite in primitive crustaceans. [Brusca and Brusca, 2002]

Caudal ramus

One of paired appendages constituting caudal furca, usually rodlike or bladelike, sometimes filamentous and multiarticular.
(syn. caudal filament, caudal style, cercus, cercopod, furcal ramus, stylet) [McLaughlin, 1980]
Single appendage of terminal abdominal somite paired with another to form caudal furca, both articulated with telson; usually rod-like or blade-like but may be filamentous and multiarticular (caudal filament).
(syn. cercus, cercopod, caudal style, stylet) [Moore and McCormick, 1969]
(Taxon-specific: Order Cladocera) One of two relatively short, claw-shaped projections at end of postabomen. May bear up to three series (pectens) of minute spines. Both caudal rami together are termed caudal furca. (denticulate, pectinate, with/without basal spine, with/without pectin).
(syn. claw, postabdominal claw, terminal claw) [Stachowitsch, 1992]
(Taxon-specific: Order Notostraca) One of two posteriorly directed projections of last segment (telson). Long and segmented ( = annulate, multiarticulate). Both caudal rami together are termed caudal furca. (unarmed, armed with minute spinules and setae).
(syn. furca ramus) [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) One of two relatively short, posteriorly directed of projections of telson. Both caudal rami together are termed caudal furca. (claw-like, styliform) (See also uropod).
(syn. cercopod, furcal claw) [Stachowitsch, 1992]
(Taxon-specific: Order Anostraca) One of two posteriorly directed projections of last segment (telson). Unsegmented, typically fringed with setae. (freely movable/variously fused with last segment; thin and slender, broadly leaf-like or plate-like).
(syn. furcal ramus, cercopod) [Stachowitsch, 1992]
(Taxon-specific: Class Cephalocarida) One of two posteriorly projections of last body segment (telson). Consists of single element with terminal setae (ramal setae, caudal setae). Both rami together are termed caudal furca. If telson is interpreted as representing anal somite, then caudal ramus may be termed uropod. (length relative to telson width: equal to or less than, less than twice, equal to twice). [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) One of two posteriorly directed projections of last body segment (telson). Both rami together termed caudal furca. (dorsoventrally flattened and leaf-like, rod-like) (see also uropod).
(syn. furcal ramus) [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) Pair of minute projections between posterior lobes of abdomen; rami flank anus. (basal, lateral, subbasal, subterminal, terminal).
(syn. anal furca, anal papilla) [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) In ascothoracican, one of two posteriorly directed projections of last segment of abdomen. Both caudal rami together termed caudal furca. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) One of two posteriorly directed projections of last abdominal segment (anal somite); typically bears a number of setae (caudal setae). (length greater than, equal to, or less than width; margins: hairy, smooth, spinulose).
(syn. furcal ramus) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) The appendage of the posterior abdominal somite of a copepod. It does not have a propodal/ramal configuration and its homologies to serially repeated limbs of the cephalon and thorax have not been determined. The caudal ramus bears setae in a pattern similar to an exopod. Its axial orientation is not known. [Ferrari and Dahms, in press]
(Taxon-specific: Subclass Copepoda) The paired, setiferous and usually articulated structures carried on the anal somite. [Boxshall and Halsey, 2004]
(Taxon-specific: Subclass Mystacocarida) One of two relatively large, posteriorly directed projections of last segment (telson). Claw-shaped, with serrate inner margin and bearing several major setae. Both rami together are termed caudal furca.
(syn. furcal ramus, furcal claw) [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) One of two projections of posterior end (thorax/abdomen) of body; extends anteroventrally due to curvature of body. (paired, unpaired; symmetrical, asymmetrical; lemelliform, rod-shaped, claw-like).
(syn. furcal ramus) [Stachowitsch, 1992]
(Taxon-specific: Class Remipedia) One of two unbranched processes projecting posteriorly from anal segment; each ramus bears setae along median margin and terminally. (shorter than, longer than anal segment). [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) In bathynellacean, one of two small protuberances at end of telson. Both caudal rami together termed caudal furca. May also be interpreted as representing lobes of telson.
(syn. furcal ramus) [Stachowitsch, 1992]

Caudal siphon

(Taxon-specific: Class Ostracoda) Posteroventral gape in valve margin; may be extended as tubular structure. [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Posteroventral opening in valve border; sometimes produced as tubular structure (Ostracoda). [McLaughlin, 1980]

Caudal style

See: Caudal ramus [Martin, 2005]
See caudal ramus. [McLaughlin, 1980]

Cecum

(Taxon-specific: Order Cladocera) Digestive cecum. [Stachowitsch, 1992]
(Taxon-specific: Order Notostraca) One of two outpocketings of midgut. Elongate and extensively branched with carapace. Opens into digestive tract posterior to esophagus/midgut border.
(syn. midgut diverticulum, digestive gland) [Stachowitsch, 1992]
(Taxon-specific: Order Diplostraca) Digestive cecum. [Stachowitsch, 1992]
(Taxon-specific: Order Anostraca) Midgut diverticulum. [Stachowitsch, 1992]
(Taxon-specific: Order Decapoda) Hepatic cecum. [Stachowitsch, 1992]
(Taxon-specific: Order Amphipoda) Midgut cecum. [Stachowitsch, 1992]
(Taxon-specific: Order Mysida) Dorsal cecum, lateral cecum. [Stachowitsch, 1992]
(Taxon-specific: Order Stomatopoda) Digestive gland. [Stachowitsch, 1992]
(Taxon-specific: Order Leptostraca) Midgut cecum, rectal cecum. [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) Highly branched diverticulum, one extending from each side of anterior midgut. Fills greater part of carapace after fish louse feeds on host tissues. [Stachowitsch, 1992]
(Taxon-specific: Subclass Cirripedia) Digestive cecum.
(syn. caecum) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Unpiared anterior extension of stomach. (See also lateral midgut diverticulum).
(syn. midgut cecum, anterior midgut cecum) [Stachowitsch, 1992]
(Taxon-specific: Class Ostracoda) Pair of large outpocketings or one of numerous smaller outpocketings of anterior section (stomach) of midgut.
(syn. caecum, liver) [Stachowitsch, 1992]
(Taxon-specific: Superorder Syncarida) In anaspidacean, one of numerous relatively thin tubules arising at anterior end of midgut and extending posteriorly to end of thorax. Also refers to short dorsal ceca of midgut, one at level of first abdominal somite, the other level at fifth.
(syn. digestive cecum) [Stachowitsch, 1992]

Celation

(Taxon-specific: Class Ostracoda) Type of valve sculpture: elaboration (tegmen) of outer layer which overlapsand obscures underlying ornamentation. [Stachowitsch, 1992]

Cement gland

Special concentrations of cells in dermal cover of cirripeds which function for secreting calcareous substance of valves; possibly equivalent to dermal glands of other crustaceans. [Moore and McCormick, 1969]
(Taxon-specific: Order Anostraca) Pair of glands dorsal and proximal to eggs in ovisac; produces outer cover of eggs. [