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].

(Order Cladocera):

Trunk [Stachowitsch, 1992].

(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].

(Order Diplostraca):

Trunk [Stachowitsch, 1992].

(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].

(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].

(Order Cumacea):

Pleon [Stachowitsch, 1992].

(Order Tanaidacea):

Pleon [Stachowitsch, 1992].

(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].

(Order Amphipoda):

Pleon [Stachowitsch, 1992].

(Order Isopoda):

Pleon [Stachowitsch, 1992].

(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].

(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].

(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].

(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].

(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].

(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].

(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].

(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].

(Class Ostracoda):

Rudimentary region of body bearing caudal rami; indistinguishably fused to thorax [Stachowitsch, 1992].

(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].

(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].

(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].