Amphipoda: Families and Subfamilies

J.K. Lowry & R.T. Springthorpe

Ceinidae J.L. Barnard, 1972

Description. Head free, not coalesced with peraeonite 1; exposed; as long as deep, or deeper than long; anteroventral margin weakly recessed or moderately recessed, anteroventral margin shallowly excavate or moderately excavate, anteroventral corner rounded or subquadrate; rostrum present or absent, short; eyes present, well developed or obsolescent; not coalesced; 1 pair; not bulging. Body laterally compressed; cuticle with deep sensory pits and dorsally carinate.

Antenna 1 shorter than antenna 2, or subequal to antenna 2, or longer than antenna 2; peduncle with sparse robust and slender setae; 3-articulate; peduncular article 1 longer than article 2; rticle 2 subequal to article 3, or longer than article 3; peduncular articles 1-2 not geniculate; accessory flagellum absent; antenna 1 callynophore absent. Antenna 2 present; short; articles not folded in zigzag fashion; without hook-like process; flagellum shorter than peduncle, or as long as peduncle, or longer than peduncle; 5 or more articulate, or less than 5-articulate; not clavate.

Mouthparts well developed. Mandible incisor dentate; lacinia mobilis present on both sides; accessory setal row without distal tuft; molar present, medium, triturative or non-triturative; palp absent. Maxilla 1 present; inner plate present, weakly setose apically; palp present or absent, not clavate, 0 -articulate or 1 -articulate. Maxilla 2 inner plate present; outer plate present. Maxilliped inner and outer plates well developed or reduced, palps present, well developed or reduced; inner plates well developed, separate; outer plates present, large or small; palp 4-articulate, article 3 without rugosities. Labium smooth.

Peraeon. Peraeonites 1-7 separate; complete; sternal gills absent; pleurae absent.

Coxae 1-7 well developed, none fused with peraeonites. Overlapping, coxae not acuminate. Coxae 1-3 not successively smaller, none vestigial. Coxae 2-4 none immensely broadened.

Gnathopod 1 not sexually dimorphic; smaller (or weaker) than gnathopod 2, or subequal to gnathopod 2; vestigial, hidden or partially hidden by coxa 2, or subequal to coxa 2; gnathopod 1 merus and carpus not rotated; gnathopod 1 carpus/propodus not cantilevered; shorter than propodus, or subequal to propodus; gnathopod 1 not produced along posterior margin of propodus; dactylus large. Gnathopod 2 sexually dimorphic, or not sexually dimorphic; subchelate; coxa subequal to but not hidden by coxa 3; ischium short, or elongate; merus not fused along posterior margin of carpus or produced away from it; carpus/propodus not cantilevered, carpus short or elongate, shorter than propodus or longer than propodus, not produced along posterior margin of propodus.

Peraeopods heteropodous (3-4 directed posteriorly, 5-7 directed anteriorly), some or all prehensile or none prehensile. Peraeopod 3 well developed. Peraeopod 4 well developed. 3-4 not glandular; 3-7 without hooded dactyli, 3-7 propodi without distal spurs. Coxa well developed, longer than broad; carpus shorter than propodus or subequal to propodus, not produced; dactylus well developed. Coxa larger than coxa 3, not acuminate, with well developed posteroventral lobe; carpus not produced. Peraeopods 5-7 with few robust or slender setae; some or all dactyli with slender or robust setae or dactyli without slender or robust setae. Peraeopod 5 well developed; shorter than peraeopod 6; coxa smaller than coxa 4, with ventrally produced posterior lobe or with posterodorsal lobe or without posterior lobe; basis expanded, subrectangular or subquadrate or subovate, with posteroventral lobe or without posteroventral lobe; merus/carpus free; carpus weakly expanded; with a few subterminal setae. Peraeopod 6 shorter than peraeopod 7, or subequal in length to peraeopod 7; merus/carpus free; dactylus with a few subterminal setae, or without setae. Peraeopod 7 with 6-7 well developed articles; longer than peraeopod 5; similar in structure to peraeopod 6; with 7 articles; basis expanded or slightly expanded, without dense slender setae; dactylus with a few subterminal setae or without setae.

Pleon. Pleonites 1-3 without transverse dorsal serrations, each with dorsal carina or without dorsal carina; without slender or robust dorsal setae, or with dense patches of short dorsal setae. Epimera 1-3 present. Epimeron 1 well developed. Epimeron 2 without setae.

Urosome not dorsoventrally flattened; urosomites 1 to 3 free; urosomite 1 much longer than urosomite 2; urosome urosomite 1 carinate, or urosomites not carinate, or urosomite 3 carinate; urosomites 1-2 without transverse dorsal serrations. Uropods 1-2 apices of rami with robust setae, or without robust setae. Uropods 1-3 similar in structure and size. Uropod 1 peduncle without long plumose setae, without basofacial robust seta, without ventromedial spur. Uropod 2 well developed; without ventromedial spur, without dorsal flange; inner ramus subequal to outer ramus. Uropod 3 not sexually dimorphic; peduncle short. Telson laminar, or weakly thickened dorsoventrally; moderately cleft, or weakly cleft, or entire; broader than long; apical robust setae absent.

Habitat. marine.

Habitat. benthic.

Remarks. In this study the Ceinidae retain on the genera of the Ceininae. Based on the advice of Wolfgang Zeidler and Exequiel Gonzalez the chiltoniine genera are placed in the Hyalellidae as intended by Bulecheva (1957), Bousfield (1993; 1996) and Zeidler (1991).


Cite this publication as: 'J.K. Lowry & R.T. Springthorpe (2001 onwards). Amphipoda: Families and Subfamilies. Version 1: 1 September 2001. http://crustacea.net/'. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).

Index