Amphipoda: Families and Subfamilies

J.K. Lowry & R.T. Springthorpe

Aoridae Stebbing, 1899

Description. Head free, not coalesced with peraeonite 1; exposed; as long as deep, or longer than deep; anteroventral margin weakly recessed or moderately recessed or strongly recessed or concave or oblique, anteroventral margin deeply excavate or shallowly excavate or moderately excavate, anteroventral corner rounded or subquadrate or hooked; rostrum present or absent, short; eyes present, well developed or obsolescent, or absent; not coalesced; 1 pair; not bulging. Body laterally compressed, or subcylindrical; cuticle smooth.

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

Mouthparts well developed. Mandible incisor dentate; lacinia mobilis present on both sides; accessory setal row without distal tuft; molar present, small or medium, triturative; palp present or absent. Maxilla 1 present; inner plate present, strongly setose along medial margin or weakly setose apically; palp present, not clavate. 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 or reduced, none fused with peraeonites. Coxae 1-4 longer than broad or as long as broad or broader than long, overlapping or discontiguous, coxa 1 anteroventrally acuminate or coxae not acuminate. Coxae 1-3 not successively smaller, none vestigial or coxa 1 reduced. Coxae 2-4 none immensely broadened.

Gnathopod 1 sexually dimorphic, or not sexually dimorphic; smaller (or weaker) than gnathopod 2, or subequal to gnathopod 2, or larger (or stouter) than gnathopod 2; smaller than coxa 2, or subequal to coxa 2, or larger than coxa 2; gnathopod 1 merus and carpus not rotated; gnathopod 1 carpus/propodus not cantilevered; shorter than propodus, or subequal to propodus, or longer than propodus; gnathopod 1 strongly produced along posterior margin of propodus, or slightly produced along posterior margin of propodus, or not produced along posterior margin of propodus; dactylus large. Gnathopod 2 sexually dimorphic, or not sexually dimorphic; simple, or subchelate, or parachelate; coxa smaller than and mostly hidden by coxa 3, or subequal to but not hidden by coxa 3, or larger than coxa 3; ischium short; 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 subequal to propodus or longer than propodus, not produced along posterior margin of propodus.

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

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

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

Habitat. marine or estuarine.

Habitat. benthic.


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