Amphipoda: Families and Subfamilies

J.K. Lowry & R.T. Springthorpe

Phronimidae Dana, 1853

Description. Head free, not coalesced with peraeonite 1; exposed; much deeper than long; anteroventral margin straight or oblique, anteroventral corner rounded; rostrum present or absent, short; eyes present, well developed or obsolescent; coalesced; 1 pair; bulging, or not bulging. Body laterally compressed; cuticle smooth.

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, or 1- or 2-articulate; peduncular article 1 longer than article 2; antenna 1 article 2 subequal to article 3; peduncular articles 1-2 not geniculate; accessory flagellum absent; antenna 1 callynophore present, or absent. Antenna 2 present, or absent; short, or medium length; articles not folded in zigzag fashion; without hook-like process; flagellum longer than peduncle, or absent; 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, medium, triturative; palp absent. Maxilla 1 present; inner plate absent; palp present, not clavate, 1 -articulate. Maxilla 2 inner plate present; outer plate present. Maxilliped inner and outer plates well developed or reduced, palps absent; inner plates well developed or absent, fused medially; outer plates present. Labium smooth.

Peraeon. Peraeonites 1-7 separate, or some or all of peraeonites 1-5 coalesced; complete; sternal gills absent; pleurae absent.

Coxae 1-7 vestigial or absent, coxae 1-7 fused with peraeonites.

Gnathopod 1 not sexually dimorphic; subequal to gnathopod 2; gnathopod 1 merus and carpus not rotated; gnathopod 1 carpus/propodus not cantilevered; subequal to 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 minute. Gnathopod 2 not sexually dimorphic; simple; ischium short; merus not fused along posterior margin of carpus or produced away from it; carpus/propodus not cantilevered, carpus elongate, shorter than propodus or subequal to propodus, strongly produced along posterior margin of propodus or slightly produced along posterior margin of propodus or not produced along posterior margin of propodus.

Peraeopods heteropodous (3-4 directed posteriorly, 5-7 directed anteriorly), some or all 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; carpus shorter than propodus, not produced; dactylus minute. Carpus not produced. Peraeopods 5-7 with few robust or slender setae; dactyli without slender or robust setae. Peraeopod 5 well developed; subequal in length to peraeopod 6, or longer than peraeopod 6; basis slightly expanded or linear, without posteroventral lobe; merus/carpus free; carpus expanded; 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; shorter than peraeopod 5; similar in structure to peraeopod 6; with 7 articles; basis linear, without dense slender setae; dactylus without setae.

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

Urosome not dorsoventrally flattened; urosomites 1 free, 2 and 3 coalesced; urosome urosomites not carinate; urosomites 1-2 without transverse dorsal serrations. Uropods 1-2 apices of rami without robust setae. Uropods 1-3 radically dissimilar in structure and size, or similar in structure and size. Uropod 1 peduncle without long plumose setae, without basofacial robust seta, without ventromedial spur. Uropod 2 well developed, or an undifferentiated lobe, or absent; without ventromedial spur, without dorsal flange; inner ramus shorter than outer ramus, or subequal to outer ramus. Uropod 3 not sexually dimorphic; peduncle elongate; outer ramus shorter than peduncle, 1-articulate, without recurved spines. Telson laminar; weakly cleft, or notched, or entire; broader than long; apical robust setae absent.


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