Podosiridae

Myers, A, 2012, Podosiridae, a new family of North Atlantic deep sea amphipod (Crustacea, Amphipoda), Zootaxa 3546, pp. 81-84 : 82-83

Podosiridae fam. nov.

(Figs 1, 2)

Diagnostic description. Body subcylindrical; without setae. Head longer than deep; eyes absent. Antenna 1 peduncle without setae; accessory flagellum absent; primary flagellum 5 or more articulate; callynophore absent; calceoli unknown. Antenna 2 with sparse slender setae; flagellum longer than peduncle; 5– or more articulate. Mouthparts well developed, forming a subquadrate bundle. Mandible incisor dentate, straight; lacinia mobilis broad, apically serrate; molar present, medium size, strongly triturating; palp 3-articulate. Maxilla 1 inner plate apically setose (setae vestigial); palp large, 2-articulate. Maxilla 2 inner plate shorter than outer plate, without oblique setal row.

Pereon. Coxae 1–7 well developed. Coxae 1–4 short, broader than long, overlapping. Coxae 4–5 without lobes. Gnathopod 1 smaller than gnathopod 2; dissimilar in form to gnathopod 2; subchelate; coxa slightly smaller than coxa 2; anteroventral corner produced, acute. Gnathopod 2 subchelate; coxa subequal in size to coxa 3; dactylus well developed. Pereonite 7 with small dorsal carina. Pereopods 3–7 basis linear; merus linear much longer than propodus; carpus linear. Pereopods 3–4 not glandular. Pereopod 4 coxa subequal in size to coxa 3, without posteroventral lobe. Pereopod 5 subequal in length to pereopod 6; coxa without lobes. Pereopod 6 shorter than pereopod 7. Pereopod 7 longer than pereopod 5; similar in structure to pereopod 6.

Pleon. Pleonites each with a small dorsal carina. Urosome dorsoventrally flattened; urosomites 1–3 free. Urosomite 1 much longer than urosomite 2. Uropods 1–2 apices of rami without robust setae. Uropods 1–3 similar in structure and size. Uropod 1 peduncle without basofacial robust seta, without ventromedial spine. Uropod 3 biramous; rami styliform; outer ramus subequal to peduncle or longer than peduncle, without recurved spines; inner ramus longer than outer ramus, inner ramus not apically setose. Telson laminar; longer than broad; entire.

Habitat. Vent communities in about 1700 m depth.

Remarks. Podosirids with their slender, evenly curved, opposable pereopods, appear to be adapted to grasping substrates, such as octocoral stems. These characteristics in place with the large second gnathopods in females (and presumably males) and the large maxilliped with elongate palps and stabbing dactyli, all indicate an ambush predator.