Pachynus Bulycheva, 1955

Lowry, J. K. & Stoddart, H. E., 2012, The Pachynidae fam. nov. (Crustacea: Amphipoda: Lysianassoidea) 3246, Zootaxa 3246 (1), pp. 1-69 : 36-37

Pachynus Bulycheva, 1955

Pachynus Bulycheva, 1955: 193 . ― Gurjanova, 1962: 345. ― Hurley, 1963: 30. ―J.L. Barnard, 1969a: 354. ― Lowry, 1984:72. ― Barnard & Karaman, 1991: 510.

Type species. Pachynus chelatum Bulycheva, 1955 , by original designation.

Diagnostic description. Body shape compact. Head lateral cephalic lobe usually small, subacute. Antenna 1 peduncular article 1 without posterodistal spine; accessory flagellum article 1 short (when present); flagellum with or without callynophore in female. Mandible with accessory setal row present on both sides or absent; left lamina dentata absent; palp attached midway or distally; palp article 2 slender, article 3 with subparallel margins or with anterior margin convex, not distally tapered. Maxilla 1 outer plate setal-teeth smooth, at least one inner row setaltooth absent; palp well developed, broad, 2-articulate. Maxilliped inner plate small; outer plate small; palp 4- articulate, article 4 small. Gnathopod 1 ischium smaller than propodus; corner of palm with simple or complex robust seta. Gnathopod 2 palm obtuse or transverse. Epimeron 3 posteroventral corner broadly rounded or subquadrate or projecting, apically acute. Uropod 3 biramous.

Species composition. Pachynus contains 5 species: P. barnardi Hurley, 1963 ; P. chelatus Bulycheva, 1955 ; P. denticulatum Lowry, 1984 ; P. obsolescens sp. nov.; P. pugilator Lowry, 1984 .

Distribution. Eastern and western North Pacific Ocean, western South Pacific Ocean; 25–800 m depth.