Postodius Hirayama, 1983

Ariyama, Hiroyuki, 2021, Five species of the family Odiidae (Crustacea: Amphipoda) collected from Japan with descriptions of a new genus and four new species, Zootaxa 5067 (4), pp. 485-516 : 499-500

Genus Postodius Hirayama, 1983

[Japanese name: Hime-subeyokoebi-zoku]

Postodius Hirayama, 1983: 97 .— Barnard & Karaman, 1991: 400.— Coleman & Barnard, 1991: 263.— Moore, 1992: 913.— Berge, Vader & Coleman, 1999: 246 (in part).— Ariyama, 2011: 3.

Type species. Postodius imperfectus Hirayama, 1983 .

Diagnosis [emended from Ariyama (2011)]. Body, anterodorsal corner of pereonite 1 strongly produced; dorsal projections of pereonites 1–6 absent, on pleonites present, but small; posterolateral margin of pleonite 3 with acute, upwardly directed projection at midpoint. Eyes reniform. Antenna 1, peduncular article 2 shorter than article 1; accessory flagellum 1-articulated; primary flagellum with many aesthetascs in male. Upper lip, tip incised asymmetrically. Mandible slender; incisor narrow; lacinia mobilis present on left side, slender; accessory blades weak; palp long, at same level as molar. Lower lip, outer lobes long, weakly notched inside. Maxilla 1, inner plate small, bearing 1–2 apical setae; outer plate styliform, with several robust setae on tip; palp 1-articulated, slender, tip with long apical seta. Maxilla 2, inner plate shorter than outer plate, mediodistal margins of both plates strongly setose. Maxilliped, inner plate slender, with 2–3 robust setae on tip; outer plate long, exceeding distal end of palp article 2; palp 4-articulated, article 2 medial margin weakly expanded, article 4 vestigial. Coxae 1–4 progressively wider, equally long; inner surfaces of coxae 2–4 each with “holder structure”. Gills present on gnathopod 2–pereopod 6. Oostegites of female present on gnathopod 2–pereopod 5. Gnathopod 1, propodus projected posterodistally, projection with short robust seta; dactylus small, triangular. Gnathopod 2, propodus not large, ca. 0.35–0.6 times of coxal length, palm transverse, distal margin serrated, with 2–3 robust setae on posterodistal corner. Pereopods 3–7 stout, meri projected distally, projections of pereopods 5–7 exceeding distal end of carpi, dactyli each with nail. Uropods, inner ramus of uropod 3 relatively wide; peduncles of uropods 1, 2 and both rami bearing many robust setae. Telson minutely cleft, lateral margins each with pair of penicillate setae.

Species included. Postodius albifacies sp. nov.; P. igneus Ariyama, 2011 ; P. imperfectus Hirayama, 1983 ; P. ornatus Ariyama, 2011 ; P. sanguineus sp. nov.; and P. striatus Ariyama, 2011 .

Distribution. Japan only.