Five species of the family Odiidae (Crustacea: Amphipoda) collected from Japan with descriptions of a new genus and four new species Author Ariyama, Hiroyuki text Zootaxa 2021 2021-11-12 5067 4 485 516 journal article 3549 10.11646/zootaxa.5067.4.2 b1a9a24a-3669-43ea-890b-7da58b7a96a6 1175-5326 5683379 1B5D8DC6-80FD-4FBD-A0FB-ACA512B5A0D9 Genus Antarctodius Berge, Vader & Coleman, 1999 [Japanese name: Mukashi-subeyokoebi-zoku] Antarctodius Berge, Vader & Coleman, 1999: 244 ; Labay, 2010: 35 . Type species. Odius antarcticus Watling & Holman, 1981 . Diagnosis [emended from Ariyama (2011) ]. Body, anterodorsal margin of pereonite 1 not produced; dorsal projections of pereonites absent, those of pleonites present or absent; posterolateral margin of pleonite 3 with or without projection. Eyes variable. Antenna 1 , peduncle with article 2 shorter than article 1; accessory flagellum absent or present. Upper lip , tip incised asymmetrically. Mandible conical; incisor narrow; lacinia mobilis present on left side; palp somewhat distal to molar. Lower lip with outer lobes long, strongly notched inside. Maxilla 1 with inner plate bearing 3 apical plumose setae; outer plate relatively short, styliform, with many robust setae on tip; palp 2-articulated, wide, exceeding outer plate, with several apical setae. Maxilla 2 , inner plate almost same length as outer plate, mediodistal margins of both plates strongly setose. Maxilliped , inner plate narrow; outer plate medium, reaching distal end of palp article 2; palp 4-articulated, article 2 not expanded medially, article 4 short or long. Coxa 1 a little shorter than coxa 2; coxae 2–4 progressively wider, equally long. Gills present on gnathopod 2–pereopod 7(?). Oostegites of female present on gnathopod 2–pereopod 5. Gnathopod 1 , propodus not projected posterodistally, posterodistal corner with long robust seta; dactylus small, triangular, with several plumose setae. Gnathopod 2 , propodus narrow, palm weakly transverse, distal margin serrated; dactylus with accessory spine. Pereopods 3–7 , meri projected distally. Uropods , inner ramus of uropod 3 slightly wide; peduncles of uropods 1, 2 and both rami bearing many robust setae. Telson cleft or entire. Species included. Antarctodius antarcticus ( Watling & Holman, 1981 ) ; A. japonicus Ariyama, 2011 ; A. noncarinatus Labay, 2010 ; and A. rauscherti Coleman & Kauffeldt, 2001 . Remarks. The diagnosis of the genus is emended mainly because the presence of the accessory flagellum and the gill on the coxa 7 is confirmed in the present study. However, in the papers dealing with the other Antarctodius species , the accessory flagellum is stated to be absent and the gill is not mentioned ( Watling & Holman 1981 , Coleman & Kauffeldt 2001 , Labay 2010 ). A closer examination of them is needed. Distribution. Antarctic Ocean, Okhotsk Sea and Japan .