Cryptodius Moore, 1992

Labay, Vjacheslav S., 2019, Review of amphipods of the genus Cryptodius Moore, 1992 (Amphipoda: Ochlesidae) from the coastal waters of Sakhalin Island (Far East of Russia), Zootaxa 4603 (3), pp. 501-519 : 514

Key to species of genus Cryptodius Moore, 1992

(based on the characteristics of the dorsal armament of abdomen and on the structure of coxa 1)

1. Abdomen without dorsal carination ( Fig. 10a )................................ Cryptodius unguidactylus Moore, 1992

- Abdomen with distinct dorsal carination ( Figs. 10b, c )........................................................ 2

2. Pleonit 3 dorsal midline with gibbous hump, urosomite 1 with slight angular dorsal gibbosity, urosomite 3 bearing a single longitudional ridge on either side of the dorsal midline ( Fig. 10b ); coxa 1 convex anteriorly ( Fig. 11i )........................................................................................... Cryptodius kelleri ( Brüggen, 1907)

- Pleonite 3 and urosomite 1 with dorsal rectangular keel in posterior half of each, urosomite 3 dorsally with paired rounded keels ( Fig. 10c ), coxa 1 concave anteriorly (11j)....................................... Cryptodius sakhalinensis sp. nov.

Figures

FIGURE 10. Diagnostic characters of genera Cryptodius Moore, 1992 and Odius Liljeborg, 1865 species: a, h, o—Cryptodius unguidactylus Moore, 1992 (from Moore 1992), b, i, p—Cryptodius kelleri (Brüggen, 1907) (from Moore 1992, Kim & Hong 2014), c, j, q—Cryptodius sakhalinensis sp. nov., d, k, r—Odius carinatus (Spence Bate, 1862) (from Sars 1895), e, l, s—Odius cassigerus Gurjanova, 1972 (from Labay, 2010), f, m, t—Odius oclairi (Moore, 1992) (from Moore 1992), g, n, u—Odius polarsterni (Brandt & Vassilenko, 1995) (from Brandt & Vassilenko 1995); a–g—carination of abdomen, arrow marks the keel of epimeron 3, urosomite 1 and urosomite 3, h–n—incisor of mandible; o–u—maxilla 1, the arrow shown setae of the palp.

FIGURE 11. Diagnostic characters of genera Cryptodius Moore, 1992 and Odius Liljeborg, 1865 species: a, h, o, u—Cryptodius unguidactylus Moore, 1992 (from Moore 1992), b, i, p, v—Cryptodius kelleri (Brüggen, 1907) (from Moore 1992, Kim & Hong 2014), c, j, q, w—Cryptodius sakhalinensis sp. nov., d, k, r, x—Odius carinatus (Spence Bate, 1862) (from Sars 1895), e, l, s, y—Odius cassigerus Gurjanova, 1972 (from Labay, 2010), f, m, t, z—Odius oclairi (Moore, 1992) (from Moore 1992), g, n, u, aa—Odius polarsterni (Brandt & Vassilenko, 1995) (from Brandt & Vassilenko 1995); a–g—maxilliped, h–n—coxa 1; o–u—pereopod 7, u–z, aa—telson.