Onisimus simus Gurjanova, 1962

Berge, Jørgen, Vader, Wim & Johnsen, Jan Roger, 2007, Studies on the genus Onisimus Boeck, 1871 (Crustacea, Amphipoda, Uristidae) II. The barentsi and edwardsii groups, Zootaxa 1410, pp. 55-68 : 64-65

Onisimus simus Gurjanova, 1962

Onisimus simus Gurjanova, 1962: 62 .

Type locality

Okhotsk Sea

Distribution

Okhotsk Sea ( Gurjanova 1962), Storfjorden at Spitsbergen (Bryazgin, 1973).

Biology

Maximum length 10.5mm. Depth: 125m (Type-locality). Bryazgin ( 1973) collected the species in Storfjorden at a depth of 100m in cold water (-1.8°C). Ovigerous females had a maximum of 9 eggs.

Remarks

The type material of this species was examined in the Zoological Institute of St. Petersburg, but the material was not suitable for making detailed descriptions. Professor Valery Bryazgin ( 1973), however, gives the following details about his Storfjorden specimen.

Barents sea specimens vary from Gurjanova’s description of Okhotsk Sea material in several ways: The surface is without granular black pigment, but has small pits with microscopic setules. Eyes light, almost invisible in alcohol. Antenna 1 peduncle article 1 with large dorso-distal protuberance, that is longer than peduncle articles 2 + 3. Peduncle article 1 with 3 plumose setae on ventrodistal margin. Flagellum with first article much longer than in typical material, and with 2 parallel rows of slender setae, flagellum 10 - to 11 - articulate, accessory flagellum with 6 articles. Antenna 2 flagellum with 14 articles.

Pereopod 1–2: Typical for the most part, but pereopod 2 propodus with oblique palm, distal protuberance present on palm (contra Gurjanova’s description). Telson cleft 1 / 3, lobes with distal bifurcation, with small setae in the “bifurcations”.