Onisimus simus Gurjanova 1962

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 article1 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”.