Figure 9
Onisimus sibiricus Brüggen 1909: 8, Gurjanova 1951: 164.
Distribution and biology
This species was originally described from the Kara Sea (Brüggen 1909), while Gurjanova (1951) added specimens from the Chukotsk Sea. Gurjanova’s map in Atlas Arktiki (Gurjanova 1985) shows a few localities in the Laptev Sea, one in the westernmost East Siberian Sea, and one most unexpected dot in the Norwegian Sea south of Bear Island, but Bryazgin (1987) does not mention the species from his extensive Barents Sea collections, and Tzvetkova & Golikov (2001) only report O. sibiricus from the Kara, Laptev, East Siberian and Chukotsk Seas, not from the Barents Sea. Thus, the distribution area, as presently known, seems to stretch from the Kara Sea almost to the Bering Strait, with most records in quite shallow water. O. sibiricus has been collected from a wide array of bottom substrates (Golikov & Tzvetkova 1994, data from Chaun Bay, East Siberian Sea). The biology of this species is otherwise completely unknown; it has never been collected from baited traps.
Remarks
Material of this species was examined in the collections of the Zoological Institute of St.Petersburg. Examination of this material did not reveal any differences between O. plautus and O. sibiricus. Brüggen, in his original description of the species in 1909, describes it as close to O. plautus, differing primary in size of coxa and in P 2 propodus. However, as type material of the two species was not available for examination, the two species are herein treated as distinct taxa.
No further descriptions are given, except the illustration of habitus (see figure 9).