58 . Aspidophoroides bartoni Gilbert 



This common species of far eastern seas was found in Bering Sea at 8 stations 

 from Avacha Bay to Cape Navarm, not found further north; avoiding low temperatures. 

 Jordan & Evermann record it from 17-121 fathoms. Our examples from 72-146 meters 

 on rocky gravel, rare on coarse sand. Absent from clay bottoms. Common at 

 temperatures above zero (0.5 to 2.6°) . In Anadyr Gulf and further north it is 

 replaced by the high -arctic Ulcina olriki (Lutken) . On the Atlantic coast of 

 North America this species is replaced by a close form (subspecies?) A. 

 monopterygius (Bloch), which is absent from European waters as are a number of 

 other amphiboreal types . 



59 . Ulcina olriki (Lutken) 



Until recently this species was recorded from Greenland, Barents, White and 

 Kara Seas, but now is known from the Chukchi Sea (Rendahl, 1931, i?opov, 1933) 

 and in 1932 was found in Bering Strait and the cold waters of Anadyr Gulf where it 

 is a common and frequent form. We have considerable material (89 examples) 

 of this form from 19 stations in the northern part of the Bering and Chukchi Sea, 

 which allows some analysis of the ecology of this high arctic circumpolar type 

 to be stated. Usually U. olriki (Lutken) is listed as an example of a stenothermal 

 arctic form, found at negative temperatures or close to zero; corroborating its 

 distribution in Greailand, White and Kara Seas and in the eastern portion of the 

 Barents Sea. (K. M. Derjugin "Barents sea on Kola meridian"), 1924. In this 

 respect U. olriki is similar where it is found with other high arctic elements, as 

 Boreogadus saida , Artediellus scaber beringianus , Myoxocephalus quadricornis 

 labradoricus , etc. at low temperatures and absent south of the Anadyr cold spot. 



The table below indicates the frequency of U. olriki at various bottom temperatures . 



Bottom temperature -1 to -1 .7 to -1 to +1 1 to 2 above 2 total 



At depths of 31 to 78 meters on rocky and sandy fades, less often on clay. 



These 11 examples taken by otter trawl; all others from beam trawls. 



36 



