Proceedings of 

 the United States 

 National Museum 



SMITHSONIAN INSTITUTION • WASHINGTON, D.C. 



Volume 112 1960 Number 3439 



THE PELAGIC AMPIIIPOD GENUS PARATHEMISTO 



(HYPERIIDEA : HYPERIIDAE) IN THE 

 NORTH PACIFIC AND ADJACENT ARCTIC OCEAN 



By Thomas E. Bowman 



Among the marine planktonic Crustacea, the amphipods frequently 

 play an important role in the economy of the sea. In general they 

 rank third in numerical abundance; they are far exceeded by the cope- 

 pods and euphausiids. In tropical and subtropical regions pelagic 

 amphipods are not usually found in large numbers, but in the cooler 

 parts of the oceans they are often extremely abundant. Members of 

 the genus Parathemisto (=Themisto auct.) overwhelmingly dominate 

 the cool-water epipelagic amphipod fauna, and their importance in 

 the north Atlantic (including the Arctic Atlantic) has been pointed 

 out by Bigelow (1926), Bigelow and Sears (1939), Stephensen (1923, 

 1924), and Dunbar (1946, 1957). Only cursory attention has been 

 given to north Pacific representatives. The present paper is an at- 

 tempt to fill in a few gaps in our knowledge of the distribution and 

 life history of species of Parathemisto in the north Pacific and the 

 Arctic Ocean north of Alaska and western Canada. 



The amphipods upon which this report is based were obtained from 

 plankton collections from several sources: (1) Off the Pacific coast 

 of the United States from the latitude of the Columbia River to that 

 of Punta Eugenia in middle Baja California, in connection with the 

 California Cooperative Oceanic Fisheries Investigation (CCOFI). (2) 



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