aXOMACH CONTENTS OF THE BERING SEA UNG CRAB 



by 



Patsy A. McLaughlin and James F. Hebard 



U. S. Fish and Wildlife Service 



Seattle, Washington 



ABSTRACT 



This preliminary study of the stomach contents of Bering Sea king crabs indicates that the major 

 food items of these crabs are molluscs and echinoderms. The frequent occurrence of echinoderms in the 

 stomachs in large amounts is in contrast to the findings of Russian workers who feel that echinoderms 

 play only a very minor dietary role ia the king crabs of the Kamchatka region. Differences in food pre- 

 ferences apparently do not exist between the sexes. 



This report is the result of the 

 cinalysis of king crab stomachs collected 

 during the summer of 1957 in southeastern 

 Bering Sea by biologists of the King Crab 

 Investigation of the U. S. Fish and Wildlife 

 Service. A study of the food habits of the 

 crab is of considerable importance because 

 food availability and utilization may play 

 important roles in the distribution, migra- 

 tion, and molting patterns of the crabs. 



Very few reports on the food habits 

 of the King crab, Paralithodes camtschatic 

 (Tilesius), are found in the literature. 

 Among the available papers, the work 

 of C. F. Feniuk (1945) is the most 

 recent and perhaps the most complete. 

 For the most part, his methods were 

 used in this analysis. Quantitative 

 studies on the species of food of 

 the crab are made exceedingly diffi- 

 cult because, in contrast to fish 

 which for the most part swallow food 

 whole, the crab breaks up his food 

 with the chelae before ingesting it; 

 hence reconstruction of individual 

 organisms is usually impossible. 

 Methods which are used in quantita- 

 tive food studies of vertebrates 

 which masticate their food are not 

 adaptable to the food studies of 

 crabs, since the quantity of crab 

 stomach contents is usually small. 

 As yet, no suitable method of quan- 

 titative analysis of these stomach 

 contents has been devised. 



Because of this lack of an 

 applicable method, the smallness of 

 samples from any one area, and the 

 limited scope of available related 



data, this report intends primarily to 

 indicate the types of organisms which con- 

 tribute to the diet of the crabs, however 

 it will show quantitatively the fullness of 

 the stomachs examined. More intensive 

 studies designed to compensate for the in- 

 adequacies noted here will be pursued in 

 1958. 



The crabs from which stomach samples 

 were taken were from catches made by the 

 chartered trawler Mitkof during the months 

 of June and July 1957 (fig. 1). Of the 329 

 stomachs obtained, the sexes were almost 



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SOUTHEASTERN 

 BERING SEA 



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PACIFIC OCEAN 



Hgure 1. — Stations at which stomach samples 

 were taken during 1957. 



