836 BIOLOGY OF THE SEAS OF THE U.S.S.R. 



side of the Bay Echinarachnius parma lives in huge numbers ; it is absent from 

 other parts of the Bay. Within the fouling and Echinarachnius parma biocoe- 

 noses there lies a wide belt with the biocoenosis Macoma calcarea — Ophiura 

 sarsi, with carnivores and carrion eating Buccinidae, Natica clausi, Leptas- 

 terias polaris, Crossaster papposus, Chionoecetes opilio, Hyas coarctatus, the 

 large-sized Polychaeta Polynoidae, Aphrodita, Nephthys and others. Numer- 

 ous Paguridae and prawns are added to these carnivores. All this huge num- 

 ber of carnivores and carrion eaters feeds on Macoma calcarea and other 

 bivalves and Polychaeta. Beds of empty shells of recently perished bivalves 

 are distributed in large patches. 



The central part of the Bay is occupied by the biocoenosis Ophiura sarsi- 

 Macoma calcarea. Carnivores and carrion eaters do not penetrate into this 

 region. Apart from Macoma there is a large number of other bivalves here 

 (Yoldia limatula, Nucula tenuis, Leda pemula^l), Axinus gouldi, Astarte and 

 Periploma). Abundant polychaete colonies are composed of Maldane sarsi, 

 Axiothella catenata, Praxilella gracilis, Nicomache sp., Terebellides stroemi, 

 Scalibregma infiatum, Chaetozone setosa, Terebellidae sp., Ampharetidae sp., 

 Lumbriconereis fragilis, L. impatiens, Onuphis parvastriata and others, i.e. 

 all forms devoured by carnivores in the surrounding biocoenoses. Other bio- 

 coenoses, shown in Fig. 424, are small in numbers {Table 327). 



Table 327. Mean number of specimens and mean biomass of Anadyr Bay biocoenoses 



according to groups 



Group 



Polychaeta 



Mollusca 



Crustacea 



Echinodermata 



Others 



Total 710 426-6 



The fauna of the Bay of Anadyr has an even greater tendency to gigantism 

 than that of Shelekhov Bay. The greatest benthos biomass is adapted to the 

 eastern and western coasts and to the region of the cold patch(500to 1 ,000 g/m 2 

 and more). 



The largest gatherings of Mollusca and Polychaetes have been recorded 

 in the central part of the Bay ; Echinodermata are most numerous in the 

 western and Crustacea in the eastern part. The whole central part of the Bay, 

 occupied by the biocoenosis Ophiura sarsi-Macoma calcarea, has a benthos 

 biomass of 100 to 200 g/m 2 (Fig. 425). There is a sector in the middle of the 

 region with a considerably increased biomass, even exceeding 1,000 g/m 2 , 

 on account of carnivores gathered on the dense colonies of Macoma calcarea 

 (starfish, Gastropoda Mollusca, and crabs). The biomass is increased off the 



