740 



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



mackerel, tuna and Cololabis to the second. The catch of sardines in the Sea 

 of Japan, which reached 1,400,000 centners in 1937, ceased altogether in 1941. 

 Among the pelagic fish herring, with its huge shoals off eastern Sakhalin and 

 in the northern part of the Sea of Okhotsk, will no doubt become the main 



Fig. 363b. Diagram of commercial aggregations of plaice (1) and pollack (2) 



(Rass, 1955). 



object of future fisheries. Mackerel approaches the Primor'e coast for spawn- 

 ing. The tuna Sajra {Cololabis sajra) fisheries are still undeveloped in the 



U.S.S.R. 



Among the bottom-living fish the most important are the flatfish (plaice 

 and halibut), the gadoids (cod, alaska-pollack (Teragra chalcogramma) and 

 navaga), rock fish (sebastodes) and atka-fish (Pleurogrammus) (Fig. 363b). 

 The shelf zone is poorly developed in the Far Eastern Seas and as a result there 

 is a considerable predominance, as compared with the Barents Sea, of pelagic 

 fish (salmon, herring, sardines, sajra) over the bottom-living fish (cod, flat- 

 fish). Owing to the abundance of food in those areas of the Far Eastern Seas 

 open to commercial fish, the latter grow rapidly and get very fat (Table 300). 



The faunas of the northern parts of the Atlantic and Pacific Oceans have 

 much in common in their ampni-boreal characteristics, Many species of their 

 fish and invertebrates, however, while not showing any essential taxonomic 



