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



northward ; and in Peter the Great Bay the dominant forms are already such 

 cold-living families as Pleuronectidae (10 species), Cottidae (37 species), 

 Agonidae (14 species), Liparidae and Cyclopteridae (13 species), Pholidae 

 and Stichaeidae (21 species). However tuna fish, Trichiurus, Geriola, Auxis 

 and others have also been recorded in Peter the Great Bay in summer. 



An even more cold-water aspect is acquired by fish in the Tartary Strait, 

 warm- water species being rare there ; in summer, however, the hammer-head 

 shark, the ray Trygon akjci, sayra, Trichiurus, and some others enter the 

 Strait. Warm-water fish penetrate much father northward along the eastern 

 side of the Sea of Japan and even through La Perouse Strait into the southern 

 part of the Sea of Okhotsk and to the southern Kuril Islands. Hence the 

 entire Sea of Japan, so far as its ichthyofauna is concerned, may be in- 

 cluded in the boreal region, with the possible exception of its most southerly 

 part. The remarkable similarity of the fish of the Sea of Japan and of the 

 Mediterranean Sea has often been noted (A. Gunther, 1880). G. Lindberg 

 (1947) gives a list of 90 families, 63 genera and 12 species common to these 

 two seas. 



Until recently only eight oceanic deep-water fish had been recorded in the 

 Sea of Japan (T. Rass, 1954), but it has now been shown that their number is 

 greater, due to some additional species which inhabit the southeastern part. 



There are apparently about twenty ' secondary ' deep-water fish (in Andria- 

 shev's terminology). 



About 40 species of the fish in the Sea of Japan are of commercial value. 

 Until recently the Pacific sardine (Sardinops sagax melanostictus) was among 

 the most important. Soviet sardine fisheries were rapidly developed in the 

 'thirties, and by 1937 they were taking 1-4 million centners a year; but they 

 began to decrease in 1940 and during the 'forties ceased altogether. The sar- 

 dines disappeared from the Sea of Japan as a consequence of a considerable 

 fall in temperature. They ceased to enter their usual spawning-places and 

 abundant grazing groups in the Sea of Japan, and one may suppose that large 

 numbers of sardine fry perished owing to unfavourable temperature condi- 

 tions and a shortage of food. Pacific herring (Fig. 384) (Clupea harengus pallasi) 

 has for a long time occupied an important place in the fisheries there. Her- 

 ring aggregations are particularly large during their spawning migrations to 

 the coast of Hokkaido and the Primor'e and especially in the waters of 

 southern Sakhalin. The number of herrings approaching the shores is greater 

 than anywhere else in the world . . . ' the approach of the shoals of herring to 

 the shores of southern Sakhalin in April is sighted by the fishermen from far 

 away by the colour and movement of the water and by the behaviour of the 

 sea-birds : flocks of sea-gulls and kittiwakes start circling over the water, 

 filling the air with their cries' (P. Schmidt, 1948). 'The herring lay their eggs 

 on the coastal sea-weeds, in the shallowest patches on the shores. The male 

 herring discharges its milt in such amounts that the water frequently becomes 

 milky white for many hundreds of metres from the coast ; since milt is fatty, 

 the swell on the banks is calmed as if oil had been poured on to it, and the 

 surface of the Sea becomes smooth. So many ova are laid that, if there is a 

 storm and the ova are cast up on the shore, they form a regular bank which 



