734 



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



Kuril-Kamchatka trench, the fauna of this latter being closest of all to the 

 fauna of the American littoral in the composition of its deep-water fish. 



Only 8 species (5 families) of deep-water fish are known in the Sea of Japan, 

 12 in the Sea of Okhotsk, 25 to 29 species in the Bering Sea and about 50 

 species in the Kuril-Kamchatka trench (Figs. 358 and 359). The greatest 

 number of species belongs to the families Gonostomidae (5 species), Scopeli- 

 dae (5 species), Moridae (5 species) and Macruridae (8 species). It is interest- 

 ing to note that all the five deep-water fish of the Sea of Japan live in the 

 waters adjacent to Japan, but are absent from the Okhotsk and Bering Seas 

 and from the Kuril-Kamchatka trench. These last two Seas and the trench 



Fig. 358. Deep-water fish of the Sea of Japan (Rass). 1 Alepocephalus umbriceps; 



2 Argentina semifasciata ; 3 Maurolicus japonicus ; 4 Physiculus japonicus ; 5 Lotella 



maximowiczi; 6 L. phycis; 7 Halleutaea stellata; 8 Cryptopsaras couesil. 



have many species in common. Their deep-water fish is an impoverished fauna 

 of the northern part of the Pacific Ocean (T. Rass, 1954). 



Among the secondary deep-water fish of the Far Eastern Seas (the families 

 Zoarcidae, Scorpaenidae, Cottidae, Cyclopteridae and Liparidae) there are 

 44 species in the Sea of Okhotsk, 27 in the Bering Sea and 14 in the Sea of 

 Japan. 



As has been shown by researches carried out by the Galathea, and especially 

 by the Vityaz, the old idea of geographical uniformity of the deep-water 

 fauna should be reconsidered, particularly as regards the bottom-living 

 organisms. Pelagic fauna is, in general, linked with the water masses which it 

 inhabits and with their distribution. First of all there are certain cases of deep- 

 water bottom fauna with most restricted habitats. Certain organisms, more- 

 over, keep strictly to the same horizon. Thus, for example, members of the 

 Monoplacophora were found only in the most easterly part of the Pacific 

 Ocean on a very small sector of the equatorial belt ; they occur, however, in 



