GENERAL CHARACTERISTICS OF FAR EASTERN SEAS 



731 



Table 298. Vertical changes in the main feeding groupings of bottom-living fauna in Kuril- 

 Kamchatka trench (M. Sokolova, 1959) 



(Zenkevitchiana and others) and different species of Foraminifera, the coastal 

 biocoenosis consists almost exclusively of agglutinating forms (Z. Shche- 

 drina, 1958), Echiuroidea (Vitjazema and Jakobia) and Polychaeta (Macelli- 

 cephala and Macellicephaloides). Farther to the southeast the Pacific Ocean 

 is characterized for large areas by the biocoenoses of deep-water holothurians 

 (Elpiidae and Psychropotidae), starfish (Porcellanasteridae and Brisingidae), 

 sea-urchins (family Pourtalesiidae, and Echinothuriidae), actinians, single 

 madreporian corals, lilies (Bathycrinus), Polychaeta (families Maldanidae and 

 Ampharetidae), Mollusca {Spinula oceanica), and some dozens of species of 

 Foraminifera. The density of the bottom population (Fig. 356) decreases to 

 10-5 and 1 g/m 2 as one moves southeastwards away from the Kuril Islands. 

 All the huge area of the open parts of the Pacific Ocean is embraced by the 

 1 g/m 2 isobenth, and by far the greater part of it by the 0T g/m 2 isobenth. 

 The benthos biomass of the Ocean bottom in some parts is no higher than 

 0-01 g/m 2 (Fig. 357). 



Some comprehensive studies on the deep-water fish of the northwestern 

 part of the Pacific Ocean are due to P. Schmidt (1948, 1950), A. P. Andriashev 

 (1935) and T. Rass (1954). Andriashev suggested differentiating between an- 

 cient and secondary deep-water fish. The first (for instance Stomiatoidei, 

 Opisthoproctoidei and many others) are, as a rule, rare in the waters of the 

 continental shelf seas ; the second belong to families widely represented in 

 shallow seas (for instance the families Cottidae, Liparidae, Zoarcidae and 

 others). The boundary between these two groups is probably rather indistinct. 



