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



the rocky littoral of the Kharlov Islands (eastern Murman coast) and of the 

 southern shores of the Gulf of Kandalaksha. 



On the sandy and silty-sand areas of the White Sea littoral among the 

 infauna forms, the predominant ones are Macoma baltica, Arenicola marina 

 and Mya arenaria. Quite characteristic, but of small significance in the bio- 

 mass, are Halicryptus spinulosus and Priapulus caudatus. Of epifauna forms 

 Mytilus edulis, Littorina rudis, Hydrobia ulvae, Rissoa aculeus are noted 

 in considerable quantity. 



As may be judged from Table 90 (according to Z. Zavistovich and K. Vosk- 

 resenski — unpublished material), the quantitative ratios between individual 

 forms among the constituents of the littoral fauna are subject to considerable 

 variations. 



A comparison of the quantitative indices of the Murman and White Sea 

 littoral fauna shows that the former is more plentiful in quantity, but that in 

 quality the difference is insignificant. 



The less favourable conditions for the development of littoral fauna in the 

 White Sea, as compared with the Murman coast, are reflected not only in a 

 decrease in the total biomass of plant and animal forms, but also in a decrease 

 in the size of the body in a series of typical forms. Mytilus, Littorina, Balanus 

 and Macoma have, in the White Sea, considerably smaller average dimen- 

 sions. Thus Macoma baltica, for instance, has at one of the low tides in the 

 Kola Inlet an average weight of 240 mg, but in the Gulf of Kandalaksha 

 only 112 mg; the Kola Inlet Littorina rudis weighs 109 mg, but the White 

 Sea one weighs 70 mg. Sea mussel similarly gives an average weight of 1,711 

 and 719 mg, and so on. Moreover a smaller size is characteristic of many repre- 

 sentatives of the White Sea fauna. The White Sea cod and herring are consider- 

 ably smaller than those of the Barents Sea. Portlandia arctica of the deeper 

 parts of the White Sea is considerably smaller than the same form taken in 

 the Novya Zemlya trough of the Barents Sea. 



Thorough study of the microbenthos of the White Sea littoral has been 

 carried out (1951) by V. Brotzkaya at the White Sea biological station of 

 Moscow University. On the sandy littoral there have been discovered no 

 fewer than 80 species of small invertebrates, mainly: Harpacticoida (24 

 species), Turbellaria (more than 20 species), Ciliata, Rotatoria, Nematoda, and 

 several other groups. Some forms give very high density of population. In 

 one cubic centimetre of bottom soil Nematoda yield up to 1,000 specimens, 

 Harpacticoida up to 200, and Ciliata more than 1,000. Brotzkaya shares 

 A. Remane's opinion (1933) that the microbenthos of the sandy sea-bed is the 

 basic source of nourishment for the remainder of the bottom-feeding fauna. 



At the White Sea biological station there has likewise been produced most 

 useful work on the calculation of the relative sizes of body and the weight 

 of different invertebrates of the littoral (N. Pertsov, 1952). This material gives 

 easy means for the calculation of size from weight, which is essential in 

 research into the feeding offish, from the contents of their intestines. 



Population of the sublittoral. As Derjugin indicates, the sublittoral zone, 

 which in the Kola Inlet extends to 200 to 250 m, extends in the White Sea 



