the second. S. ovata has two mass larvae spat-falls, in June and in August- 

 September. The characteristic features of the S. ovata biocoenosis and its 

 separate components are shown in Tables 210 and 211. 



The amount of S. ovata consumed by fish per 1 m 2 (it is the prey also of the 

 small crab Brachynotus lucasi) was calculated by Vorobieff in a manner 

 similar to that used for Cardium edule and appears by components in Table 

 212. . 



The processes of growth, however, prevail over losses, and by November 

 the biomass is 100-75 g/m 2 greater than that of the spring. As for the preced- 

 ing species in the winter natural mortality must take place, thereby bringing 

 the autumn numbers down to the spring ones. The actual production of 

 S. ovata is 377 g/m 2 , and its P/B coefficient is equal to 2-05. 



