-t-1 



7 

 6 

 S 

 4 

 3 



; 

 / 



u 



4-* 



Stage V 



Stage IV 



Stage III 



Stage II 



Stage I 



Stage VI 



M m K I n in i m m n 7 yi 



Month 



Figure 12. Index and duration of the maturity stages in the Murmansk herring (the periods 

 in which the stages are most often found, are signified by thick lines). (Verti- 

 cal, -index of maturity, horizontal, - months). 



In summer, a considerable number of herring which have not yet spawned for the first time, 

 is again observed in the Barents Sea. 



The bulk of the summer catches consists of fat herring in stage II. Herring, maturing fu^ 

 the first time, are found in July, and especially in August. In the autumn, the maturation has pro- 

 ceeded further, characterized by the transition from stage III to IV. 



In the herring catches in the Barents Sea, the maturing herring constitute from 15 to 65% 

 (Table 9). 



The Numerical Relation between the Sexes 



The numerical relation of males to females varies in the same area during the course of 

 the year . 



As yet we have no reason to assume that this variation is conditioned by selection of the 

 drift nets. First, the fishery itself is still not so intensive that it may influence the structure of 

 the schools to any remarkable extent; second, the sexual dimorphism is very feebly expressed in 

 the herring (the females are about one per cent larger than the males). Finally it is assumed that 

 males and females do not appear in equal numbers in the various areas at different times of the 

 year. For example, from April 4 to May 16, 1939, male herring dominated in the samples from 



233 



