tlnue growing after they become sexually mature and reach 32-33 cm. in length at the age of 12 to 

 15 years. The herring from the continental shelf are characterized by a drastic drop in the rate 

 of growth following sexual maturation. 



Sexual maturity in the Atlantic -Scandinavian herring occurs most frequently at the age of 4 

 to 6 years. Individual specimens become sexually mature at the age of 3 years. The herring that 

 are strongly inhibited in their development mature late . Small herring from the continental shelf 

 become sexually mature at the age of 2 to 3 years . Bank herring attain sexual maturity at the age 

 of 4 to 5 years . 



Atlantic-Scandinavian herring are characterized by a great longevity. 



As a rule the 10-to 15-year-old herring form at least 30-40 per cent of commercial catches. 

 Individual specimens found in catches are 17 to 18 years old and older. The longevity of Iceland 

 herring, spawning in the summer, is equally great. The remaining herring races do not live long- 

 er than 8 to 10 years . Herring from the Baltic Sea have the shortest life cycle . 



TABLE 7 . 



GROWTH RATE OF HERRING FROM THE 

 NORTHEASTERN ATLANTIC 



V Figures in brackets indicate the regions as marked in Figure 10. 



2/ The age of herring spawning in the summer and autumn corresponds in the foreign literature to 



the number of winter rings, i.e. is 1 year younger. We present in the table the true age, i.e. 



we regard the increment of the first winter as the first year of development. For the herring 



from Dogger Bank that increment must be equal to 2-4 cm., i.e. is ^proximately the same as 



for the sprat. 



52 



