fused together. The latter phenomenon is possible caused by the fixation. 



The Maturity Stages of the Ovaries 



Stage I (Figure 5 a, b). In Stage I or the juvenile stage the sex cannot be discerned by the 

 naked eye. The ovaries are long narrow threads lying close to the upper wall of the body cavity 

 (close to the spine). The color of the ovary is light -yellow . In this stage the ovaries are already 

 asymmetrical, the left being longer. The blood circulatory system is slightly developed. The 

 length of the ovary varies from 40 to 50 mm., average weight 0.5% of the fish weight. 



In the juvenile stage, most of the ovary consists of egg cells in the juvenile phase, close 

 together, of an irregular, angular shape. Along the edge of the ovigerous lamellae the germinal 

 tissue and the youngest ovocytes are found. In herring up to 4 years old, ovaries in the juvenile 

 stage can be found all the year round in all the fishing areas of the Barents Sea. In spring and sum- 

 mer the young, immatiire herring are subject to fishery from the Murmansk coast to the fjords of 

 Kola and the Motovski Bay . 



Stage II . Whereas stage I comprises exclusively young herring which have not yet spawned, 

 the fish in stage n may as well be immature, as in the transition from spent to stage II. 



Figure 5. Ovary from Murmansk herring in the juvenile stage (1) a, from the eastern part 



of the Murmansk Bank, July 9, 1937, length of fish 137 mm., age 2 years; b, from 

 the Motovski Bay, Oct. 21, 1938, length 105 mm., age 2+. x 100. 



In herring which have not yet spawned, the ovaries in stage n are by 1 1/2 times larger than 

 in stage I, and more roundish. In immature herring the ovaries are lig^t yellow, in mature fish 



216 



