Species 



TABLE 8. A TABLE OF MATURITY SCALES FOR FISH (CONT'D). 



Criteria, on which the descriptions are based 



Author 



Lukin with histolog- 

 ical criteria. 



Lucioperca 

 lucioperca 

 in the Don 

 river. 



Color, transpvarency of the ovaries, 

 eggs with the naked eye. 



visibility of the 



Trusov (1947). Some- 

 what changed and 

 supplemented the 

 scale of Filatova. 

 Distinguishes the 

 stages IV- A, IV -B, 

 IV-V. 



Coregonus 

 1 . laveretus 

 ludoga 



Color of the gonads, presence of ovocytes in various 

 phases of development, form of the gonads. 



Lapitskiy (1949) 



A Scale of the Maturity Stages of the Ovaries 

 in the Murmansk Herring 



Stage I (juvenile). The sex cannot be distinguished by the naked eye. The ovaries are long, 

 thin threads lying close to the dorsal spine. The left ovary is usually longer than the right one. 

 Color - light yellow. Blood vessels feebly developed. Length of the roe 40-50 mm. Weig^it not 

 more than 0.5% of the fish weight. At an enlargement of 40-60 times, the main mass of the roe is 

 seen to consist of egg cells in the juvenile phase, of an irregular, polygon shape. 



Stage II (preparatory). The egg cells are easily seen with the naked eye. In first time 

 spawners the roe is light yellow, in herring which have spawned earlier, more intensively colored, 

 yellow, to brownish yellow. Weight of the roe- 3% of the body weight. The main part of the roe is 

 made out of egg cells in the single -layered follicle phase. 



Ovaries in stage II may be found in immature herring in the Barents Sea all the year round. 

 The transition from stage II to III starts in the Barents Sea during the second half of July, in the 

 Greenland Sea about one month earlier. 



Stage III (ripening) . The roe occupies about 2/3 of the body cavity. The height of the roe 

 is about double that of stage II. Small, rounded eggs are visible with the naked eye. Among them 

 are found a few smaller eggs of an irregular, polygon shape. Blood vessels are well developed. 

 They branch off from a main vessel as bundles, which end towards the lower part of the ovary. 



The weight of the roe is about 6% of the body weight, 

 ovocytes at the beginning of yolk formation. 



The main part of the roe consists of 



Stage IV (ripe). The roe fills the whole body cavity. Blood vessels are well developed. 

 The eggs are large, irregularly edged, lying close together. If the membrane of the roe is torn, 

 the eggs keep together in the stroma, but assume a rounded shape. The membrane of the roe is 

 very thin and easily torn. The roe is yellow -red, constituting 10% of the weight of the fish. In a 

 histological respect, stage IV is distinguished by the presence of ovocytes filled with yolk, consti- 



231 



