Pimpicka E., 1990. Formation of fecundity of tench, Tinca tinca (L.) females in Lake Drwęckie. Acta Ichthyol. Piscat. 20 (2): 53-75.

Analyses were made of 108 ovaries of tench females from Lake Drwęckie. Measurement of oocyte diameter revealed that in order to calculate absolute fecundity of tench females it was necessary to include oocytes with diameter of from 0.2 mm onwards. In these oocytes the trophoplasmatic growth had been initiated. Quantitative analyses showed that the pool of oocytes of trophoplasmatic growth in the annual cycle reached 4.9-31.9% of all oocytes. This pool was 2.1-19.4-fold lower than the pool of oocytes of protoplasmatic growth. However, number of trophoplasmatic cells was sufficient to form the oocytes which could be spawned in the given season. Absolute fecundity calculated before fish spawning was much higher than the physiological fecundity. This was due to the resorption of maturing oocytes. The process was especially intensive when water temperature decreased rapidly.