The fecundity of 169 roach females from Lake Gardno and 210 females from Lake Łebsko was estimated in 1998-2001. The dependency of body length, weight and age and the realized fecundity in roach females from both lakes was determined. The roach females spawned for the first time at the age of 3+, and the oldest specimens able to spawn were 13+. The roach from Lake Gardno had higher absolute fecundity than did Lake Łebsko specimens of the same size. The diameter of roach eggs from Lake Gardno was smaller. Roach females with a body length of 20 cm produced an average of 26 400 eggs in Lake Gardno and 25 800 eggs in Lake Łebsko. These are equal to the average European values.

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