Abstract
The weight-length relationships of bream (Abramis brama L. 1758, family Cyprinidae) were studied in Lake Balaton, Hungary. Fish were randomly collected with a gill net from Keszthely bay between March and November 1995. The condition of bream was investigated monthly, using morphometric parameters of the body, fecundity estimations, and gonadosomatic indices (GSI). The weight-length relationships show that the body weight of bream increased at an approximately 3.4 times higher rate than its length (b = 3.41). The GSI of females were always higher than those of the males. The GSI values of females reached their maximum (14.76-22.22) from March to May. Egg diameter is positively correlated with the spawning months, as demonstrated by the relationship found between egg diameter and GSI (r = 0.94; P < 0.001). Fecundity estimates exhibited a linear relationship to length and weight.