| gonadosomatic index and testis morphology of common carp (cyprinus carpio) in rivers contaminated with estrogenic chemicals. | to study the effect of estrogenic chemicals on fish, the gonadosomatic index (gsi = [testis weight/body weight] x 100) and testis histology of mature common carp (cyprinus carpio) from 2 contaminated sites (ishizu and wada rivers, osaka) and a control site were examined between june 1998 and march 2001. the concentration of nonylphenol, bisphenol a and 17beta-estradiol in the ishizu river was 3-4 times higher than in the wada river. in the pre-breeding and breeding seasons, there were no signifi ... | 2002 | 12419869 |