Intersex is a much more common condition caused by early exposure offish larvae to estrogenic substances. The intersex condition in males usually takes the form of ovotestis. The subject has been reviewed by Bortone and Davis particularly with respect to the masculinization of females caused by pulpmill effluents. Ovotestis is a partial feminization in which oocytes may appear in otherwise normal testes. Little is known about the implications ofthis condition for reproductive functionality. Ovotestis can be induced in the laboratory by exposing fish larvae to weak estrogens like nonylphenol and has also been observed at prevalences ranging from
2% to 100% in wild fish populations exposed to estrogenic effluents