Responses of the genital system and the urinogenital papilla of the female catfish,Heteropneustes fossilis (Bloch) to sex hormones.

Intraperitoneal injections of diethylstilbestrol and testosterone propionate into the catfish,Heteropneustes fossilis (BLOCH) elicited pronounced changes in the female reproductive system and the urinogenital papilla. Considerable gonadal and oviducal hypotrophy occurred in the hormone recipients. Marked histological alterations were also encountered in the genital system of the experimental females. Another interesting response was the inhibition of the urinogenital papilla of the treated fishes. It is suggested that the changes in the ovary and the oviduct were induced by the sex hormones throught the inhibition of the gonadotrophic activity of the anterior hypophysis. The changes in the urinogenital papilla proved that this structure in the female catfish is a true secondary sexual character and is under the estrogenic control of the ovary.