Induced spawning in the catfish Heteropneustes with mammalian chorionic gonadotrophins.

We have already reported [1956, 1957] on the possibilities of using fish and frog pituitaries to induce gravid catfish Heteropneustes to spawn during and im¬mediately after the breeding season. Many workers are of the opinion that the mammalian gonadotrophins have no effect on fish gonads, thereby showing certain specificity in their action. Houssay [1931], Koch and Scheuring [1936], von Ihering and Azevedo [1937), Khan [1938, 1945], Mathews [1939], Hasler, Meyer and Field [1939] and Husain [1945] have all subscribed to this view. We wished to determine if the Indian catfish Ileteropneustes (Saccobranchus) fossilis (Bloch) were also refractory to mammalian gonadotro¬phins. In this connection, we have also tried a few oestrogens and progesterone, Rasquin 119511 having suggested that the former also caused ovulation.