Prove preliminari di riproduzione indotta e allevamento larvale del pesce gatto africano, Clarias gariepinus (Burch.)

In spring and summer 1988, hormone-induced reproduction trials were carried out on Clarias gariepinus, a species of catfish which, although native to Africa, is also reared in temperate areas in heated waters from power and industrial plants. Half the tested females were injected with carp pituitary extract (3 mg/kg live weight), while the other half received 10 mg/kg of 20- β-dihydro-progesterone. Males were not treated. All the females spawned successfully and the eggs were fertilized with testes homogenate. Hatching rate was 33% from the group treated with pituitary extract and 25% from the other group. For a period of 10 days after resorption of the yolk sac, half the fry from each group received nauplia of Artemia salina and the other half a commercial feed. The best survival rates were obtained with the natural diet (35 and 55% vs 20 and 25% respectively) and in the fry from females treated with 20-β-dihydro-progesterone.