Pituitary Dose Optimization for Induced Ovulation, In Vitro Fertilization and Production of Normal Fry of Clarias batrachus (Linn.)

An effective dose optimization with varying doses of carp pituitary (Labeo rohita) extract injection (10-60 mg· kg·1) was attempted in order to standardize the carp pituitary dose for induction of ovulation and in vitro fertilization of stripped eggs of the catfish Clarias batrachus. Fish of body weight 140-158 g were selected. Female catfish were in­jected with pituitary extract; after 17 h latency, the eggs were stripped and fertilized with testicular homogenate taken from minced testes of males in normal saline solution. Males were not injected with pituitary extract. Hatching occurred after 30 h incubation at 27-28 °C in a plastic bucket with water flow system. The 40 mg• kg-1 dose of carp pituitary extract resulted in the production of 87% normal fry, which corresponds to 4,768 fry per 100 g body weight of the fish. Doses of 50-60 mg·kg·1 pituitary extract gave similar results.