Successful, induced propagation of African catfish (Clarias gariepinus) by ovarian lavage with sperm and hormone mixture

The in vitro fertilisation method is widespread in fish aquaculture. In general, calculated doses of different hormones are injected intramuscularly or intraperitoneally, by using a syringe and needle, to induce ovulation and spermiation. We tested a novel approach to delivering sperm and hormone together to eggs, in African catfish, and concluded that sperm plus carp pituitary extract injection into the ovary lobes (through the oviduct) leads to successful ovulation and recovery of developing embryos in all of the experimental conditions applied. These results indicate that injected spermatozoa with suspended carp pituitary are stored in the ovary lobes for up to 10 h without loss of biological activity and that the ovulated eggs could be fertilised by the injected sperm, after being released from the body cavity. In addition, the seminal fluid was an appropriate delivery vehicle for the ovulation inducing hormone (i.e. carp pituitary) via ovarian lavage.