Interpopulation crossbreeding of farmed and wild African catfish

Introduced African catfish Clarias gariepinus (Burchell 1822) have been cultivated in Indonesia since 1985 and have made a significant contribution to aquaculture production. Unfortunately, the rapid development of catfish farming was not accompanied by proper genetic improvement of broodstock and this led to poor production performances. A method that can potentially provide rapid improvement in the genetic quality of broodstock is the crossbreeding technique. The present study evaluated growth and survival performances up to 81 days post-hatching (nursing stage) of reciprocal interpopulation crossbreeds generated from five existing introduced African catfish populations in Indonesia, i.e. from Indonesia, Egypt, Kenya, the Netherlands and Thailand. Artificial spawning was applied to form five purebred populations and 20 crossbreed populations. There were significant differences in body length growth (specific growth rate – SGR), survival rate (SR) and number of over-size fish (OS) averages. The Egypt female × Netherlands male (EN) crossbreed showed the best performance with cumulative SGR, SR, and OS of 9.69 ± 0.03%, 63.98 ± 6.75% and 0.22 ± 0.04%, respectively. The result also revealed a correlation between the OS and the SR; the higher the OS, the lower the SR. This correlation tended to be weak at the sequential nursing stages. Our study suggested that the EN crossbreed has high potential to improve offspring quality in the near future