African catfish, Clarias gariepinus, is an introduced species and has been an important food fish supporting the fulfillment for food security in Indonesia. Along with increasing popularity as a farmed fish, it gradually showed lower aquaculture performance due in part to deterioration of the genetic quality of fry resulting from inappropriate and uncontrolled of broodstock. An African catfish breeding program aimed to cope with the problem was set in 2010 at the Research Institute for Fish Breeding, Sukamandi, Indonesia. Started with four founder populations, namely Egypt (29%), Paiton (27%), Sangkuriang (24%) dan Dumbo (20%) a synthetic base population was established in 2011, and an individual selection targeting on growth improvement was conducted. A hundred broodstock were spawned to produce 30.000 breeding candidates, and 3 percent of best-performing fish were selected in each generation. Genetic parameters (genetic gain and genetic variability) and a series of aquaculture performance-related traits including growth, feed conversion ratio (FCR), productivity, disease resistance, size uniformity, and benefit/cost ratio were recorded. Following three successive generations, over 50% accumulative genetic gain relative to the base population was obtained. This genetic gain consisted of 20%, 11% and 20% from the first, second and third generation, respectively. Field farm tests aiming at comparing the aquaculture performance of the selected strain against the existed local strains also showed promising results.  It was 10-40% better in growth, 15-70% better in productivity, 2-9 times higher in benefit-cost ratio, shorter growing period (45-60 days), lower feed conversion ratio (0.6-0.8 in nursery and 0.6-1.0 in grow out), and higher survival (60-70% ) following challenge test against  Aeromonas hydrophyla infection. It also produced a higher uniformity in size; 80-90% in fry production stage and 70-80% in grow out production. Genetic variability analysis showed that three generations of selection did not result in a decline in genetic diversity within the population.   Selective breeding in African catfish by applying individual selection carried out at RIFB managed to obtain a significant genetic improvement while maintaining genetic diversity.

Imron

Bambang Iswanto
Rommy Suparapto
Huria Marnis