A test of an on-farm selection procedure for tilapia growth in Indonesia

Modern intensive fish farming encourages the use of superior strains of fish developed in centralized research institutions. In many artisanal fish farms these strains may not be available or suitable: environmental conditions may differ from those optimal for the superior strains, or the species of fish desired in particular farming systems may not have been the subject of a selection programme. In such cases, the option would be for farmers to improve their own strains using procedures that are within their financial and technical capabilities. One generation of mass selection for size-specific growth rate of tilapia was performed on a fish farm in West Java, Indonesia. Selection was applied in two steps over the 6 month grow out period following the initial stocking of size-graded fingerlings acquired from the farmer. Size grading, rather than age-matching, was a key step in simplifying the procedure for on-farm use. Selection and testing of the offspring were conducted in hapa nets set up in farm ponds. The selection resulted in a significant positive response of 2.3% as measured by the percent differences of the lengths of the selected offspring from the control offspring. A rough estimate of realized heritability amounted to 0.12.