Principles of fish seed production

Abstract

Teleosts are poikilothermic animals whose sexual maturity depends on water temperature. Under tropical conditions, most fishes become sexually mature within the first year (Horvath et al., 1984). For example, Barbodes gonionotus matures sexually at the age of 8 months, when the length is only 8.5 cm (TL) and the weight 9 g (Paohorm, 1969). Although the fish is mature, the fertility of the eggs is poor. Thus, a low survival rate of the larvae has been reported from female B. gonionotus weighing 100 g. Therefore, the appropriate size of this species for breeding purposes is about 200 g (Joragun, 1978). In some tropical freshwater species, sexual maturation takes longer than one year: for example, 2 years in Morulius chrysophekadion (Unsrisong et al., 1990), 3 years in Osphronemus gouramy (Pasukdee, personal communication), 4 years in Probarbus jullieni (Rodrarung et al., 1990) and more than 10 years in Pangasianodon gigas (Sukumasavin, personal observation). [Extract]