Population control in farmed tilapias

Abstract

First paragraph: Breeding at a small size in tilapia diverts energy from growth into reproduction (territorial/courtship behavior and the metabolic cost of gamete production). Further, the progeny produced by the stocked fish compete for available space and food resources, thereby inhibiting the growth of the stocked fish, especially in ponds, where space and food quickly become limiting. Even in many parts of Southeast Asia where marketable size of tilapia is small (80-100 g), recruitment results in harvests that include 10-20% of small, larely unmarketable, fish. In African countries and urban areas in Asia where the premium market size for fresh fish is much larger, this figure can be as high as 50%.