The food and feeding of tropical marine fishes in floating net cages: Asian seabass, Lates calcarifer (Bloch), and brown-spotted grouper, Epinephelus tauvina (Forskal)

Abstract

. A 156-day cage feeding trial was conducted with fingerling seabass, Lates calcarifer (Bloch), and grouper, Epinephelus tauvina (Forskal), so as to test six different dietary feeding regimes, namely no exogenous feeding (NF), frozen fish (FF), commercial shrimp finisher pellet (SP), in-house prepared dry pellet RDI (RDI) and RD2 (RD2), and an in-house prepared moist pellet (frozen fish: diet Rd1, 40:60 mixture w/w — code MP). Seabass fed FF and MP displayed the best growth response, with fish (30/m3) growing from an initial weight of 8·9g and 8·5g to a final weight of 285·5g and 257·5 g in 156 days, with a food conversion ratio of 3·77–5·10 (dry matter basis 1·15 – 1·95), and with a survival of 93·3 and 93·3% respectively. Similarly, grouper fed FF and MP also displayed the best growth response, with fish (30/m3) growing from an initial weight of 23·8 g and 25·8g to a final weight of 471·7g and 388·7g in 156 days, with a food conversion ratio of 3·53–4·16 (dry matter basis 0·89–1·06) and 1·73–2·96 (dry matter basis 1·06–1·80), and with a survival of 90 and 98·3% respectively. The results are analysed from an economical viewpoint and discussed on the basis of other published studies.