Natural spawning and larval rearing of silver bream, Rhabdosargus sarba (Forsskål), in captivity

Abstract

Silver bream, Rhabdosargus sarba, was spawned naturally in captivity without the use of hormones or other treatment. Spawning occurred continuously from 24 December 1989 to 29 March 1990 over a period of 96 days, with a water temperature range of 13.8–23.5°C. It is estimated that a female laid about 2 586 000 eggs during the spawning period. The hatched larvae were reared in 5-t rectangular concrete tanks and fed initially on rotifers, Brachionus plicatilis, followed by Artemia nauplii and finally weaned onto an artificial diet. Larval rearing trials for growth and survival to 45 days produced juveniles of 19.4 mm average total length, at a survival rate ranging from 7.3 to 43.2%. Few agonistic attacks were observed throughout the rearing period, despite high initial stocking densities. After 105 days the juveniles reached an average size of 61.6 mm fork length with a survival rate of 12.5%.