Egg production and larval rearing of orange-spotted grouper (Epinephelus coioides) using reared broodstocks in Hormozgan Province , Iran

Abstract

Egg production of cultivated broodstocks of orange-spotted grouper, Epinephelus coioides and larvae rearing were surveyed in Iran from 2008 to 2012. . Broodstocks were obtained by rearing of 7 wild juveniles (587.57 ± 132.63 g body weight) which were caught from the north of Persian Gulf in October 2008 and reared to December 2012.. Captured juvenile fishes were fed using defrosted trash fish at a rate of 4-6 percent of body weight per day.. Four-year-old fishes spawned spontaneously, when average weight of females and males were about 7020 ± 1277 g and 5128 ± 253g respectively. Effects of four temperature ranges (23-24, 26-27, 28-29 and 31-32 °C ) and three tank size ( 40L, 300L and 2400L) on hatching and survivle rates were examined. Eggs were stocked as a density of 25 Eggs L-1. Effects of tank size on hatching rate and survival of larvae were assessed at 1, 5, 10, 20 and 30 days after hatching (DAH). The optimal temperature range for hatching was 28-29 °C. No difference was observed among hatching rates of fish within the various tank sizes. Survival rates of larvae in 2400L fiber glass tanks until 30 days after hatching were significantly higher than the other tanks. Results indicate this species can be reproduced and reared in large numbers under normal rearing conditions and carefully controlled temperature.