Embryonic and Larval Development and Effect of Salinity Levels on Egg and Ovary Performance in Rabbit Fish (Siganus guttatus)

摘要

In this study we investigated embryonic and larval development of rabbit fish (Siganus guttatus) in captivity. Embryonic development lasted 18-19 hours at 28-30oC, pH: 7.6-8.0, salinity: 30-32‰. Average total length of larvae at day 1 after hatching (DAH) was 1.58 mm, average yolk sac length was 0.35 mm containing one yolk ellipsoid (0.92±0.146 mm in length and 0.54±0.107 mm in width) in dorsal and lateral views. At day 2 (DAH) larval length increased to 2.16 mm, and pigmented eyes, mouth, and caudal-fin rays developed. Day 3 (DAH) larval length was 2.25 mm and the yolk was completely absorbed. Our findings provide fundamental information regarding seed larvae production of rabbit fish. In a further experiment we investigated the effect of salinity on gonad maturation, gonadosomatic index (GSI), egg biochemical composition and fecundities. Broodfish were cultured in three salinities, 25, 30, and 35‰ during reproductive season from February to July 2015. No statistically significant effects on gonadal development, fecundities, and egg quality in rabbit broodfish held in different salinities during the reproductive season were found