FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

This study aimed to conduct experiments on reproductive behavior and larval culture of gray demoiselle (Chrysiptera glauca) to establish aquaculture techniques on gray demoiselle farming that would reduce the dependence of the ornamental fish industry on wild stock. The adhesive demersal eggs were colored from white to light yellow with ellipsoidal shape. The fertilized egg was about 1.18 ± 0.05 mm in total length and 0.53 ± 0.02 mm in width. The yolks were about 0.68 ± 0.03 mm long and contained several oil droplets. Parental care for laid egg was observed and mainly carried out by males. Incubation period was approximately 78 h at the water temperature of 27.9 ± 0.4 ℃. The newly hatched larvae were about 2.64 ± 0.22 mm in length. The live feeds at initial larvae stage were ciliate, rotifer and copepod. Microalgae were added to stabilize water quality and to nourish rotifers. Hatching rate varied and was significant with salinity (p ≦ 0.05). Hatching rate was the highest (80.0%) at 25 psu, but failed at 0 psu. The deformity rate was inversed to salinity. Deformity rate was the highest (12.5%) at 5 psu, but no deformity occurred as salinity was greater than 20 psu.