First onboard fertilization of Asian seabass, Lates calcarifer: Effects of egg stocking density on the fertilization, hatching and survival rate

Abstract

Asian seabass, Lates calcarifer is a highly valuable and potential candidate species for mariculture. The objectives of the present study were to conduct an onboard fertilization trail to produce viable offspring and see the effects of stocking density of eggs on the fertilization, hatching and survival rate of Asian seabass juveniles. Eggs and sperm were collected during the full moon in May 2019 from the Moheshkhali channel estuary, the Northeast Bay of Bengal, by hand stripping method. Pooled sperm from two males and eggs from a female were used for insemination. Three egg stocking densities (T1- 37 40,000 eggs/batch; T2- 60,000 eggs/batch and T3- 80,000 eggs/batch) was used for this study. The one-way ANOVA (p < 0.05) showed significant effects of egg stocking density on fertilization, hatching success, and survival rate of Asian seabass larvae. The maximum fertilization and hatching success of Asian seabass eggs were 83.05 ± 2.22 and 76.51 ± 1.19%, respectively, achieved with 40,000 eggs/batch stocking density. The highest survival rate was observed in treatment 1 (56.25 ± 3.97%) at 30 DPH, which was significantly different from the other treatments (p < 0.05). Our results indicated that eggs of Asian seabass with a lower stocking density (40,000 eggs/batch) could achieve higher success in fertilization, hatching and survival compared to higher stocking densities (60,000 eggs/batch and 80,000 eggs/batch, respectively). Results from this study could be useful for assisted breeding of Asian seabass in captivity.