Abstract:Embryonic and early larval development and growth of Epinephelus septemfasciatus,including morphological features and developmental period, were observed and studied. Starvation tolerance test was also conducted and other index such as larvae survival and growth, yolk sac, and oil globule utilization rate were recorded under the condition of water temperature 22±0.5℃ and salinity 30. Based on the obtained data, the embryonic development of E.septemfasciatus was divided into five stages, namely cleavage stage, blastula stage, gastrula stage, neurula stage, as well as organogenesis stage. The embryos hatched at 38h45min after fertilization in seawater at 20.5±0.5 ℃ and salinity of 30.0. The whole length of newly-hatched larva was 1.059±0.07 mm. The yolk sac of larvae disappeared 4d post hatching at a whole length of 2.27~2.36 mm, and air bladder of larvae formed during 8~15d post hatching. Then the soft rays of caudal fin developed finally at 30d post hatching.Newly-hatched larvae showed 100% mortality after 7 days of starvation, and the half mortality time was 5d and themortality peaked at 4~6d post hatching. The growth of yolk sac larvae can be divided into three periods: rapid growth period of newly hatched larvae, slow growth period before and after the disappearance of yolk sac,and negative growth period afterwards due to the lack of exogenous feeding. Starvation magnified the difference of growth between starved and normal larvae (P<0.05). Larvae had shorter soma length, bigger head and thinner body after a period of food deprivation. The rear part of head sunk after long-time starvation.
