LAUSR

In this study, fertilized eggs of Sinibrama taeniatus were incubated in a 45 cm×25 cm×25 cm aquarium at water temperature of 16, 19, 22, 25, 28 and 31 ℃ to explore the effect of temperature on the embryonic development of the fish. It was found that the embryonic development process of S.taeniatus was divided into 8 stages including fertilized egg stage, uplift of blastoderm stage, cleavage stage, blastula stage, gastrula stage, neurula stage, organogenesis stage and hatching stage. It took 44.83 h for hatching of the embryo at water temperature of(25±0.5) ℃. However, the embryos were all died at gastrula stage at water temperature of 16 ℃, with hatching rate of only 30.00% at water temperature of 19 ℃, with the abnormality rate of 87.19%, significantly higher than that in other four groups(P<0.05). The incubation period was shortened at water temperature ranging from 19 ℃ to 31 ℃, significant difference among different temperatures(P<0.05), organogenesis stage being the longest stage in the 8 stages, accounting for 72.53%-77.07% of incubation period. Meanwhile, the abnormality rate was increased with increasing temperature, slightly twice at 31 ℃ as at 28 ℃. The maximal fertilization rate, hatching rate and survival rate and minimal abnormality were observed at water temperature varying from 22 ℃ to 28 ℃, with the optimal incubating temperature of 25 ℃. The regression equation between egg size(y)and the incubation period(x) was described as: y=49.56-44.36x+47.92x^2+47.92x^2(r~2=0.996) in embryonic development of S.taeniatus at(19±1) ℃, with biological zero point of 12.69 ℃ and the effective accumulative temperature of 522.35-595.11 ℃·h.