温度对四川华鳊胚胎发育的影响

为探索温度对四川华鳊胚胎发育的影响,笔者观察16、19、22、25、28、31℃6个温度条件下四川华鳊的胚胎发育过程,描述总结(25±0.5)℃下胚胎发育各个阶段的形态特征。研究结果显示,四川华鳊胚胎发育过程可划分为受精卵、胚盘形成、卵裂、囊胚、原肠胚、神经胚、器官分化和出膜等8个连续发育阶段;在(25±0.5)℃下孵化总历时44.83 h;在温度为16℃时,胚胎发育至原肠胚晚期全部死亡;19℃时孵化率为30.00%,其中畸形致死占87.19%,显著高于其余4个温度组(P<0.05);温度由19℃升至31℃时,胚胎发育所需时间变短,各温度间差异显著(P<0.05),其中器官分化阶段均用时最长,占整个胚胎孵化历时的72.53%~77.07%;胚胎畸形率随着温度升高而上升,31℃的胚胎畸形率约为28℃的2倍;在22~28℃时,胚胎的受精率和孵化率、成活率最高,畸形率最低。研究结果表明,水温在(19±1)℃,卵径(y)与胚胎孵化时间(x)的关系为y=49.56-44.36x+47.92x^2(r^2=0.996);水温22~28℃为适宜孵化温度,最佳水温约为25℃;胚胎发育的生物学零度为12.69℃,有效积温为522.35~595.11℃·h。

Effect of Temperature on Embryonic Development of Sinibrama taeniatus

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.