温度对四川华鳊仔、稚鱼生长发育及存活率的影响

Effects of different temperatures on the growth and survival rate of Sinibrama taeniatus larvae and juveniles

中文关键词: 四川华鳊  仔、稚鱼  温度  生长发育  存活率

英文关键词: Sinibrama taeniatus  Larvae and juveniles  Temperature  Growth  Survival rate

中文摘要:

      为探索温度对四川华鳊(Sinibrama taeniatus)仔、稚鱼早期发育的影响，本研究以刚出膜且发育正常的四川华鳊仔鱼为研究对象，共设置16℃、19℃、22℃、25℃、28℃和31℃ 6个温度梯度，并定期观察仔、稚鱼的生长发育进程。整个发育过程分为开口摄食、卵黄囊消失、鳞片出现、鳞被完整4个阶段，统计各阶段的发育天数并测定全长、体长、体重等生长参数，统计死亡数量，旨在掌握仔、稚鱼发育阶段的最适生长温度。结果显示，温度对仔、稚鱼生长发育影响较大。随着温度的升高，仔、稚鱼的发育进程加快，28℃、31℃组鳞被完整的时间均早于其他温度组，但与25℃组的时间差距不大。从全长和体重来看，28℃组均最大，25℃与31℃次之。随着温度的升高，四川华鳊仔、稚鱼存活率先上升后下降，22℃~28℃存活率均较高，其中，25℃组存活率最高。四川华鳊仔、稚鱼的全长(L)和日龄(D)的关系拟合函数相关系数值均达到0.99以上，表明Cubic生长模型能很好地反映其在不同温度条件下随日龄的生长情况。综合四川华鳊仔、稚鱼的发育进程、生长指标及存活率可知，25℃~28℃为四川华鳊仔、稚鱼生长发育的适宜温度。

英文摘要:

      Sinibrama taeniatus is a rare and unique small economic fish found in the upper reaches of the Yangtze River, including the Qinjiang, Qingyi, Jialing, and Dadu Rivers. In recent years, due to the Three Gorges Project and overfishing, wild populations of S. taeniatus have decreased sharply. Water temperature is a critical factor for newly hatched larvae, significantly affecting growth, differentiation, and survival. Determination of the optimal water conditions for S. taeniatus growth performance is essential to maximize production. To explore the effects of temperature on the growth and survival of S. taeniatus larvae and juveniles, an experiment was conducted at 16℃, 19℃, 22 ℃, 25℃, 28℃ and 31℃. The entire developmental process was divided into four stages: Larvae feeding, disappearance of the yolk sac, appearance of the scales, and intact scales. The length of each stage (in days) was counted, and the growth parameters such as total length and weight were measured. The results showed that the development process accelerated with increasing water temperature. The time to intact scales in the 28℃ and 31℃ groups was shorter than in the other temperature groups but did not differ from the 25℃ group. At 80 days of development, the body weight of S. taeniatus in the 25℃ and 28℃ groups was significantly heavier, especially in the 28℃ group. With increasing temperatures, the survival rate of S. taeniatus larvae and juveniles initially increased and then decreased. The survival rate was higher at 22℃~28℃, and the composition survival rate was highest at 25℃. The correlation coefficients of the fitting function between total length (L) and the days after hatching (D) were greater than 0.99, indicating that a cubic growth function properly reflects growth at different temperatures. Based on the development process, growth index, and survival rates of S. taeniatus larvae and juveniles, 25℃~28℃ is the optimal temperature range for S. taeniatus production.