酸性水和投加铝、钙对鲢鱼早期发育和鳃超微结构的影响

在实验室条件下,研究了酸性水和投加铝、钙对鲢鱼胚胎孵化和鱼苗存活以及幼鱼鳃超微结构的影响。pH4.0引起所有胚胎在24小时内死亡,暴露于pH4.5-6.0的胚胎孵化率和暴露于pH4.0-6.0的5-15日龄鱼苗存活率随pH值上升而增高。投加0.5mgAl³⁺/L使在酸性pH暴露条件下的胚胎孵化率和鱼苗存活率进一步降低。投加3.0mgCa²⁺/L可显著提高暴露于pH4.5和5.0的胚胎孵化率;投加2.0mgCa²⁺/L可在一定程度上提高暴露于pH4.5和5.0的鱼苗存活率。幼苗经pH4.5暴露8小时后出现严重的鳃超微结构损害;投加1.0mgAl³⁺/L使鳃结构损害加剧;投加5.0mgCa²⁺/L可明显缓解酸性水对鳃的损害。

Effect of acidic water with addition of Al and Ca on early development and gill ultrastructure of silver carp

The effects of acidic water with addition of Al and Ca on the embryo hatchability, fry survival and juvenile gill ultrastructure of silver carp (Hypophthalmichthys molitrix)were studied under laboratory conditions. All eggs were died at pH4.0 within24 hours. The increase in pHvalue was accompanied by a progressive increase in the hatchability of embryo exposed to pH4.5-6.0 and in the survival of fry with age in day from 5 to 15 exposed to pH4.0-6.0. The addition of 0.5mg Al³⁺/L not only further reduced the hatching of embryo, but also caused decrease in the survival of fry under acidic pH. The addition of 3.0mg Ca²⁺/L significantly increased the hatching of embryo under pH4.5 and 5.0. The added 2.0mg Ca²⁺/Lincreased the survival of fry to a certain extent at pH4.5, especially at pH5.0. The exposure to pH4.5 for 8 hours resulted in a severe damage of gill ultrastructure of juvenile; The addition of 1.0mg Al³⁺/L to pH4.5 water enhanced the syndrome; 5.0mg Ca²⁺/L added obviously mitigated the gill damage by acidic water.