酸碱胁迫对奥尼罗非鱼幼鱼鳃组织结构及Na^+-K^+-ATP酶活力的影响

Effects of p H Stress on Structure,Activity of Na^+-K^+-ATPase in Gill of Tilapia( Oreochromis aureus × Oreochromis niloticus)

[目的]探讨酸碱胁迫对奥尼罗非鱼幼鱼鳃组织结构及Na^+-K^+-ATP酶活力的影响。[方法]将初始体质量(6.81±0.85)g奥尼罗非鱼(Oreochromis aureus×Oreochromis niloticus)幼鱼暴露于不同酸碱度(p H分别为4.5、6.0、7.5、9.0、10.5,依次设为试验Ⅰ、Ⅱ组、对照组及试验Ⅲ、Ⅳ组)的水体中,每组3个重复,每个重复30尾鱼。胁迫后0、12、24、48、72 h采集鱼鳃样本,采用HE染色石蜡组织切片及分光光度法比较酸碱胁迫对鱼鳃组织结构及其中Na^+-K^+-ATP酶活力的影响。[结果]对照组鱼鳃的组织结构未发现有明显病变的症状,且鳃中的Na^+-K^+-ATP酶活力维持在一定水平;各胁迫组鱼鳃组织结构均不同程度发生病变,出现鳃丝融合,动脉血管破损,鳃小片肿胀弯曲,顶端与末端粘充血和肿胀,黏液细胞增多,上皮细胞增生、脱落,泌氯细胞肿胀,细胞质空泡化等一系列病态症状,且其症状会随着酸碱程度的加深、暴露时间的延长而加重;酸碱胁迫后各胁迫组鱼鳃中Na^+-K^+-ATP酶活力均出现先升高后降低的变化,其中酸胁迫的峰值出现在48 h,而碱胁迫出现在12 h。[结论]该研究结果可为奥尼罗非鱼的养殖生产提供理论依据。

[Objective] The aim was to study effects of pH stress on structure,activity of Na ＋-K ＋-ATPase in gill of tilapia.[Method] Tilapia juvenile （initial average weight was 6.81 ± 0.85） g was exposed in different pH water （pH were：4.5,6.0,7.5,9.0 and 10.5,arranged as experiment 1,2,control,3 and 4 group）,with 3 repetition,each repeated 30 fish.Samples were collected at 0,12,24,48 and 72 h,HE staining and absorptiometry were used to compare the effects of pH stress on the structure and Na＋-K＋-ATP activity of the gill tissues.[Result] The results showed that there was no obvious displayed histopathologic alteraions in gill,the Na ＋-K ＋-ATPase activity of control group in gill was maintained at a certain level.The structures of the gill of the stress groups were pathological changes in different degree,such as fusion,arterial blood vessel damage,swelling and swelling of the gill lamellae,swelling of the cells in the apical and terminal,the symptoms can be aggravated by prolonged exposure time.Na ＋-K ＋-ATPase activity in gill of the stress groups was increased and then decreased,the peak of acid stress group appeared at 48 h,while the alkali stress group appeared at 12 h.[Conclusion] The study results can provide theoretical basis for aquaculture production of tilapia.