Department of Zoology, Hazara University, Mansehra, 21300, Pakistan.
Department of Animal Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
Chemosphere. 2016 Feb;144:697-705. doi: 10.1016/j.chemosphere.2015.09.007. Epub 2015 Sep 25.
The present study was conducted to investigate the effect of sub-lethal doses of Cypermethrin (CYP) on the survival and morphological and biochemical aspects of rohu (Labeo rohita) during early developmental stages. Newly fertilized eggs were incubated in the presence of sub-lethal concentration of CYP (20% of LC50 i.e., 8.43 μg L(-1)) in a well designed flow through system. Increased mortality was found with increase in exposure time. Deformities like eroded yolk and margins, elongated yolk sac, larvae with short tail, no eyes or larvae with zigzag movement and paralyzed larvae were observed in CYP treated group from blastula to fry stage. The activities of antioxidant like Catalase (CAT), Peroxidase (POD) and Lactoperoxidase (LPO) were decreased from 24 to 96 h in the control group whereas increased in CYP treated group. The Glutathione reducatse (GR) activity was also increased with time in both the control and treated groups; however, the activity was significantly higher in CYP treated group. Similarly, the whole body cortisol level showed an increasing trend with time in both control and treated groups. However, in CYP exposed group the cortisol level was considerably higher after 24 h exposure but statistically comparable to the control group after 96 h. It can be concluded from the present results that CYP even at very low concentration adversely affects the early development of L. rohita and enhances mortality. The obtained results reveal that CYP may affect the wild population of fish by inducing oxidative stress and modulating stress response during early ontogenesis.
本研究旨在探讨亚致死剂量的氯菊酯（CYP）对罗非鱼（Labeo rohita）早期发育阶段存活、形态和生化方面的影响。在设计良好的流动系统中，将新受精的卵暴露于亚致死浓度的 CYP（LC50 的 20%，即 8.43 μg/L）下进行孵育。随着暴露时间的增加，死亡率增加。在 CYP 处理组中，从囊胚期到鱼苗期观察到畸形，如卵黄侵蚀和边缘、卵黄囊伸长、尾巴短的幼虫、无眼或呈之字形运动的幼虫和瘫痪的幼虫。在对照组中，CAT（过氧化氢酶）、POD（过氧化物酶）和 LPO（乳过氧化物酶）等抗氧化剂的活性从 24 小时到 96 小时降低，而在 CYP 处理组中则增加。GR（谷胱甘肽还原酶）活性在对照组和处理组中均随时间增加；然而，在 CYP 处理组中的活性明显更高。同样，在对照组和处理组中，整个鱼体皮质醇水平均随时间呈上升趋势。然而，在 CYP 暴露组中，暴露 24 小时后皮质醇水平显著升高，但在 96 小时后与对照组相比无统计学差异。从目前的结果可以得出结论，即使 CYP 浓度非常低，也会对 L. rohita 的早期发育产生不利影响，并增加死亡率。研究结果表明，CYP 可能通过在早期个体发育过程中诱导氧化应激和调节应激反应，对鱼类的野生种群产生影响。
