Zn contamination stimulate agonistic behavior and oxidative stress of crayfishes (Procambarus clarkii)

Abstract

BackgroundAs a result of the global industrial revolution, contamination of the ecosystem by heavy metals has given rise to one of the most important ecological and organismic problems. The current study aimed to evaluate the effect of Zn contamination on agonistic behavior and oxidative damage of crayfish. MethodsCrayfishes of the field study group were collected from a polluted area (Rosetta branch), where the highest concentration for heavy metals in water was zinc (Zn). Besides the field study group, other crayfishes were exposed to different doses of ZnSO4 (0, 203, and 406 mg L−1), which corresponding to Zn concentration (0, 46.03, and 92.06 mg L−1) respectively in aquariums for consecutive four days. Agonistic behavior is quantified by decreasing fast retreat, slowly back away and no response, increasing initial claw use, active claw use, approach with the threat, approach without threat, and unrestrained behavior. ResultsThe result revealed that agonistic behavior increases significantly with the increase of water Zn concentration. Malondialdehyde and catalase levels increased, while glutathione concentration reduced with the increase of Zn concentration. ConclusionOur current study reveals that zinc exposure is capable of inducing an increase in the social status (agonistics behavior) and oxidative stress parameters in Procambarus clarkii. The increase in aggressive behavior may have major population-level consequences given the high mortality experienced by this crayfish.