Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum) Exposed to Sublethal Concentrations of Permethrin

Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the effects of permethrin on bioaccumulation of mercury in zebra cichlid. Acute toxicity (LC50) of permethrin and mercury chloride was evaluated by estimating mortality in Probit Model in SPSS (version 19.0 IBM). In sub-lethal toxicity, zebra cichlid (Cichlasoma nigrofasciatum) was exposed to various concentrations of permethrin (0.0, 0.40, 0.80, 1.20 and 1.60 µg.L-1) combined with 20 µg.L-1 mercury chloride for 15 days.At the end of the experiment, mercury concentrations were measured using ICP-OES-Perkin elmer (optima 7300-DV).96 h LC50 values of permethrin and mercury for C. nigrofasciatum were calculated to be 17.55 µg.L-1 and 140.38 µg.L-1, respectively. Our results clearly showed that the bioaccumulation of mercury in the specimens increased with increasing concentrations of permethrin to 1.20 and 1.60 µg.L-1. Increasing the concentration ofpermethrinhad synergistic effects on the bioaccumulation of mercury in fish.