Metal Mixtures Toxicity and Bioaccumulation in Tilapia nilotica at 96-Hr LC50 Exposure

Laboratory tests were conducted on fingerlings of Tilapia nilotica to check the bioaccumulation patterns of lead (Pb), cadmium (Cd) and cobalt (Co) during acute toxicity at constant water temperature, pH and total hardness. Metal mixtures viz. Lead + Cadmium, Cobalt-Lead and Cadmium-Cobalt were selected to assess the acute toxicity in terms of 96-hr LC50 along with bioaccumulation patterns in selected organs of Tilapia nilotica (skin, muscles and liver). Sensitivity of Tilapia nilotica in terms of 96-hr LC50 for all mixtures varied significantly. The 96-hr LC50 of binary metal mixtures agreed in that order: cadmiumcobalt > lead-cadmium > cobalt-lead with statistically significant differences at p<0.05. Regarding overall tendencies of organs to accumulate metals, the liver exhibited a significantly higher tendency to amass metals, followed by skin, while muscles showed the least metallic ion load. Among mixtures, the lead-cadmium mixture exposure caused significantly higher (107.60 µg/g) accumulation in fish, while cadmium-cobalt showed a significantly lower (94.22 µg/g) tendency to cause amassing of these metals.