Investigating the 96h LC<Sub>50</Sub> of Mercury and Cadmium on <i>Channa punctatus</i> (Bloch): A Comparative Acute Toxicity Bioassay

Abstract

Acute and chronic exposure of heavy metals exerts detrimental effect at the cellular level and is a rising global concern. The pollutants once introduced in the water bodies, subsequently enters the food chain, and poses risks not only to the aquatic organisms, but to the human consumers as well. Therefore, understanding the toxicological level of these metals is vital for assessing the severity of potential risks. The study aimed to conduct a comparative analysis of the acute toxicity of mercury and cadmium on Channa punctatus through a 96-hour bioassay. It was carried out in a semi-static laboratory condition following the standard guidelines. The behavioural, and mortality response was recorded at the 24, 48, 72, and 96 h of exposure duration for both toxicants. The results demonstrated distinct differences in toxicity levels between mercury and cadmium. The 96h-LC50 value for cadmium was measured at 6.19 mg/l, while for mercury, it was significantly lower at 0.44 mg/l. It was revealed that even the trace concentration of metals can induce toxicity, if given for a prolonged period of time. Furthermore, the study observed heightened toxicity of mercury, exerting adverse effects at lower concentrations compared to cadmium within the same exposure duration.