Vol. 6, Issue 6, Part B (2020)

Abstract
Toxicity study is essential to provide the safe level of concentration and determine the sensitivity of animals towards the toxicant. The active substance TBT is highly toxic and also damaging to a multitude of non-target species. Static bioassays were performed on bivalve, Lamellidens marginalis to evaluate the median lethal concentrations of TBTCl (tributyltin chloride) for 24, 48, 72 and 96 hrs. The LC₅₀ values were 3.55 ppm, 2.42ppm, 1.79 ppm and 0.98ppm respectively. The study revealed that the bivalves were more sensitive to TBTCL stress and the result LC₅₀ values decreased with increase in exposure period.