Parinita Kumari, Shekhar Phadtare, Paramanand Tiwari and Vinod Ragade
Abstract
Triclosan is a widely used antimicrobial compound frequently detected in freshwater environments and is recognized as a potential endocrine-disrupting chemical. The present study evaluated the acute toxicity of triclosan in the freshwater fish Oreochromis mossambicus (Mozambique tilapia) by determining median lethal concentration (LC) values at multiple exposure durations. Juvenile fish were exposed to Triclosan concentrations ranging from 0 to 2.0 mg l-¹ under static laboratory conditions for 24, 48, 72, and 96 h. Mortality was recorded at each interval, and LC values were calculated using Finneyâs Probit analysis. Mortality increased in a clear concentration- and time-dependent manner. The 96-h LC value was estimated at 1.12 mg l-¹ (95% confidence limits: 1.05-1.20 mg l-¹). Behavioral abnormalities such as erratic swimming, frequent surfacing, increased opercular movement, and losses of equilibrium were observed at higher concentrations prior to mortality. This study provide baseline acute toxicity data for triclosan in O.mossambicus and indicate potential ecological concern under accidental or high-exposure scenarios. However, interpretation of endocrine-related affects remains limited due to the absence of chronic and biochemical endpoints.