Evaluation of Acute Toxicity and Lethal Concentration (LC50) of Cypermethrin (25% EC) in Adults of Cyprinus carpio (Linnaeus 1758)

Abstract

The present study attempted to determine the acute toxicity and medial lethal concentrations of Cypermethrin (25% EC) for common carp Cyprinus carpio using Finney’s static bioassay (1971), probit analysis method. The LC50 values for 24, 48, 72 and 96 hr were found to be 3.962 µl Lit-1, 3.767 µl Lit-1, 3.349 µl Lit-1 and 2.924 µl Lit-1 respectively. Fish (weight 90–100 g, length up to 18±2 cm) were exposed to different concentrations of cypermethrin which were 1.5 µl Lit-1, 2.0 µl Lit-1, 2.5 µl Lit-1, 3.0 µl Lit-1, 3.5 µl Lit-1, 4.0 µl Lit-1 and 4.5 µl Lit-1 up to 96 hr. LC50 value decreases with an increase in exposure time. During this exposure period, abnormal behaviors like restlessness, hyperactivity, erratic movements, increased opercular movements, and loss of equilibrium and response were noticed in carp. Over secretion of mucous all over the body surface along with respiratory stress and mortality was also observed.