Abstract

This evaluates the 28-day toxicity and 7-day post treatment effect of LCT on the behaviour, liver and kidney of Clarias gariepinus. Prior to the experiment, fishes were acclimatized for two weeks. 120 fishes of standard length (SL) / weight (W) 10-12 cm, 8 - 17 g were used for median lethal concentration (LC₅₀) test and 120 fishes of SL / W 16 - 40 cm, 200 - 250 g were used for the behavioural, hepato - nephrotoxicity and 7-day post treatment tests. The behavioural response of C. gariepinus upon exposure to LCT was observed from 24 to 96 h. The experiment had four treatments with LCT concentrations of 0.00, 2.5 x 10^-4 µg/L, 5.0 x 10^-4 µg/L and 6.25 x 10^-4 µg/L and 30 fishes per treatment in triplicates for 28 days. In days 1, 7, 14, 21 and 28 of treatment and 7 days after treatment, fishes were brought out for blood samples collected through caudal alteration for liver and kidney marker enzymes tests (alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatinine and urea) using standard methods. There was a concentration dependent increase in faster swimming movement, hyperactivity, jerky movement, gulping of air, repeated closing and opening of the mouth and percentage mortality of C. gariepinus exposed to LCT. ALT, AST, ALP, creatinine (CR) and urea levels showed concentration and duration significant increased (p < 0.05) while total protein significantly decreased (p < 0.05) compared with controls. After 7 days of depuration, ALT, AST, CR and total protein were not different from the control.  This study has demonstrated that LCT caused hepato-nephrotoxicity in C. gariepinus. The severity of LCT hepato-nephro in C. gariepinus toxicity was evident in this studies because ALP and urea levels did not return to normal after 7 days of depuration.

Key words: Liver enzymes, kidney enzymes, toxicity, lambda-cyhalothrin,behavioural responses, Clarias gariepinus.