Pathological Assessment Of Climbing Perch, Anabas Testudineus Exposed To 1,1-Dimethyl-4,4bipyridinium Dichloride (Paraquat)

Abstract

Paraquat is one of the most widely used herbicide in agricultural activities. Uncontrolled usage will lead to chemical runoff that runs directly into aquatic ecosystem. The toxicant exposure is a common situation which has considerable impact on the aquatic organism, namely fish. This study provides significant evidences that paraquat does negatively impacted Anabas testudineus health status. The research focuses on four different biomarkers; fish behavioural changes, haematological parameters evaluation, histopathological assessment and paraquat residual in fish muscle. The 96h median lethal concentration (96hLC50) of paraquat was 16.81 mgL -1 . The effects of sub lethal concentrations of paraquat on behaviour, haematology and tissues were subsequently study by exposing fish to 2, 5, 12 and 15 mgL -1 paraquat. In behavioural study, exposed fish exhibited significant changes (P<0.05) in frequent surface to bottom movement, erratic swimming, opercula movement, air gulping, excessive mucous secretion, sluggish and swirling movement compared to control. The erythrocyte indices (total erythrocyte count, haematocrit, haemoglobin, mean corpuscular value and mean corpuscular haemoglobin) and leukocyte indices (total leukocyte count) were determined in paraquat exposed fish.