Sub-lethal effects of potassium dichromate on hematological and histological parameters in climbing perch, Anabas testudineus (Anabantidae)

Chromium, which enters the river through anthropogenic sources, is one of the potent heavy metals. The present study is an attempt to determine the LC 50 of Potassium dichromate for the climbing perch, Anabas testudineus and to study the impact of two sub-lethal concentrations (6 and 12 mg/l) of Potassium dichromate the toxic hexavalent Cr(VI) form of Chromium on this fish through investigating hematological and histopathological parameters. Experimental set up included quadruplicate treatments for each dosage, and the results were compared with control treatments. The results showed that the LC 50 value at 96 hr was 59.92 mg/l. The fishes exposed to sub-lethal concentrations showed severe abnormalities such as; degeneration of hepatocytes, necrosis of hepatic tissue and extensive haemorrhage in gills and renal tissue. The present study brings out the harmful impact of Cr(VI) in the aquatic environment and necessitates regulations of its inflow to natural water bodies as a management plan to curb its contamination.