Deltamethrin is a broad spectrum synthetic pyrethroid pesticide. It is considered less toxic as compared to organochlorine and organo-phosphate pesticides. Deltamethrin was selected to study the biochemical and histological
alterations in liver of silver carp. The LC50 1.6 μg/L was determined. Fish (n=6) were dividing into 4 groups A (control)
B, C and D (experimental). Experimental groups B, C and D were exposed to 25%, 50% and 75% of LC50
respectively for acute exposure. The blood and liver tissue sampling was done after 96hrs for histology and
biochemical analysis [alanine amino transferase (ALT), and aspartate amino-transferase (AST)]. Liver histology
revealed that necrosis, nuclear pycnosis, hypertrophy of hepatocytes, vacuolization, nuclear atrophy and congestion
of blood vessels were observed as compare to control group. This result was also supported by the significant
increase in levels of hepatic enzymes AST and ALT in blood plasma of exposed fish as compared to control fish.
These results suggested that deltamethrin is highly toxic for aquatic organism like silver carp causing malfunctioning
of liver.