Backgrounds and Aim:  Active pharmaceutical ingredients are produced each year that their use is growing at a very high scale and diversity. The aim of this study was to evaluate the lethal effects of agricultural poison Abamectin on the liver and gills tissue of common carp (Cyprinus carpio).

Material and Methods: To perform this study, 147 carp were kept for two weeks to adjust to aquarium environment. For determining the toxicity of Abamectin, Guide Number 203 (Static-constant test condition) of OECD standard method was used. Finally based on toxicity of lethal concentration (LC₅₀), the samples have been exposed to Abamectin with concentration of 2, 3, and 6 ppm for 96 hours and then liver and gill samples have been taken from them.  

Results: In this study, the most damages observed in gill tissue were primary blade hyperplasia, secondary blades attachment, destruction and curvature of secondary lamellas, and in liver tissue were, liver cells destruction, sinusoidal space destruction and ascites.

Conclusions: The results showed that with the increase of poison concentration (6ppm), more damages will be made in the liver and gill of common carp. This study showed that the lethal concentrations of Abamectin can cause toxicity and eventually led to the death of the fish.