Determination of toxicity of ammonia on narrow clawed crayfish (Astacus leptodactylus Esch. 1823)

In this study, the toxic effects of ammonia on fresh water crayfish were investigated. Four different measuring times (24, 48, 96 and 168 hour) and two different sub-lethal doses of ammonia (12,3 mg/L and 60.25 mg/L) exposed to fresh water crayfish (Astacus leptodactylus). Changes in biochemical parameters hemolymph of fresh water crayfish, total hemocyte counts, gill and hepatopancreas histology were examined. As a result of the experiments, all biochemical parameters except total protein were found statistically significant (p <0.05). Glucose and lactic acid which are known as a secondary stress parameters were increased significantly (p <0.05). As a result of the histological examinations on the gill tissues hyperemia, infiltration of hemolymph and melanisation were determined.In the hepatopancreas tissues; degeneration in the lumen, the lumen enlargement and edema were determined. Total number of hemocyte and hemolymph glucose were used to determine the health status of crayfishes. The count of total hemocyte on the hemolymph samples that were taken from fresh water crayfish was compared to the control group. We conclude that, due to the fact that fresh water crayfishes (Astacus leptodactylus) are the standard test organisms OECD test guidelines and feeding network, our findings contribute to the literature can be found in critical position.Science code : 903.1.032Key words : Sublethal ammonia, fresh-water crayfish (Astacus leptodactylus), hepatopancreas, gills, hemolemf biochemical parameters, total number of hemocytePage Number : 70Supervisor : Assoc. Prof. Dr. Aylin Sepici DİNÇEL