PATHOLOGY OF THE TOXIC EFFECT OF SOME PHENOLIC COMPOUNDS ON CARP FISH

Abstract

A total number of 215 common carp fish (Cyprinus carpio L.) were collected from Barseek farm, Behera Province. They were used to evaluate the pathologic lesions associated with both acute and chronic toxicosis of some phenolic compounds namely phenol and m-cresol.

Fifty fish were used to estimate the LC50 of each compound and these pilot tests revealed that LC50 for phenol was 45 ppm and that of m-cresol was 75 ppm. The tested acute dose in this work was 30 ppm for phenol and 60 ppm form-cresol for 1 week. However, the chronic dose was 1/5 LC 50 (9 and 15 ppm for phenol and m-cresol, respectively up to 1 month).

Generally, the resultant toxicosis was more severe in phenol than that of m-cresol. Clinically, the acutely intoxicated fish with either phenol or cresol were nervous and respiratory in nature as excitation followed by depression together with gasping. Regarding the signs of chronic toxicosis of both two compounds they resembled those of acute experiment but with very milder pattern. Mortalities in acute experiments were 20 and 5.7% in phenol and m-cresol, respectively. But in case of chronic toxicosis, mortality rates were 5% in each of phenol or cresol toxicosis.