ACUTE TOXICITY OF 4-OCTYLPHENOL ON THE HISTOPATHOLOGICAL CHANGES OF OVARY IN THE FRESHWATER STINGING CATFISH HETEROPNEUSTES FOSSILIS

Abstract

4-Octylphenol (4-OP) is a degradation product of alkylphenol polyethoxylates (APEs).APEs represent an important class of non-ionic surfactants widely used in many pesticide formulations, oil paint formulations, detergent formulations and plastic products for industrial and domestic use. The 96 hrs LC<inf>50</inf> value of 4-Octylphenol was 0.9 mg/L for the fish Heteropneustes fossilis. Mortality of fish was recorded for each of the concentrations during exposure period and used for the estimation of LC<inf>50</inf> value. Therefore 1/10th and 1/50th of the LC<inf>50</inf> value i.e., 0.9 mg/Lwas used for the experimental study. For 4-octylphenol two doses were decided, i.e., high dose (0.09 mg/L) and low dose (0.018 mg/L).After exposure to these doses behavior and histopathology changes were determined after 1 and 7 days. In the present study, ovary-somatic index (OSI) decreased significantly in a duration and dose dependent manner. Further considering behavioral changes catfish showed frequent jumping, decreased opercular movement and resting time, erratic movement, secretion of excess mucous from the body and increased air gulping activities. Histopathological changes in ovary tissues of Heteropneustes fossilis by hematoxylin-eosin staining showed architectural deformities in oocytes with increase in interfollicular spaces with damaged oocytes and increased in atretic and dead oocytes in comparison to control sections. Shifting and clumping of nucleus with cytoplasm was observed. The changes were duration and dose dependent manner. In conclusion, present study suggests that 4-OP can be a potent toxicant for aquatic organisms and further detailed investigation is required in this area, which is under progress in our laboratory. © 2025, Prof (Dr.) P. R. Yadav. All rights reserved.