Histopathological effects of diethyl phthalate on <i>Clarias gariepinus </i>juveniles

Abstract

The acute toxicity of diethyl phthalate to Clarias gariepinus fingerlings was investigated using static bioassays with continuous aeration over a period of 96 h. The LD50 of DEP for Clarias gariepinus was determined at 95% confidence limit for log toxicant concentration after 24 h, 48 h, 72 h and 96 h. The LD50 after 24 h, 48 h, 72 h and 96 h were 2.22, 2.73, 3.44 and 3.93 ìg/L, respectively. The LD50 for total death was estimated as 1.87 ìg/L. During the exposure period, the test fish was restless, swam erratically and hemorrhaging of the gill filaments was evident. These observations are indicative of stress due to effect of the diethyl phthalate on the fish. Sub acute Diethyl phthalate concentrations (30 ìg/L, 40 ìg/L, 60 ìg/L and 80 ìg/L) was obtained from the LC 50 of the acute study and the fish were exposed to the graded concentrations for period of 30 days. The fish were killed at 15 days interval and the liver and kidney were excised and the histopathological changes of DEP on the liver and kidney were determined by light microscopy. Pyknotic nuclei, destruction or fusion of tubules, condensation of the glomeruli and severe destruction of the tubule were observed in kidney tissue of fish. Cellular proliferation, congestion, necrosis, sinusoid enlargement, paranchymatous degeneration and fatty or glycogen degeneration were observed in the liver tissue of fish. The morphological changes of the tissues were dosage dependent.