Histological Alterations in the gills of TILAPIA MOSSAMBICUS exposed to Kerosene

Abstract:

PAHs are rapidly accumulated by aquatic organisms reaching level higher than those in the ambient medium and affecting normal functions of the aquatic life. Kerosene is a well-known source of harmful compound including PAHs. Histopathological investigations have been proved to be a sensitive tool to detect effects of chemical compounds within target organs of fish in laboratory experiments. In this study it was proposed to find out whether exposure to kerosene for 96 hrs has an effect on the gills of Tilapia mossambicus because, gills are the first organ and main target for many aquatic pollutants. Varied morphological changes occurred in the gills of Tilapia mossambicus treated with kerosene. The gill exhibited marked alterations in their epithelia.  The epithelium was no longer continuous, particularly the more delicate respiratory lamellae.  Thus, there was fusion at adjacent secondary lamellae as a result of hyperplasia.  Oedema at the secondary lamellae and swelling of the epithelial cells were observed. The pillar cells have been altered and blood spaces expanded.  There is a severe hyperplasia with profound oedematous changes characterized by epithelial detachment.  The elongated secondary lamellae with club-like structures were the other pathological changes observed in the histological sections of gills of Tilapia treated with water soluble fraction of kerosene. the number of lesions caused by kerosene is related to its concentration. Thus the result of these studies clearly indicates that PAH has diverse effects on the gills.

Keywords: Environmental pollution, Tilapia mossambicus, Kerosene, Gills, Histopathology

http://www.ijbst.org/Home/papers-published/ijbst-2012-volume-5-issue-9