Ultrastructure changes in hepatocytes of catfish

Clarias gariepinus from Lake Mariut, Egypt

Ashraf M. Abdel-Moneim*¹ and Hala A. Abdel-Mohsen²

¹Department of Zoology, Faculty of Science, Alexandria University, Alexandria - 215 11, Egypt

²National Institute of Oceanography and Fisheries, Kayet-Bay, Al-Anfoushy, Alexandria, Egypt

(Received: February 26, 2009; Revised received: July 18, 2009; Accepted: August 25, 2009)

Abstract: In the present study, specimens of catfish (Clariidae) were collected from a polluted location (Main Basin) and a relatively clean area (East Basin) in Lake Mariut, one of the Nile Delta Lakes in Egypt. Fifteen fish were taken from each site. Liver preparations of fish from the two sources were comparatively examined for cellular changes using transmission electron microscopy. Fish hepatocytes from the polluted area showed accumulation of the heterochromatin, enlarged nucleoli, and an extremely folded nuclear envelope. Perichromatin granules were increased and progressively formed small clusters closely associated with patches of heterochromatin. In the cytoplasm, fractionation, dilation, and vesiculation of rough endoplasmic reticulum (RER), and elevated amounts of smooth endoplasmic reticulum (SER) tubules were noted. The most frequent pathological modifications were the swelling of mitochondria, cristae regression and changes in the electron-transparency of the matrix. Lysosomes showing myelin-like stacks of membraneous material (phospholipidosis), glycogenosomes (i.e., glycogen rosettes enclosed by membranes) and cytoplasmic myelinated bodies were strongly developed. Furthermore, increasing numbers of secondary lysosomes with degraded cell organelles were found. With reference to the storage vesicles, there appeared to be an increase in the lipid droplets (lipidosis) within many hepatocytes. This study reinforces the need to select representative sentinel species from different habitats for biomonitoring purposes and it provides further support for the use of biomarkers in assessing the health of aquatic ecosystems.

Key words: Clarias gariepinus, Liver, Ultrastructure, Pollution, Lake Mariut

PDF of full length paper is available online

Copyright © 2010 Triveni Enterprises. All rights reserved. No part of the Journal can be reproduced in any form without prior permission. Responsibility regarding the authenticity of the data, and the acceptability of the conclusions enforced or derived, rest completely with the author(s).