Histopathological studies on gill of Cynoglossus bilineatus, in coastal areas of Hormozgan Province

Gills of fish in direct contact with the water environment and hence is vulnerable to aquatic pollutants. In this study, 20 adult fish, Cynoglossus bilineatus, were caught at two different sites in Hormozgan. Province, namely Bandar Kong and Bandar Abbas in summer and gill histology were studied. The histological changes in gills were detected microscopically. Histopathologial changes in gill were classified and histopathological alternation index (HAI) was calculated separately for each station. HAI value in Bandar Kong represents slight alteration. In contrast, we observed severe and irreversible changes in gill tissue in Bandar Abbas. Meanwhile, various histopathological abnormalities were observed in gills of fish specimens. In the gill filaments, cell proliferation, lamellar cell hyperplasia, lamellar fusion, lifting of the respiratory epithelium, and the presence of aneurysmal areas were observed. Because Bandar Abbas city is near to waterfront and oil refineries, effects of environmental stress factors such as environmental pollution are more intense. Gill tissue is sensitive to pollutants and so can be used as a biomarker for monitoring the environment. For this reason, the use of histopathological analysis of gill fish, particularly fish Demersal, in application to evaluating water quality can be used as a tool for more accurate evaluation of environmental quality in the region.