Histopathological study and heavy metal lead and chromium bioaccumulation in gills and liver of tigertooth croaker (Otolithes ruber) in the Gulf of Oman

The aim of this study was investigated the accumulation of lead and chromium in liver and gills of tigertooth croaker (Otolithes ruber) and use of histopathological changes of gills and liver to evaluate the effects of Oman Sea pollutants. Tigertooth croakers with an average weight of 382.5±1.93g were collected from four stations include: Konarak desalination, Beris, Pasabandar and Gowatr and samples of liver and gill tissues were studied based on the routine histological methods. Chromium and lead concentrations in liver and gill tissues were measured by atomic absorption spectrophotometer. Most of the observed changes in liver tissue were destruction, vacuolation of hepatocytes, expansion of disk space, recession bile, hyperemia and hemorrhage, melanomacrophage centers, fat accumulation, pyknosis and necrosis. Also, in the gills, lifting epithelium, clubbing, hyperplasia and hypertrophy of chloride cells, mucus secretion, shorter blade and necrosis were recorded. The results showed that the Pasabandar station had the highest severity of tissue lesions and the highest bioaccumulation of metals in liver and gill tissues. Histopathological lesions of the tissue in tigertooth croaker can be considered as a bioindicator of the negative effects of contamination in the studied area.