Histomorphological alterations in organs of the plaicePleuronectes obscurus from a polluted part of Peter the Great Bay, Sea of Japan

This paper describes the results of a histological study of the internal organs of the plaicePleuronectes obscurus from a polluted part of Amurskii Bay, Sea of Japan. A variety of histomorphological alterations were found in the gills and liver, while the kidney and spleen were affected to a lesser degree. The most frequent lesions in gills were edemas of gill lamellae, epithelial detachments, fusions of the secondary lamellae, hypertrophies and hyperplasias of respiratory cells, pigment accumulations, the presence of parasites, increased quantities of mucous cells, lymphocyte infiltrations, and disturbances of blood circulation. Characteristic morphological changes in the liver were lipid and hydropic dystrophy, pigment accumulation, and the presence of regenerative and necrotic foci. Telangiectasia, globate filaments, and xenomas were found in the gills ofP. obscurus for the first time. These morphological alterations appear to be a result of the chronic effect of pollution in Amurskii Bay.