Gill lesions in Prespa barbel (Barbus prespensis) inhabiting a polluted area of Lake Prespa

Abstract

The study focused on gill lesions observed in Prespa barbel individuals caught on the north littoral site of Lake Prespa in the area of the Golema River confluence, which is under agricultural, industrial and urban pollution pressure. Microscopic analysis revealed a series of circulatory, regressive, progressive and, to a less extent, inflammatory changes of which the most prominent were: telangiectasia, necrosis of respiratory epithelium accompanied by collapsed secondary lamellae, necrosis and proliferation of interlamellar and lamellar respiratory epithelium, and parasite infection. These results indicate that the reiterated gill lesions were probably due to the double influence of the toxic effects of a polluted aquatic environment and opportunistic infections, which indicates that the application of mitigating measures is urgently needed in order to protect the Prespa Lake ecosystems.