A Scanning Electron Microscopic Study on Distortion in the Scale of Common Carp, Cyprinus carpio Inhabiting a Polluted Lake (Umiam) in North East India

摘要

Scanning electron microscopy of the scale of Cyprinus carpio inhabiting a polluted lake Umiam located in Meghalaya, a North East Indian state revealed a number of abnormalities in the lepidonts, the teeth like projections at the edge of circulii which are meant for attachment of scales with the skin. Hence, their abnormalities such as dislocation, distortion, tearing, and complete removal can make the attachment between scale and underlying skin weak. This can make the scales sloughed off from the skin, thereby causing the later devoid of the protective covering of scales. Distortion and removal of scales may expose the skin to toxic chemicals and a number of pathogens, which can adversely affect the general health and physiology of the fish. Besides these, distinct lesions were observed on the scale surface between the adjacent circulii. The structural abnormalities of the lepidonts and the circulii of scale in Cyprinus carpio in relation to contamination of the lake by city garbage, municipal wastes and other pollutants are discussed with the help of relevant literature.