Histology of gills of Labeo rohita infected by crustacean parasite Argulus sps.

The present study was conducted on the gills of L. rohita of river Tawi parasitised by a crustacean parasite Argulus to reveal the histopathological characteristics of the gills of these fresh water carps. Histopathology provides a rapid method to detect effects of pathogens on different tissues and it can be considered as an indicator of the extent of deteoration of fish environment. In Indian major carps argulosis disease is caused by the crustacean parasite.The parasites are leaf like in appearance and were found to attatch with skin, fins and gills of the fishes. The affected sites were haemorrhagic, ulcerated and mucus studded. The histopathological changes in the skin of affected fish exhibited hypertrophy, telangiectasis, aneurism and fusion of lamellae along with the shortening and degeneration of gill lamellae accompanied by edematic or haemorrhagic spots. The histopathological observations due to the presence of pathogens in fish also play a vital role in disease control and health management in aquaculture.