Histopathological study of parasitic effect of Dactylogyrus vastator (Nybelin, 1924) on the Catla catla in culture ponds in Darbhanga

The current investigation was undertaken to study the gill histopathologies due infestation of helminth parasite, monogenetic trematode, Dactylogyrus vastator (Nybelin, 1924) in Indian major carp, Catla catla. There were only symptomatic samples diseased fishes comprised fingerlings and adults catla collected examined. Behaviour respond studied- partial suffocation, lethargic swimming clinical sign observed as their gills very pale colour had haemorrhagic inflamed areas at sites parasite attachments. significant histopathological lesions changes seen where parasites found attached lamellar tissues causing local erosions epithelium hyperplasia secondary fusion adjacent lamellae, vascular congestion leading aneurysm besides, clumbing tips congested showed accumulation blood swelling hypertrophy autolysis lamellae severe edema necrosis C. No noticed other organs affected fishes. In infestations growth retardation. analysis for fish will be useful tool health management.