Lernaea susceptibility, infestation and its treatment in indigenous major and exotic Chinese carps under polyculture system.

Present study was aimed to find out the Lernaea susceptibility, infestation and its treatment in indigenous major and exotic Chinese carps under polyculture system. 450 fishes were reared in the 0.5 acre ponds at Fish Pond Complex, Department of Fisheries and Aquaculture, University of Veterinary and Animal Sciences, Ravi Campus Pattoki and parasitic load was checked for the month of June, July and August. Five specimens of each species were caught on fortnightly basis and examined for the presence of Lernaea cyprinacea species on different body parts. The parasites were removed, preserved in 5% formalin and identified. Intensity of Lernaea was highest in the Catla catla followed by Hypophthalmichthys molitrix and Ctenopharyngodon idella in the month of June. Highest number of Lernaea (100) were counted in Catla catla and lowest in the Labeo rohita and Cirrhinus mrigala after the Cyprinus carpio which did not showed any parasite and behave as most resistant species among the Chinese and Indian major carps. Treatment with Thunder however, reduce the parasitic infection to a large extend and at the end of experiment all fishes were became free of parasite. Abdomen was the most prevalent site for the parasite attachment followed by the gills and caudal fins whereas head was the least.