Aquatic fungi parasitic on temperate fishes of Kumaun Himalaya, India.

Eighty isolates of different species of aquatic fungi belonging to Achlya, Aphanomyces, Dictyuchus, Protoachlya, Saprolegnia, Thraustotheca and Pythium are observed as parasites of certain temperate fish of Kumaun Himalaya, India. The parasitic ability of each isolate was confirmed by artificial inoculation experiments under laboratory conditions. The genera of Saprolegnia and Achlya were more virulent fish parasites than Aphanomyces, Dictyuchus, Protoachlya, Thraustotheca and Pythium. All the fish species observed are new hosts for these pathogens. Protoachlya paradoxa, Achlya klebsiana, Thraustotheca clavata and Pythium undulatum are reported for the first time as natural pathogens of fish.