PCR Based Identification of Saprolegnia parasitica Affecting Rainbow Trout Aquaculture in Kashmir Region of Indian Himalayas

Saprolegnia parasitica infecting Rainbow trout (Oncorhynchus mykiss), has been a major bottleneck in the intensification and propagation of trout culture in northern Himalayas of India. Present study was to ascertain the presence of S. parasitica infections using molecular diagnostic techniques in cultured rainbow trouts collected from different hatcheries of Kashmir valley. Growth of S. parasitica at different incubation temperatures was examined. The molecular detection of fungus done by using PCR, revealed that the twenty trout specimens out of 144 collected samples were found infected with Saprolegnia parasitica with overall prevalence of 13.88%, with a PCR product size of around 750 bp. No growth of S. parasitica was reported at 4°C after 48 h of incubation. S. parasitica infections were more frequent in cold water months when water temperature was recorded between 7°C – 9°C.