Epidemiological studies of Isoparorchis hypselobagri (Digenea: Trematoda) infecting freshwater catfish Wallago attu in the Aligarh region of Uttar Pradesh.

ABSTRACT

Fisheries and aquaculture are crucial for ensuring food security and are significant sources of income and social advancement in developing nations. Parasitic infections among fish in natural and artificial culture systems are detrimental to their health and growth. Epidemiological studies are a prerequisite to understanding the dynamics of the disease in a fish population. In the present study, we have evaluated the prevalence and seasonal variation of the digenetic trematode parasite Isoparorchis hypselobagri infecting the catfish Wallago attu from the Aligarh region of Uttar Pradesh. To perform epidemiological studies, regular sampling of fish was carried out from March 2018 to February 2023. A total of 1110 fish were examined, of which 293 were infected with I. hypselobagri. The total number of parasites recovered from the fish host W. attu was 1297 and the prevalence and mean intensity were 26.39% and 4.42, respectively. The highest prevalence of infection, with a value of 34.94%, was observed during the winter season, while the summer season exhibited the lowest prevalence of 12.78%. The findings suggest that the prevalence of the parasite is highest during the late monsoon to early winter months and lowest during the summer to early monsoon months. This variation in prevalence may be attributed to environmental conditions, particularly temperature fluctuations. The necessity to assess parasite infection arises because parasitic infection or sickness in fish causes significant damage to the fishing industry, and as a consequence, livelihoods in poor or developing countries are affected.