Detection and Prevalence of Capillaria Pterophylli, an Endoparasitic Nematode, in Labeo Rohita (Rohu), Cyprinus Carpio (Common Carp), and Oreochromis Niloticus (Nile Tilapia) From the River Indus, Dera Ismail Khan

Fish are solely aquatic and cold-blooded vertebrates having a streamlined body with lateral line sense organs. Keeping in view the importance of fish endoparasites, the present study was designed to assess the prevalence of endoparasites Capillaria pterophylli in freshwater fishes of the Indus River at D.I. Khan. Capillaria pterophylli are smooth, cylindrical, large, relatively long roundworms that appear rather frequently in the gut of fish. The samples of fish were collected from December 2023 to April 2024 from the Indus River. In total, 360 fishes were examined for parasites, of which 23 fishes (6.3 % of the total sample) were infected with parasites. Among the fish species, Oreochromis niloticus showed the maximum prevalence of infection, with 7.5%, and Cyprinus carpio with 6.6%. Labeor rohita showed a minimum prevalence of 5%. Among all fishes, the infection of nematode was highest with a percentage of 6.3%. It is found that freshwater fish are highly diverse in terms of endoparasites. In this context, prevention is always the best option for the nematode that infects the gastrointestinal tracts of fish. Since the use of fish as a ready source of food is increasing, the overall health status of fish in any system is becoming more valuable.