PREVALENCE AND IDENTIFICATION OF LERNAEA CYPRINACEA INFESTING MAJOR CARPS (LABEO ROHITA, CATLA CATLA, AND CIRRHINUS MRIGALA) OF THE RIVER INDUS DERA ISMAIL KHAN

Background: Fish play a critical role in human nutrition, offering high-quality protein, essential fatty acids, and micronutrients. In South Asia, freshwater fish such as Labeo rohita, Catla catla, and Cirrhinus mrigala are extensively cultured and consumed. However, the aquaculture industry faces significant challenges due to parasitic infestations, particularly by ectoparasites like Lernaea cyprinacea (anchor worm), which adversely affect fish health, growth, and survivability. Aim: This study investigates the prevalence, intensity, and morphological identification of Lernaea cyprinacea infesting major carps (Labeo rohita, Catla catla, and Cirrhinus mrigala) collected from the Indus River Dera Ismail Khan (D.I. Khan). Material and Methods: A total of 119 fish were sampled from river sites over a five-month period. Specimens underwent ectoparasite isolation using scale and gill washes, 54 μm filtration, centrifugation at 6000 rpm for 10 minutes, Giemsa staining, and microscopic examination at 10X magnification. Findings: A marked seasonal rise was noted, from 7.53% in December to 47.61% in April. Species-specific ratios were L. rohita 18.36% (9/49), C. catla 20.00% (7/35), and C. mrigala 14.28% (5/35). C. catla and C. mrigala shows the greatest increase (reaching 50% in April), followed by L. rohita (42.85%). Conclusion: The study demonstrates a significant seasonal increase in Lernaea cyprinacea infestation among major carps from the Indus River, with peak prevalence in April. Catla catla exhibited the highest overall infection rate, followed by Labeo rohita and Cirrhinus mrigala. These findings highlight the need for timely monitoring and management strategies to mitigate parasitic outbreaks and safeguard aquaculture productivity.