A report on two new myxozoan parasites infecting gills of fingerlings of Indian major carps cultured in nursery ponds in Punjab (India).

This paper presents the morphological characteristics of two new species belonging to the genus Myxobolus viz M. knobii n. sp. and M. majraiensis n. sp., parasites infecting gill lamellae and gill filaments of fingerlings of Cirrhinus mrigala (Ham.) and Catla catla (Ham.) respectively collected from nursery ponds located in the village Fagan Majra, District Fatehgarh Sahib, Punjab (India). A total of 90 fingerlings were examined (40 Catla catla and 50 Cirrhinus mrigala). Out of which, 32 C. mrigala and 19 C. catla fishes were found infected. The total prevalence rate was recorded as 56.66%. The age of the fish was recorded as 2-3 months and length of the fish ranged 4-4.5 cm. The plasmodia of M. knobii n. sp. were round to irregular, 0.6-1.0 mm in diameter. Myxospores oval to spherical, pot-shaped in frontal view with a prominent knob at anterior end, measured 5.83 × 4.29 µm in size. Polar capsules were equal, broadly pyriform, 1.95 × 1.70 µm in size having 3-4 polar filament coils. The plasmodia of M. majraiensis n. sp. were round to oval, 0.8-1.5 µm in diameter. Myxospores egg-shaped in frontal view also having prominent knob at the anterior end, measured 8.58 × 5.2 µm in size. Polar capsules were equal, pyriform, 3.47 × 1.80 µm in size having 5-6 polar filament coils. Gill plasmodium index showed heavy infection in both of the species. This is the first report of myxobolid infection in the fingerlings of Indian major carps in nursery ponds in Punjab (India).