Ishtiyaq Ahmad and Harpreet Kaur*
During the present study, two myxosporean species, M. potularis Madhavan et al. (2013) and M. rocatlae Basu and Haldar (2002) have been described from the gills of Labeo rohita Hamilton vern. rohu and Cirrhinus mrigala Hamilton vern. mrigal at nursery ponds located in village Fagan majra, District Fategarh Sahib, Punjab, India. Earlier, both the species M. potularis and M. rocatlae were described from West Bengal. 30 speciemens of Labeo rohita and 40 specimens of Cirrhinus mrigala were examined. Out of which 23 and 21 fishes were infected respectively. The prevalence rate was more in M. potularis (76.66%) than M. rocatlae (52.5%). At the time of collection various physico-chemical parameters like temperature, pH, TDS, DO etc. were also recorded. The histological effects of the pathogen were observed by light microscopy. The plasmodia of M. potularis were located in the afferent artery of the gill filament and plasmodia of M. rocatlae were located in the fine blood capillaries at the tip of the gill lamellae. M. potularis was highly pathogenic than M. rocatlae. The plasmodia of M. potularis were typed in “D” category caused complete destruction of all the cellular elements of gills and caused inflammation and abscesses. When present in large number and regarded as highly pathogenic parasite infects fingerlings in aquaculture. The gill plasmodial index (GPI) was 4 for M. potularis n. sp. indicated severe infection and 1 for M. rocatlae indicated light infection.
