Two new species of Myxobolus (Cnidaria: Myxosporea) infecting freshwater fishes of Ranjit Sagar Wetland, Punjab, India.

Two novel myxosporeans have been identified during the present study namely, Myxobolus upmae sp. nov. infecting gills of Hypophthalmichthys nobilis and Myxobolus hardevi sp. nov. infecting gills of Labeo bata inhabiting Ranjit Sagar Wetland, Punjab (India). The identification was done on the basis of morphological and molecular attributes of the myxospores. Myxospores of both the species possessed distinct morphological and morphometric characteristics, hence, validated as new species. Prevalence of infection was found to be 31.25% and 24% in M. upmae and M. hardevi, respectively. The intensity of infection or the mean abundance was determined by the gill plasmodial index (GPI) and was found to be 3 in M. upmae (heavy infection) and 1 in M. hardevi (light infection). Histopathological analysis of both the myxosporeans showed necrosis, hypertrophy, lamellar fusion and the cavity of each plasmodium was filled with numerous fully mature myxospores. The phylogenetic analysis of M. upmae sp. nov. showed maximum homogeneity with M. catlae (KM029967) infecting gills of Catla catla from India followed by M. dujardini (DQ439804) infecting gills of Leuciscus cephalus from Hungary and M. alvarezae (FJ716096) infecting gills of Aspius aspius from Hungary. The phylogenetic tree obtained by Maximum-Likelihood showed the paraphyletic nature of M. upmae sp. nov. with other myxosporean species.