Morphological and Molecular description of a new species, Trichodina cirhinii sp. nov. (Ciliophora: Tichodinidae), infesting native freshwater fish Cirrhinus mrigala

Trichodina is a genus of common protozoan parasites mostly known as ectoparasites (i.e. infecting skin, fin and gills) in wild and cultured fishes. The present study describes a new species of the genus Trichodina found on the gills of Indian major carp, Cirrhinus mrigala . Trichodina cirhinii were isolated and smears of the gills were air dried at room temperature and impregnated with silver nitrate. Morphometric data and comparative descriptions of these trichodinids are provided along with details of their prevalence of infestation. The new species was compared with other similar congeneric species reported from the same and other hosts. Furthermore, partial 18S rRNA gene sequences of the Trichodina cirhinii was acquired and used for the construction of phylogenetic trees. The present findings through morphological and molecular study suggest that the genus Trichodina cirhinii is a new species.