Molecular and morphological description of Myxidium parvum (Cnidaria) from Salaria pavo (Blenniidae) in the Black Sea.

Members of the predominantly coelozioc genus Myxidum Bütschli, 1882 with more than 232 species have been reported from a wide variety of marine and freshwater fish species worldwide. In this study, 25 specimens of peacock blenny, Salaria pavo, were collected from Sinop on the Turkish Black Sea coast. The gills, fins, skin, urinary bladder, gal bladder, kidney, liver, gonads and smooth muscle tissue of the collected samples were investigated for myxosporean parasites. Myxidium parvum Yurakhno, 1991 was the only myxosporean found in the gall bladder of host fishes. Based on spore morphology, M. parvum had mostly overlapping measurement data of original description in spore length and width, polar capsule length but differed slightly in width; however, they were within the ranges previously reported from other blenniid host fish species in the Black Sea. Moreover, in this study, molecular analysis of the 18S rDNA gene of M. parvum isolates from S. pavo was done for the first time and our M. parvum genotypes appeared as sister to Myxidium incurvatum within the "Lineage II" of the marine Myxidium clade.