New freshwater Ceratomyxa species, Ceratomyxa affinis n. sp. (Myxozoa: Ceratomyxidae) in the gallbladder of Leporinus affinis from Brazilian Amazon.

The genus Ceratomyxa is composed of approximately 300 described species, most of which are found parasitizing hosts in marine aquatic environments. The present study, through phylogenetic, molecular and morphological analyses, described a new species of Ceratomyxa found parasitizing Leporinus affinis specimens from the Tartarugalzinho River, in municipality of Tartarugalzinho, state of Amapá, Brazil. The new species was found parasitizing the urinary bladder of L. affinis. The myxospores of Ceratomyxa affinis n. sp. are 7.2 µm long and 43.2 µm thick with a posterior angle of 170º. The polar capsules measure 3.9 µm long and 4.05 µm wide. Based on morpho-molecular analyses, it was possible to prove that Ceratomyxa affinis n. sp. is a new species, contributing to the knowledge of the parasitic fauna of fish in the Amazon region.