Morphology and molecular phylogeny of a new Myxidium species (Cnidaria: Myxosporea) infecting the farmed turtle Podocnemis expansa (Testudines: Podocnemididae) in the Brazilian Amazon.

Abstract

This study reports, for the first time, a myxosporan species of the genus Myxidium in a Neotropical turtle. Myxidium turturibus n. sp., was found in the gall bladder of Podocnemis expansa (Testudines: Podocnemididae) farmed in Brazilian Amazon. Numerous disporic pseudoplasmodia in different developmental stages, and mature spores were free in the bile. Mature myxospores were fusiform, slightly arcuate in valval view, measuring 13.6±0.4 (13.1-15.1) μm in length and 4.1±0.3 (3.4-4.6) μm in width. The two polar capsules were piriform, with 3.4±0.4 (2.5-4.0) μm in length and 2.4±0.4 (1.5-2.7) μm in width and had five to six polar filament turns. Phylogenetic analysis inferred by 18S rDNA shows the new species closely related with M. hardella and M. chelonarum, which are parasites of freshwater/terrestrials turtles from Oriental Region.