New species of Myxidiidae Th′elohan, 1892 (Myxosporea: Bivalvulida) found in characiform fish from the basin of Tocantins River in eastern Brazilian Amazonia

Coelozoic parasites of the family Myxidiidae were observed in fish of the order Characiformes captured in the middle Tocantins River, Maranha similar to o, Brazil, within the transition between the Cerrado savanna biome and the eastern extreme of the Brazilian Amazon Forest. The analysis of the morphological characteristics of the parasites, complemented with a Bayesian phylogenetic analysis, supported the description of new specie Myxidium imperatrizensis n. sp., found parasitising the gallbladder of specimens of the fish Triportheus angulatus. The study is also only the second report of the occurrence of Myxidium parasites in fish of the family Triportheidae in Brazilian rivers. The results of the present study expand the known distribution of the genera Myxidium the basin of the Tocantins River, the largest hydrographic basin located entirely within Brazil, which encompasses parts of both the Cerrado and Amazon biomes.

Automated summary

This study identified a new species, Myxidium imperatrizensis n. sp., parasitizing the gallbladder of Triportheus angulatus fish captured in the middle Tocantins River in Brazil. It is the second report of Myxidium parasites in fish of the family Triportheidae in Brazilian rivers. The findings expand the known distribution of the genus Myxidium in the Tocantins River basin, which covers parts of the Cerrado savanna biome and the Amazon Forest in Brazil.