Morphological features and molecular phylogeny of Hoferellus azevedoi n. sp. (Myxozoa: Myxobilatidae) found in Chaetobranchus flavescens Heckel, 1840 (Teleostei: Cichlidae) from Marajó Island, northern Brazil.

ABSTRACT

Hoferellus azevedoi n. sp. was found in the urinary bladder of Chaetobranchus flavescens Heckel, 1840 from the Arari River on Marajó Island in Pará, Brazil. This is the first record of a species of the genus Hoferellus in a host from the Brazilian Amazon region. The new species has disporous and polysporous plasmodia, which vary in size and shape, with some being found adhered to the epithelium of the urinary bladder, and others floating in the liquid. The mature spores are sub-spherical in the sutural view, with a number of peripheral projections around the whole surface of the spore. In the sutural view, the spores are 5.3 ± 0.2 (5.2-5.6) µm in length and 7.0 ± 0.7 (6.3-7.7) µm in width, with two piriform polar capsules of equal size, 2.5 ± 0.2 (2.3-2.8) µm long and 1.8 ± 0.2 (1.6-2.0) µm wide. Based on a partial (1312 bps) sequence of the SSU rDNA gene, Hoferellus azevedoi n. sp. was distinguished from all the other myxozoan species deposited in GenBank. Phylogenetically, based on Bayesian inference and p-distances, the new species was allocated to the "Freshwater Urinary-Bladder" clade, together with other myxozoan parasites of the excretory system. Based on the morphological data, supported by the partial sequence of the SSU rDNA gene, we describe a new species of myxozoan, Hoferellus azevedoi n. sp.