Host-parasite and phylogenetic relationships of Myxobolus filamentum sp. n. (Myxozoa: Myxosporea), a parasite of Brycon orthotaenia (Characiformes: Bryconidae) in Brazil

Abstract

Myxobolus filamentum sp. n. was found infecting gill filaments of three of 39 Brycon orthotaenia Günther specimens examined (8%), which were taken from the river São Francisco in Minas Gerais state, Brazil. Plasmodia of the parasite were white and long, measuring 5 mm in lenght. Mature spores of M. filamentum sp. n. were oval from the frontal view and biconvex from the lateral view, measuring 7.5-9.7 µm (9.0 ± 0.3 µm) in length and 5.2-7.3 µm (6.2 ± 0.4 µm) in width. The polar capsules were elongated and equal in size, measuring 3.8-5.5 µm (4.7 ± 0.3 µm) in length and 1.3-2.2 µm (1.7 ± 0.1 µm) in width. The development of the parasite led to compression of the adjacent tissues and inflammatory infiltrate with granulocytic cells. Ultrastructural observation revealed that the plasmodia were delimited by two membranes, which had numerous and extensive pinocytotic channels extending into the wide ectoplasm zone. The plasmodial wall exhibited abundant villi-like projections and a thin layer of granular material prevented direct contact between the plasmodial wall and the host tissue. Phylogenetic analysis, based on 18S rDNA, showed M. filamentum sp. n. as a sister species of Myxobolus oliveirai Milanin, Eiras, Arana, Maia, Alves, Silva, Carriero, Ceccarelli et Adriano, 2010, a parasite of other fish species of the genus Brycon Müller et Troschel from South America.

Phylogeny and comprehensive revision of mugiliform-infecting myxobolids (Myxozoa, Myxobolidae), with the morphological and molecular redescription of the cryptic speciesMyxobolus exiguus

“…This feature has been reported for few other histozoic species, e.g. M. insignis (Azevedo et al ., 2013) and M. filamentum (Naldoni et al ., 2015), since the differentiation of peripheral projections is common to the plasmodial development of coelozoic species (Sitjà-Bobadilla and Alvarez-Pellitero, 1993; 2001; Rocha et al ., 2011). Overall, the ultrastructural study performed revealed significant unique features of the plasmodial development of M. exiguus , namely in its attachment to the mesothelial cells.…”

Morphology, ultrastructure and phylogeny of Myxobolus curimatae n. sp. (Myxozoa: Myxosporea) a parasite of Prochilodus costatus (Teleostei: Prochilodontidae) from the São Francisco River, Brazil

“…parasites of other species of South America fishes [3,26,27] The comparison of M. curimatae n. sp. with Myxobolus spp.…”

New morphological data and molecular diagnostic of Henneguya friderici (Myxozoa: Myxobolidae), a parasite of Leporinus friderici (Osteichthyes: Anostomidae) from southeastern Brazil

“…Bayesian posterior probability were determined running the Markov chains (two runs and four chains) for 4 × 10 6 generations, discarding the initial 1/4 of sampled trees (trees sample every 4 × 10 3 generations) as burn in fraction. Phylogenetic trees were rooted using Ceratonova shasta (Noble, 1950) as outgroup based upon previous Myxobolidae phylogenies ( ADRIANO et al, 2009;CAPODIFOGLIO et al, 2015;NALDONI et al, 2015).…”