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Ultrastructure of Myxobolus brycon n. sp. (Phylum Myxozoa), Parasite of the Piraputanga Fish Brycon hilarii (Teleostei) from Pantanal (Brazil)
Author(s) -
AZEVEDO CARLOS,
CASAL GRAÇA,
MARQUES DÉBORA,
SILVA EDINAEL,
MATOS EDILSON
Publication year - 2011
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.2010.00525.x
Subject(s) - polar filament , biology , myxozoa , ultrastructure , myxobolus , parasite hosting , teleostei , anatomy , spore , characidae , protein filament , operculum (bryozoa) , cyprinidae , myxosporea , gill , zoology , microsporidia , fish <actinopterygii> , fishery , paleontology , genetics , world wide web , computer science , genus
. Light and electron microscopy studies of a myxosporean, parasitizing the gill filaments of the freshwater fish Brycon hilarii (Valenciennes, 1850) (Characidae) collected in the Paraguay River (18°49′S, 57°39′W) (Pantanal), Brazil, is described. This parasite produces spherical to ellipsoidal polysporic histozoic plasmodia (Pmd) (up to ∼180 μm in diameter) delimited by a double membrane and with several pinocytic channels. The plasmodial cyst contained the youngest developmental stages at the cortical periphery and immature and mature spores more internally. The Pmd developed near the cartilaginous structure of the gill filament, forming a prominent deformation where the gill lamellae disappear. Pyriform spores measured 6.9±0.6 (range 6.5–7.2) μm long, 4.2±0.5 (range 3.9–4.8) μm wide, and 2.5±0.7 (range 1.9–2.8) μm thick. The spores composed of two equal shell valves (∼70 nm thick), adhering together along the straight suture line, surrounded two equal symmetric and elongated to pyriform polar capsules (PC) 4.2±0.6 (range 3.8–4.7) × 1.9±0.6 (1.7–2.5) μm; each PC contained a coiled polar filament with eight or nine (rarely 10) turns and a binucleated sporoplasm cell. Dense irregular masses were observed among the polar filaments coils. An intercapsular appendix was not observed. The sporoplasm contained several globular sporoplasmosomes randomly distributed among an extensive rough endoplasmic reticulum system with numerous vesicles and cisternae. Based on the morphological and ultrastructural differences and specificity of the host, we establish the new species, Myxobolus brycon n. sp.