Light and Ultrastructural Description of Meglitschia mylei n. sp. (Myxozoa) from Myleus rubripinnis (Teleostei: Serrasalmidae) in the Amazon River System

Abstract

Meglitschia mylei n. sp. found in the gall bladder of the teleostean fish Myleus rubripinnis (Serrasalmidae) from the middle Amazonian region of Brazil is described using light and transmission electron microscopy. The spores observed in the bile averaged 24.6±0.8 μm long, 8.7±0.4 μm wide and 5.1±0.3 μm thick and were strongly furcate and arcuate ∩-shaped composed of two symmetric equal-sized valves, up to ∼70 nm thick. Each valve possessed one opposed tapering appendage, 20.1±0.7 μm long, oriented parallel towards the basal tip of the appendages and joined along a right suture line forming a thick strand. The strand goes around the central part of the spore, which in turn surrounds two equal and symmetric spherical polar capsules (PC), 2.1±0.3 μm in diameter, located at the same level. Each capsule contains a polar filament with five (rarely six) coils. The binucleate sporoplasm was irregular in shape, contained several sporoplasmosomes, ∼175 nm in diameter and filled all the space of the two caudal appendages. Based on the arc shape of the spore with two tapering caudal appendages oriented to the basis of spores, on the number and position of the PC and of the polar filament coils and arrangements, and on the host specificity, we propose the name M. mylei n. sp. for this new myxozoan. Accordingly, this is the second described species of this genus.

Meglitschia spp. (Myxozoa) Infecting the Gallbladder of Eugerres Brasilianus (Teleostei: Gerreidae) from the Atlantic Coast of Maceió (Brazil)

“…The morphological and ultrastructural aspects of the myxospores showing a furcate and arcuate ∩-shaped organization show that these myxospores are similar with those previously described belonging to the genus Meglitschia [1][2][3][4]. Based on the arc shape of the myxospore with two tapering caudal appendages oriented to the basis of spores, on the number and position of the PC and of the polar filament coils (PFc) and arrangements, the morphology of the myxospores suggested that this parasite belongs to genus Meglitschia.…”

“…The observation in aquarium of the living fish does not present altered behavior. The typical morphology of the myxospores suggests that the present microparasite belongs to the genus Meglitschia, according the previous descriptions [1][2][3][4].…”

“…Among these parasites the monotypic genus Meglitschia Kovaleva, 1988 has been reported infecting the gallbladder (Gb) of a marine fish from the New Zealand fauna [1,2] and a freshwater fish from Brazil, collected in a tributary of Amazon River [3]. The teleostean host (Eugerres brasilianus) a commercially important fish of the family Gerreidae, common in the NE Atlantic coast of Brazil, was infected Gallbladder by myxospores of the genus Meglitschia.…”

“…This genus is a small taxonomic group within the class Myxosporea that contains only two named species, M. insolita [1] (formerly described as Ceratomyxa sp.) [2] from New Zealand and M. mylei [3] from Brazil. These two species were described on the base of a schematic drawing [1] and based in light and transmission electron microscopies [3].…”

“…[2] from New Zealand and M. mylei [3] from Brazil. These two species were described on the base of a schematic drawing [1] and based in light and transmission electron microscopies [3]. The present study provides light and ultrastructural for the description of Meglitschia sp., a myxosporean parasite infecting the Gallbladder of a marine fish on the Brazilian northern Atlantic coast.…”