Morphology and 18S rDNA sequencing identifies Henneguya visibilis n. sp., a parasite of Leporinus obtusidens from Mogi Gua double dagger u River, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)During a survey of myxozoan parasites of freshwater fish from the Mogi Gua double dagger u River in So Paulo State, Brazil, plasmodia of Henneguya visibilis n. sp. were found on the fins of Leporinus obtusidens (Characiformes: Anostomidae). The plasmodia, which were observed on five out of eight (62.5 %) L. obtusidens examined, were 400-1,000 mu m long. Mature spores were elongated with a spore body 10.8 +/- 0.6 mu m long and 3.9 +/- 0.2 mu m wide, a caudal process 18 +/- 1.2 mu m long, and a total spore length of 26.8 +/- 1.1 mu m. Polar capsules were elongated 4.9 +/- 0.3 mu m long and 1.4 +/- 0.1 mu m wide. Histological examination indicated that the plasmodia developed in the connective tissue, and no inflammatory infiltrate was observed at the infection site. Ultrastructural analysis showed a plasmodium wall with a single membrane and several pinocytotic canals. Sporogenesis occurred from the periphery to the center of the plasmodia. Phylogenetic analysis of the 18S rDNA sequence using maximum likelihood and maximum parsimony methods showed H. visibilis n. sp. positioned in a sub-clade composed of Henneguya/Myxobolus parasites of several freshwater fish families.11318190Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [477658/2010-5

The morphological and molecular characterization of Henneguya rotunda n. sp., a parasite of the gill arch and fins of Salminus brasiliensis from the Mogi Guacu River, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A new species of myxosporea (Henneguya rotunda n. sp.) was found in the membrane of the gill arch and the fins of Salminus brasiliensis in the Mogi Gua double dagger u River, municipality of Pirassununga, So Paulo state, Brazil. Morphological and morphometric analyses using light microscopy revealed parasites with similar characteristics at both infection sites. The mature spores found infecting the fins had oval spore body with 7.1 +/- 0.2 mu m in length, 5.6 +/- 0.2 mu m in width, 3.7 +/- 0.1 mu m in thickness, 16.4 +/- 1.2 mu m in length of the caudal process, and 23.6 +/- 1.1 mu m in total length of the spore. In a frontal view, the polar capsule was observed to be symmetrical with 3.4 +/- 0.2 mu m in length and 1.8 +/- 0.1 mu m in width. Mature spores contain six to seven turns of the polar filaments. The morphometric data concerning the spores obtained from plasmodia from the membrane of the gill arch were similar to those from the fins. Ultrastructure analysis revealed that the plasmodial wall was formed by a single membrane and had numerous pinocytotic canals connecting the outside of the plasmodia to the ectoplasm zone. Beyond that, various electron-translucent vesicles also were observed at the periphery of the plasmodium. The molecular analyses of the 18S rDNA gene from the spores obtained from the gill arch membrane and fin membrane showed that these sequences shared 100 % similarity. Phylogenetic studies using maximum parsimony and maximum likelihood methods demonstrated the polyphyletic clustering of the myxosporean parasites of characiform fishes. H. rotunda n. sp. clustered as a sister species of Myxobolus pantanalis, also a parasite of S. brasiliensis.113517031711Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [477658/2010-5