Myxobolus freitasi n. sp. (Myxozoa: Bivalvulida), a parasite of the brain of the electric knifefish in the Brazilian Amazon region

• Autor(a) principal: Sindeaux-Neto,José Ledamir
• Data de Publicação: 2021
• Outros Autores: Velasco,Michele, Silva,Diehgo Tuloza da, Matos,Patrícia, Silva,Marcelo Francisco da, Gonçalves,Evonnildo Costa, Matos,Edilson
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Brasileira de Parasitologia Veterinária (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1984-29612021000100307
• topic: Cnidaria; Myxozoa; molecular biology; histology

Abstract A total of 30 specimens of the Amazonian electric knifefish, Brachyhypopomus beebei Schultz, 1944 (Gymnotiformes: Hypopomidae), were collected from the Peixe-Boi River in the state of Pará, Brazil (1°06’59” S; 47°18’26” W). Fragments of the brain tissue were extracted for analysis via optical microscopy, and 18 specimens (60%) presented microparasites of the genus Myxobolus, with unequal capsules. The spores were 18.6 µm (17.7-19.8 µm) long and 8.6 µm (8.4-9.0 µm) wide; the largest polar capsule was 13.0 µm (12.4-13.4 µm) long and 5.6 µm (5.3-6.0 µm) wide, and the smallest capsule was 5.0 µm (4.5-5.3 µm) long and 2.5 µm (2.3-2.6 µm) wide. Infected brain fragments were extracted for histological processing and staining with hematoxylin-eosin and Ziehl-Neelsen. Some fragments were conserved in ethanol for molecular genetics analysis. A partial sequence of the 18S DNA gene was obtained from the spores, which did not correspond to any other sequences deposited in GenBank, although it did form a clade with other Myxobolus parasites of the nervous system. The morphological data, together with molecular phylogeny, supported the designation of a new species Myxobolus freitasi n. sp.