Navegando por Autor "Viana, Lúcio André"

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Artigo
Eimeria spp. (Apicomplexa: Eimeriidae) in black caiman Melanosuchus niger (Crocodilia: Alligatoridae) from the Amazon Region, Brazil, with a description of two new coccidian species.
(2014-01-29) Viana, Lúcio André; Motta, Adarene Guimarães da Silva; Coutinho, Marcos Eduardo; Rocha, Carlos Frederico Duarte
During November 2011, faeces from 23 black caimans (Melanosuchus niger) were collected from the Brazilian Amazon, and coccidians were found in 83% of the individuals examined. Three Eimeria species were found in the black caiman faeces, two of which were recognised as new species and are subsequently described in the present study. Eimeria paraguayensis was found in 17 of 23 animals sampled. Eimeria nigeri n. sp were found in 16/23 animals examined. Oocysts were spherical to sub-spherical, 29.2 × 28.1 (23–32 × 23–30) μm, and 12.1 × 11.0 μm spherical oocyst residuum was present. Sporocyst was ovoid, 15.5 × 9.7 (8–11 × 12–17) μm, and had a Stieda body at a slightly pointed end. The sporocyst residuum consisted of a compact mass of refractile granules. Eimeria portovelhensis n. sp. were found in 16/23 animals examined. Oocysts were spheroidal, 19.5 × 19.1 (16–21) μm, and had 9.0 × 7.8 μm spherical oocyst residuum present. The spindle-shaped sporocysts were 11.0 × 4.0 (8–13 × 2–5) μm and had two apparent Stieda bodies, one at each pole and with one filament curved at each pole. Sporocyst residuum was present, with four or five small refractile granules. The two new species are differentiated from the five species of Eimeria recorded within the crocodilian family Alligatoridae.
Artigo
Phylogenetic analysis of chelonian hemogregarines reveals shared species among the Amazonian freshwater turtle Podocnemis spp. and provides a description of two new species of Haemogregarina.
(Parasitology Research, 2022-01-21) Correa, Jamille Karina Coelho; Picelli, Amanda Maria; da Silva, Maria Regina Lucas; Valadão, Rafael Martins; Hernández-Ruz, Emil José; Viana, Lúcio André
This study describes two new species of the genus Haemogregarina living in the Amazonian freshwater turtles Podocnemis expansa and Podocnemis sextuberculata. Haemogregarina species isolated from P. expansa have been characterized by the presence of encapsulated, folded immature gamonts, with the parasitophorous vacuole and fragmented chromatin located in the central region. In Haemogregarina found in P. sextuberculata, curved immature gamonts were observed inside a parasitophorous vacuole, with small, slightly arched meronts with rounded nuclei, and mature gamonts with trapezoid-shaped condensed nuclei. The novel 18S rRNA sequences obtained in this study clustered within a well-supported clade composed of hemogregarines isolated from other neotropical freshwater turtles from the families Podocnemididae and Geoemydidae. The hemogregarines found in this study were compared to Haemogregarina podocnemis from Podocnemis unifilis and Haemogregarina sp. from Podocnemis expansa, based on morphological, morphometric, and molecular data. The analysis supports the new species Haemogregarina karaja sp. nov. isolated from P. expansa and Haemogregarina embaubali sp. nov. found in P. sextuberculata.