Unit for Environmental Sciences and Management, African Amphibian Conservation Research Group, North-West University, Potchefstroom, 2531, South Africa.
South African Institute for Aquatic Biodiversity, Makhanda, Grahamstown, 6140, South Africa.
Acta Parasitol. 2021 Sep;66(3):954-961. doi: 10.1007/s11686-021-00352-0. Epub 2021 Mar 16.
The nematode Spiroxys ankarafantsika was described parasitising freshwater turtles Pelusios castanoides and Pelomedusa subrufra from Madagascar. During parasitological surveys at different localities in Mozambique and South Africa the species was recovered from the digestive tract of Pelusios sinuatus, P. subniger and P. castanoides.
The species were identified based on the morphology of the anterior extremity (absence of additional teeth on pseudolabia) and the male caudal end (number and arrangement of caudal papillae, size and shape of spicules). Molecular data included a 720 bp sequence fragment of 18S rDNA, the entire internal transcribed spacer 1 (ITS1), 5.8S rRNA, and internal transcribed spacer 2 (ITS), flanked by a 288 bp 18S rDNA sequence and about 1000 bp 28S rDNA sequence, and the mitochondrial cytochrome c oxidase subunit I (cox1) gene marker obtained in the present study.
All specimen recovered were identical, based on morphological and molecular data, with the exception of two specimens showing an intraspecific divergence of 9% based on a 694 bp sequence fragment of the cox1 gene. Additionally, a Contracaecum sp. third stage larva and an unidentified larva with mushroom-shaped anterior extremity were found. Descriptions of S. ankarafantsika and the two above-mentioned larval stages, supported by photomicrographs and molecular data 18S rDNA, ITS1-5.8S-ITS2-28S and cox1 gene fragments are presented herein.
寄生在马达加斯加淡水龟 Pelusios castanoides 和 Pelomedusa subrufra 体内的线虫 Spiroxys ankarafantsika 被描述。在莫桑比克和南非不同地点进行寄生虫学调查时,该物种从 Pelusios sinuatus、P. subniger 和 P. castanoides 的消化道中被回收。
该物种的鉴定基于前体极端的形态(伪唇上无额外牙齿)和雄性尾部末端(尾部乳头的数量和排列、刺的大小和形状)。分子数据包括 18S rDNA 的 720bp 片段、完整的内部转录间隔区 1(ITS1)、5.8S rRNA 和内部转录间隔区 2(ITS),侧翼为 288bp 的 18S rDNA 序列和约 1000bp 的 28S rDNA 序列,以及本研究中获得的线粒体细胞色素 c 氧化酶亚基 I(cox1)基因标记。
所有回收的标本在形态和分子数据上都是相同的,除了两个标本在cox1 基因的 694bp 序列片段上显示出 9%的种内差异。此外,还发现了一条 Contracaecum sp. 第三期幼虫和一条以前端呈蘑菇状为特征的未识别幼虫。本文提供了 S. ankarafantsika 以及上述两个幼虫阶段的描述,附有照片和分子数据 18S rDNA、ITS1-5.8S-ITS2-28S 和 cox1 基因片段的支持。