Malta Lennon S, Paiva F, Elisei Carina, Tavares Luiz E R, Pereira Felipe B
Programa de Pós-Graduação em Ecologia e Conservação, Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Av. Costa e Silva s/n, Campo Grande, MS CEP 79070-900, Brazil.
Programa de Pós-Graduação em Biologia Animal, Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Av. Costa e Silva s/n, Campo Grande, MS CEP 79070-900, Brazil.
Parasitol Int. 2020 Feb;74:101978. doi: 10.1016/j.parint.2019.101978. Epub 2019 Aug 27.
Sprentascaris mahnerti (Nematoda: Raphidascarididae) collected from Loricariichthys labialis (Siluriformes: Loricariidae) in the Pantanal wetlands, State of Mato Grosso do Sul (Brazil), was redescribed using light and scanning electron microscopy (SEM), and genetically characterised along with two other raphidascaridids: Raphidascaroides brasiliensis and Ro. moraveci. Due to the systematic discussion regarding Raphidascaris and Sprentascaris, as well as the poor knowledge about the phylogenetic relationships within Raphidascarididae, phylogenies were reconstructed based on partial sequences of the 18S and 28S nuclear rRNA gene, the nuclear ITS1-5.8S-ITS2 and the cytochrome c oxidase subunit I (cox1) mtDNA. Morphological study of S. mahnerti, confirmed some previously described features, revealed new characteristics and permitted to elucidate some inconsistencies noted in the literature. Morphological and genetic characterisation of S. mahnerti supported its validity. Phylogenetic reconstructions supported the monophyly of Sprentascaris, which has three pairs of interlabial conspicuous cuticular projections as a synapomorphy. The relationships among several lineages of raphidascaridids were unsolved, albeit Goezia and Ichthyascaris formed well-supported monophyletic assemblages, in which the first included species with no relations regarding the habitat of hosts and the geographic origin. The present findings represent one more step towards the understanding of the interrelationships of raphidascaridid nematodes. In this sense, Sprentascaris should be considered valid as an independent lineage from Raphidascaris.
从巴西南马托格罗索州潘塔纳尔湿地的唇纹吸甲鲶（Siluriformes: Loricariidae）体内采集到的马氏斯普伦蛔虫（Sprentascaris mahnerti）（线虫纲：裂蛔科），通过光学显微镜和扫描电子显微镜（SEM）进行了重新描述，并与另外两种裂蛔科线虫：巴西裂蛔（Raphidascaroides brasiliensis）和莫氏裂蛔（Ro. moraveci）进行了基因特征分析。由于关于蛔虫属（Raphidascaris）和斯普伦蛔虫属（Sprentascaris）的系统讨论，以及对裂蛔科内系统发育关系的了解不足，基于18S和28S核糖体RNA基因、核内转录间隔区ITS1-5.8S-ITS2以及细胞色素c氧化酶亚基I（cox1）线粒体DNA的部分序列重建了系统发育树。对马氏斯普伦蛔虫的形态学研究证实了一些先前描述的特征，揭示了新的特征，并澄清了文献中指出的一些不一致之处。马氏斯普伦蛔虫的形态学和基因特征支持了其有效性。系统发育重建支持斯普伦蛔虫属的单系性，该属具有三对唇间明显的表皮突起作为共有衍征。尽管戈氏线虫属（Goezia）和鱼蛔线虫属（Ichthyascaris）形成了得到充分支持的单系类群，但裂蛔科几个谱系之间的关系尚未解决，其中第一个类群包括与宿主栖息地和地理起源无关的物种。目前的研究结果是朝着理解裂蛔科线虫相互关系迈出的又一步。从这个意义上说，斯普伦蛔虫属应被视为一个独立于蛔虫属（Raphidascaris）的有效谱系。
