The University of Queensland, School of Biological Sciences, St Lucia, QLD 4072, Australia.
The University of Queensland, School of Biological Sciences, St Lucia, QLD 4072, Australia.
Parasitol Int. 2020 Dec;79:102164. doi: 10.1016/j.parint.2020.102164. Epub 2020 Jun 24.
Lasiotocus Looss, 1907 is the largest genus within the Monorchiidae Odhner, 1911, with 52 species currently considered valid. Species belonging to this genus exhibit wide morphological variation and it is likely that many of them belong in other genera; however, testing the validity of the group has been hampered by a lack of molecular sequence data, especially for the type-species. Here, we report the first DNA sequences for Lasiotocus mulli (Stossich, 1883) Odhner, 1911, the type-species of the genus, and only the sixth Lasiotocus species to be sequenced. Sequences were generated for three ribosomal DNA markers, the ITS2, 18S and 28S regions, and for one mitochondrial DNA marker, the cox1 region. Phylogenetic analyses show that the six sequenced species form four clearly distinct clades, each of which we argue require separate genera. On the basis of these relationships and review of the morphology of all species in the genus, we propose a system of six genera. Four genera, Lasiotocus, the resurrected concept of Ancylocoelium Nicoll, 1912, Infundiburictus n. gen., and Sinistroporomonorchis n. gen., represent the four molecular clades. Two genera, Paralasiotocus n. gen. and Alloinfundiburictus n. gen., are proposed on the basis of morphology only. Ancylocoelium is resurrected for Ancylocoelium typicum Nicoll, 1912, Infundiburictus is erected for Lasiotocus arrhichostoma Searle, Cutmore & Cribb, 2014, Sinistroporomonorchis is erected for Lasiotocus glebulentus Overstreet, 1971and Lasiotocus lizae Liu, 2002, Paralasiotocus is erected for Lasiotocus okinawaensis Machida, 2011, and Alloinfundiburictus is erected for Lasiotocus cacuminatus Nicoll, 1915. Of the 52 species presently recognised in Lasiotocus, 43 are distributed among these genera; nine are considered species inquirendae or are transferred to other genera. We think it likely that more genera will be required for the species reviewed here but more sequence data are essential to further refine the classification.
拉西托库斯属 Looss, 1907 是 Monorchiidae Odhner, 1911 中的最大属，目前有 52 种被认为是有效种。属于这个属的物种表现出广泛的形态变异，很可能其中许多种属于其他属；然而，由于缺乏分子序列数据，特别是对模式种的缺乏，对该组的有效性进行测试受到了阻碍。在这里，我们报告了拉西托库斯属的模式种——马氏拉西托库斯（Stossich, 1883）Odhner, 1911 的第一个 DNA 序列，也是第六种测序的拉西托库斯物种。我们为三个核糖体 DNA 标记物生成了序列，即 ITS2、18S 和 28S 区，以及一个线粒体 DNA 标记物，cox1 区。系统发育分析表明，这六个测序的物种形成了四个明显不同的分支，我们认为每个分支都需要单独的属。基于这些关系和对该属所有物种形态的回顾，我们提出了一个由六个属组成的系统。四个属，拉西托库斯属、复活的Ancylocoelium Nicoll, 1912 概念、Infundiburictus n. gen. 和 Sinistroporomonorchis n. gen.，代表四个分子分支。两个属，Paralasiotocus n. gen. 和 Alloinfundiburictus n. gen.，仅基于形态提出。Ancylocoelium 被复活为 Ancylocoelium typicum Nicoll, 1912，Infundiburictus 为 Lasiotocus arrhichostoma Searle, Cutmore & Cribb, 2014 建立，Sinistroporomonorchis 为 Lasiotocus glebulentus Overstreet, 1971 和 Lasiotocus lizae Liu, 2002 建立，Paralasiotocus 为 Lasiotocus okinawaensis Machida, 2011 建立，Alloinfundiburictus 为 Lasiotocus cacuminatus Nicoll, 1915 建立。在目前被认为是拉西托库斯属的 52 种物种中，有 43 种分布在这些属中；有 9 种被认为是待研究种或被转移到其他属。我们认为，这里审查的物种可能需要更多的属，但更多的序列数据对于进一步细化分类是必不可少的。
