目的:分子系统发育学一直在改进无头鱼系统,然而,许多类群仍未开发。Yamaguti,1959年及其类型物种M.lateolabracisYamaguti,1959年是这样一个待探索的分类单元。我们的目标是完善(I)系统的位置,(ii)形态界限,和(iii)该属的分类成分。我们还旨在检查已分配给该属的物种的分类状况。
方法:对新采集的标本以及长尾类动物的类型材料进行了形态学观察。此外,使用最大似然法和贝叶斯推断的分子系统发育分析是基于新收集的标本进行的.至少在Metarhadinorhynchus中分配过一次的标称物种,以及相关的形式,GorgorhynchuslateolabriYin和Wu,1984年,是根据文献信息进行分类重新评估的。
结果:我们对M.lateolabracis类型材料的重新检查显示,水泥腺体的数量为六个,而不是原始描述中描述和说明的八个。在由此产生的系统发育树中,lateolabracis。Gorgorhynchoides电缆和Linderoth,1963年被发现是Metarhadinorhynchus的初级同义词。对曾经属于Metarhadinorhynchus的六个标称物种的分类学重新评估导致对IndorhynchusGolvan的通用诊断进行了修改,1969年和NeotegorhynchusLisitsyna,Xi,Orosová,巴恰克,和Oros,2022年。
结论:Metarhadinorhynchus已被分配给Leptorhynchodae(Echinorhynchida),但是我们的研究现在将其定位在鱼科(Polymorphida)中。我们在Metarhadinorhynchus中提出了13种新的特定名称组合,在Indorhynchus中提出了3种新的组合。Metarhadinorhynchuslateolabri(Yin和Wu,1984)梳子。11月。可能是东方分枝杆菌(Wang,1966)梳子。11月。
OBJECTIVE: Molecular phylogenetics has been improving the acanthocephalan systematics, yet numerous taxa remain unexplored. The palaeacanthocephalan Metarhadinorhynchus Yamaguti, 1959 and its type species M. lateolabracis Yamaguti, 1959 are such to-be-explored taxa. We aim to refine (i) the systematic placement, (ii) the morphological circumscription, and (iii) the taxonomic components of the genus. We also aim to examine the taxonomic status of the species that have been assigned to the genus.
METHODS: Morphological observations on newly collected specimens as well as the type material of Metarhadinorhynchus lateolabracis were conducted. Also, molecular phylogenetic analyses with maximum-likelihood method and Bayesian inference were performed based on freshly collected specimens. Nominal species that have at least once been assigned in Metarhadinorhynchus, as well as a related form, Gorgorhynchus lateolabri Yin and Wu, 1984, are taxonomically re-evaluated based on literature information.
RESULTS: Our re-examination of the type material of M. lateolabracis revealed that the number of cement glands is six, instead of eight as described and illustrated in the original description. In the resulting phylogenetic tree, M. lateolabracis was nested in Isthmosacanthidae. Gorgorhynchoides Cable and Linderoth, 1963 was found to be a junior synonym of Metarhadinorhynchus. Taxonomic re-evaluations of six nominal species that have once belonged in Metarhadinorhynchus led to modifications of generic diagnoses for Indorhynchus Golvan, 1969 and Neotegorhynchus Lisitsyna, Xi, Orosová, Barčák, and Oros, 2022.
CONCLUSIONS: Metarhadinorhynchus has been assigned to Leptorhynchoididae (
Echinorhynchida), but our study now locates it in Isthmosacanthidae (Polymorphida). We propose 13 new combinations of specific names in Metarhadinorhynchus and three in Indorhynchus. Metarhadinorhynchus lateolabri (Yin and Wu, 1984) comb. nov. may be synonymous with M. orientalis (Wang, 1966) comb. nov.