Chisholm L A, Morgan J A, Adlard R D, Whittington I D
Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia.
Int J Parasitol. 2001 Sep;31(11):1253-63. doi: 10.1016/s0020-7519(01)00223-5.
The current classification of the Monocotylidae (Monogenea) is based on a phylogeny generated from morphological characters. The present study tests the morphological phylogenetic hypothesis using molecular methods. Sequences from domains C2 and D1 and the partial domains C1 and D2 from the 28S rDNA gene for 26 species of monocotylids from six of the seven subfamilies were used. Trees were generated using maximum parsimony, neighbour joining and maximum likelihood algorithms. The maximum parsimony tree, with branches showing less than 70% bootstrap support collapsed, had a topology identical to that obtained using the maximum likelihood analysis. The neighbour joining tree, with branches showing less than 70% support collapsed, differed only in its placement of Heterocotyle capricornensis as the sister group to the Decacotylinae clade. The molecular tree largely supports the subfamilies established using morphological characters. Differences are primarily how the subfamilies are related to each other. The monophyly of the Calicotylinae and Merizocotylinae and their sister group relationship is supported by high bootstrap values in all three methods, but relationships within the Merizocotylinae are unclear. Merizocotyle is paraphyletic and our data suggest that Mycteronastes and Thaumatocotyle, which were synonymized with Merizocotyle after the morphological cladistic analysis, should perhaps be resurrected as valid genera. The monophyly of the Monocotylinae and Decacotylinae is also supported by high bootstrap values. The Decacotylinae, which was considered previously to be the sister group to the Calicotylinae plus Merizocotylinae, is grouped in an unresolved polychotomy with the Monocotylinae and members of the Heterocotylinae. According to our molecular data, the Heterocotylinae is paraphyletic. Molecular data support a sister group relationship between Troglocephalus rhinobatidis and Neoheterocotyle rhinobatidis to the exclusion of the other species of Neoheterocotyle and recognition of Troglocephalus renders Neoheterocotyle paraphyletic. We propose Troglocephalus incertae sedis. An updated classification and full species list of the Monocotylidae is provided.
单殖吸虫科（单殖亚纲）目前的分类是基于由形态特征构建的系统发育关系。本研究使用分子方法对形态学系统发育假说进行检验。研究采用了来自七个亚科中六个亚科的26种单殖吸虫28S rDNA基因的C2和D1结构域以及部分C1和D2结构域的序列。使用最大简约法、邻接法和最大似然法算法构建系统发育树。最大简约树中，自展支持率低于70%的分支被合并，其拓扑结构与最大似然分析得到的拓扑结构相同。邻接树中，自展支持率低于70%的分支被合并，仅在将角异杯吸虫作为十杯亚科分支的姐妹群的位置上有所不同。分子系统发育树在很大程度上支持了基于形态特征建立的亚科分类。差异主要在于亚科之间的相互关系。在所有三种方法中，高自展值都支持了杯殖亚科和中殖亚科及其姐妹群关系，但中殖亚科内部的关系尚不清楚。中殖吸虫属是并系的，我们的数据表明，在形态支序分析后与中殖吸虫属同义的微杯吸虫属和奇杯吸虫属或许应恢复为有效属。单杯亚科和十杯亚科的单系性也得到了高自展值的支持。十杯亚科以前被认为是杯殖亚科加中殖亚科的姐妹群，现在与单杯亚科和异杯亚科的成员一起被归为一个未解决的多歧类群。根据我们的分子数据，异杯亚科是并系的。分子数据支持了鼻蝠穴首吸虫和鼻蝠新异杯吸虫之间的姐妹群关系，排除了新异杯吸虫的其他物种，并且将穴首吸虫属独立出来使得新异杯吸虫属成为并系的。我们提出穴首吸虫属（地位未定）。本文提供了单殖吸虫科的更新分类和完整物种列表。
