Tkach Vasyl V, Kudlai Olena, Kostadinova Aneta
Department of Biology, University of North Dakota, 10 Cornell Street, Grand Forks, ND 58202, USA.
Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic; Laboratory of Parasitology, Nature Research Centre, Akademijos 2, LT-08412 Vilnius, Lithuania.
Int J Parasitol. 2016 Mar;46(3):171-185. doi: 10.1016/j.ijpara.2015.11.001. Epub 2015 Dec 15.
The Echinostomatoidea is a large, cosmopolitan group of digeneans currently including nine families and 105 genera, the vast majority parasitic, as adults, in birds with relatively few taxa parasitising mammals, reptiles and, exceptionally, fish. Despite the complex structure, diverse content and substantial species richness of the group, almost no attempt has been made to elucidate its phylogenetic relationships at the suprageneric level based on molecules due to the lack of data. Herein, we evaluate the consistency of the present morphology-based classification system of the Echinostomatoidea with the phylogenetic relationships of its members based on partial sequences of the nuclear lsrRNA gene for a broad diversity of taxa (80 species, representing eight families and 40 genera), including representatives of five subfamilies of the Echinostomatidae, which currently exhibits the most complex taxonomic structure within the superfamily. This first comprehensive phylogeny for the Echinostomatoidea challenged the current systematic framework based on comparative morphology. A morphology-based evaluation of this new molecular framework resulted in a number of systematic and nomenclatural changes consistent with the phylogenetic estimates of the generic and suprageneric boundaries and a new phylogeny-based classification of the Echinostomatoidea. In the current systematic treatment: (i) the rank of two family level lineages, the former Himasthlinae and Echinochasminae, is elevated to full family status; (ii) Caballerotrema is distinguished at the family level; (iii) the content and diagnosis of the Echinostomatidae (sensu stricto) (s. str.) are revised to reflect its phylogeny, resulting in the abolition of the Nephrostominae and Chaunocephalinae as synonyms of the Echinostomatidae (s. str.); (iv) Artyfechinostomum, Cathaemasia, Rhopalias and Ribeiroia are re-allocated within the Echinostomatidae (s. str.), resulting in the abolition of the Cathaemasiidae, Rhopaliidae and Ribeiroiinae, which become synonyms of the Echinostomatidae (s. str.); and (v) refinements of the generic boundaries within the Echinostomatidae (s. str.), Psilostomidae and Fasciolidae are made.
棘口吸虫总科是一大类广泛分布于世界各地的复殖吸虫，目前包括9个科和105个属，绝大多数成虫寄生于鸟类，仅有少数类群寄生于哺乳动物、爬行动物，极少数寄生于鱼类。尽管该类群结构复杂、内容多样且物种丰富，但由于缺乏数据，几乎没有人尝试基于分子水平阐明其科级以上的系统发育关系。在此，我们基于核小亚基核糖体RNA（lsrRNA）基因的部分序列，对广泛多样的类群（80个物种，代表8个科和40个属）进行评估，以探讨目前基于形态学的棘口吸虫总科分类系统与其成员系统发育关系的一致性，其中包括棘口科5个亚科的代表物种，棘口科目前在该总科中展现出最复杂的分类结构。棘口吸虫总科的这一首次全面系统发育研究对当前基于比较形态学的分类框架提出了挑战。基于形态学对这一新的分子框架进行评估，导致了一些系统分类和命名上的变化，这些变化与科级和科级以上分类单元界限的系统发育估计一致，并产生了基于新系统发育的棘口吸虫总科分类。在当前的系统分类处理中：（i）两个科级谱系，即原希马斯泰勒科和棘隙科，提升为科级地位；（ii）卡瓦列罗吸虫属在科级水平上被区分出来；（iii）修订了狭义棘口科的内容和诊断标准以反映其系统发育，导致肾口亚科和驼背亚科作为狭义棘口科的同义词被废除；（iv）伪棘口属、卡泰马属、罗帕利亚属和里贝罗属被重新划归到狭义棘口科内，导致卡泰马科、罗帕利科和里贝罗亚科被废除，成为狭义棘口科的同义词；（v）对狭义棘口科、裸口科和片形科内的属级界限进行了细化。
