Dutton Haley R, Bullard Stephen A
Aquatic Parasitology Laboratory, School of Fisheries, Aquaculture & Aquatic Sciences, College of Agriculture, Auburn University, 203 Swingle Hall, Auburn, AL, 36849, USA.
Syst Parasitol. 2020 Aug;97(4):335-345. doi: 10.1007/s11230-020-09920-w. Epub 2020 Jun 24.
Enterohaematotrema Mehra, 1940 is emended herein based upon a review of the literature and a description of a new species (Enterohaematotrema triettruongi n. sp.) infecting yellow-headed temple turtles, Heosemys annandalii (Boulenger) (Cryptodira: Geoemydidae), in the Mekong River, Vietnam. The new species differs from the published descriptions of its congeners Enterohaematotrema palaeorticum Mehra, 1940 and Enterohaematotrema hepaticum (Simha, 1958) Simha & Chattopadhyaya, 1980 by having two distinctive oesophageal glands, a short and eversible cirrus (vs protrusive with 3 distinct processes), a dorsal common genital pore that is sinistral (vs ventral and medial), a transverse (vs longitudinal) external seminal vesicle, an oviducal seminal receptacle that is sinistral (vs dextral), and a vitellarium distributing from the caecal bifurcation (anterior to the ventral sucker) to the caecal tips (vs vitellarium not extending anteriad beyond ventral sucker in E. palaeorticum or vitellarium wholly posterior to the terminal genitalia in E. hepaticum). A phylogenetic analysis of the D1-D3 domains of the nuclear large subunit ribosomal DNA (28S) recovered Enterohaematotrema and Platt Roberts & Bullard, 2016 as sister taxa that share a recent common ancestor with the clade comprising Ruavermis Dutton & Bullard, 2020 and Coeuritrema Mehra, 1933. These flukes collectively comprise a monophyletic group of southeast Asian turtle blood flukes. This analysis also indicated that the massive, longitudinal metraterm of species of Enterohaematotrema and Uterotrema Platt & Pichelin, 1994 represents homoplasy (convergent evolution). The present study comprises the first morphological study of original specimens of any species of Enterohematotrema in more than 50 years and is the first molecular phylogenetic placement of the genus among the various turtle blood fluke lineages.
基于对文献的回顾以及对一种新物种（三氏肠血吸虫，新物种）的描述，本文对1940年的肠血吸虫属进行了修订。该新物种感染越南湄公河的黄头庙龟（安南潮龟，布尔伦格）（潜颈龟亚目：地龟科）。新物种与已发表的同属物种古肠血吸虫（1940年，梅拉）和肝肠血吸虫（1958年，西姆哈；1980年，西姆哈和查托帕迪亚）的描述不同，其具有两个独特的食管腺、一个短且可外翻的阴茎（而非突出且有3个明显突起）、一个位于左侧的背侧共同生殖孔（而非腹侧和中间）、一个横向（而非纵向）的外部精囊、一个位于左侧的输卵管受精囊（而非右侧），以及从盲肠分支（腹吸盘前方）到盲肠尖端分布的卵黄腺（在古肠血吸虫中，卵黄腺不向前延伸至腹吸盘前方；在肝肠血吸虫中，卵黄腺完全位于终末生殖器后方）。对核糖体DNA大亚基（28S）的D1 - D3结构域进行的系统发育分析显示，肠血吸虫属与普拉特·罗伯茨和布拉德（2016年）是姐妹分类单元，它们与包括鲁阿弗米斯（2020年，达顿和布拉德）和心盘吸虫属（1933年，梅拉）的进化枝有着最近的共同祖先。这些吸虫共同构成了东南亚龟血吸虫的一个单系类群。该分析还表明，肠血吸虫属和子宫吸虫属（1994年，普拉特和皮谢林）物种的粗大纵向子宫末段代表了趋同进化（同功进化）。本研究是50多年来对任何肠血吸虫物种原始标本的首次形态学研究，也是该属在各种龟血吸虫谱系中的首次分子系统发育定位。
