Achatz Tyler J, Burkman Clara A, Fecchio Alan, Pulis Eric E, Tkach Vasyl V
Department of Natural Sciences, Middle Georgia State University, Macon, GA, 31206, USA.
Department of Biology, University of North Dakota, Grand Forks, ND, 58202, USA.
Acta Parasitol. 2023 Mar;68(1):159-171. doi: 10.1007/s11686-022-00643-0. Epub 2022 Dec 2.
The Diplostomidae is a globally distributed family of digeneans that parasitize a wide variety of tetrapod definitive hosts. Recent molecular phylogenetic studies have revealed unknown diplostomid diversity in avian hosts throughout the New World. Herein, we provide descriptions of a novel genus of diplostomids with two new species.
Two species of diplostomids belonging to the new genus were collected from anhinga birds in Mississippi (USA) and Brazil. Partial nuclear 28S ribosomal and mitochondrial cox1 genes were sequenced. Ribosomal data were used for phylogenetic inference.
Both species of Anhingatrema n. gen. were positioned in a 100% supported, monophyletic clade in the phylogenetic tree. The molecular phylogenetic position and a combination of morphological features (e.g., presence of pseudosuckers, testes shape and orientation) supported erection of the new genus. Anhingatrema overstreeti n. sp. and Anhingatrema cararai n. sp. are morphologically similar, but differ in size of and ratios associated with pseudosuckers. The two species differ by 2% of 28S sequences and 13.8% of cox1 sequences. Comparison of DNA sequences revealed that Diplostomidae gen. sp. in GenBank (MZ314151) is conspecific with An. overstreeti n. sp.
Anhingatrema n. gen. is the sixth genus of diplostomids known from anhingas worldwide. Anhingatrema cararai n. sp. is the first diplostomid to be reported from anhingas in South America. Combined with previous studies, the molecular phylogenies revealed at least two host switches to anhingas from other birds during the evolutionary history of the Diplostomidae.
双穴科是一类分布于全球的复殖吸虫，寄生于多种四足动物终末宿主。近期的分子系统发育研究揭示了新大陆鸟类宿主中未知的双穴吸虫多样性。在此，我们描述了一个双穴吸虫新属及两个新物种。
从美国密西西比州和巴西的美洲蛇鹈鸟体内采集到属于新属的两种双穴吸虫。对部分核28S核糖体基因和线粒体细胞色素c氧化酶亚基1（cox1）基因进行测序。核糖体数据用于系统发育推断。
美洲蛇鹈双穴吸虫新属的两个物种在系统发育树中位于一个得到100%支持的单系分支中。分子系统发育位置以及形态特征（如伪吸盘的存在、睾丸形状和方位）的组合支持了新属的建立。奥氏美洲蛇鹈双穴吸虫新种和卡拉拉美洲蛇鹈双穴吸虫新种在形态上相似，但伪吸盘的大小和相关比例不同。这两个物种的28S序列差异为2%，cox1序列差异为13.8%。DNA序列比较显示，GenBank中的双穴科属种（MZ314151）与奥氏美洲蛇鹈双穴吸虫新种同种。
美洲蛇鹈双穴吸虫新属是全球已知的第六个来自美洲蛇鹈的双穴吸虫属。卡拉拉美洲蛇鹈双穴吸虫新种是南美洲首次报道的来自美洲蛇鹈的双穴吸虫。结合先前的研究，分子系统发育显示在双穴科的进化历史中至少有两次从其他鸟类宿主转换到美洲蛇鹈的宿主转换事件。
