We propose Dulcitransversotrema n. gen. for the freshwater transversotrematids Dulcitransversotrema patialense (Soparkar, 1924) n. comb. and Dulcitransversotrema chauhani (Agrawal and Singh, 1960) n. comb. Dulcitransversotrema is unique by the combination of lacking an oral sucker and an extensively coiled uterus as well as having testes that are not deeply lobed and that abut or nearly abut the inner posterolateral margins of the digestive tract (vs. deeply lobed testes that abut the cyclocoel region of the digestive tract only or that do not abut the ceca), a pre-oral genital pore (vs. post-oral genital pore), an ovary that is anterior to and abuts or nearly abuts the sinistral testis (vs. an ovary that is separated from the sinistral testis by some distance or having an ovary that is median and immediately pre-testicular), non-embryonated eggs (vs. embryonated eggs), typically having none or sparse vitelline follicles between the testes and ceca (vs. having a wholly inter-cecal vitellarium comprising a pair of highly compacted clusters of vitelline follicles anterolateral to the testes or having numerous vitelline follicles between the testes and ceca), an oblong, median, and primarily inter-testicular vitelline reservoir (vs. an extensively elongate, pre-testicular vitelline reservoir that arches anteriorly around the sinistral testis), and a subterminal excretory pore opening on the dorsal body surface between the level of the cyclocoel and posterior body end (vs. a terminal excretory pore). We describe the redia and cercaria of Dulcitransversotrema cf. patialense from the red-rimmed melania snail, Melanoides tuberculata (Müller, 1774) (Cerithioidea: Thiaridae), and their corresponding adult from beneath the scales of the zebrafish, Danio rerio (Hamilton, 1822) (Cypriniformes: Danionidae). All hosts were sampled from a spring-fed earthen pond at a private aquaculture facility near Ruskin, Florida. No transversotrematid life cycle was known from North America previously. The large subunit ribosomal DNA and ribosomal internal transcribed spacer 2 sequences of D. cf. patialense from Florida were most similar to those from D. patialense infecting red-rimmed melania from Mayagüez, Puerto Rico and differed by 134 and 69 nucleotides, respectively. Both phylogenetic analyses recovered Dulcitransversotrema as monophyletic and sister to a clade comprising Transversotrema spp. plus Crusziella formosaCribb, Bray, and Barker, 1992.

我们建议Dulcitransversotrema n。将军淡水横蝽Dulcitransversotrema patialense (Soparkar, 1924) n.梳子。和Dulcitransversotrema chauhani（Agrawal 和 Singh，1960）梳子。肠横膈的独特之处在于缺乏口腔吸盘和广泛卷曲的子宫，以及具有不深裂且邻接或几乎邻接消化道内后外侧边缘的睾丸（与邻接环腔的深裂睾丸相比）仅消化道区域或不邻接盲肠）、口前生殖孔（相对于口后生殖孔）、位于左睾丸前面并邻接或几乎邻接的卵巢（相对于卵巢）与左睾丸相隔一定距离或具有位于正中且紧邻睾丸前的卵巢）、非​​胚卵（相对于含胚卵）、通常在睾丸和盲肠之间没有或稀疏卵黄卵泡（相对于盲肠）。具有完全盲肠间卵黄囊，包括睾丸前外侧的一对高度致密的卵黄卵泡簇，或在睾丸和盲肠之间具有大量卵黄卵泡），椭圆形、正中且主要是睾丸间卵黄囊（与睾丸间卵黄囊相比）。一个广泛细长的睾丸前卵黄囊，在左睾丸周围向前拱起），以及在环腔和后体末端水平之间的背体表面上开口的亚末端排泄孔（相对于末端排泄孔）。我们描述了Dulcitransversotrema cf.的红虫和尾蚴。patialense来自红边梅拉尼亚蜗牛Melanoides tuberculata (Müller, 1774)（Cerithioidea: Thiaridae），以及来自斑马鱼鳞片下的相应成虫Danio rerio (Hamilton, 1822)（Cypriniformes: Danionidae）。所有寄主都是从佛罗里达州拉斯金附近的一个私人水产养殖设施的泉水土池中取样的。此前，北美地区并没有横臂动物的生命周期。D.的大亚基核糖体 DNA 和核糖体内部转录间隔区 2 序列。来自佛罗里达州的patialense与来自波多黎各马亚圭斯的感染红缘黑猩猩的D. patialense最为相似，分别有 134 和 69 个核苷酸差异。两次系统发育分析都发现Dulcitransversotrema是单系的，并且是包含Transversotrema spp的进化枝的姐妹。加上Crusziella formosa Cribb、Bray 和 Barker，1992。