Abstract：
Herein, we provide a supplemental description of Caballerotrema annulatum (Diesing, 1850) Ostrowski de Núñez and Sattmann, 2002 (Digenea: Caballerotrematidae Tkach, Kudlai, and Kostadinova, 2016) based on specimens collected from the intestine of an electric eel, Electrophorus cf. varii (Gymnotiformes: Gymnotidae) captured in the Amazon River (Colombia). This caballerotrematid can be differentiated from its congeners by the following combination of morphological features: body surface spines forming contiguous transverse rows, concentric (wrapping dorso-ventrally around body), distributing into posterior body half (vs. restricted to anterior body half in Caballerotrema brasiliensePrudhoe, 1960; indeterminate for Caballerotrema aruanenseThatcher, 1980 and Caballerotrema piscicola [Stunkard, 1960] Kostadinova and Gibson, 2001); head collar lacking projections (vs. having them in C. brasiliense, C. aruanense, and C. piscicola), narrow (head collar more narrow than maximum body width vs. the head collar being obviously wider than the body in C. brasiliense, C. aruanense, and C. piscicola); corner spines clustered (vs. corner spines distributing as 2 separated pairs in C. brasiliense, C. aruanense, and C. piscicola); pharynx approximately at level of the corner spines (vs. pharynx far anterior to corner spines in C. brasiliense, C. aruanense, and C. piscicola); and testes ovoid and nonoverlapping (C. aruanense; vs. sinuous and overlapping in C. brasiliense and C. piscicola). Based on our results, we revise the diagnosis of CaballerotremaPrudhoe, 1960 to include features associated with the shape and distribution of body surface spines, orientation and position of head collar spines, cirrus sac, seminal vesicle, oviduct, Laurer\'s canal, oötype, vitellarium, and transverse vitelline ducts. We performed Bayesian inference analyses using the partial large subunit ribosomal (28S) DNA gene. Our 28S sequence of C. annulatum was recovered sister to that of Caballerotrema sp. (which is the only other caballerotrematid sequence available in GenBank) from an arapaima, Arapaima gigas (Schinz, 1822) (Osteoglossiformes: Arapaimidae) in the Peruvian Amazon. Our sequence of C. annulatum comprises the only caballerotrematid sequenced tethered to a morphological description and a voucher specimen in a lending museum. The present study is a new host record and new locality record for C. annulatum. The phylogeny comprises the most resolved and taxon-rich evolutionary hypothesis for Echinostomatoidea published to date.
摘要：
在这里，我们提供Caballerotremaannulatum(Diesing，1850）OstrowskideNúñez和Sattmann，2002(Digenea:CaballerotrematidaeTkach,Kudlai,还有Kostadinova,2016)根据从电鳗鱼肠道采集的标本，电声cf.在亚马逊河（哥伦比亚）捕获的varii（gynotiformes：gymnotidae）。这种caballerotrematid可以通过以下形态特征的组合与其同源物区分开来：体表棘形成连续的横向行，同心(背部腹侧围绕身体)，分布到后半身体(vs.仅限于巴西卡瓦列罗玛的前半身，1960年；不确定CaballerotremaaruanenseThatcher，1980年和Caballerotremapiscicola[Stunkard，1960]Kostadinova和吉布森，2001年)；头领缺乏投影(与把它们放在巴西，C.Aruanense,和C.piscicola)，窄(头领比最大车身宽度窄与在巴西，头领明显比身体宽，C.Aruanense,和C.piscicola）；角刺聚集（与角刺在巴西以2对分开的形式分布，C.Aruanense,和C.piscicola）；咽部大约在角刺的水平（与咽远前方到角棘在巴西，C.Aruanense,和C.piscicola)；和睾丸卵圆形和不重叠(C.阿鲁安斯；vs.C.brasiliense和C.piscicola中的弯曲和重叠）。根据我们的结果,我们修改了CaballerotremaPrudhoe的诊断,1960年，包括与体表棘的形状和分布相关的特征，头领刺的方向和位置，卷云囊,精囊,输卵管,劳雷尔的运河，oötype,玻璃体,和横向卵黄管。我们使用部分大亚基核糖体（28S）DNA基因进行贝叶斯推断分析。我们的28S序列与Caballerotremasp。（这是GenBank中唯一可用的其他caballerotrematid序列）来自arapaima，Arapaimagigas(Schinz，1822年）秘鲁亚马逊河中的（骨齿形：Arapaimidae）。我们的C.annulatum序列包括唯一的Caballerotrematid序列，该序列与形态学描述和借阅博物馆中的凭证标本相连。本研究是一个新的宿主记录和新的局部记录。系统发育包括迄今为止发表的最有决心和分类群丰富的Echinostomatoidea进化假设。
