Scholz Tomáš, de Chambrier Alain, Mariaux Jean, Kuchta Roman
Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, Branišovská 31, 370 05 České Budějovice, Czech Republic.
J Parasitol. 2011 Dec;97(6):1142-51. doi: 10.1645/GE-2705.1. Epub 2011 Jul 1.
The proteocephalidean tapeworm, Corallobothrium solidum, type species of the genus, is redescribed on the basis of the examination of its type specimens and extensive material recently collected from Malapterurus electricus (type host). Some morphological characteristics of taxonomic importance are reported for the first time, such as the presence of semispherical (U-shaped) sphincters on the external (outer) margin of the suckers, a vaginal sphincter, a well-developed seminal receptacle, and a unique morphology of the eggs. Corallobothrium solidum differs from the 2 remaining species of the genus, both parasitic in channel catfishes (Ictaluridae), in its scolex shape, morphology of its suckers, presence of longitudinal and transverse grooves on the body surface, dense network of excretory canals in the apical part of the scolex, morphology of the eggs, and uterine development. The non-monophyletic nature of Corallobothrium is further supported by molecular data (partial sequences of the 28S rRNA gene) because C. solidum and the 2 remaining species from ictalurids do not form a monophyletic assemblage. Therefore, Essexiella n. gen. is proposed to accommodate Essexiella fimbriatum new comb. (type and only species; syn. Corallobothrium fimbriatum) from channel catfish. Essexiella n. gen. differs from Corallobothrium, Megathylacoides, and Megathylacus by the absence of a sphincter in the suckers, from Corallotaenia by the shape of the scolex and the number and shape of proglottids, and from Paraproteocephalus by the structure of the uterus. The diagnosis of Corallobothrium, which becomes monotypic and restricted to electric catfishes in Africa, is emended. The remaining species of Corallobothrium, Corallobothrium parafimbriatum, is tentatively transferred to Corallotaenia as Corallotaenia parafimbriata n. comb., based on molecular data, small size of the strobila, and shape of the scolex.
基于对其模式标本的检查以及最近从电鲇（模式宿主）采集的大量标本，对头槽绦虫科的绦虫——坚实珊瑚绦虫（Corallobothrium solidum）进行了重新描述，该种为珊瑚绦虫属的模式种。首次报道了一些具有分类学重要性的形态特征，如吸盘外缘（外侧）存在半球形（U形）括约肌、阴道括约肌、发育良好的受精囊以及独特的虫卵形态。坚实珊瑚绦虫在头节形状、吸盘形态、体表纵沟和横沟的存在情况、头节顶端排泄管的密集网络、虫卵形态以及子宫发育等方面，与该属另外两种均寄生于沟鲶（鮰科）的绦虫不同。分子数据（28S rRNA基因部分序列）进一步支持了珊瑚绦虫属的非单系性质，因为坚实珊瑚绦虫与另外两种来自鮰科的绦虫并未形成单系类群。因此，提议建立新属埃塞克斯绦虫属（Essexiella n. gen.），以容纳来自沟鲶的具缘埃塞克斯绦虫（Essexiella fimbriatum new comb.）（模式种且为唯一物种；同物异名：具缘珊瑚绦虫Corallobothrium fimbriatum）。埃塞克斯绦虫属与珊瑚绦虫属、巨槽绦虫属和巨槽绦虫的区别在于吸盘无括约肌，与珊瑚带绦虫属的区别在于头节形状以及节片的数量和形状，与副头槽绦虫属的区别在于子宫结构。对珊瑚绦虫属的诊断进行了修订，该属现成为单型属，且仅限于非洲的电鲇寄生。基于分子数据、虫体链体较小以及头节形状，将珊瑚绦虫属的另一个物种——类缘珊瑚绦虫（Corallobothrium parafimbriatum）暂定为转移至珊瑚带绦虫属，成为具缘珊瑚带绦虫（Corallotaenia parafimbriata n. comb.）。
