Adult forms of members of the Callodistomidae always parasitize the gallbladder of freshwater fishes and occur in Africa and America. This study provides a description of a new South American species belonging inProsthenhysterafrom the gallbladder of a characid fish (Bryconamericus ikaa), and ribosomal gene sequences (28S rDNA and ITS1-5.8S-ITS2) are used to demonstrate molecular differences between the new species and congeners as well as explore interrelationships among congeners. Additionally, the first cytological analysis is conducted for a member of the family to determine chromosome number and arrangement.Prosthenhystera gattiin. sp. most closely resemblesProsthenhystera caballeroiin morphology, but the vitellarium is more extensive reaching anterior to the caecal bifurcation in the new species and the uterus is confined to the hindbody inP. gattiin. sp., whereas it extends to the level of the pharynx inP. caballeroi. Also, the testes, cirrus sac, seminal receptacle and the ratio of body length to width are larger inP. gattiin. sp. Independent Bayesian inference analyses of 28S rDNA and ITS1-5.8S-ITS2 sequence fragments produced phylograms that showedP. gattiin. sp. is more similar toProsthenhystera obesa+Prosthenhystera oonasticathanP.caballeroi +two unidentified species ofProsthenhystera, but with poor posterior probability support for the node in the ITS1-5.8S-ITS2-based phylogram. Further, the genetic distance betweenP. oonasticaandP. gattiin. sp. are the largest amongProsthenhysteraspp. Cytological analysis revealed ten metacentric chromosomes, which is fewer than the 12–18 chromosomes present in species from the closely related Gorgoderidae.

中文翻译：

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Prosthenhystera gattiin。sp。（Digenea：Callodistomidae），一种来自伊瓜苏河下游的 Bryconamericus ikaa 的胆囊寄生虫，基于分子和形态学证据的综合描述

Callodistomidae 成员的成年形式总是寄生在淡水鱼的胆囊中，并出现在非洲和美洲。这项研究提供了一种新的南美洲物种的描述，该物种属于子宫内膜异位症来自characid鱼的胆囊（野蔷薇) 和核糖体基因序列（28S rDNA 和 ITS1-5.8S-ITS2）被用来证明新物种和同源物之间的分子差异以及探索同源物之间的相互关系。此外，对家庭成员进行第一次细胞学分析以确定染色体数目和排列。螳螂n. sp。最相似螳螂在形态上，但新种的卵母体更广泛，到达盲肠分叉前部，子宫局限于后体。P. gattiin. sp.，而它延伸到咽部的水平P. caballeroi. 此外，睾丸、卷囊、精囊和体长宽比较大P. gattiin. sp。28S rDNA 和 ITS1-5.8S-ITS2 序列片段的独立贝叶斯推理分析产生的系统图显示P. gattiin. sp。更类似于肥胖蜈蚣+蝮蛇比磷.马车 +两种不明物种子宫内膜异位症，但对基于 ITS1-5.8S-ITS2 的系统图中的节点的后验概率支持较差。此外，之间的遗传距离P. oonastica和P. gattiin. sp。是最大的子宫内膜异位症spp. 细胞学分析揭示了 10 条中着丝粒染色体，少于密切相关的 Gorgoderidae 物种中存在的 12-18 条染色体。