Laboratorio de Ictioparasitología, Instituto de Invest\igaciones Marinas y Costeras (IIMyC). Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Funes 3350, (7600), Mar del Plata, Argentina.
Instituto de Ecología, A.C., Red de Biología Evolutiva, Carretera antigua a Coatepec 351, El Haya, 91070, Xalapa, VER, Mexico.
Parasitol Res. 2020 Jun;119(6):1713-1728. doi: 10.1007/s00436-020-06680-w. Epub 2020 May 13.
In this study, we followed an integrative taxonomy approach to describe two new species of Gyrodactylus von Nordmann, 1832, and to identify specimens of G. breviradix Vega, Razzolini, Arbetman, and Viozzi, 2019, all three collected from ten spotted live-bearer Cnesterodon decemmaculatus (Jenyns, 1842), an endemic and widespread poeciliid from the Pampean region, which is the southernmost occurring species of the Poeciliidae in the Americas. Gyrodactylids were first characterized morphologically and mophometrically, and when possible, sequences of the Internal Transcribed Spacers (ITS1-5.8S-ITS2) and the cytochrome oxidase II (COII) were used to delimit species. Gyrodactylus breviradix, Gyrodactylus marplatensis n. sp., and Gyrodactylus pampeanus n. sp. were found on the fins and body surface of C. decemmaculatus in La Tapera Creek, Mar del Plata, Buenos Aires province, Argentina. A phylogenetic analysis combining newly generated sequences of one of the new species, G. marplatensis n. sp., and of G. breviradix, along with those available in GenBank for a further 36 species of Gyrodactylus, revealed that G. marplatensis n. sp. is a sister taxon of Gyrodactylus decemmaculati Vega, Razzolini, Arbetman, and Viozzi, 2019. Genetic distances for the ITS and COII gene were estimated among Gyrodactylus spp. and further supported the validity of the new species. Overall, morphometric and molecular data coincided in delimiting the new taxa, thus demonstrating the value of integrative taxonomy for the erection of new species of Gyrodactylus and species identification.
在这项研究中，我们采用综合分类学方法来描述两种新的 Gyrodactylus von Nordmann, 1832 物种，并鉴定出 G. breviradix Vega, Razzolini, Arbetman, 和 Viozzi, 2019 的标本，所有这些都是从来自潘帕斯地区的十种斑纹活胎鱼 Cnesterodon decemmaculatus (Jenyns, 1842) 身上采集的，这是美洲最南端的 Poeciliidae 物种。Gyrodactylids 首先通过形态学和形态测量学进行了特征描述，并且在可能的情况下，使用内部转录间隔区 (ITS1-5.8S-ITS2) 和细胞色素氧化酶 II (COII) 的序列来界定物种。在阿根廷布宜诺斯艾利斯省马德普拉塔的拉塔佩拉溪中，在 C. decemmaculatus 的鳍和身体表面发现了 G. breviradix、Gyrodactylus marplatensis n. sp. 和 Gyrodactylus pampeanus n. sp.。结合新生成的序列之一 G. marplatensis n. sp. 和 G. breviradix 的序列，以及在 GenBank 中可获得的 36 种 Gyrodactylus 物种的序列进行的系统发育分析表明，G. marplatensis n. sp. 是 Gyrodactylus decemmaculati Vega, Razzolini, Arbetman, 和 Viozzi, 2019 的姊妹分类单元。ITS 和 COII 基因的遗传距离在 Gyrodactylus spp. 之间进行了估计，并进一步支持了新物种的有效性。总体而言，形态和分子数据在划定新分类群时是一致的，因此证明了综合分类学在建立 Gyrodactylus 新物种和物种鉴定方面的价值。
