Laboratório de Sistemática de Vertebrados, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Av. Ipiranga 6681, Prédio 40, sala 110, 90619-900, Porto Alegre, RS, Brazil..
Zootaxa. 2021 Apr 6;4951(2):zootaxa.4951.2.1. doi: 10.11646/zootaxa.4951.2.1.
Allobates trilineatus is the second most geographically widespread species in the genus Allobates, its range extending from northern Ecuador to southern Peru along the Andean foothills of Amazonia and to the east, into Acre, Brazil. However, detailed phenotypic and genetic variation from topotypic specimens is lacking, raising doubts about the identification of specimens in the literature. To solve this problem, we collected 16 topotypic specimens-including male and female adults and juveniles-and associated data such as advertisement calls and tissue samples. Based upon this material, we redescribe the phenotypic variation within A. trilineatus and evaluate its phylogenetic position using a fragment of the mitochondrial gene 16S rDNA. Allobates trilineatus is distinguished from its congeners by its small body size (adult snout-to-vent-length = 14.6-16.6 mm), preserved males with dark gray throat, and gray chest and belly, pale dorsolateral stripe straight and conspicuous, and advertisement call formed by the emission of groups of note-pairs with dominant frequency at 5.06-5.81 kHz. Our phylogenetic results indicate that none of the specimens assigned to this species in previous phylogenetic studies cluster within the clade formed by topotypic samples, except for the sample of one tadpole. Furthermore, our comparison of published phenotypic and genetic data assigned to A. trilineatus with our new data led us to conclude that A. trilineatus as previously recognized was actually a complex of cryptic, closely related species. Although with the data at hand we cannot fully resolve the taxonomy of all sampled populations in previous studies, we provide a new definition and delimitation of A. trilineatus sensu stricto, assign other specimens to different evolutionary units corresponding to candidate species, and flag other important taxonomic issues.
三线蛙是 Allobates 属中第二大地域分布最广的物种，其分布范围从厄瓜多尔北部延伸到秘鲁南部，沿着安第斯山脉的山麓地带一直延伸到亚马逊地区的东部，并延伸到巴西的阿克里州。然而，缺乏来自模式标本的详细表型和遗传变异，这引起了对文献中标本鉴定的怀疑。为了解决这个问题，我们收集了 16 个模式标本——包括雄性和雌性成体和幼体——以及相关数据，如广告叫声和组织样本。基于这些材料，我们重新描述了 A. trilineatus 内的表型变异，并使用线粒体基因 16S rDNA 的一个片段评估其系统发育位置。A. trilineatus 与其近缘种的区别在于其体型较小（成体吻肛长=14.6-16.6 毫米），保存的雄性具有深灰色的喉咙，灰色的胸部和腹部，苍白的背外侧条纹笔直而明显，以及由一系列音符对组成的广告叫声，主导频率在 5.06-5.81 kHz。我们的系统发育结果表明，在以前的系统发育研究中分配给这个物种的标本，除了一个蝌蚪样本外，没有一个聚类在由模式样本形成的分支内。此外，我们将以前发表的表型和遗传数据与我们的新数据进行比较，得出结论认为，以前被认为的 A. trilineatus 实际上是一个由隐密、亲缘关系密切的物种组成的复合体。尽管我们手头的数据不能完全解决以前研究中所有采样种群的分类学问题，但我们提供了 A. trilineatus 严格意义上的新定义和界定，将其他标本分配到不同的进化单元，对应候选种，并标记了其他重要的分类问题。
