Garg Sonali, Sivaperuman Chandrakasan, Gokulakrishnan G, Chandramouli S R, Biju S D
Systematics Lab, Department of Environmental Studies, University of Delhi, Delhi 110007, India. E-mail:
Andaman and Nicobar Regional Centre, Zoological Survey of India, Port Blair 744102, Andaman and Nicobar Islands, India. E-mail:
Zool Stud. 2022 Feb 14;60:e2. doi: 10.6620/ZS.2022.61-02. eCollection 2022.
Recent studies on frogs of the species complex have demonstrated that high genetic variation exists among its various known populations from regions across Asia. We assessed the taxonomic identity of the Nicobar population of cf. and compared it to the typical from Taiwan and the two recently described species in this complex from Vietnam. Our study demonstrates that the Nicobar population is both genetically and morphologically divergent and warrants recognition as a new species, which we formally describe here as sp. nov. The new species is closely related to , , and , but diagnosable from all three species by a suite of morphological characters, such as the presence of two small tubercles at mid-dorsum along with ( )-shaped markings, length of finger I longer than half the length of finger II, presence of three distinct metacarpal tubercles on hand, rudimentary foot webbing, as well as its slender body shape, granular dorsal skin texture, and other colour characters and body markings. Statistical analyses based on multiple morphometric characters also clearly separate our new taxon from , with which it was previously confused. Our phylogenetic analyses based on the mitochondrial 16S rRNA locus find sp. nov. to be nested in the species group, where it is delimited as a distinct species. This lineage shows genetic distances of ≥ 3.5% from all the other known congeners. Currently, the known distribution of the new taxon is restricted to the southernmost group of Nicobar Islands-Great Nicobar, Kondul, and Little Nicobar-where it is found in abundance across a wide range of habitats during the monsoon season. Our study underlines the need to reassess the identity of all the known populations of '' from other regions in Southeast and East Asia. To facilitate future taxonomic work in the light of our and other recent findings, we also provide a detailed redescription and revised diagnosis for based on morphological examination of its century-old type material originating from Taiwan.
近期对该物种复合体青蛙的研究表明，在其来自亚洲各地的不同已知种群中存在高度的遗传变异。我们评估了尼科巴群岛种群的分类身份，并将其与来自台湾的典型种群以及该复合体中最近在越南描述的两个物种进行了比较。我们的研究表明，尼科巴群岛种群在遗传和形态上都存在差异，有理由被认定为一个新物种，我们在此正式将其描述为新物种。这个新物种与、和密切相关，但可通过一系列形态特征与这三个物种区分开来，例如在背部中部有两个小瘤以及（）形斑纹、第一指的长度长于第二指长度的一半、手上有三个明显的掌突、蹼不发达，以及其细长的体型、颗粒状的背部皮肤质地和其他颜色特征及身体斑纹。基于多个形态测量特征的统计分析也清楚地将我们的新分类单元与之前混淆的区分开来。我们基于线粒体16S rRNA基因座的系统发育分析发现新物种嵌套在物种组中，并被界定为一个独特的物种。该谱系与所有其他已知同属物种的遗传距离≥3.5%。目前，新分类单元的已知分布仅限于尼科巴群岛最南端的大尼科巴岛、孔杜尔岛和小尼科巴岛，在季风季节，它在广泛的栖息地中大量存在。我们的研究强调有必要重新评估东南亚和东亚其他地区所有已知种群的身份。为了根据我们和其他近期的研究结果促进未来的分类学工作，我们还基于对其来自台湾的百年老模式标本的形态学检查，对进行了详细的重新描述和修订诊断。
