Department of Tropical Biology, Faculty of Biology, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia.
Systematics Lab, Department of Environmental Studies, University of Delhi, Delhi 110007, India .
Zootaxa. 2021 Sep 2;5027(4):451-488. doi: 10.11646/zootaxa.5027.4.1.
A tiny new species of narrow-mouthed frog of the genus Microhyla is described from the island of Belitung and southeastern Sumatra, Indonesia. The most distinctive feature of the new frog is its diminutive adult size, snout-vent length ranging only from 12.3 to 15.8 mm in adult males. Phylogenetic analyses based a fragment of the mitochondrial 16S rRNA gene, along with detailed morphological and acoustic comparison differentiate the new taxon from all known congeners. The new species, formally described as Microhyla sriwijaya sp. nov., is a member of the M. achatina species group and the sister taxon to M. orientalis. It is diagnosable from other congeners by a combination of characters: (1) smaller male snout-vent size 16 mm; (2) snout obtusely rounded in dorsal view; (3) absence of mid-dorsal line and skin fold; (4) first finger reduced (finger I length less than half of finger II length); (5) dorsum with a prominent dark median mark extending posteriorly, narrow anteriorly near the level of the shoulder and expanding dorsolaterally up to the vent; margins of the dorsal marking concave with broad reddish-brown or orange colouration on either side; (6) foot webbing rudimentary, reaching just up to the first subarticular tubercle on all toes; (7) dorsal skin with prominent tubercles, especially in life; (8) tibiotarsal articulation of adpressed limb reaching beyond the snout tip; and (9) males produce a single type of call with pulsatile temporal structure, calls of relatively short duration ranging between 31.862.8 s, with two to three pulses delivered at a rate ranging between 32.236.0 pulses per second, and the mean overall dominant frequency of 4.3 kHz. The uncorrected pairwise genetic distances between Microhyla sriwijaya sp. nov. and all other known congeners are > 3.8% for the studied 16S gene fragment. The new species was discovered from wayside rural areas with oil palm plantations at four localities in the small island of Belitung (type locality), and from coffee plantation and secondary forest at Lampung in southeastern Sumatra. It is not known from any protected area and appears to be threatened due to tin mining activity, intensive logging, oil palm, and other commonly practiced agriculture activities.
一种新的小袋蛙属的窄口蛙，即 Microhyla sriwijaya sp. nov.，被描述为来自印度尼西亚的勿里洞岛和苏门答腊东南部。这种新蛙类最显著的特征是其微小的成体体型，雄蛙的吻肛长度仅为 12.3 至 15.8 毫米。基于线粒体 16S rRNA 基因片段的系统发育分析，以及详细的形态和声学比较，将新分类群与所有已知的同属种区分开来。新种被正式描述为 Microhyla sriwijaya sp. nov.，是 M. achatina 物种群的成员，也是 M. orientalis 的姊妹种。它可以通过以下特征与其他同属种区分开来：（1）雄蛙的吻肛长度较小，为 16 毫米；（2）在背面观察时，吻部钝圆；（3）无中背线和皮肤褶皱；（4）第一指节退化（第一指节长度小于第二指节长度的一半）；（5）背部有一个明显的深色中线标记，向后延伸，在肩部附近变窄，向外侧扩展至腹部；背部标记的边缘凹陷，两侧有宽阔的红棕色或橙色着色；（6）足部蹼不发达，仅延伸到所有脚趾的第一个亚关节结节；（7）背部皮肤有明显的结节，尤其是在活体中；（8）跗跖关节的压缩肢体伸展超过吻尖；（9）雄性发出一种具有脉冲时间结构的单一类型的叫声，叫声持续时间相对较短，介于 31.862.8 秒之间，每秒发出两到三个脉冲，平均总主导频率为 4.3 kHz。在研究的 16S 基因片段中，Microhyla sriwijaya sp. nov.与所有其他已知同属种之间的未校正配对遗传距离均大于 3.8%。新种是在勿里洞岛（模式产地）的四个地点的路边农村地区以及苏门答腊东南部的 Lampung 的咖啡种植园和次生林中发现的，在任何保护区都没有发现它，由于锡矿开采活动、密集的伐木、油棕榈和其他常见的农业活动，它似乎受到威胁。
