A New Limnonectes (Anura: Dicroglossidae) from Southern Thailand.

Siriporn Yodthong,Bryan L Stuart,Anchalee Aowphol,Attapol Rujirawan

doi:10.3390/ani11020566

Abstract

Simple SummaryNew species of frogs continue to be discovered at a rapid rate in Southeast Asia, often as a result of reexamining populations of geographically widespread species using new molecular and bioacoustic tools. Here, we show that members of the fanged frog genus Limnonectes from Ko Pha-ngan, Ko Samui, and Ko Lanta Yai Islands in southern Thailand can be distinguished from the morphologically similar species Limnonectes doriae in molecular, advertisement call, morphometric, and qualitative morphological characters. On the basis of these multiple lines of evidence, we describe the insular populations in southern Thailand as a new species, Limnonectes pseudodoriae sp. nov. The new species occurs near small streams in low to mid-elevation forests and breeds in terrestrial nests consisting of moist, clay depressions in which the eggs and larvae develop.A new species in the dicroglossid frog genus Limnonectes is described from Ko Pha-ngan, Ko Samui, and Ko Lanta Yai Islands in southern Thailand. Males of Limnonectes pseudodoriae sp. nov. lack a caruncle on top of the head and very closely resemble L. doriae (Boulenger, 1887) from Myanmar and western and southern Thailand. However, the new species is distinguished from L. doriae and its congeners using an integrative taxonomic approach of morphology, mitochondrial DNA, and bioacoustics. Limnonectes pseudodoriae sp. nov. differs from L. doriae and its congeners by having a unique combination of morphological characters, including body size; skin texture of the interorbital region, dorsum, and shank; toe webbing; relative size of the inner metatarsal tubercle; and coloration of the tympanum, venter, and ova. The advertisement call of the new species is also readily differentiated from that of L. doriae in temporal parameters. Limnonectes pseudodoriae sp. nov. is highly divergent in mitochondrial DNA from L. doriae and its congeners, but its phylogenetic position within the genus is not resolved. The natural history of the new species is presented, and the geographic range of L. doriae in Thailand is clarified.

Highlights

The dicroglossid frog genus Limnonectes Fitzinger, 1843, contains 76 recognized species and is widely distributed in East and Southeast Asia [1]
The first two principal components (PC) accounted for a cumulative 63.9% of the total variation and loaded most heavily for EYEadj, INDadj, SHKadj, TGHadj, HNDadj, FTLadj, IMLadj, TMPadj, and TMP/EYE along PC1 (40.6% of the total variation), for HDLadj, HDWadj, SNTadj, IODadj, and IMWadj along PC2 (23.2% of the total variation; Table 3). These results indicated that males of the new species had larger tympana (TMPadj, TMP/EYE), but smaller eye (EYEadj ), internarial distance (INDadj ), forelimbs (HNDadj ), hindlimbs (SHKadj, THGadj, FTLadj ), and inner metatarsal tubercles (IML adj ) than did males of L. doriae based on scores of the first two axes (Figure 3A)
The first two PC accounted for a cumulative 81.0% of the total variation and loaded most heavily for the most characters except TMPadj and TMP/EYE along PC1 (66.1% of the total variation), for TMPadj, and TMP/EYE along PC2 (14.9% of the total variation; Table 3). These results indicated females of the new species had smaller body size (SVL), heads (HDLadj, HDWadj ), snout length (SNTadj ), internasal distance (INDadj ), eye (EYEadj ), interorbital distance (IODadj ), forelimbs (HNDadj, LALadj ), hindlimbs (SHKadj, TGHadj, FTLadj ), and inner metatarsal tubercles (IMLadj, IMWadj ) did than females of L. doriae based on scores of the first two axes (Figure 3B)

Summary

Introduction

The dicroglossid frog genus Limnonectes Fitzinger, 1843, contains 76 recognized species and is widely distributed in East and Southeast Asia [1]. Males of some Limnonectes species have a swollen or cap-like structure on the top of the head or “caruncle” [2,3,4,5,6,7,8]. Members of this genus tend to exhibit a great deal of morphological similarity [9,10]. Limnonectes lauhachindai Aowphol, Rujirawan, Taksintum, Chuaynkern, and Stuart, 2015, from northeastern Thailand morphologically resembled L. gyldenstolpei (Andersson, 1916) and L. dabanus (Smith, 1922); L. coffeatus Phimmachak, Sivongxay, Seateun, Yodthong, Rujirawan, Neang, Aowphol, and Stuart, 2018, from southern Laos morphologically resembled L. kohchangae (Smith, 1922); and L. savan Phimmachak, Richards, Sivongxay, Seateun, Chuaynkern, Makchai, Som, and Stuart, 2019, from northeastern Thailand and southern and central Laos morphologically resembled L. dabanus

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