Wednesday, August 31, 2016

[Herpetology • 2016] Theloderma lacustrinum • A New Small-sized Theloderma (Anura: Rhacophoridae) from Laos


Theloderma lacustrinum 
Sivongxay, Davankham, Phimmachak, Phoumixay & Stuart, 2016

Abstract

A new species of the rhacophorid frog genus Theloderma is described from the forested shoreline of the Nam Lik Reservoir, Vientiane Province, Laos. The new species differs from its congeners by having the combination of males with SVL 17.0–20.6; pearly asperities on dorsum; no vomerine teeth; disc diameter of finger III ca. 40% of tympanum diameter; uniformly gray venter; light brown dorsum with darker brown and black markings; and a uniformly bronze iris with small black reticulations. Molecular phylogenetic analysis of mitochondrial DNA sequence data infers that the new species is most closely related to T. lateriticum from northern Vietnam. Evidence for the monophyly of Theloderma is reviewed.

Keywords: Amphibia, Nam Lik Reservoir, FrankixalusNasutixalusTheloderma lateriticumTheloderma moloch



Etymology. The specific epithet taken from lacustrinus L., of lakes, in reference to Nam Lik Reservoir, a large, man-made reservoir formed by a hydropower dam that has inundated the vicinity of the type locality.

Diagnosis. Assigned to the genus Theloderma on the basis of molecular data (Fig. 2). A very small-sized (second smallest known) species of Theloderma having the combination of males with SVL 17.0–20.6; pearly asperities on dorsum; no vomerine teeth; disc diameter of finger III ca. 40% of tympanum diameter; uniformly gray venter; light brown dorsum with darker brown and black markings; and a uniformly bronze iris with small black reticulations.



Distribution, natural history, and conservation. Theloderma lacustrinum sp. nov. is currently known only from the type and paratype localities (Fig. 3), where it was collected at night (1820–2215 h) on leaves 30–80 cm above the ground near two rocky streams (292–361 m elev.) in semi-evergreen forest that flow into the Nam Lik Reservoir (Fig. 1). The two known localities are approximately 5.7 air-km apart. We did not observe the new species at these localities during visits in April, July, and September 2015, suggesting that it may be seasonally active or most detectable during cooler, drier months (e.g., at lower heights in the forest canopy). The vicinity of the two known localities had not been surveyed for amphibians prior to construction of the hydroelectric dam, and thus it is not known how inundation from the reservoir may have impacted the range of the species.

Sivongxay, Niane, Monekham Davankham, Somphouthone Phimmachak, Keochay Phoumixay & Bryan L. Stuart. 2016. A New Small-sized Theloderma (Anura: Rhacophoridae) from Laos. Zootaxa.  4147(4); 433–442.  DOI: 10.11646/zootaxa.4147.4.5



  

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