Monday, April 27, 2015

[Herpetology • 2015] Pseudophilautus dilmah | Dilmah Shrub Frog | Dilmah panduru madiya • A New Species of Shrub Frog (Anura: Rhacophoridae) from A Threatened Habitat Loolkandura in Sri Lanka

Dilmah Shrub Frog | Dilmah panduru madiya 
Pseudophilautus dilmah
Wickramasinghe, Bandara, Vidanapathirana, Tennakoon, Samarakoon & Wickramasinghe, 2015


A new species of shrub frog Pseudophilautus dilmah is described from the Central Hills of Sri Lanka. This unique species is distinguished from all the other congeners from a combination of characters; snout rounded in lateral aspect, bluntly pointed in dorsal and ventral aspect, canthus rostralis rounded, vomerine teeth, lingual papilla and nuptial pads absent, dermal fringe distinct on inside of fingers III and IV, small blunt tubercles on metacarpal and ulnar folds, toes basally webbed, interorbital area smooth, upper eyelid prominent tubercles present, anterior and posterior dorsum without horny spinules but tubercles present, upper part of flank weakly granular, supratympanic fold distinct, prominent small calcar present at the distal end of the tibia, throat granular, chest and belly coarsely granular. Based on comparison of 16s rRNA gene we also show that the species is genetically distinct from other members of Pseudophilautus for which gene sequences are available. The high rate of deforestation and anthropogenic activities threaten this population in its natural habitat.

Keywords: Amphibian, biodiversity hotspot, Dilmah Shrub Frog, new taxa, Pseudophilautus dilmah.

Etymology: The species epithet dilmah is named after Dilmah Conservation [], for its dedicated efforts to biodiversity conservation on the Island. Dilmah is treated as an invariable noun in apposition to the generic name.

Suggested vernacular names: Dilmah panduru madiya, and Dilmah Shrub Frog in Sinhala, and English respectively.

Pseudophilautus dilmah sp. nov., appears to be more resembling to P. bambaradeniyai, (Fig. 2) than to any other species of the same genus. But considering molecular evidences P. bambaradeniyai has been placed in a well separated clade with P. frankensbergi (Meegaskumbura & Manamendra-Arachchi 2005) with a pairwise genetic distance of 10%, which suggests a species level divergence. Although they were both found from the Central Hills they are allopatric. Loolkandura the type locality of P. dilmah sp. nov., is positioned towards the northern tip of the Central Hills where as Peak Wilderness the type locality of P. bambaradeniyai, and the only locality it is found in, is positioned towards south-west of Loolkandura (Fig. 1).

Although P. dilmah sp. nov., is genetically most closest to P. hankeni and P. schmarda, with genetic
distances of 1.6% and 1.9%, respectively, the species is morphologically distinct and can be separated by the characters mentioned in the comparison. Furthermore P. hankeni is distributed in the Knuckles massif which is geographically well separated, and although P. schmarda is distributed in the Central Hills they are allopatric (Fig. 1). Although 3% genetic distance is a good indication

Vences et al. (2005) mention that interspecies genetic distances could be from 1% to 10% and allopatric species are known with less than 3% differences. The pairwise distance for P. pleurotaenia (Boulenger 1904) and P. hoipolloi (Manamendra-Arachchi & Pethiyagoda 2005), for P. asankai (Manamendra-Arachchi & Pethiyagoda 2005) and P. hoffmanni (Meegaskumbura & Manamendra-Arachchi 2005), for P. decoris and P. mittermeieri, were 0.5%, 1%, and 1.4%, respectively. All of which are considered valid morphologically yet have a lower genetic distance than 1.6% for P. dilmah and P. hankeni, and 1.9% for P. dilmah and P. schmarda, hence our current genetic distances from its sister taxa suggests species level divergence.

Wickramasinghe, L.J.M., I.N. Bandara, D.R. Vidanapathirana, K.H. Tennakoon, S.R. Samarakoon & N. Wickramasinghe. 2015. Pseudophilautus dilmah, A New Species of Shrub Frog (Amphibia: Anura: Rhacophoridae) from A Threatened Habitat Loolkandura in Sri Lanka. Journal of Threatened Taxa. 7(5): 7089–7110. DOI: 10.11609/JoTT.o3501.7089-110