Description of a new species of Pseudophilautus (Amphibia: Rhacophoridae) from southern Sri Lanka

We describe a new Pseudophilautus species, P. conniffae sp. nov. from southern Sri Lanka. It was previously confused with Pseudophilautus rus (Manamendra-Arachchi & Pethiyagoda). The new species differs from the latter by the combination of the following characters: fourth toe webbing to penultimate subarticular tubercle on inner and outer sides (vs. fourth toe webbing in between penultimate and anetpenultimate subarticular tubercles on inner and outer sides), presence of conical median lingual process (vs. absent), and black patches on the posterior flank, anterior and posterior edges of the thigh (vs. black patches on the anterior surface of the thigh). Pseudophilautus conniffae sp. nov. may be sympatric with P. limbus (Manamendra-Arachchi & Pethiyagoda), which shares certain characters with the new species. The new species is, however, distinguished from P. limbus by the following characters: having supernumerary tubercles on manus (vs. lacking), absence of frontoparietal ridges (vs. presence), fourth toe webbing to penultimate subarticular tubercle on both sides (vs. fourth toe webbing between penultimate and anetpenultimate subarticular tubercle on both sides), third toe webbing to distal subarticular tubercle on both sides (vs. distal subarticular tubercle on outer side and below penultimate subarticular tubercle on inner side), and having the dorsum light brown with dark brown patches (vs. black and yellow variegated pattern on dorsum). The new species may be restricted to the southwestern wet zone of Sri Lanka. It is compared with all known Pseudophilautus species and also provided with a field key to identify it from those species that are sympatric with it or inhabit the southwestern wet zone.

INTRODUCTION Sri Lanka possesses highly diverse endemic fauna and flora and is a reservoir of a unique evolutionary history (Myers et al. 2000;Bossuyt et al. 2004). It is also included in the revised hotspots of the world along with the Western Ghats of India (Mittermeier et al. 1998). It was estimated that India's Western Ghats along with Sri Lanka lost more than 70% of its original habitat due to the rapid growth of human population (Myers et al. 2000). In Sri Lanka, the most sensitive and unique amphibian biodiversity is found to be confined to the southwestern wet zone stretching up to the southwestern side of the central massif covering the Peak Wilderness and the Horton Plains Meegaskumbura & Manamendra-Arachchi 2005, 2011Meegaskumbura et al. 2007Meegaskumbura et al. , 2009Meegaskumbura et al. , 2012Wickramasinghe et al. 2013Wickramasinghe et al. , 2015.
The new species described herein was first observed during a biodiversity survey of the Dediyag ala Forest Reserve by the Wildlife Conservation Society-Galle (WCSG).

MATERIALS AND METHODS
Materials used for this study are deposited in the collection of WCSG and will be deposited in the collection of the National Museum Colombo (NMSL). Measurements were taken with KWB dial vernier calipers to the nearest 0.1mm under a stereoscope. The methodology of measurements and anatomical nomenclature follow , except for the lingual papillae. For lingual papillae, we follow the terminology introduced by Grant et al. (1997), the median lingual process. Images were taken using Canon IXUS 50 and Nikon D700 digital cameras. Specimens were fixed in 10% formalin bath and were subsequently stored in 70% ethanol. Bioacoustics data were recorded in the field using a Marantz PMD660 recorder with a Sennheiser MKH20 microphone mounted on to a parabola. Ambient relative humidity and temperature were noted during the recordings. Calls were analyzed using Raven Lite software, Raven Pro: Interactive Sound Analysis Software, Version 1.0 (The Cornell Lab of Ornithology, Ithaca, NY). The calls of the new species (n= 5) were recorded at 76% relative humidity and 27.5 0 C air temperature (during 2000-2300 hr), while the calls of P. rus (n= 4) were recorded at 80% relative humidity and 26 0 C (during 1800-2300 hr). For call character terminology, we followed Cocroft & Ryan (1995). Canthal edges more or less straight. Skin on head coossified with cranium. Nuptial pads absent. Median lingual process present, small and conical. Tarsal tubercle present. Supernumerary tubercles present on manus and pes. Toes medially webbed. Chest and belly heavily granular. Large, dark brown more or less square-shaped blotch on middorsum between forelimbs. Anterior and posterior surfaces of thigh and posterior flank region with black and white patches (Image 1D).
Skin of ventral surface of throat with isolated granules; chest, belly, and underside of thigh heavily granular (Image Forelimbs moderately slender (Image 1A), their dorsal and ventral surfaces smooth. Relative length of fingers: III>IV>II>I (Image 2A); tips of fingers rounded, lateral dermal fringe absent; circum-marginal groove present. Subarticular tubercles rounded to ovoid, distributed on fingers as follows: one on fingers І, ІІ, and ІV, two on finger III (Images 2B); inner palmar tubercle ovoid (Image 2B); outer almost granular, minute; supernumerary palmar tubercles absent. Nuptial pads absent (Image 2A).
Hind limbs slender (Image 1A,B); tarsal fold absent; tarsal tubercle present. Dorsal areas of thigh, shank, and pes with a few scattered granules. Toes long, slender, their relative length: IV>III~V>II>I (Image 2C); toes medially webbed (Image 2C), their tips rounded; inner metatarsal tubercle elongate, no external tubercle (Image 2B). Subarticular tubercles rounded, small, distributed on toes as follows: one on toes I and II, two on toes III and V, three on toe IV (Image 2B,C).
Colour in life: (See Images 2D,E). Dorsum light brown  B). Dorsum greyish with dark grey-brown patches. Anterior mid-region of the body with a large, dusky, square-shaped patch. The region below supratympanic fold dusky brown than that above, tympanum dusky brown than the area surrounding it, lower margin of tympanum whitish. Loreal region greyish. Anterior flank greyish; posterior flank, anterior, and posterior thigh marbled in black and white. Dorsal and lateral sides of forelimb, dorsal side of thigh, dorsal side of shank, and dorsal side of pes brown with dark brown crossbars. Throat pale white with dark brown pigments; margins of lower jaw, anterior chest, belly, and underside of thigh pale white with dark brown pigments. Webbing black with small grayish patches.
Vocalization: Pseudophilautus conniffae sp. nov. is able to emit two different call types, of which one consists of a long series of unpulsed click-like notes repeated at regular intervals. The other call type consists of a shorter series of very short whistling notes repeated in fast succession (Fig. 1A). The latter call appears to be the advertisement call of P. conniffae sp. nov. The advertisement call of the species may be distinguished from that of P. rus by the greater call length  Variation: Single specimen had less prominent warts on dorsum (NMSL WCSG 0003): snout, interorbital region, sides of head, and dorsum had isolated glandules. The angle of snout in dorsal view was approximately 80 0 in females and ~90 0 in males.
Etymology: The species name is an eponym honoring Karen Iynn Conniff for her generous support for the establishment of the WCSG and for her efforts to document the Odonata of Sri Lanka.
Distribution: Pseudophilautus conniffae sp. nov. was recorded from Galle and Matara districts (~80-300 m elevation; Fig. 2). It is confined to the rainforest areas in both districts. Pseudophilautus conniffae sp. nov. appears to be a habitat specialist as it was often observed in bamboo Davidsea attenuata vegetation (on dry bamboo leafs). It was observed calling from leaves and bamboo branches less than 1m above the ground.  Fig. 95f vs. Image 2B,C).
We note in passing that although Manamendra-Arachchi & Pethiyagoda (2005) stated that nuptial pads were absent in males of P. silvaticus, we observed these to be present in all male specimens of its type series. While examining the type specimens of the species described recently by Wickramasinghe et al. (2013), we observed a few discrepancies: the authors mentioned that the tympanum of P. newtonjayawardanei is wanting, but we observed the presence of tympanum in the holotype and its upper one-third is covered by supratympanic fold. Wickramasinghe et al. (2013) stated that P. dayawansai lacks vomerine teeth, whereas we observed the same in the holotype.    (Boulenger, 1904): vomerine teeth absent and toes fully webbed; P. poppiae (Meegaskumbura & Manamendra-Arachchi, 2005): vomerine teeth and supernumarary tubercles absent on pes; P. popularis : nuptial pads present in males and vomerine teeth absent; P. procax : supernumarary tubercles absent on pes and a suborbital pale blotch present; P. puranappu Wickramasinghe et al., 2013: presence of nuptial pads and supernumarary tubercles absent on pes; P. regius : throat heavily granular and nuptial pads present in males; P. rus : absence of conical median lingual process and anterior surface of thigh with black patches; P. samarakoon Wickramasinghe et al, 2013: nuptial pads present, absence of both median lingual process and vomerine teeth; P. sarasinorum (Müller, 1887): skin on head not co-ossified with cranium and vomerine teeth absent; P. schmarda (Kelaart, 1854): prominent lateral dermal finge on lower arm and tarsus and vomerine teeth absent; P. semiruber (Annandale, 1913): vomerine teeth absent and supratympanic fold feebly developed; P. silus : throat heavily granular and skin on head not co-ossified with cranium; P. silvaticus : skin on head not co-ossified with cranium and presence of a V-shaped tubercular pattern starting behind eyes extending towards midline of dorsum; P. simba : skin on head not co-ossified with cranium and no vomerine teeth; P. sirilwijesundarai Wickramasinghe et al., 2013: absence of vomerine teeth, presence of nuptial pads and absence of median lingual process; P. steineri (Meegaskumbura & Manamendra-Arachchi, 2005): skin on head not co-ossified with cranium and nuptial pads present in males; P. stellatus (Kelaart, 1853): supratympanic fold indistinct and spotted dorsal colouraton; P. stuarti (Meegaskumbura & Manamendra-Arachchi, 2005): vomerine teeth absent and skin on head not co-ossified with cranium; P. viridis : vomerine teeth absent and skin on head not co-ossified with cranium; P. zorro : calcar present and vomerine teeth absent.
The new species can also compared with three Indian species of Pseudophilautus (Dinesh et al. 2017) (only opposing characters are mentioned): P. amboli (Biju & Bossuyt, 2009): presence of nuptial pads in males and absence of median lingual process; P. kani (Biju & Bossuyt, 2009): absence of nuptial pads in males and median lingual process; P. wynadensis (Jerdon, 1853): absence of both vomerine teeth and median lingual process.  Meegaskumbura et al. 2007Meegaskumbura et al. , 2009Meegaskumbura et al. , 2012Wickramasinghe et al. 2013aWickramasinghe et al. ,b,c, 2015Dinesh et al. 2017). The discovery of P. conniffae sp. nov. increases the assemblage of frog fauna of the lowland wet zone of Sri Lanka to 17.
Based on their morphological and mensural data ( Table 1 vs. Table 2), Pseudophilautus conniffae sp. nov. is easily distinguished from P. rus. To support our conclusion, however, we here analyzed the call structure of both species. The two species are easily distinguished by their call length, frequency, pulse length, and the pulse per call (Fig. 1A vs. 1B). In addition, the type series of Pseudophilautus rus were collected from Kandy (7.283 N & 80.583 E,~500m) in the Kandy District, whereas the type locality of P. conniffae sp. nov. is Dediyagala (6.166 N & 80.433 E, 80m) in Matara District. The two localities are at a ~200km straight-line distance and also in different zoogeographic zones (Central Hills and lowland wet zone, respectively). We confirmed that P. conniffae sp. nov. is restricted to lowland wet zone rain forests (in Galle and Matara districts), while P. rus is confined to forests and forest buffer zones of the Central Hills around Kandy District (see Fig. 2) and to Morningside in the Rakwana Hills (Meegaskumbura et al. 2012 in lowland wet zone forests such as Kottwa-Kombala, Kanneliya, and Dediyagala. Grant et al. (1997) stated no intraspecific variation in the median lingual process in frogs and also mentioned that both sexes and all sizes of frogs had this character. Interestingly, we observed a paratype of P. silvaticus (WHT 3378, an adult male) wanting this character (see also Manamendra-Arachchi & Pethiyagoda 2005; e.g., P. folicola and P. viridis). Thus, the individual variation of such characters, including the median lingual process, in Sri Lankan Pseudophilautus needs to be studied in the future.
Based on its present distribution data, Pseudophilautus conniffiae sp. nov. can be a Near Threatened species. The species has a restricted distribution and is highly vulnerable due to habitat fragmentation (Manamendra-Arachchi & Pethiyagoda 2005). Hence, conservation assessment of the species needs to be initiated in the future. www.threatenedtaxa.org The Journal of Threatened Taxa (JoTT) is dedicated to building evidence for conservation globally by publishing peer-reviewed articles online every month at a reasonably rapid rate at www.threatenedtaxa.org. All articles published in JoTT are registered under Creative Commons Attribution 4.0 International License unless otherwise mentioned. JoTT allows allows unrestricted use, reproduction, and distribution of articles in any medium by providing adequate credit to the author(s) and the source of publication.