Pseudophilautus semiruber ( Annandale, 1913 )

Meegaskumbura, Madhava, Manamendra-Arachchi, Kelum, Bowatte, Gayan & Meegaskumbura, Suyama, 2012, Rediscovery of Pseudophilautus semiruber, a diminutive shrub frog (Rhacophoridae: Pseudophilautus) from Sri Lanka, Zootaxa 3229, pp. 58-68 : 60-62

Pseudophilautus semiruber ( Annandale, 1913)

Figs 2−4

Ixalus semiruber Annandale, 1913: 305 .

Material examined. Mature female, 13.4 mm SVL, WHT5831, Agra-Bopath forest, 1750 m a.s.l. (06º50'15"N, 80º40’50"E), coll. 01 August 2005, Madhava Meegaskumbura & Mohomed Bahir.

Diagnosis. ‘ Ixalus ’ semiruber is assigned to the genus Pseudophilautus as it is well nested within the Sri Lankan monophyletic group ( Fig. 1 ) of shrub frogs ( Meegaskumbura et al. 2002; Bossuyt et al. 2004; Yu et al. 2010) characterized by terrestrial direct development ( Bossuyt and Dubois 2000). Pseudophilautus semiruber is distinguished from all other Sri Lankan congeners by a combination of the following characters: size small, mature individuals [12.0]– 13.4 mm SVL; canthal edges rounded; tympanum distinct; vomerine ridge absent; supratympanic fold feebly defined; throat, chest, belly and underside of thigh smooth.

Description. Body stout. Head laterally convex. Snout oval in dorsal and lateral view. Canthal edges rounded. Loreal region flat. Interorbital space concave. Internarial space flat. Nostrils oval. Pupil oval, horizontal. Tympanum distinct, oval, vertical, its outer rim narrow but clear. Pineal ocellus absent. Vomerine ridge absent. Tongue moderate, elongate, emarginate; no lingual papilla. Supratympanic fold feebly defined. Cephalic ridges absent.

Skin on head not co-ossified. Upper arm short, lower arm slender. Fingers slender, relative length of fingers, 1<2<4<3. Tips of fingers with discs bearing circum-marginal grooves, lacking lateral dermal fringes but with rudimentary webbing. Subarticular tubercles on fingers feebly defined, oval, single. Prepollex oval, feebly defined. Two palmar tubercles, oval, feebly defined. Supernumerary tubercles present on fingers and palm. Thigh, shank, toes slender. Relative length of toes, 1<2<5<3<4. Tips of toes with discs bearing circum-marginal groves. Webbing present on toes. Subarticular tubercles on toes distinct, oval, single, all present. Inner metatarsal tubercle distinct, oval. Tarsal fold absent. Outer metatarsal tubercle absent. Supernumerary tubercles present on toes and on foot. Tarsal tubercle absent. Dorsal and lateral parts of head and body, and lower part of flank, smooth. Dorso-lateral fold absent. Dorsal and lateral parts of upper arm, lower arm, thigh, shank and foot smooth. A narrow dermal ridge on mid-dorsum to back of head, then to vent. Throat, chest, belly and underside of thigh smooth.

Coloration. In life, dorsal surface of head ashy brown, inter-orbital region and dorsum gray. Flank ashy brown with a few white patches outlined in red. Inguinal zone dark brown with white patches. Loreal region, tympanic region, tympanum and lips ash. Entire upper arm and proximal half of lower arm dorsally red, a black band extending antero-dorsally from base of the upper arm to proximal half of lower arm. Distal half of lower arm and fingers dorsally reddish brown, vaguely banded with black. Thigh and inner shank dorsally red with ashy-brown crossbars outlined in black. Thigh and shank ventrally light red with white patches; inguinal zone red-orange. Foot dorsally red, ventrally ashy brown. Area around vent ashy brown. Throat and margin of throat ashy brown with whitish patches; chest and belly reddish brown with white patches.

Stored in 70% ethanol, following fixing in 10% buffered formalin, mid-dorsal area dark brown, mid-dorsal ridge pale brown. Head dorsally dark brown. Both upper and lower flanks pale brown. Inguinal zone pale brown with dark-brown patches. Loreal, typanum, tympanic region, supratympanic fold, upper and lower lips dark brown. Dorsal and lateral areas of limbs dark to pale brown. Anterior and lateral margins of lower arm and upper arm with dark-brown markings. Dorsal area of thigh, shank and foot with wide, dark cross-bars. Knees dark brown. Ventral parts of head, body, both upper and lower arms, fingers, thigh, shank, foot and toes dark brown with yellow spots and patches.

Measurements of WHT5831 (in mm): DBE, 4.0; DFE, 2.5; DL, 0.4; DW, 0.5; ED, 1.7; EN, 1.0; ES, 2.4; FEL, 5.9; FL I, 1.0; FL II, 1.2; FL III, 2.2; FL IV, 1.8; FOL, 8.6; HL, 5.4; HW, 5.5; IML, 0.7; IN, 2.0; IO, 1.8; LAL, 6.5; MBE, 1.8; MFE, 3.2; MN, 4.1; NS, 0.8; PAL, 3.4; SVL, 13.4; TBL, 6.3; TL I, 1.1; TL II, 1.3; TL III, 1.9; TL IV, 3.0; TL V, 1.8; TYD, 0.5; TYE, 0.8; UAW, 3.3; UEW, 0.9.

Distribution. Pseudophilautus semiruber was originally described from a single specimen collected at Pattipola (06º51'20"N, 80º49’40"E; 1,850 m a.s.l.), about 8 km southeast of Agra-Bopath (06º50'15"N, 80º40’50"E). The species is probably restricted to the montane forests of this area ( Fig. 5 ), and is probably under-represented in collections because its diminutive size may have led to it being overlooked as the juvenile of an arboreal Pseudophilautus and because relatively little collection effort has involved searching through leaf litter on the forest floor, which is apparently the habitat of this ‘shrub-frog’.

Figures

FIGURE 1. Maximum likelihood tree of 12 s and 16 s rRNA gene fragments, with posterior probabilities from the Bayesian analysis shown above and Maximum Parsimony Bootstrap values shown below the nodes respectively. Pseudophilautus semiruber (**) forms a clade with P. s i m b a and P. cf. simba (*).

FIGURE 2. Pseudophilautus semiruber (WHT 5831), in life, Agra-Bopat Forest Reserve. A. profile; B. dorsal aspect; C. fronto-dorsal aspect; D. ventral aspect.

FIGURE 3. Pseudophilautus semiruber: a, dorsal (whole body); b, profile; c, dorsal; d. ventral aspects, respectively, of head of female, WHT 5831, 13.4 mm SVL. Scale bar: 1 mm.

FIGURE 4. Pseudophilautus semiruber: a, ventral aspect of right manus; b, ventral aspect of right pes; and c, semi-diagramatic representation of the right-pes webbing pattern of female, WHT 5831, 13.4 mm SVL. Scale bar: 1 mm.

FIGURE 5. Distribution of Pseudophilautus semiruber (open circle) and P. s i m b a (blue circle) and P. t a nu (purple circles), in Sri Lanka.