Description
Pseudophilautus semiruber is an extremely small frog with a stout body. The skin is smooth on the entire body (flanks, dorsum, and venter), with the exception of a mid-dorsum dermal ridge running from back of the head to the vent. The head is convex laterally, and the snout is oval viewed from either the top or the side. The skin on the head is not co-ossified. The space between the eyes is concave, while the area between the nostrils is flat. The nostrils themselves are oval in shape. The pupil of P. semiruber, which runs horizontally, is oval as well. The tympana are distinctly oval and vertical. The tongue is elongate with no lingual papilla. No vomerine ridges are present. A very weakly defined supratympanic fold is present. The forelimbs are short and slender. The fingers are slender as well with relative length (from shortest to longest) I, II, IV, III. The fingertips have discs with circumarginal grooves. The hands have rudimentary webbing, with no dermal fringes. The dorso-lateral fold is absent. The rear limbs and digits are slender, with relative toe length (from shortest to longest) of I, II, V, III, IV (Meegaskumbura et al. 2011).

P. semiruber can be distinguished from its close relatives by its small size when adult (12-13.4 mm snout-vent length), rounded canthal edges, distinct tympanum, lack of a vomerine ridge, weakly defined supratympanic fold, and smooth skin on its underside (Meegaskumbura et al. 2011).

Coloration: In life, P. semiruber is generally a gray-brown color when viewed from above. The front half of the head is ashy brown. The face and lips are ash-colored. The area from the interorbital region through the back of the dorsum is gray. The flanks are ash-brown with occasional white patches outlined in red. The mid-dorsal ridge is red. The upper portions of the arms, thighs, and feet are red, with darkened crossbars on the hind limbs. The undersides of the thighs are an orange-red, with white patches. The throat is ashy-brown with white patches while the chest and belly are reddish brown with white patches.

When preserved in ethanol, the gray and ash-brown colors appear as a dark brown. The white patches become yellowish, and all red coloration fades to brown. The mid-dorsal ridge appears pale brown (Meegaskumbura et al. 2011).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Sri Lanka

View distribution map in BerkeleyMapper.

P. semiruber inhabits the montane forest of the area around Pattipola and Agra-Bopath in Sri Lanka. The elevation of this region is around 1800 m (Agra-Bopath 1750 m, Pattipola 1829 m) above sea level. P. semiruber inhabits the shaded leaf litter on the forest floor (Meegaskumbura et al. 2011).

Life History, Abundance, Activity, and Special Behaviors
P. semiruber is diurnal and inhabits the leaf litter on the forest floor (as opposed to the shrubbery inhabited by many members of the genus) (Meegaskumbura et al. 2011).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Loss of genetic diversity from small population phenomena

Comments
P. semiruber was first described as Ixalus semiruber in 1913 by Annandale, but had not been seen in nearly 100 years until its rediscovery and re-analysis by Meegaskambura et al. (2011) in the early twenty-first century. The holotype (ZSIC 17401) had been lost, but the 1913 drawings and descriptions were sufficient to identify the species.

P. semiruber is most closely related to P. simba (4% different in 16s mtDNA sequences), which is slightly larger (12.6-15.6 mm SVL in P. simba vs. 12-13.4 mm SVL in P. semiruber). There is one other diminutive Pseudophilautus species, P. tanu (13.5-13.9 mm SVL), which is more distantly related than P. simba, and is a nocturnal shrub dweller while both P. semiruber and P. simba are diurnal and inhabit the leaf litter (Meegaskumbura et al. 2011).

References

Meegaskumbura, M., Manamendra-Arachchi, K., Bowatte, G., and Meegaskumbura, S. (2012). ''Rediscovery of Pseudophilautus semiruber, a diminutive shrub frog (Rhacophoridae: Pseudophilautus) from Sri Lanka.'' Zootaxa, 3229, 58-68.

Species Account Citation: AmphibiaWeb 2012 Pseudophilautus semiruber <https://amphibiaweb.org/species/6484> University of California, Berkeley, CA, USA. Accessed Nov 22, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Nov 2024.

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