Fig. 1. Holotype of Rhacophorus penanorum sp.
n. (ZMB 70718) in life. Photograph taken in the
A new treefrog of the genus Rhacophorus is described from a small montane stream on the southern slope of Gunung Mulu in eastern Sarawak, Malaysian Borneo. The new species is distinguishable from its Southeast Asian congeners by the combination of the following characters: small size; snout sharply pointed, forming a low swollen rostral tubercle at its anteriormost tip; supratympanic fold thick and conspicuous; tympanum diameter one-third of that of eye; canthus rostralis sharp; interorbital distance greater than upper eyelid width and internarial distance; vomerine teeth in two oblique series; dermal appendages on trunk and limbs absent; hands and feet not fully webbed; dorsum uniformly yellowish-green in life; iris ruby-coloured in life with a light grey margin; advertisement call consisting of three or four notes, with energy maximum at 4050-4380 Hz.
Key words: Amphibia, Anura, Rhacophoridae, Rhacophorus penanorum sp. n., taxonomy, natural history, advertisement call, Gunung Mulu National Park, Sarawak, Malaysia, Borneo.
Rhacophorus penanorum sp. n. (Figs. 1-7)
Holotype: ZMB 70718, adult male, from a small stream, 45 minutes by foot below camp four on the southern ﬂank of Gunung Mulu, approx. 1650 m elev., Gunung Mulu National
Park, Miri Division, Sarawak, Malaysia, collected by J. M. Dehling, 4 January 2008.
Distribution and ecological notes: The new species is known only from the type locality, a small permanent headstream of Sungai Tapin on the southern ﬂank of Gunung Mulu (approx. 1650 m elev.), 45 minutes by foot below camp four. he streambed consists of rock in steep, fast-ﬂowing sections and gravel in sections where the current is slower and the stream forms small, shallow pools. he site is also described in Dring (1983a, 1983b). All specimens were found calling fromleaves overhanging the stream at heights between 1.5 and 2 m. he following species were found sympatric with the new species: Ansonia hanitschi Inger, 1960, A. torrentis Dring, 1983, Leptobrachella brevicrus Dring, 1983, Xenophrys dringi (Inger, Stuebing & Tan, 1995), Limnonectes kuhlii (Tschudi, 1838) - complex, Meristogenys kinabaluensis (Inger, 1966), Staurois natator (Günther, 1858), and Philautus mjobergi Smith, 1925. Dring (1983b) reported Leptolalax sp. (= L. dringi Dubois, 1987) from the site.
Etymology: he species epithet is a patronym honouring the Penan people who live in the Gunung Mulu area. he type locality of the new species is situated on one of their traditional hunting trails.
Fig. 4. Type series of Rhacophorus penanorum sp.
n. (top to bottom: ZMB 70719, 70718, 70720),
showing the variation in daytime-colouration.
Dehling, J.M. 2008. A new treefrog (Anura: Rhacophoridae: Rhacophorus) from Gunung Mulu, Borneo. Salamandra. 44(4): 193-205.: