Polypedates megacephalus, known as the Hong Kong whipping frog, spot-legged treefrog, white-lipped treefrog, and hour-glass-marked treefrog, is a brown rhacophorid treefrog common in tropical/subtropical central, southern and south-western China including Hong Kong, northeastern India, northern Vietnam, and Thailand.It may also occur in Myanmar and Laos (Frost 2016; Lau 2009).This species is taxonomically difficult because it is part of the large and widespread Polypedates leucomystax cryptic species complex. Much work has gone into clarifying this complex. In 1986, Matsui et al. distinguished P. megacephalus as a distinct species on the basis of karyotype, acoustic calls and adult morphological characters (but not coloration patterns).More recently, molecular analyses have confirmed P. megacephalus, P. leucomystax (the four-lined treefrog), and a number of other lineages as distinct species from as well as a number of other lineages in the P. leucomystax complex. This research indicates that the wide-spread P. megacephalus is itself a complex that likely includes more than one species (Frost 2016; Li et al. 2008; Pan et al. 2013, Yu et al. 2008; Kuraishi et al. 2013).
Found between sea level and 1500 m asl, P. megacephalus inhabits marshes, plantations, ponds and forests near still water.Adults are brown in color, with a diverse variation of coloration patterns.Males are distinctly smaller than females (44.5 vs 60.9 mm average SVL measured from western China).Fingers are not webbed, toes about half webbed, as is characteristic of the genus.Adults hide under rocks and vegetation during the day, and are active at night often migrating into nearby water.During its long breeding season, which can last from May to late August, frogs start calling at twilight (Liu 1950).Like most rhacophorid species, female frogs generate a sticky foam nest for its eggs, often depositing it near the edge of a still pool or on emergent vegetation. Females lay 300-400 small, white eggs per nest (Lau et al. 2008).The tadpoles drop into the water when they hatch about a week later.The tadpoles have creamy white bellies, and a small cream round spot on the snout (Liu 1950).The full development of this species in lab has been studied (Xu, Li and Li 2007).
This frog is abundant in its range, and is able to live in a wide range of habitats including disturbed areas and those converted to agricultural use and near human habitation. Like other species in the P. leucomystax complex, its very sticky toe pads and ability to withstand desiccation make it adept to being inadvertently transported. Development of forest to homogeneous agriculture land may well have enlarged its range and altered population and range restrictions. Kuraishi et al. (2013) suggest for these reasons that humans may have played an important role in the complicated evolution of these lineages since the origination of the complex in the Pleiocene.Established breeding colonies are known from Guam since 2004 (Lau et al. 2009; Christy et al. 2007), and perhaps (as P. leucomystax) from islands of Japan (Kuraishi 2009).
The full mitochondrial genome of P. megacephalus has been sequenced (Zhang 2005).
