For more detailed description of color (often from preserved specimens), see Brown and Alcala (1980).
(Coloration in preservative; Brown and Alcala, 1980)
Dorsal Coloration: yellowish brown to light brown, 7-8 large irregular, diamond-shaped blotches between head and hind limbs
Ventral Coloration: dirty ivory to light tan, beneath head and on throat coloration grayish to slate brown, sometimes with whitish scales
Of the 28 currently recognized species of skink in the genus Tropidophorus, four are recognized to occur in the Philippines (T. davaoensis, T. grayi, T. misaminius, and T. partelloi). Commonly referred to as Water or Keeled Skinks, this enigmatic radiation of Southeast Asian lizards consists of species that prefer habitat in and around stream and river systems.
In the Philippines, all four species are commonly observed underneath leaf litter, rocks, and collected piles of debris on the banks and in the middle of stream systems. Their unique morphologies make them easily identifiable in comparison to all other genera of Philippine lizards. Although variation in morphological characters has been documented between populations in the Philippines (Taylor, 1922), Brown and Alcala (1980) were the last to categorize and describe the country's diversity, recognizing only four species. The widespread species, T. grayi, exhibits large differences in adult body sizes between island populations, and likely includes multiple, unique evolutionary lineages in need of recognition.
There are only four recognized species of the genus Tropidophorus that are recongized to occur in the Philippines. Tripidophorus davaoensis can be distinguished from its congeners by the following combination of characters: (1) keels on dorsal scales of body low, not terminating in projecting spines; (2) keels on dorsal scales of tail may or may not terminate in low prejecting spines; (3) midbody scale rows 36-38; (4) scale rows between parietals and base of tail 56-60; (5) 4th toe lamellae 19-22; (6) frontonasal divided; (7) parietals usually in contact behind interparietal; and (8) anterior loreal forming 2 superimposed scales (Brown and Alcala, 1980).
This species is recognized to occur in south central Mindanao Island in the Philippines. A single individual (SM 28071) was reportedly collected from the Zamboanga Peninsula in western Mindanao Island (Brown and Alcala, 1980); however, subsequent surveys of the region have resulted in the observation of Tropidophorus misaminius only. Additional survey work in western Mindanao Island will be required to confirm whether the distribution of T. davaoensis extends across Mindanao.
Named in recognition of its type locality, Davao Province
Mindanao Pleistocene Aggregate Island Complex (PAIC; Brown and Diesmos, 2002).
This species has been observed beneath rocks around and within a damp stream bed within mid-elevation forest (600-750 m) (Brown and Alcala, 1980).
SVL 92-97 mm (Bacon in Brown and Alcala, 1980)
Near sea level in the Municipality of Caburan, Davao Province, Mindanao Island, Philippines; type in the Field Museum of Natural History; FMNH 52677, adult male