Gekko palawanensis is one of ten currently recognized, endemic species of Gekko in the Philippines. This species is the smallest species of the genus Gekko known to occur in the Philippines. It is rare in museum collections and historically has been confused with juvenile and subadult Gekko monarchus on Palawan Island (C. Siler and R. Brown, personal observation). Gekko palawanensis is known only from the island of Palawan in the west-central Philippines.

Recent studies and increased survey efforts throughout the Philippines have resulted in a dramatic increase in the diversity of gekkonid lizards in the country. The archipelago is now known to support ten genera and at least 48 described species in the genera Cyrtodactylus (9 species), Gekko (12–13), Gehyra (1), Hemidactylus (5; including platyurus, a species formerly assigned to Cosymbotus), Hemiphyllodactylus (2), Lepidodactylus (6), Luperosaurus (8), Pseudogekko (4), and Ptychozoon (1) (Taylor, 1922a,b; Brown and Alcala, 1978; Brown and Diesmos, 2000; Brown et al., 1997, 1999, 2007, 2008, 2009, in press; Gaulke et al., 2007; Linkem et al., 2010; Welton et al., 2009, 2010a, b; Zug, 2010).

Ten species of Gekko are considered endemic to the archipelago (Brown et al., 2009; Linkem et al., 2010) and two additional species with broad geographic distributions (G. gecko, G. monarchus) are also known from the country (Taylor, 1922a, b; Brown and Alcala, 1978; Ota et al., 1989). The ten endemic Philippine species are G. athymus, G. carusadensis, G. crombota, G. ernstkelleri, G. gigante, G. mindorensis, G. palawanensis, G. porosus, G. romblon, and G. rossi. These species represent a considerable range in body size, general appearance, and ecological attributes, but all possess the following combination of morphological traits: (1) body size moderate, with relatively long, slender limbs; (2) near complete absence of interdigital webbing or cutaneous body expansions; (3) dorsal tubercles arranged in longitudinal rows on the dorsum (except for G. athymus, in which dorsal tuberculation is absent); (4) scales of dorsum between tubercle rows minute, non-imbricate; (5) scales of venter enlarged, imbricate, flat; (6) differentiated postmentals elongate; and (7) subcaudals enlarged, plate-like (Brown and Alcala, 1978; Brown et al., 2007, 2008, 2009).

Gekko palawanensis can be distinguished from congeners by the following combination of characters (1) small body size (SVL 57.2–65.7 mm for adult males; 44.5–61.8 for females); (2) vertebral coloration with dark paired spots; (3) supralabials 12–14; (4) preanofemorals 64–70; (5) Toe IV scansors 16–19; (6) internasals contacting rostral 1; (7) scales contacting nostril 5; (8) midbody ventral scales 38–43; (9) midbody dorsal scales 114–121; (10) midbody tubercle rows 10–20; (11) vertebral tubercles in axilla–groin distance 23–27; (12) paravertebral scales in axilla–groin distance 155–170; (13) ventral scales in axilla–groin distance 54–58.

Gekko palawanensis is recognized to occur in the Palawan Pleistocene Aggregate Island Complex.

Gekko palawanensis, as the name implies, is known only from Palawan Island in the Philippines.

SVL 57.2–65.7 mm for adult males; 44.5–61.8 for females

Besides being the smallest enemic species of Gekko in the Philippines, G. palawanensis looks surprisingly similar to G. monarchus and G. mindorensis in having the commonly observed banded body pattern among species of Gekko. However, scale and pore counts, as well as coloration and other diagnostic features, can be used to easily diagnose G. palawanensis from these larger congeners.

• Terrestrial