Gekko monarchus

Rösler, Herbert, Bauer, Aaron M., Heinicke, Matthew P., Greenbaum, Eli, Jackman, Todd, Nguyen, Truong Quang & Ziegler, Thomas, 2011, Phylogeny, taxonomy, and zoogeography of the genus Gekko Laurenti, 1768 with the revalidation of G. reevesii Gray, 1831 (Sauria: Gekkonidae), Zootaxa 2989, pp. 1-50 : 17

Gekko monarchus group

( Figure 5 B–D)

Species. G. carusadensis Linkem, Siler, Diesmos, Sy & Brown, 2010 ; G. e r n s t k e l l e r i Rösler, Siler, Brown, Demegillo & Gaulke, 2006 ( Figure 5 C); G. kikuchii Oshima, 1912 ; G. mindorensis Taylor, 1919 ( Figure 5 D); G. m o n a rchus ( Schlegel, 1836) ( Figure 5 B); G. palawanensis Taylor, 1925 .

Characters. 63.0–100.0 mm SVL; nares in contact with rostral; nasals 3 (rarely 4 in G. e r n s t k e l l e r i); postmentals relatively large; dorsal tubercle rows 10–24; precloacal pores 32–70; postcloacal tubercles 2–3 (1 in G. c a r u - sadensis and G. palawanensis ); no webbing between fingers and toes; tubercles on fore and hind limbs (not on fore limbs of G. ernstkelleri ); lateral folds without tubercles; subcaudals mostly enlarged, in a longitudinal row; more or less distinct, W-shaped head pattern; light (white to gray), mostly asymmetrically arranged dorsal and lateral flecks.

Distribution. G. monarchus is known from the Philippines westwards to Myanmar and to Indonesia (Aru Islands, Kei Islands, New Guinea) in the south ( Figure 3 A); G. kikuchii is endemic to Lanyu Island, Taiwan; remaining group members are endemic to the Philippines.

Remarks. G. kikuchii was described by Oshima (1912) from Botel Tobago (Lanyu) near Taiwan. Many subsequently published taxonomic papers refer to Oshima (1912) but do not provide further insights in the form of a redescription of the species or new material (e.g., Horikawa 1927; Wang & Wang 1956; Lue et al. 1988); see also relevant comments in Ota (1989b). In describing G. mindorensis, Taylor (1919) compared the new species with G. kikuchii and G. monarchus . According to Taylor (1919), G. mindorensis differs from the former species by its longer limbs, more preanofemoral pores and by lacking webbing between toes in both sexes; G. mindorensis differs from G. m o n a rc h u s by a relatively larger ear opening, a larger eye diameter, a smaller interorbital distance, more flattened dorsal tubercles, more ventrals and preanofemoral pores, and a distinctly different dorsal pattern (see also Taylor 1922a). However, Wang (1962) pointed to the similarity of G. kikuchii with G. monarchus and G. mindorensis . Brown & Alcala (1978) redescribed G. mindorensis based on new specimens, but only provided thorough comparisons with G. monarchus , but not with G. kikuchii . Based on the new variation in size and scalation reported in the redescription provided by Brown & Alcala (1978), G. mindorensis was in fact no longer distinguishable from G. kikuchii based on the data on the latter species provided by Taylor (1919), as is also obvious from Table 1. Crombie (in Bauer 1994) thus had doubts on the distinct status of G. mindorensis and stated “probably a junior synonym of Gekko kikuchii .” Finally, Ferner et al. (2001) and Kluge (2001) listed G. mindorensis as a synonym of G. kikuchii . However, there might be differences in pattern between G. kikuchii and G. mindorensis . Figures of different specimens of G. kikuchii in Ota (1989b, 1991), Lue et al. (1999), Shang (2001), and Henkel & Schmidt (2003) show a brown ground coloration with a nearly identical dorsal pattern, consisting of two parallel dark brown pairs of blotches. In contrast, the ground coloration of G. mindorensis seems to be gray, with transverse rows (see Gaulke 2003: fig. 8) or rows dissolved into four to six blotches each (see Rösler et al. 2006: fig. 13). In addition, the light dorsal blotches in G. mindorensis appear to be more distinct than in G. kikuchii . We must add that the detailed figures provided by Okada (1936: fig. 4) most probably belong to a Hemidactylus species (maybe H. stejnegeri ), but certainly not G. kikuchii . The synonymy of G. mindorensis with G. kikuchii is also contradicted on zoogeographic grounds. The amphibian and lizard fauna of Lanyu Island shows, according to Okada (1936) and Ota et al. (1988), greater affinities to Taiwan than to the Philippines, and G. mindorensis does not occur on the northern Philippine Islands (e.g., Luzon, Batanes) that are closest to Taiwan ( Brown & Alcala 1970, 1978; Alcala 1986; Gaulke & Altenbach 2006). Kuntz & Ming (1970) listed G. kikuchii for Penghu Lieh-tao (Pescador Island), but the species is endemic to Lanyu Island (“Botel Tobago ”) (see Ota 1989b). Further taxonomic research is required on more specimens, especially of G. kikuchii , to clarify whether G. mindorensis is a junior synonym of G. kikuchii , or whether two closely related cryptic species are involved.

Figures

FIGURE 3. Map of East and Southeast Asia and the Indo-Australian Archipelago showing the approximate distribution of (A) the Gekko japonicus, G. petricolus, and G. monarchus groups and G. a t h y m u s and (B) the G. g e c k o, G. p o ro s u s, and G. vittatus groups and G. vietnamensis.

FIGURE 5. A. Male Gekko vertebralis (G. japonicus group), photo by J. Boone; B. G. monarchus (G. monarchus group), Banggai Islands, Indonesia, photo by A. Koch; C. G. ernstkelleri (G. monarchus group), Panay Island, Philippines, photo by M. Gaulke; D. G. mindorensis (G. monarchus group), Cebu Island, Philippines, photo by M. Gaulke.