Thursday, June 2, 2022

[Herpetology • 2022] Cyrtodactylus monilatus • A New Species in the Cyrtodactylus oldhami Group (Squamata, Gekkonidae) from Kanchanaburi Province, western Thailand

 

Cyrtodactylus monilatus  
Yodthong, Rujirawan, Stuart, Grismer, Aksornneam, Termprayoon, Ampai & Aowphol, 2022

Kanchanaburi Spotted Bent-toed Gecko || ตุ๊กแกป่าลายจุดเมืองกาญจน์

Abstract
Cyrtodactylus monilatus sp. nov. is described from Si Sawat District, Kanchanaburi Province, in western Thailand. The new species superficially resembles C. zebraicus Taylor, 1962 from southern Thailand. However, differences between the new species from C. zebraicus and other congeners were supported by an integrative taxonomic analysis of molecular and morphological data. Phylogenetic analyses based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene showed that the new species is a member of the C. oldhami group and closely related to Cyrtodactylus sp. MT468911 from Thong Pha Phum National Park, Thong Pha Phum District, Kanchanaburi Province. Uncorrected pairwise genetic divergences (p-distances) between the new species and its congeners, including C. zebraicus, ranged from 7.7–17.7%. Cyrtodactylus monilatus sp. nov. can also be distinguished from all members of the C. oldhami group by having a unique combination of morphological characters, including a snout to vent length of 53.7–63.3 mm in adult males and 58.6–75.8 mm in adult females; 22–34 paravertebral tubercles; 34–42 ventral scales; 30–39 enlarged contiguous femoroprecloacal scales; femoral pores and precloacal pores absent in both sexes; four or five rows of postprecloacal scales; enlarged median subcaudal scales absent; weak ventrolateral folds present; 4–7 rows of paired, paravertebral, dark-brown blotches edged in yellow or yellowish white; and two rows of small, diffuse, yellow or yellowish white spots on flanks. The new species occurs in a narrow range of forest at mid to low elevations associated with karst landscapes in the Tenasserim mountain range.

Keywords: Cyrtodactylus monilatus sp. nov., Cyrtodactylus zebraicus, integrative taxonomy, mitochondrial DNA, morphology, phylogeny, Southeast Asia

Adult male holotype of Cyrtodactylus monilatus sp. nov. (ZMKU R 00943) in life from Tham Phrathat Protection Unit, Si Sawat District, Kanchanaburi Province, Thailand
 A lateral view B dorsal view C ventral view D precloacal region showing distribution of continuous, enlarged femoroprecloacal scales E palmar view of the left hand F plantar view of the left foot, and G ventral view of tail showing not enlarged median subcaudal scales.

Paratypes of Cyrtodactylus monilatus sp. nov. in life showing variation in color pattern
 A adult male (ZMKU R 00935)
B adult male (ZMKU R 00944) from Tham Phrathat Protection Unit
C adult female (ZMKU R 00927) from Erawan Waterfall
D adult female (ZMKU R 00926) from Tham Than Lot Noi-Tham Than Lot Yai Nature Trail, Si Sawat District, Kanchanaburi Province, Thailand.

 Cyrtodactylus monilatus sp. nov. 
Common English name: Kanchanaburi Spotted Bent-toed Gecko 

Diagnosis: Cyrtodactylus monilatus sp. nov. is assigned to the C. oldhami group on the basis of its recovered phylogenetic position (Fig. 1). This species can be distinguished from all other species of the C. oldhami group (sensu Grismer et al. 2021b) by having the following combination of characters: (1) a medium-sized Cyrtodactylus, SVL 53.7–63.3 mm in adult males, 58.6–75.8 mm in adult females; (2) 10–13 supralabial and 8–11 infralabial scales; (3) 22–34 paravertebral tubercles; (4) 16–21 longitudinal rows of dorsal tubercles; (5) 34–42 ventral scales; (6) 12–16 total subdigital lamellae on the fourth finger; (7) 15–19 total subdigital lamellae on the fourth toe; (8) 30–39 contiguous enlarged femoroprecloacal scales; (9) femoral pores and precloacal pores absent in both sexes; (10) four or five rows of postprecloacal scales; (11) precloacal groove or depression absent; (12) enlarged median subcaudal scales absent; (13) 9–12 dark and light caudal bands encircling the original tail; (14) weak ventrolateral folds present; (15) subconical to slightly prominent trihedral keeled tubercles on body that extend past the base of the tail but no further than 1/3 of anterior portion of tail; (16) top of head bearing large, dark-brown blotches edged in yellow or yellowish white with no light-colored network; (17) 4–7 dorsal body bands composed of paired, paravertebral, dark-brown blotches edged in yellow or yellowish white; and (18) two rows of small, diffuse, yellow or yellowish white spots on flanks.

Etymology: The specific epithet monilatus is taken from monile (L.) for necklace or string of beads and latus (L.) for flank, in reference to the new species having two rows of small, diffuse, yellow or yellowish white spots on the flanks that resemble a beaded necklace. These spots are an important color pattern difference between the new species and C. zebraicus
We propose “Kanchanaburi Spotted Bent-toed Gecko” for the common English name and “ตุ๊กแกป่าลายจุดเมืองกาญจน์” (Took kae pa lai jud Mueang Kan) for the common Thai name of the new species.

Sampling localities of Cyrtodactylus monilatus sp. nov. 
A the type locality in Tham Phrathat Protection Unit
B Erawan Waterfall
C Tham Than Lot Noi-Tham Than Lot Yai Nature Trail, Si Sawat District, Kanchanaburi Province, Thailand.

Habitat of Cyrtodactylus monilatus sp. nov. Tham Phrathat Protection Unit, Si Sawat District, Kanchanaburi Province, Thailand
A adult female (ZMKU R 00941) on boulder outcrops B adult male (not collected) on shrub.


Siriporn Yodthong, Attapol Rujirawan, Bryan L. Stuart, L. Lee Grismer, Akrachai Aksornneam, Korkhwan Termprayoon, Natee Ampai and Anchalee Aowphol. 2022. A New Species in the Cyrtodactylus oldhami Group (Squamata, Gekkonidae) from Kanchanaburi Province, western Thailand.  ZooKeys. 1103: 139-169. DOI: 10.3897/zookeys.1103.84672