Cyrtodactylus chumuensis, Ngo & Hormann & Pham & Phung & Ostrowski & Nguyen & Ziegler, 2023

Ngo, Hanh Thi, Hormann, Helene, Le, Minh Duc, Pham, Cuong The, Phung, Trung My, Do, Dang Trong, Ostrowski, Sabrina, Nguyen, Truong Quang & Ziegler, Thomas, 2023, The discovery of two new species in the Cyrtodactylus irregularis group highlights that hidden diversity remains in the largest clade of the mega-diverse genus Cyrtodactylus, European Journal of Taxonomy 875 (1), pp. 70-100 : 78-84

Cyrtodactylus chumuensis sp. nov.

urn:lsid:zoobank.org:act:F6A019B5-B1ED-4976-8C1D-803CC0D91DD9

Figs 3–5 ; Table 2

Diagnosis

The new species can be distinguished from remaining congeners of the irregularis species group by a combination of the following characters: maximum SVL 67.5 mm; dorsal pattern with 6 irregularly shaped and short longitudinal stripes on the neck; nuchal band thin, interrupted, reaching the posterior margin of the orbits; the absence of transversely enlarged median subcaudal scales; 4 or 5 enlarged femoral scales on each thigh, 17–19 distinctly enlarged precloacal scales; males with 0 or 1 femoral pore on each thigh, 6 or 7 precloacal pores in a continuous series, ˄-shaped; ventral scales 43–45; dorsal tubercles in 20 irregular longitudinal rows; precloacal groove absent; internasal scales 2; supralabials 8–14; infralabials 9–11; number of subdigital lamellae on fourth finger 16–19 and on fourth toe 19–21.

Etymology

The new species is named after its type locality, Chu Mu Mountain in Dak Lak Province. We propose the following common names: Chu Mu Bent-toed Gecko (English) , Thạch sùng ngón chư mư (Vietnamese).

Type material ( Figs 3–5 )

Holotype

VIETNAM • ♂; Dak Lak Province, M'Drak District, Ea M’Doal Commune , Chu Mu Mountain ; 12°41.330′ N, 108°55.450′ E; 500 m a.s.l.; 20 Jun. 2014; T.M. Phung leg.; Field No. PMT01; IEBR R.4928 .

Paratypes

VIETNAM • 1 ♂ (subadult); Dak Lak Province, M'Drak District, Ea M’Doal Commune , Chu Mu Mountain ; 12°41.321′ N, 108°55.382′ E; 400 m a.s.l.; 20 Jun. 2014; T.M. Phung leg.; Field No. PMT02; IEBR R.4929 .

Description of holotype

Adult male; snout-vent length SVL 67.5 mm; tail regenerated 51.4 mm in length (regenerated portion 43.7 mm); body slender, elongate (AG/SVL 0.4); head distinct from neck, elongate (HL/SVL 0.26), relatively wide (HW/HL 0.71) and depressed (HH/HL 0.36); loreal region concave; snout long, blunt in dorsal profile (SE/HL 0.44), longer than diameter of orbit (OD/SE 0.56); scales on snout small, round or oval, granular, larger than scales on occiput; orbit large (OD/HL 0.24), pupils vertical; ear opening small, oval (ED/HL 0.06); rostral wider than high, indented medially the top, in contact with first supralabial, naris and nasorostral on each side, two internasal scales; nostril opening small, oval, surrounded by rostral, nasorostral, two supranasals and one or two postnasals; mental scale triangular, wider than high (ML/MW 0.74); two enlarged, triangular postmentals; supralabials 8/9; infralabials 9/9.

Dorsal scales granular, dorsal tubercles round, keeled, conical, in 20 irregular rows at midbody; tubercles on occiput small; tubercles surrounded by 10–12 granular scales; ventral scales smooth, round, midventral scales three times as large as dorsal granular scales, in 45 longitudinal rows at midbody between ventrolateral folds; precloacal groove absent; enlarged femoral scales 4 or 5 on each thigh, the third bearing a femoral pore ( Fig. 4C ); enlarged precloacal scales 17, arranged in a rhombus; precloacal pores 6, arranged in a ˄-shaped series.

Fore and hindlimbs moderately slender (ForeaL/SVL 0.14 mm, CrusL/SVL 0.17); forelimbs dorsally covered by several slightly enlarged tubercles; dorsal hindlimbs with well-developed tubercles; two postcloacal tubercles on each side on the hemipenal swellings; phalanges without webbing; each claw sheathed by two scales, the ventral sheath larger than the upper; number of subdigital lamellae on first finger 11/11, on first toe 10/11, on fourth finger 17/17, on fourth toe 19/19.

Coloration in preservative

Dorsal surface of head, body and limbs light-brown with some dark-brown bands, pattern without light bordering; occiput marbled with small, irregular dark-brown blotches; rostral, mental and infralabials creamy white, supralabials dark-beige with short greyish brown vertical stripes; neck bands dark-brown, extending in two thin stripes along lateral sides of the snout to the orbits, broader on the neck, interrupted on the left side; two dark-brown longitudinal stripes, disconnected from the neck band extending to shoulders, one dark-brown blotch next to each stripe; dorsal pattern consisting of 6 irregular bands, each formed by two triangularly shaped blotches, shifted medially along the body axis; dorsolateral region covered with small, irregular dark-brown blotches arranged in a longitudinal row from neck to groin; a blurry dark-brown transverse band on dorsal surface of original part of the tail, regenerated part greyish beige and speckled with very small light-greyish brown blotches; dorsal surface of limbs with 3 or 4 dark-brown, blurry bands; phalanges brown with creamy white knuckles; tubercles white or dark-brown depending on position on pattern or background; venter creamy white; ventral tail greyish beige without bands. For coloration of the paratype in life that closely resembles the holotype in life see Fig. 3 .

Variation

The paratype is a subadult and therefore differs greatly in size. Its original tail showed some dark-brown irregular bands, although broken at the base. The number of precloacal pores is 7 and it lacks femoral pores. For more morphological characters see Table 2 .

Comparisons

The new species can be distinguished from all other member of Cyrtodactylus irregularis group from Vietnam by morphological characteristics (see Table 2 ).

Cyrtodactylus chumuensis sp. nov. differs from C. badenensis by having more ventral scale rows (43– 45 vs 25–29 in C. badenensis ), the presence of enlarged femoral scales (4–5 vs absent in C. badenensis ), the presence of precloacal pores in males (6–7 vs absent in C. badenensis ), and the absence of transversely enlarged subcaudals (vs present in C. badenensis ); differs from C. bidoupimontis by having a smaller size (SVL 67.5 mm vs 74.0– 86.3 mm in C. bidoupimontis ), fewer enlarged femoral scales (4 or 5 vs 8–10 in C. bidoupimontis ), a different dorsal color pattern (irregularly banded with longitudinal stripes on the neck vs transversal bands with light borders in C. bidoupimontis ), and a thin discontinuous nuchal band (vs well developed, widened posteriorly in C. bidoupimontis ); differs from C. bugiamapensis by having fewer enlarged femoral scales (4 or 5 vs 6–10 in C. bugiamapensis ) and the different dorsal color pattern (irregularly banded with longitudinal stripes on the neck vs unclear transversal bands formed by irregular round to oblong, dark-brown spots in C. bugiamapensis ); differs from C. buchardi by having more ventral scale rows (30 vs 43–45 in C. buchardi ), the presence of enlarged femoral scales (4–5 vs absent in C. buchardi ), more subdigital lamellae under the fourth finger (16–19 vs 14 in C. buchardi ), more subdigital lamellae under the fourth toe (17–21 vs 12 in C. buchardi ); differs from C. cattienensis by having more ventral scale rows (43–45 vs 28–42 in C. cattienensis ), more subdigital lamellae under the fourth finger (16–19 vs 12–16 in C. cattienensis ), and different dorsal color pattern (irregularly banded with longitudinal stripes on the neck vs irregular dark-brown banded, first band on the shoulder x-shaped C. cattienensis ); differs from C. caovansungi by having a smaller size (SVL 67.5 mm vs 90.4–94 mm in C. caovansungi ), fewer enlarged femoral scales (4 or 5 vs 8 in C. caovansungi ), fewer femoral pores on each thigh in males (0–1 vs 6 in C. caovansungi ), fewer precloacal pores in males (6 or 7 vs 9 in C. caovansungi ), fewer lamellae under the fourth finger (16–19 vs 22 in C. caovansungi ), fewer lamellae under the fourth toe (17–21 vs 23–25 in C. caovansungi ), and the absence of transversely enlarged subcaudal plates (vs present in C. caovansungi ); differs from C. chungi by having more ventral scale rows (43–45 vs 30 or 31 in C. chungi ), more dorsal tubercle rows (20 vs 18 in C. chungi ), different dorsal color pattern (irregularly banded with longitudinal stripes on the neck vs irregular transversal bands with a closed nuchal band), and a thin, discontinuous nuchal band (vs continuous nuchal band in C. chungi ); differs from C. cryptus by having fewer ventral scale rows (43–45 vs 47–50 in C. cryptus ), the presence of enlarged femoral scales (vs absent in C. cryptus ), fewer precloacal pores in males (6 or 7 vs 9–11 in C. cryptus ), a thin, discontinuous nuchal band (vs well developed, widened posteriorly in C. cryptus ), and different dorsal color pattern (irregularly banded with short, longitudinal stripes on the neck vs irregular transverse bands in C. cryptus ); differs from C. cucdongensis by having more dorsal tubercle rows (20 vs 16–19 in C. cucdongensis ), fewer enlarged femoral scales (4 or 5 vs 5–9 in C. cucdongensis ), more enlarged precloacal scales (20–21 vs 6–13), and a different dorsal colour pattern (irregularly banded with short, longitudinal stripes on the neck vs irregular dark brown transverse bands); differs from C. culaochamensis by having a smaller size (SVL 67.5 mm vs 69.8–79.8 mm in C. culaochamensis ), the presence of enlarged femoral scales (vs absent in C. culaochamensis ), fewer lamellae under the first finger (11 vs 13 or 14 in C. culaochamensis ), and fewer lamellae under the first toe (10 or 11 vs 13–15 in C. culaochamensis ); differs from C. dati by having fewer femoral pores in males (0–2 vs 3 or 4 each side in C. dati ), fewer lamellae under the first toe (10 or 11 vs 12 or 13 in C. dati ), the presence of blotches on head (vs absent in C. dati ), and different dorsal color pattern (irregularly banded with longitudinal stripes on the neck vs irregular dark blotches); differs from C. gialaiensis by the presence of enlarged femoral scales (vs absent in C. gialaiensis ), fewer precloacal pores in males (6 or 7 vs 9 or 10 in C. gialaiensis ), and more subdigital lamellae under the fourth finger (16–19 vs 14 or 15 in C. gialaiensis ) as well as under the fourth toe (17–21 vs 15–17 in C. gialaiensis ); differs from C. huynhi by having more dorsal tubercle rows in males (20 vs 16–18 in C. huynhi ), fewer lamellae under first finger (11 vs 12–15 in C. huynhi ), fewer lamellae under first toe (10 or 11 vs 13–17 in C. huynhi ), and a thin discontinuous nuchal band (vs well developed, widened posteriorly in C. huynhi ); differs from C. irregularis by having a smaller size (SVL 67.5 mm vs 72.0–86.0 mm in C. irregularis ), more ventral scale rows (43–45 vs 37–42 in C. irregularis ), fewer enlarged femoral scales (4 or 5 vs 7 or 8 in C. irregularis ), and different dorsal color pattern (irregularly banded with short longitudinal stripes on the neck vs blotched in C. irregularis ); differs from C. kingsadai by having a smaller size (SVL 67.5 mm vs 83.0–94.0 in C. kingsadai ), fewer enlarged femoral scales (4 or 5 vs 9–12 in C. kingsadai ), the absence of transversely enlarged subcaudal plates (vs present in C. kingsadai ), and more internasals (2 vs 1 in C. kingsadai ); differs from C. orlovi by having more ventral scale rows (43–45 vs 36–39 in C. orlovi ); a thin, discontinuous nuchal band (vs continuous nuchal band in C. orlovi ), and different banded pattern ranges (6 vs 3–5 in C. orlovi ); differs from C. phnomchiensis by having a smaller size (SVL 67.5 vs 76.1–80.7 mm in C. phnomchiensis ), more precloacal pores in males (6 or 7 vs 5 in C. phnomchiensis ), and different dorsal color pattern (irregularly banded vs banded in C. phnomchiensis ); differs from C. phuocbinhensis by having a larger size (SVL 67.5 mm vs 46.0– 60.4 mm in C. phuocbinhensis ), different dorsal color pattern (irregularly banded vs stripes or blotches in C. phuocbinhensis ), and dark-brown transverse banded of the tail than light-brown interspaces (vs dark transverse banded wider than light interspaces in C. phuocbinhensis ); differs from C. phumyensis by having more ventral scale rows (43–45 vs 33–41 in C. phumyensis ), fewer enlarged femoral scales (4 or 5 vs 5–7 in C. phumyensis ), more dorsal tubercle row (20 vs 18 or 19 in C. phumyensis ), fewer enlarged precloacal scales (17–19 vs 21–41 in C. phumyensis ), and different dorsal color pattern (irregularly banded with short longitudinal stripes on the neck vs anteriorly irregularly spotted and posteriorly banded in C. phumyensis ); differs C. pseudoquadrivirgatus by the presence of enlarged femoral scales on each thigh (vs absent in C. pseudoquadrivirgatus ), the presence of precloacal pores in males (0–2 vs absent in C. pseudoquadrivirgatus ), and more enlarged precloacal scales (17–19 vs 1–12 in C. pseudoquadrivirgatus ); differs C. raglai by having a smaller size (SVL 67.5 mm vs 87.5–111.7 mm in C. raglai ), more ventral scale rows (43–45 vs 36–39 in C. raglai ), fewer enlarged femoral scales (4 or 5 vs 9 or 10 in C. raglai ), fewer precloacal pores in males (0–2 vs 5 in C. raglai ), and the absence of transversely enlarged subcaudal plates (vs present in C. raglai ); differs from C. sangi by having a larger size (SVL 67.5 mm vs 49.9–56.3 mm in C. sangi ) and more ventral scale rows (43–45 vs 37 in C. sangi ); differs from C. takouensis by having a smaller size (SVL 67.5 mm vs 74.7–81.1 mm in C. takouensis ), more ventral scale rows (43–45 vs 39–40 in C. takouensis ), more precloacal pores in males (6 or 7 vs 3 or 4 in C. takouensis ), the absence of transversely enlarged subcaudal plates (vs present in C. takouensis ), a thin discontinuous nuchal band (vs well developed, widened posteriorly in C. takouensis ), and different dorsal color pattern (irregularly banded vs banded in C. takouensis ); differs from C. taynguyenensis by the presence of enlarged femoral scales on each thigh (vs absent in C. taynguyenensis ); irregularly banded of the tail (vs banded in C. taynguyenensis ), and different dorsal color pattern (irregularly banded vs blotched in C. taynguyensis ); differs from C. yangbayensis by having a smaller size (SVL 67.5 vs 78.5–92.3 mm in C. yangbayensis ), more subdigital lamellae under the fourth toe (17–21 vs 15–17 in C. yangbayensis ), fewer subdigital lamellae under the first toe (10–11 vs 18–20 in C. yangbayensis ), and the absence of transversely enlarged subcaudal plates (vs present in C. yangbayensis ); differs from C. ziegleri by having a smaller size (SVL 67.5 vs 84.6–93.0 mm in C. ziegleri ), more ventral scale rows (43–45 vs 33–39 in C. ziegleri ), and fewer enlarged femoral scales (4 or 5 vs 8–10 C. ziegleri ).

Distribution

Cyrtodactylus chumuensis sp. nov. is currently known only from the Chu Mu Mountain, M'Drak District, Dak Lak Province, Vietnam ( Fig. 1 ).

Natural history

Specimens were found at night between 19:00 and 22:00, on granite rock, along a rocky stream, approximately 0.5–1.0 m above the ground, at elevations between 400 and 500 m a.s.l. The surrounding habitat was evergreen forest of medium and small hardwoods mixed with shrubs and vines ( Fig. 5 ). The humidity was approximately 50–71% and the air temperature ranged from 27.5 to 32.1°C. Other reptile species found at the sites included Gekko gecko (Linnaeus, 1758) , Hemidactylus platyurus (Schneider, 1792) , Ahaetulla prasina (Boie, 1827) , Lycodon sp. , and Oligodon sp.

Figures

Fig. 3. Cyrtodactylus chumuensis sp. nov., holotype, ♂ (IEBR R.4928), in life.

Fig. 4. Cyrtodactylus chumuensis sp. nov. in preservative. A. Holotype, ♂ (IEBR R.4928, left) and paratype, ♂ (IEBR R.4929, right). B. Paratype, ♂ (IEBR R.4929). C. Holotype, ♂ (IEBR R.4928). A. Dorsal view. B. Precloacal region with precloacal pores. C. Precloacal region with precloacal pores and femoral pores.

Fig. 5. Habitat of Cyrtodactylus chumuensis sp. nov. in the Chu Mu Mountain, M'Drak District, Dak Lak Province.

Fig. 1. Type locality of Cyrtodactylus chumuensis sp. nov. in Dak Lak Province (black circle) and Cyrtodactylus arndti sp. nov. in Binh Dinh Province (black triangle), Vietnam.