Cyrtodactylus tambora, Riyanto, Awal, Mcguire, Jimmy A., Kusrini, Mirza D., Basyir, Irfan Haidar & Kaiser, Hinrich, 2017

Riyanto, Awal, Mcguire, Jimmy A., Kusrini, Mirza D., Basyir, Irfan Haidar & Kaiser, Hinrich, 2017, A new small bent-toed gecko of the genus Cyrtodactylus (Squamata: Gekkonidae) from the lower slopes of Mount Tambora, Sumbawa Island, Indonesia, Zootaxa 4242 (3), pp. 517-528 : 520-525

Cyrtodactylus tambora sp.nov.

English common name: Tambora Bent-toed Gecko Indonesian common name: Cicak Jari-Lengkung Tambora ( Figs. 1–3 )

Holotype. MZB.Lace.13298 (field number AM 042), an adult male ( Fig. 1 A) from Oi Marai River , desa (village) Kawinda Toi , kecamatan (subdistrict) Tambora , kabupaten (district) Bima, Nusa Tenggara Barat Province, Sumbawa Island, Indonesia (8.1145°S, 118.0073°E; elev. 134 m), collected on 20 April 2015 by A. Riyanto and Mulyadi.

Paratypes. MZB.Lace.13296 (field number AM 019), a subadult male ( Fig. 1 B) from near the type locality (8.0986°S, 118.0072°E; elev. 21 m), collected on 20 April 2015 by A. Riyanto and Mulyadi; MZB.Lace.13297 (field number AM 037), an adult female ( Fig. 1 C) from near the type locality (8.1187°S, 118.0079°E; elev. 155 m), collected on 19 April 2015 by A. Riyanto and Mulyadi; MZB. Lace.13909 (field number SKT-R007), an adult female from the same locality as the holotype collected on 21 June 2015 by Irfan Haidar Basyir and the Himakova Team.

Diagnosis. Cyrtodactylus tambora sp. nov. can be distinguished from Greater Sunda Islands (including Sulawesi) and Lesser Sunda Islands species of Cyrtodactylus by the following combination of characters: (1) two scales between the second pair of postmentals in contact with the first pair; (2) dorsal surface of antebrachium tuberculate; (3) no tubercles on dorsal surface of brachium; (4) dorsal surfaces of thigh and crus tuberculate; (5) 18 irregularly aligned, longitudinal rows of keeled tubercles at midbody; (6) 26–27 paravertebral tubercles; (7) 40 ventral scales between indistinct ventrolateral folds; (8) 16–17 fourth-toe subdigital scales; (9) a continuous enlarged precloacal and femoral scales present, with the enlarged femoral scales arranged in three rows; (10) males with five to six precloacal pores, with four larger pores situated in a short groove; (11) femoral pores absent in both sexes; (12) lack of transversely enlarged subcaudal scales; and (13) 7–9 irregular, paired black blotches on the body.

Description. A small Cyrtodactylus species reaching 39.4–47.4 mm SVL in adult females and 39.8–42.4 mm in adult males; head triangular in dorsal view, distinct from neck; in males (n = 2) HeadL 29.2–31.4% of SVL, HeadW 61.6–69.6% of HeadL, HeadD 12.1–12.3% of SVL, and HeadD 60.5–62.3% of HeadW; in females (n = 2) HeadL 25.3–26.3% of SVL, HeadW 60.3–64.2% of HeadL, HeadD 9.5–10.5% of SVL, and HeadD 59.7–64.9% of HeadW; prefrontal region concave, canthus rostralis rounded; in males (n = 2) SnL 40.0–44.4% of HeadL, OD 25.0–25.6% of HeadL, EarL 7.2–8.1% of HeadL, and OD 88.6–100% of EyeEar; in females (n = 2) SnL is 39.2% of HeadL, OD 25.0–25.5% of HeadL, EarL 7.5–9.7% of HeadL, and OD 78.9–88% of EyeEar.

Rostral rectangular, height 68.1–75.7% of width in males (n = 2), 56.2–60.4% in females (n = 2), incompletely divided dorsally by a Y-shaped shallow suture; rostral bordered dorsally by three postrostral scales; naris oval, bordered anteriorly by rostral, anterodorsally by one postrostral, posteriorly by two scales, and ventrally by first supralabial; orbit separated from supralabials by two rows of small lorilabial scales; 8–9 supralabial scales to the angle of jaw; 8–9 infralabial scales; scales on occiput interspersed with tubercles.

Mental triangular, length 72.9–76% of width in males (n = 2), 67.3–90.6% of width in the females (n = 2); bordered laterally by first infralabials and posteriorly by one pair of enlarged first postmentals, which contact medially over about 50% of their length; second postmentals ovoid, pentagonal, about two-thirds as wide as first pair and separated from one another by two granular scales (n = 3) that are larger than other gular scales ( Fig. 2 A); gular scales small, granular, grading to slightly smaller size posteriorly.

Forelimbs relatively short, ForL 13–14% of SVL (14 ± 0.01, n = 3); dorsal scales on forelimbs slightly larger than those of body; antebrachium with keeled tubercles, brachium without tubercles; palmar scales flat, smooth, subimbricate; digits well-developed, inflected at basal interphalangeal joints; subdigital scales transversely expanded along the entire length of each digit, but slightly compressed in both length and width immediately distal to interphalangeal inflection, digits slightly narrower distal to inflection; 8–10 LamF1, 10–11 LamF2, 12–13 LamF3, 12–13 LamF4, and 10–12 LamF5 (n = 3); claws well developed, sheathed by two dorsal scales and one ventral scale.

Hind limbs longer than forelimbs, TibL 37–47 % of SVL (42 ± 0.05; n = 3); covered dorsally by granular scales interspersed with larger, conical tubercles and covered anteriorly by flat, slightly larger imbricate scales mixed with fewer, smaller tubercles; ventral scales of thigh rounded, smooth, subimbricate to juxtaposed, larger than dorsals; enlarged precloacofemoral scales present, with the enlarged femoral scales part arranged in two rows; males with pores and a short precloacal groove; 5–6 precloacal pores, with four paired, enlarged pores inside the groove and with additional precloacal pores on the precloacal scales at the edge of the groove; precloacal pores inside the groove larger than those at the edge of the groove ( Fig. 3 ); ventral tibial scales flat, imbricate; plantar scales slightly raised, imbricate; digits well-developed, inflected at basal, inflected at metapodial-phalangel joint; 7–9 LamT1, 12–14 LamT2, 12–16 LamT3, 16–17 LamT4, and 13–15 LamT5 (n = 4); claws well-developed, sheathed by two dorsal scales and one ventral scale.

Body relatively short about 40.2–41.3% of SVL in males (n = 2) and 36.9–45.1 % in the females (n = 2); ventrolateral folds indistinct; dorsal scales small, granular, interspersed with large, conical, semi-regularly arranged, keeled tubercles; tubercles extend from occiput to tail; 18 (n = 3) DorsT; 26–27 (n = 3) PVT; 40 (n = 3) VentS; ventral scales larger than dorsals, smooth, flat, imbricate, between indistinct ventrolateral body folds.

Tail subcylindrical, somewhat flattened dorsally and ventrally, relatively long about 85.4–113.8 of SVL (n = 2); tubercles extend along 26.5–43.8% (n = 2) of original tail; distribution of tubercles at base of tail similar to dorsal body; tubercles not projecting distally, forming 7 or 8 whorls, each separated by 5–7 smaller scales along the dorsal midline; tubercles on tail not extending to ventral side; transversely enlarged subcaudal plates absent; subcaudals flat, cycloid, homogenous, about 1.5–2 times as large as scales on sides of tail; 2–3 cloacal tubercles, rounded, smooth, slightly smaller than dorsal tubercles; tip of tail capped by granular scales.

Color and pattern in life. Photographs in life of holotype MZB.Lace.13298 show that prior to conservation the ground color of body, head, limbs, and tail was cream with a mixture of black and yellow blotches; a diffuse dark stripe extending from the postnasal region past the eye, continuing to the upper ear opening; dorsum and dorsal surface of head with whitish tubercles; iris pale gold with vertical black pupil and vertical, dark brown venation, with extensive fine, light yellow-brown reticulation; supraciliary scales yellow on dorsal and black on ventral surfaces.

Dorsum between fore- and hind limbs with 7–9 transverse, irregular blotches; in MZB.Lace.13296 the blotches are vague. Dorsal surface of original tail with 13 dark bands.

Etymology. The species name tambora is a noun used in apposition. It is used not only to identify the collection locality, but also to commemorate the large eruption of Gunung Tambora in 1815, which no doubt significantly realigned the local natural world on its slopes.

Distribution and natural history. Cyrtodactylus tambora currently is known only from the type locality ( Fig. 4 ). We were searching up to elevation 800 meters so we assume that C. tambora is a lowland species occuring on the foot of Mount Tambora only, where it inhabits low forest floor vegetation close to water ( Fig. 5 ). The species was not abundant at the type locality, as only three specimens were found during eight nights’ searching by AR and M; also only one specimen was found after six nights’ searching by IHB and team during an expedition in June– July 2015. The holotype and subadult male paratype were collected in leaf litter on a riverbank at night, at 2100 h, while the while the female paratype MZB.Lace.13297 was collected while foraging on a small tree with diameter approximately 10 cm, 60 cm above the ground in April and other female (MZB.Lace.13309) was collected on the leaf litter same location with the holotype in June. The females are gravid with two eggs, indicating that oviposition occurs during the dry season (April and June).

Species comparisons. Cyrtodactylus tambora can be readily distinguished from Lesser Sunda congeners with the exception of the superficially similar C. celatus and C. laevigatus . It is distinguished from C. celatus (characteristics in parentheses) by having 5 or 6 precloacal pores in males (four pores; data from Rösler & Kaiser 2016), enlarged femoral scales (absent; data from Kathriner et al. 2014; Rösler & Kaiser 2016; Mecke et al. 2016). The new species can be distinguished from C. laevigatus (characteristics in parentheses; data from Kathriner et al. 2014; Mecke et al. 2016) by having 40 ventral scales (30–34 ventral scales), a precloacal groove in males (absent), 5–6 precloacal pores in males (absent), and 16–17 (10–15) LamT4.

Cyrtodactylus tambora can be distinguished from other Lesser Sunda Cyrtodactylus as follows (characteristics of other Lesser Sunda species in parentheses): from C. darmandvillei (data from Mecke et al.2016; HK, pers. obs.) by its smaller SVL in adults (80–82 mm), absence of tubercles along the ventrolateral fold (present), presence of a precloacal groove in males (absent), 16–17 (23–24) LamT4, and absence of enlarged median subcaudals (present); from C. gordongekkoi (data from Das 1993; Biswas 2007; Mecke et al. 2016) by smaller SVL in adults (71–73 mm), 40 ventral scales (30–32 scales), presence of precloacal groove in males (absent), presence of precloacal pores in males (absent), and 16–17 (20–22) LamT4; from C. wetariensis (data from Mecke et al. 2016; HK pers. obs.) in having smaller SVL (58–67 mm), a precloacal groove in males (absent), 5–6 precloacal pores in males (11 pores in an angular series), and number of femoral pores (12–16 pores on each side in males). A comparison of selected mensural and meristic characters used to distinguish the new species from congeneric species in the Lesser Sundas is presented in Table 2 and the arrangement of scales of the mental region among Lesser Sunda species is presented in Figure 2 .

a. Mecke et al. 2016 noted that a female specimen (MCZ Herp R-26998) collected by the Douglas Burden East Expedition (1926) has nine precloacal pores, and no femoral pores on the right and two on the left thigh.

We also compared Cyrtodactylus tambora to other congeners from the Greater Sunda Islands (including Sulawesi), and Eastern Indonesia. All characters listed in this comparison apply to both male and female individuals unless otherwise noted. Unlike the new species, males (and females) of C. baluensis ( Mocquard, 1890) , C. batik Iskandar, Rachmansah & Umilaela, 2011 , C. consobrinus ( Peters, 1871) , C. deveti ( Brongersma, 1948) , C. hitchi , C. ingeri , C. jellesmae ( Boulenger, 1897) , C. majulah Grismer, Wood & Lim, 2012 , C. matsuii Hikida, 1990 , C. petani 1, C. psarops , C. rosichonariefi , C. semiadii Riyanto, Bauer & Yudha, 2014 , C. spinosus Linkem, McGuire, Hayden, Setiadi, Bickford & Brown, 2008 , C. quadrivirgatus Taylor, 1962 , C. wallacei Hayden, Brown, Gillespie, Setiadi, Linkem, Iskandar, Umilaela, Bickford, Riyanto, Mumpuni & McGuire, 2008 and C. zugi Oliver, Tjaturadi, Mumpuni, Krey & Richards, 2008 , do not possess a precloacal groove. Enlarged precloacofemoral scales are present in Cyrtodactylus tambora , whereas C. baluensis , C. batik , C. boreoclivus Oliver, Mumpuni, Krey & Richards, 2011 , C. cavernicolus Inger & King, 1961 , C. consobrinus , C. elok Dring, 1979 , C. hitchi , C. ingeri Hikida, 1990 , C. jarakensis Grismer, Chan, Grismer, Wood & Belabut, 2008 , C. jellesmae , C. leegrismeri Chan & Norhayati, 2010 , C. majulah , C. matsuii , C. pantiensis Grismer, Chan, Grismer, Wood & Belabut, 2008 , C. peguensis ( Boulenger, 1893) , C. pubisulcus Inger, 1958 , C. quadrivirgatus , C. rosichonariefi , C. semenanjungensis Grismer & Leong, 2005 , C. semiadii , C. sermowaiensis (De Rooij, 1915) , C. stresemanni Rösler & Glaw, 2008 , and C. yoshii Hikida, 1990 , lack such a series.

Unlike C. aurensis , C. baluensis , C. batik , C. boreoclivus , C. brevipalmatus ( Smith, 1923) , C. consobrinus , C. fumosus ( Müller, 1895) , C. hikidai Riyanto, 2012 , C. hitchi , C. ingeri , C. leegrismeri , C. macrotuberculatus Grismer & Ahmad, 2008 , C. malayanus (de Rooij, 1915) , C. peguensis , C. pulchellus Gray, 1827 , C. rex Oliver, Richards, Mumpuni & Rösler, 2016 , and C. wallacei , the new species lacks enlarged median subcaudal scales.

Figures

FIGURE 1. Photographs in life of Cyrtodactylus tambora sp. nov. from the northern slopes of Mount Tambora, Sumbawa Island, Indonesia. (A) The holotype, an adult male (MZB. Lace. 13298). (B) A subadult male paratype (MZB. Lace. 13296). (C) The female paratype, gravid with two eggs (MZB. Lace. 13297). Photograph by A. Riyanto.

FIGURE 2. Comparison of chin shields for the six known Cyrtodactylus species from the Lesser Sunda Islands. (A) Cyrtodactylus tambora sp. nov., holotype, MZB. Lace. 13298. (B) C. celatus, holotype, BMNH 1926.10. 30.45. (C) C. laevigatus, FLMNH 28911. (D) C. darmandvillei, lectotype, ZMA 10943. (E) C. gordongekkoi, paratype, ZRC 2.3381. (F) C. wetariensis, holotype, AMNH 32165. Photograph by A. Riyanto (A) and H. Kaiser (B – F).

FIGURE 3. Precloacal and femoral region of the holotype of Cyrtodactylus tambora sp. nov. (MZB. Lace. 13298), showing the arrangement of precloacal pores that four pores situated in a short groove, and enlarged precloacofemoral scales. Photograph by A. Riyanto.

FIGURE 4. Map of the Lesser Sunda Islands showing the positions of the Inner and Outer Banda Arcs as well as the type localities of Cyrtodactylus endemic to this archipelago. Map modified from Kathriner et al. 2014.

FIGURE 5. Habitat of Cyrtodactylus tambora sp. nov. along the riverbank of the Oi Marai River, Sumbawa Island, Indonesia. Photograph by A. Riyanto.

Tables

TABLE 2. List of characters useful to distinguish Cyrtodactylus species occurring in the Lesser Sunda Islands. We employed the following character coding: presence (1); absence (0); male (♂); female (♀); character state unavailable / unknown (?); absence of a precloacal depression (N); presence of a groove (G); blotched dorsal pattern (bl); mottled dorsum (mo); and patternless dorsum (pl). If taxa possess precloacofemoral scales (scales in a continuous series), precloacal and femoral scales (separated from each other by infrascales) are coded ‘ n / a. ’ If precloacal and / or femoral pores are present only, precloacofemoral scales are coded ‘ n / a’ as well. References are abbreviated alphabetically, as A = Biswas (2007), B = Das (1993), C = Hartmann et al. (2016), D = Kathriner et al. (2014), E = Mecke et al. (2016), and F = Rösler & Kaiser (2016). The number of adult specimens we examined personally is denoted by ‘ n ’.

	tambora sp.nov	Celatus	darmandvillei	gordongekkoi	laevigatus	wetariensis
References	this paper	D, E, F	C, D, E	A, B, E	C, D, E	C, E
n	4	2	2	2	2	1
Adult SVL (mm)	40–47	38–44	80–82	71–73	38–47	58–67
Tubercles on anterobrachium	1	1	1	1	0	1
Tubercles on brachium	0	0	1	0	0	0
Tubercle in the ventrolateral fold	0	0	1	0	0	1
Expression of precloacal depression	G (♂)	G (♂)	N	N	N	N
Number of precloacal pores	5–6(♂)	4 (♂)	0	0	0	11 (♂), 9 (♀)a
Number of femoral pores	0	0	0	0	0	12–16 (♂), 2 (♀)a
Enlarged precloacofemoral scales	1	n/a	1	1	?	1
Enlarged precloacal scales	n/a	1	n/a	n/a	0	n/a
Enlarged femoral scales	n/a	0	n/a	n/a	0	n/a
Enlarged median subcaudals	0	0	1	0	0	0
VentS	40	34–42	34–36	30	30–34	36–38
LamT4	16–17	15–18	23–24	22–23	10–15	20–22
Pattern of dorsum	bl	bl	bl	bl	mo, pl	bl