A new species of Gekko (Squamata: Gekkonidae) from Tà Kóu Nature Reserve, Binh Thuan Province, Southern Vietnam.

Abstract

A new species of Gekko Laurenti is described from Ta Kou Mountain, an isolated granitic peak in Ta Kou Nature Reserve, Ham Thuan Nam district, Binh Thuan province, southern Vietnam. The species is distinguished from its congeners by its moderate size, with snout to vent length (SVL) reaching a maximum 107.0 mm; dorsal pattern of 5-8 white vertebral blotches between the nape and sacrum and 6-8 pairs of short white bars on the flanks; 11-14 precloacal pores in males; 14-17 longitudinal rows of smooth dorsal tubercles; and 18-20 broad lamellae beneath the fourth toe. Gekko takouensis sp. nov. is the second endemic gekkonid discovered in the Ta Kou Nature Reserve, Cyrtodactylus takouensis Ngo & Bauer being the first.

Full text

Page 1

Accepted by A. Bauer: 24 Dec. 2009; published: 28 Jan. 2010
17
ZOOTAXA
ISSN 1175-5334 (online edition)
ISSN 1175-5326 (print edition)
Copyright © 2010 · Magnolia Press
Zootaxa 2346: 17–28 (2010)
www.mapress.com/zootaxa/
Article
A new species of Gekko (Squamata: Gekkonidae) from Tà Kóu Nature Reserve,
Binh Thuan Province, Southern Vietnam
NGO VAN TRI1,3 & TONY GAMBLE2
1Department of Environmental Management and Technology, Institute of Tropical Biology, Vietnamese Academy of Sciences and
Technology, 85 Tran Quoc Toan Street, District 3, Hochiminh City, Vietnam. E-mail: trigeckonid@hotmail.com
2Department of Genetics, Cell Biology and Development, University of Minnesota 6-160 Jackson Hall, 321 Church St SE, Minneapolis
MN 55455. USA. E-mail: gambl007@umn.edu
3Corresponding author
Abstract
A new species of Gekko Laurenti is described from Tà Kóu Mountain, an isolated granitic peak in Tà Kóu Nature
Reserve, Ham Thuan Nam district, Binh Thuan province, southern Vietnam. The species is distinguished from its
congeners by its moderate size, with snout to vent length (SVL) reaching a maximum 107.0 mm; dorsal pattern of 5–8
white vertebral blotches between the nape and sacrum and 6–8 pairs of short white bars on the flanks; 11–14 precloacal
pores in males; 14–17 longitudinal rows of smooth dorsal tubercles; and 18–20 broad lamellae beneath the fourth toe.
Gekko takouensis sp. nov. is the second endemic gekkonid discovered in the Tà Kóu Nature Reserve, Cyrtodactylus
takouensis Ngo & Bauer being the first.
Key words: Conservation, Gekko takouensis sp. nov., granitic outcrop, Tà Kóu Mountain, Vietnam
Introduction
The last decade has seen a dramatic increase in the number of gekkotan species described from Vietnam and
21 of the 22 new species described since 2000 are endemic (Geissler et al. 2009; Grismer & Ngo 2007;
Heidrich et al. 2007; Hoang et al. 2007; Nazarov et al. 2008; Ngo 2008; Ngo & Bauer 2008; Ngo et al. 2008;
Ngo & Ziegler 2009; Nguyen et al. 2006; Orlov et al. 2007; Orlov et al. 2008; Rösler et al. 2005; Ziegler et al.
2002; Ziegler et al. 2008). The majority of these newly described geckos have limited distributions occurring
on offshore islands or in isolated, rocky terrain such as karst outcrops and limestone caves. Most have been
within the genera Cyrtodactylus Gray and Cnemaspis Strauch but two new Goniurosaurus Barbour, a new
Dixonius Bauer, Good & Branch and three new Gekko Laurenti have also been described (Ngo et al. 2009;
Ngo & Ziegler 2009; Rösler et al. 2005; Rösler et al. 2010; Ziegler et al. 2008).
There are 14 species of Gekko in Indochina (Bauer et al. 2008; Bobrov 1995; Darevsky & Orlov 1994;
Grossmann & Ulber 1990; Günther 1994; Ngo et al. 2009; Ota et al. 1995; Rösler et al. 2005; Rösler et al.
2010; Szczerbak & Nekrasova 1993; Taylor 1962). Eight occur in Vietnam: Gekko gecko (Linnaeus), G.
palmatus Boulenger, G. ulikovskii Darevsky & Orlov; G. badenii Szczerbak & Nekrasova, G. grossmanni
Günther, Gekko scientiadventura Rösler, Ziegler, Vu, Herrmann & Böhme Gekko canhi Rösler, Nguyen,
Doan, Ho, Nguyen & Ziegler, 2010 and G. russelltraini Ngo, Bauer, Wood & Grismer (Bobrov & Semenov
2008; Ngo et al. 2009, Rösler et al. 2010). Gekko chinensis (Gray) and G. japonicus (Schlegel) have
historically been listed as occurring in Vietnam but their presence is doubtful (Ota et al. 1995).
Recent surveys conducted on Tà Kóu Mountain, an isolated peak in Binh Thuan Province, southern
Vietnam, have uncovered two new gecko species. Cyrtodactylus takouensis was described by Ngo & Bauer
(2008) and here we describe another of the genus Gekko from the same region.

Page 2

NGO & GAMBLE
18 · Zootaxa 2346 © 2010 Magnolia Press
Materials and methods
Field surveys were conducted in November 2005 and June – August 2009. Voucher specimens were collected
by hand during the day and at night. Geographic coordinates and elevation were recorded using a Garmin III
GPS. Photographs were taken using a Panasonic DMC–FZ30 digital camera and Sony DCR–TRV22.
Specimens were first euthanized with tricaine methanesulfonate (MS–222) following Conroy et al. (2009) and
subsequently fixed in 10% neutral buffered formalin, rinsed in water and finally stored in 75% ethanol. Liver
samples, for use in subsequent DNA analyses, were stored in 95% ethanol and kept in cool conditions. All
type specimens were deposited in the Zoological Collection of the University of Natural Sciences (UNS) in
Hochiminh City, Vietnam.
The following measurements were taken with a digital caliper following the methods of Bauer et al.
(2002; 2003): crus length (CrusL); ear length (EarL); eye to ear distance (EyeEar); forearm length (ForeaL);
head depth (HeadD); head length (HeadL); head width (HeadW); internarial distance (Internar); interorbital
distance (shortest distance between left and right supercilliary scale rows) (Interorb); orbital diameter (OrbD);
snout to eye distance (SnEye); nare to eye distance NarEye; snout–vent length (SVL); tail length (TailL);
trunk length (TrunkL). Measurements are reported to the nearest 0.1 mm, but mensural ratios calculated from
raw measurements are reported to the nearest 0.01 mm. Measurements and scale counts were taken from the
right side of each gecko unless otherwise noted. Scale counts and external observations on morphology were
made using an Olympus SZ binocular dissecting microscope. The following meristic values were recorded:
number of dorsal scale rows at midbody (MidBod); number of longitudinal rows of tubercles at midbody
(TubRow); number of ventral scales between the ventrolateral folds at midbody (VentSc); number of chin
scales bordering posterior margin of the first postmental scales (ChinSc); number of supralabials (SupraL);
number of infralabials (InfraL); number scales across narrowest point of frontal bone (FrontSc); number of
interorbital scale rows (IntOrb); number of subdigital lamellae under digit I of pes (LamPesI); number of
subdigital lamellae under digit IV of pes (LamPesIV); number of postanal tubercles at tail base (PAT); number
of precloacal pores (PrecP); and the number of middorsal scales rows in the third caudal whorl (Whorl3).
Comparisons were made with specimens in the Zoological Museum of the National University of Hanoi
and the Zoological Collection of University of Natural Sciences, as well as original species descriptions and
other published faunal and taxonomic treatments (e.g., Bauer et al. 2008; Darevsky & Orlov 1994;
Grossmann & Ulber 1990; Günther 1994; Ngo et al. 2009; Ota et al. 1995; Rösler et al. 2005; Rösler et al.
2010; Szczerbak & Nekrasova 1993; Taylor 1962; Zhou et al. 1982).
Systematics
Gekko takouensis sp. nov.
Figs 1–2.
Holotype. Zoological Collection of University of Natural Sciences in Hochiminh City UNS 0491, adult male
(Fig. 1A); Tà Kóu Mountain, Ham Thuan Nam district, Binh Thuan Province, Vietnam, approximately 425 m
elevation (10°48.815’N, 107°53.718’E), collected by Ngo Van Tri, 30 June 2009.
Paratypes. UNS 0489–90 and 0492–0497 (Figs 1B, C), adult males except for UNS 0495, subadult male,
were also collected by Ngo Van Tri with holotype. UNS 0206 and UNS 0208 were collected on 2 November
2005.
Etymology. The specific epithet takouensis denotes the name of the mountain and nature reserve where
the type series was collected. We suggest the following common names: English — Ta Kou Marbled Gecko;
Vietnamese — Thằn lằn đá Tà Kóu.
Diagnosis. A medium sized Gekko, maximum SVL 107.0 mm, distinguished from its congeners by the
following combination of characteristics: dorsum with 14–17 longitudinal rows of enlarged, smooth tubercles;
83–93 scale rows at midbody; 30–34 ventral scale rows between ventrolateral folds at midbody; 11–14
precloacal pores in males in an angular, continuous series; 18–20 subdigital lamellae on fourth toe; dorsal

Page 3

Zootaxa 2346 © 2010 Magnolia Press · 19
A NEW GEKKO FROM BINH THUAN PROVINCE, VIETNAM
pattern of 5–7 whitish vertebral blotches between nape and sacrum, and 6–8 pairs of short, sometimes
irregular spots or white bars on flanks between limb insertions.
FIGURE 1. Gekko takouensis sp. nov. (A) Holotype UNS 0491 in hand; B: Paratype UNS 0492 photographed in situ; C:
Paratype UNS 0489 showing the lighter coloration often observed at night. Photographed in situ under a neon light on
the dormitory wall of the Linh Son Pagada on Tà Kóu Mountain.

Page 4

NGO & GAMBLE
20 · Zootaxa 2346 © 2010 Magnolia Press
FIGURE 2. Detailed photographs of the holotype of Gekko takouensis sp. nov., UNS 0491 (A) Detail of the rostrum,
note the small scale in the dorsal cleft of the supralabials; B: Ventral view of the chin illustrating three enlarged
postmental scales; C: Dorsal scalation at midbody, note smooth, enlarged rows of tubercles; D: Ventral view at midbody
illustrating subimbricate ventral scales; E: Dorsal scalation of the base of the tail showing two smooth, postanal
tubercles; F: Ventral view of the colacal area showing 13 precloacal pores; G: Dorsal view of the tail, note segmented
scales and lack of tubercles; H: Ventral view of the tail illustrating the enlarged median subcaudal scales.

Page 5

Zootaxa 2346 © 2010 Magnolia Press · 21
A NEW GEKKO FROM BINH THUAN PROVINCE, VIETNAM