2004

Asiatic Herpetological ResearchVol. 10, pp. 8-11

A New Species of Leptolalax (Anura: Megophryidae) fromPulau Tioman, West Malaysia
L. LEE GRISMER, JESSE L. GRISMER, AND TIMOTHY M. YOUMANS
Department of Biology, La Sierra University, Riverside, CA 92515-8247
Abstract. - A new species of Leptolalax is described from a cave at the top of Gunung Kajang, Pulau Tioman, Pahang,West Malaysia. It differs from all other Malaysian species of Leptolalax in several aspects of coloration and in having smooth as opposed to rough or pebbled skin on the dorsum.
Key words. - Leptolalax, Anura, Tioman, Malaysia.

Introduction
There are at least eight species of Leptolalax foundthroughout West Malaysia and Borneo (Berry, 1975;Inger et al., 1995; Inger et al., 1997; Matsui, 1997) but
only one of these, L. gracilis, is known from bothregions. In an unpublished document, Day (1990)
reported Leptobrachium sp. from Pulau Tioman,Pahang, West Malaysia based on five larvae collected inthe Tengkuk Air Cave (Gua) at 1000 m elevation onGunung Kajang. Lim and Lim (1999) referred these larvae to Leptolalax gracilis based on three additional larvae they collected at a lower elevation (ca. 400 m) on
Gunung Kajang. More recently, Grismer et al. (2004)
reported two adults from Gua Tengkuk Air.
Examination of those adults indicates that they belong to
the genus Leptolalax not Leptobrachium (but they are
not L. gracilis). We therefore, refer these specimens andthe larvae of Lim and Lim (1999) to the new species
described herein.

Materials and Methods
The following measurements were made with sliding
calipers to the nearest 0.1 mm: adults; snout-vent length(SVL), tibial length (TL), head width (HW), head length(HL), and diameter of tympanum (TYM). Tadpoles(Table 1); interorbital distance (IOD), internarial distance (IND), tail length (TL), and tail height (TH).
Tadpoles were preserved in 10% formalin and transferred to 70% ethanol. Due to shrinking and wrinkling,head-body width (HBW), head-body height (HBH), andtail height (TH) are likely to be underestimated.
Observations on external morphology were made withthe use of a dissecting microscope. Specimens werecompared to material listed in Appendix I and descriptions in Berry (1975), Inger (1985), Inger et al. (1997),Inger et al. (1995), Inger and Stuebing (1997), Malkmus(1992), and Matsui (1997).

© 2004 by Asiatic Herpetological Research

Leptolalax kajangensis, new species(Figs. 1-2)
Holotype. - ZRC 1.7714; adult male, 34.0 mm SVL;
found inside Gua Tengkuk Air, Gunung Kajang, Pulau
Tioman, Pahang, West Malaysia at 1000 m in elevation.
Collected by Jesse L. Grismer and Timothy M. Youmans
on 21 July, 2001.
Paratype. - ZRC 1.7715; adult male, 35.0 mm SVL.
Same data as holotype.
Diagnosis. - Leptolalax kajangensis differs from allother Malaysian species of Leptolalax in lacking distinct
dark crossbands on the limbs and having a generally
dark, unicolor to weekly patterned dorsum. It differs further from L. arayai, L. dringi, L. gracilis, L. hamidi, andL. maurus, in having smooth, as opposed to rough, warty
skin. It differs further from L. dringi, L. gracilis, and L.
heteropus in lacking dark spots on the ventrum. It differs further from L. gracilis and L. hamidi in lacking adark inguinal blotch and from L. gracilis in lacking a
distinctly bicolored forelimb and dark markings on theventral surface of the foreleg.
Description of holotype. - Habitus moderately slender,head longer than wide; snout rounded in dorsal profile,
weakly projecting beyond lower jaw; nostrils raised,directed dorsolaterally, and situated on canthi, near tip ofsnout; canthi rounded; lores slightly oblique; eye large,
diameter slightly longer than length of snout; internarial
distance less than interorbital distance; interorbital widthslightly greater than length of snout; tympanum visible,
less than one-half diameter of eye, separated from eye
by width of tympanum; vomerine teeth absent; tongue
notched, without papillae.
Forelimbs slender; fingers slender, unwebbed, tips
rounded; first finger equal in length to second; no subarticular tubercles or elongate cornified pads visible
beneath fingers; large inner palmar tubercle present andVol. 10, p.9

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Variation. - The paratype closely approximates theholotype in all aspects of coloration and morphology. It
differs in the following measurements: SVL 35.0 mm;
TL 14.6 mm; HW 19.4 mm; HL 9.4 mm TYM 1.8 mm.
Etymology. - This species is named after the type locality of Gunung Kajang, Pulau Tioman, West Malaysia

Figure 1. Photograph of Leptolalax kajangensis, newspecies, on forest leaf litter.

much smaller outer palmar tubercle at base of fourth
digit.
Hindlimbs relatively short; heels overlap whenlimbs flexed; tibiotarsal articulation of adpressed limb
reaches tip of snout; tips of toes rounded; third and fifth
toe equal in length; slight webbing between first andsecond and second and third toes only; oval inner
metatarsal tubercle present; subarticular tubercles
absent.
Skin on back smooth to faintly pebbled; flanks
faintly pebbled; limbs smooth to faintly pebbled; prominant supratympanic fold extending from eyelid to shoulder; ventral surfaces smooth.
Coloration. - In life and ethanol, dorsal surfaces almost
black with no visible pattern except for minute, faint,
light-colored spots; limbs slightly lighter with faint darkmottling; faint dark mottling on flanks blending to grayish dusty ventral surfaces punctated by minute grayspots. Supratympanic fold darker than dorsum. Iris
metallic gold in life.
Measurements of holotype. - SVL 34.0 mm; TL 14.2mm; HW 18.5 mm; HL 10.0 mm; TYM 1.6 mm.

Tadpoles. - Table 1 lists measurements, growth stages,and tooth row formulae of tadpoles. Based on specimens(ZRC 1.3339-41); stages 30, 36, and 37 (Gosner, 1960)
from a small stream at 333 m below Gua Tengkuk Air onG. Kajang and specimens (0051-54 uncatalogued specimens in the British Museum reported by Day, 1990)
stage 30 (Gosner, 1960) from Gua Tengkuk Air. Headand body relatively large and round; nostrils dorsally
located, closer to tip of snout than eye; eyes dorsolateral, not visible from below; spiracle sinistral, nearer toeye than vent; vent dextral, opening at margin of ventral
fin; dorsal fin slightly deeper than ventral fin, notextending onto head-body; fins not deeper than caudal
musculature; oral apparatus not emarginate; mouth subterminal; bordered by a single row of conical papillae;
large submarginal papillae without denticles; jaw
sheaths black, robust, strongly arched, and finely serrated; upper jaw lacking medial notch; denticles small;rows A1 and P5 markedly shorter than adjacent rows.
Tadpoles (ZRC.1.3339-41) from stream dusky brownabove with faint darker mottling; venter cream colored,nearly immaculate; faint dark stippling on caudal fins,edges clear and immaculate; lateral line hash marks distinct. Tadpoles from Gua Tengkuk Air (uncataloguedBM specimens) lack pigment and are white to transparent in life.
Comparisons with other species. - Leptolalax kajangensis differs from all other Malaysian species ofLeptolalax on the basis of skin surface texture and coloration. Leptolalax arayai, L. dringi, L. gracilis, L.
hamaidi, L. maurus, and L. pelodytoides all have coarsely textured skin ranging from distinctive corrugations inTable 1. Selected measurements (mm), growth stage (GS), and labial tooth row formulae (LTRF) of Leptolalaxkajangensis. Abbreviations follow Materials and Methods. * = Specimen damaged.
Cat. no.

HBW

HBL

HBH

IOD

INDTL

TH

GS

LTRF

0051
0052
0053
0054
0055
ZRC.1.3339
ZRC.1.3340
ZRC.1.3341

13.5
15.2
13.5
14.5
14.1
11.2
19.6
18.0

23.3
23.8
23.5
25.5
25.9
23.5
30.8
31.9

8.4
9.3
10.0
10.0
10.0
8.2
14.5
14.2

4.8
6.6
5.0
5.4
6.7
6.0
7.3
7.8

3.2
4.9
4.3
3.9
4.8
2.6
4.5
4.6

39.9
49.9
*
45.5
43.5
41.4
56.4
51.9

10.0
13.7
*
11.0
12.0
*
*
*

30
3830
30
38
30
35
36

6(2-6)/5(1-4)
6(2-6)/5(1-4)
6(2-6)/5(1-4)
6(2-6)/5(1-4)
6(2-6)/5(1-4)
6(2-5)/5(2-4)
6(2-6)/1(1-3)
5(4)/4(1-3)

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Asiatic Herpetological Research

Figure 2. Tadploe of Leptolalax kajangensis at type locality.

L. dringi to isolated tubercles of varying sizes in L. gracilis (Inger and Stuebing, 1997; Inger et al. 1997;Matsui, 1997). Leptolalax kajangensis resembles L. pictus and L. pelodytoides in having smooth to weakly pebbled skin on the dorsum (Inger et al. 1995) but differsfrom L. pictus in lacking small tubercles on its sides(Malkmus, 1992). Leptolalax kajangensis falls within
the size range (SVL 34.0-35.0 mm) of L. dringi (SVL30.0-38.8 mm), L. gracilis (SVL 31.0-48.0 mm), L. heteropus (SVL 33.0-35.0 mm), L. pelodytoides (SVL 30.042.0 mm), and L. pictus (SVL 31.0-47.0 mm) but is larger than L. arayai (SVL 29.9) and L. marus (SVL 26.032.0). Leptolalax kajangensis differs most notably fromother species in coloration. Its generally unicolor black
dorsal pattern contrasts sharply with the various mottled
body patterns of L. dringi, L. hamidi, L. heteropus, Lpelodytoides, and L. pictus. It does resemble L. maurus
to some extent in that L. maurus has a black unicoloreddorsum but differs in that the latter also has lighter colored limbs with darker crossbars and light colored spots
on the flanks, patterns which are absent in L. kajangensis. Leptolalax gracilis also has a generally dark dorsal
coloration with varying degress of dark mottling but isdistinctive in having a light colored brachium. The single specimen of L. arayi has a light ground color withdarker crossbands on the limbs.
Natural history. - Both specimens of Leptolalax kajangensis were found in a cave (Gua Tengkuk Air) near thesummit of Gunung Kajang at approximately 1000 m inelevation. This subterranean, obliquely oriented cavern
is formed from the overhang of large boulders piled on
top of one another. It contains a small pond (3 m x 4 m)
drained by a small subterranean stream (1-3 m in widthby 2-4 cm in depth) running for 3-4 m along the cavefloor. Both specimens of L. kajangensis were observedin the afternoon sitting on top of large rocks adjacent tothe stream approximately 10 m from the entrance to thecave and approximately 10 m below the outside groundlevel. It was from the subterranean pond that Day (1990)
collected "large tadpoles" he referred to as
Leptobrachium sp. We observed additional tadpoles andVol. 10, p. 10

assume these to be larvae of Leptolalax kajangensis
based on the fact that the type material were collectedfrom the same stream and adults were observed callingfrom the edge of the pond.
Three additional larvae examined here(ZRC.1.3339-41) were collected from a lower stream on
Gunung Kajang at approximately 400 m on 26 June
1996 (Lim and Lim, 1999). We tentatively assign theseto Leptolalax kajangensis because they match the larvae
from Tengkuk Air in morphology (Table 1). However,
the Tengkuk Air specimens lack pigment and are white
to transparent in life (Fig. 2). ZRC.1.3339-41 are countershaded with dark pigment above and have minutedark flecks on a light venter. This indicates that either L.
kajangensis is not confined to only the upper most elevations of Gunung Kajang or that there may be an additional species of Leptolalax found lower down on themountain.
Biogeography. - Pulau Tioman had a land positive connection with Peninsular Malaysia as late as thePleistocene (Voris, 2000). The presence of amphibian
species on Pulau Tioman such as Leptolalax kajangensis, Megophrys nasuta, Rana hosii, R. picturata and others that require streams with moderate to strong currents
for reproduction suggests these species are unlikely candidates for long distance dispersal over flat, low-lying
landscape (Inger and Voris, 2001). Pulau Tioman waspart of a large granitic arc of mountains extending fromwhat is currently peninsular Malaysia through theKepulauan Anambas and Natunas across the GreaterSunda Shelf which provided a dispersal corridor formontane species (Inger and Voris, 2001) across the flat,
low-lying exposed Sunda Shelf. Thus, the presence of
stream-breeding species requiring moderate to fast flowing water on Pulau Tioman is most likely a result of vicariance.

Acknowledgments
We thank Mr. Sahir bin Othman, Director of Wildlife,
PERHILITAN, for permission to conduct field work in
the Seribuat Archipelago. We thank Peter Ng andKelvin Lim of Raffles Museum of Biodiversity
Research (ZRC) and Harold Voris and Alan Resetar of
the Field Museum of Natural History (FMNH) for
allowing us to examine specimens in their care. Forcomments on the manuscript we are grateful to R. F.
Inger and for field assistance we thank Geoff Powells.

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