Leptolalax sabahmontanus Matsui, Nishikawa & Yambun, 2014, sp. nov.

Leptolalax sabahmontanus sp. nov.

(Figures 2, 3, 4)

Holotype. BORNEENSIS 22684, an adult male from Silau Silau trail along Sungai Silau-Silau (06o00'N, 116o32'E, alt. 1450 m a.s.l.), Kinabalu National Park (KNP), Ranau District, Sabah, Malaysia, collected on 31 July 2005 by M. Matsui.

Paratypes. BORNEENSIS 22683, 22685, 22687–22691, 22701, KUHE 48014–48016 (former BORNEENSIS 22681, 22682, 22686), 11 males data, same as the holotype. BORNEENSIS 22757, 22760, KUHE 48017 (former BORNEENSIS 22756), three males from the type locality, collected on 2 August 2005 by M.

Matsui, P. Yambun, K. Nishikawa, and T. Shimada. SP 26736, 26737, two males from the type locality, collected on 14 August 2008 by Majin Silim. BORNEENSIS 22748, 22749, two males from Pandanus trail (06o00'N, 116o32'E, 1500 m a.s.l.), KNP, collected on 1 August 2005 by M. Matsui, P. Yambun, K. Nishikawa, and T. Shimada. KUHE 48018 (former BORNEENSIS 22784), BORNEENSIS 22785, 22786, three males from junction of Sg. Liwagu and Sg. Silau-Silau (06o00’ N, 116o33’ E, 1400 m a.s.l.), KNP, collected on 5 August 2005 by M. Matsui, P. Yambun, K. Nishikawa, and T. Shimada. SP 26740, an adult female from Bundu Tuhan view trail, KNP, collected on 14 August 2008 by S. David. BORNEENSIS 22980, 23029, 23034, three males from Sayap (06o11’ N, 116o34’ E, 950m a.s.l.), KNP, Kota Belud District, collected on 12 August 2005 by M. Matsui, Y. B. Paul, K. Nishikawa, and T. Shimada.

Referred specimens. BORNEENSIS 8711, 8726, 8729, three males from Trail 4 (05o29’ N, 116 o01’ E, 754 m a.s.l.) of UMS 2002 expedition to the Crocker Range, Ulu Kimanis, Crocker Range National Park (CRNP), Tambunan District, collected on 9 September 2002 by M. Matsui. BORNEENSIS 8179, one male from Trail 5 (05o29’ N, 116o01’ E, 820 m a.s.l.) of Ulu Kimanis, CRNP, collected on 1 September 2002 by M. Matsui. BORNEENSIS 8673, one male collected on 7 September 2002 by M. Matsui, and KUHE 48020 (former BORNEENSIS 23470), one male collected on 19 August 2005 by M. Matsui, from Trail 11 (05o27’ N, 116o03’ E, 1427 m a.s.l.) of Ulu Kimanis, CRNP. KUHE 48019 (former BORNEENSIS 8855), one male collected on 12 December 2003, BORNEENSIS 12454, one male collected on 5 August 2003 by M. Matsui, BORNEENSIS 12632–12634, three males collected on 9 August 2003 by M. Matsui, K. Nishikawa, and T. Shimada, and BORNEENSIS 23482, one male collected on 20 August 2005 by M. Matsui, all from Mahua, CRNP (05o48’ N, 116o24’ E, 1063 m a.s.l.).

Etymology. The specific epithet is from Sabah and a Latin adjective montanus denoting mountain, alluding to the fact that the species inhabits on mountains of Sabah, northern Borneo.

Diagnosis. The new species is assigned to Leptolalax on the basis of the following: lack of vomerine teeth; fingers rounded in tips and lacking webbing; inner palmar tubercle elevated, not extending to the first finger; subarticular tubercles indistinct, replaced by low callous tissue; lack of nuptial pad; toe webbing basal; lack of outer metatarsal tubercle; snout tip with white vertical bar (Dehling & Matsui 2013). A medium-sized form of the genus, adult males about 25–28 mm in SVL; snout rounded in both ventral view and lateral view; interorbital space narrower than upper eyelid; male vocal sac not bipartite; toe webbing basal; dorsal skin of trunk and head smooth with tiny tubercles; pectoral gland small and indistinct; supraaxillary gland and ventrolateral glandular ridges absent; venter spotted; advertisement call consisting of long series of 1–149 notes, each composed of one to two indistinct pulse groups, dominant frequency at 6.75–7.35 kHz, without prominent frequency modulation. Most similar to L. dringi, but differing in smaller body size, relatively smaller eye-tympanum distance and inner metatarsal tubercle, and larger interorbital distance, upper eyelid width, snout length, eye length, and forearm and hand length compared to L. dringi.

Description of holotype (measurement in mm). SVL 26.3; head and body moderately stocky (Figures 3); head longer (10.7) than broad (9.7) and wider than trunk; snout rounded in both ventral view and lateral view, slightly protruding beyond lower jaw; eye large (4.1) subequal to snout length (4.0); pupil vertical; canthus rostralis distinct, slightly concave in dorsal view between eye and nostril; convex between nostril and tip of snout; loreal region oblique, concave; nostril lateral, below canthus, distinctly closer to eye (2.1) than to tip of snout; internarial space (2.5) narrower than interorbital distance (3.0), latter slightly narrower than upper eyelid (3.2); pineal spot invisible; tympanum distinct, rounded, diameter (2.4) three-fifths that of eye, and separated from eye by about onethird tympanic diameter (0.9); symphysial knob on anteriormost part of mandible; vomerine ridge and teeth absent; tongue large, broad, notched distally, without papillae; a median, subgular vocal sac in the mid-ventral line; vocal openings small, just posterior to rictus, close to eustachian tube openings.

Forelimb slender, moderately long (19.7); hand and forearm long (15.0); fingers long and slender, without webbing or lateral fringe of skin (Figure 4 A); relative length of fingers II<I<IV <III; tips rounded and thickened; nuptial pad absent; inner metacarpal tubercle large, subquadratic, and prominent in thenar and metacarpal region of fingers I and II, divided subequally in proximal and distal part by shallow superficial depression, separated by a distinct groove from much smaller, outer metacarpal tubercle in metacarpal region of fingers III and IV; subarticular tubercles indistinct, replaced by long, low callous tissue.

Hindlimb relatively long (43.7), more than two times length of forelimb; tibia (14.0) longer than foot (12.2); heels overlapping when limbs are held at right angles to body; tibiotarsal articulation of adpressed limb reaching level between nostril and snout; relative length of toes I<II<V<III<IV; toe tips rounded and thickened, smaller than finger tips; toe webbing basal, webbing formula I 1 3/4–2+ II 2–3 + III 3– 4 IV 4+–2 3/ 4 V (Figure 4 B); fringes of skin on lateral sides of toes very narrow, hardly discernible; inner metatarsal tubercle low, oval, large, length (1.4) slightly more than half length of first toe (2.0); no outer metatarsal tubercle; subarticular tubercles obscure, but elongate, replaced by low callous tissue from base to distal half of penultimate phalanx.

Skin on dorsum and dorsal side of head scattered with tiny tubercles, weakly wrinkled on dorsal surfaces of limbs (Figures 3 A); lateral surface of trunk with an irregular row of several larger, low tubercles; weak wrinkles on dorsal surfaces of limbs forming indistinct, reticulated, predominantly longitudinal, low ridges; supratympanic fold low but distinct, slightly angular, running from posterior margin of eye to level of insertion of forelimb; several enlarged tubercles at posterior end of rictus; chest and abdomen smooth, skin of gular region not modified; pectoral gland very small and low, hardly discernible, at insertion of forelimb; supraaxillary gland hardly discernible, and femoral gland and ventrolateral glandular ridges absent.

Colour. In life, olive brown dorsally on head and body, with large, dark brown, irregularly shaped markings, some with trace of light outline; medial dark brown markings comprising small reverse-triangle pattern on snout, much larger, similar-shaped one between eyes and continuous W-shaped pattern on shoulder region, and irregular pattern on sacral region; dorsolateral stripe-like pattern formed by dark spots from shoulder to groin, with series of smaller dark spots ventrolaterally on side of trunk; discontinuous black band below canthus rostralis surrounding nostril; light brown stripe from between nostrils to anteriormost edge of upper jaw; upper lip barred with dark and light brown; white spots on region posteroventral to eye and on rictus conspicuous; ventral edge of supratympanic fold and tympanum except for lower part dark brown; groin with dark brown spot extending onto thigh; limbs light brown dorsally marked with alternating light and dark brown crossbars; basic colouration on upper arm lighter than on lower arm; dark crossbars restricted to lower arm and fingers; dark brown crossbars on tibia incomplete, absent on dorsal surface; area of tibio-tarsal articulation not cream-coloured dorsally; throat and chest cream-coloured with fine, light brown mottling; posterolateral portion of throat without paired unpigmented areas; chin with dark brown mottling, denser along edge of lower jaw; abdomen cream-coloured with dark brown speckling, forming diffuse spots of various size; limbs ventrally cream-coloured, heavily dusted with brown on lower arm and hindlimb; posterior surface of thigh brown speckled with cream; iris red in upper half and along outer margin of pupil, silver with black reticulation in lower half. In alcohol, colour generally darker, although brown marking on upper part of tympanum lighter; pattern generally faded but still distinct (Figure 3).

Variation. Individuals of the type series are generally similar to each other in morphology. Variation in size and body proportions is given in Table 2. Angle of supratympanic fold varies, and in six of eight paratypes, is more strongly angular than in the holotype. Pectoral glands are more distinct in one paratype. Dark brown marking on abdomen varies from scattered dots to large round spots. Male specimens from Kinabalu and Crocker do not differ in size and proportions of body. The single female available is larger (SVL = 35.0 mm) than the largest male (27.9 mm), and has smaller values than males in HL, HW, IND, IOD, UEW, SL, EL, LAL, FLL, TL, FL, and HLL, all relative to SVL.

Call characterics. The advertisement call of four paratypes (BORNEENSIS 22690, 22691; KUHE 48015, 48016) from KNP, recorded at the air temperatures of 17.2–17.7o C were 0.02 to 11.6 (mean±SD = 1.8±2.1, n = 54) s in duration, with a call interval of 0.1–4.0 (0.5±0.6, n = 48) s (Figure 5, Table 3). A call consisted of a series of 1 to 149 (mean±SD = 24.2±26.9, n = 54) distinct notes. Each note lasted 3–23 (11.7±4.6, n = 46) ms with a note interval of 54–78 (65.4±6.0, n = 32) ms, and a note repetition rate of 12.5–17.3 (13.4±0.9, n = 51) notes per second. Each note was composed of 1–2 (1.5±0.5, n = 46) indistinct pulse groups. There was no marked frequency modulation within a note, and the dominant frequency at the beginning of the call, 6.90–7.35 (7.10±0.11, n = 46) kHz, ended at 6.75–7.10 (6.94±0.09) kHz, with the decrease of only 0.0–0.4 (0.16±0.08, n = 46) kHz.

The advertisement calls of two males from CRNP (BORNEENSIS 8673 from Trail 11 and 12454 from Mahua) recorded at the air temperature of 19.8 o C and 21.3o C, respectively, were basically similar to Kinabalu calls. However, calls of BORNEENSIS 12454 consisted of longer notes (22–25 [24.0±1.1, n = 11] ms) with shorter intervals (39–44 [41.9±1.4, n = 10] ms) and higher frequency (initial dominant 7.40–7.60 [7.53±0.06, n = 11] kHz and final dominant 7.20–7.35 [7.29±0.05] kHz) than in others. Additionally, a harmonic frequency was detected at 20.25–20.45 (20.33±0.08, n = 11) kHz in the calls of BORNEENSIS 12454, probably because of the quieter environment in which the recording was made.

Comparisons. Leptolalax sabahmontanus differs from congeneric species occurring outside Borneo in the same manner as in L. fritinniens (Dehling & Matsui 2013), and comparisons with Bornean species are pertinent. Leptolalax sabahmontanus morphologically differs from all the described Bornean species in the following way. By the presence of ventral markings, it resembles L. dringi, L. gracilis and L. fritinniens. Of these, the new species is most similar to L. dringi, but results of statistical tests in males indicated that the new species (Kinabalu and Crocker combined, n = 17) is smaller than L. dringi from Mulu (n = 7) in SVL (mean = 26.4 mm vs. 29.1 mm in L. dringi), and that it has smaller eye-tympanum distance (median = 3.0% vs. 4.1%) and inner metatarsal tubercle (5.1% vs. 5.8%), and larger interorbital distance (11.3% vs. 9.9%), upper eyelid width (12.1% vs. 11.2%), snout length (15.2% vs. 13.1%), eye length (15.6% vs. 14.0%), and forearm and hand length (55.1% vs. 52.4%), all relative to SVL, than L. dringi (Mann-Whitney U-test, p <0.05). Leptolalax sabahmontanus is similar to L. gracilis in the absence of dark cross bars on the upper arm, but differs from it by a smaller (male SVL 25.4–27.9 mm vs. 31.1–39.2 mm in L. gracilis) and stockier body, and less developed ventral dark marking (body more slender and dark marking usually conspicuous in L. gracilis). Leptolalax sabahmontanus and L. gracilis are markedly different in advertisement calls (see below). From L. fritinniens, the new species differs by the smaller body size (male SVL 25.4–27.9 mm SVL vs. 27.4–34.8 mm SVL in L. fritinniens) and having a single, medially arranged vocal sac in males (vs. bipartite vocal sac in L. fritinniens).

Voucher BORNENSIS BORNENSIS BORNENSIS BORNENSIS BORNENSIS BORNENSIS

22686 22691 22690 22682 8673 12454 (0.2–2.6) (0.8–11.6) (0.02–3.8) (0.02–4.0) (0.3–5.0) (0.1–2.4)

Call ITV (s) 0.5±0.4 (16) 0.8±1.4 (8) 0.3±0.2 (13) 0.4±0.1 (13) 0.3±0.1 (10) 0.3±0.1 (14) (0.2–2.0) (0.2–4.0) (0.1–0.6) (0.1–0.6) (0.2–0.4) (0.1–0.5)

Notes/Call 17.3±8.7 (17) 54.0±53.1 (9) 18.6±12.8 (14) 19.0±15.0 (15) 32.0±20.7 (11) 18.2±10.4 (15)

(3–33) (10–149) (1–48) (1–53) (5–72) (2–37)

Note RR (/s) 13.3±0.8 (17) 13.2±0.2 (9) 13.3±1.0 (14) 13.8±1.2 (15) 14.8±0.9 (11) 16.4±1.0 (15) (12.7–16.2) (12.8–13.4) (12.5–16.4) (13.0–17.3) (14.2–17.2) (15.6–18.9)

Note L (ms) 6.0±1.3 (11) 18.2±2.4 (11) 10.3±1.0 (13) 12.6±1.2 (11) 15.0±3.0 (10) 24.0±1.1 (11)

(3–8) (14–23) (9–12) (11–15) (10–18) (22–25)

Note ITV (ms) 73.1±1.4 (10) 58.7±2.2 (10) 71.9±2.5 (12) 64.3±1.5 (10) 54.3±2.6 (9) 41.9±1.4 (10) (6.80–7.00) (7.00–7.10) (6.95–7.05) (6.75–6.90) (6.70–6.85) (7.20–7.35)

Df decrease 0.13±0.07 (11) 0.13±0.06 (11) 0.22±0.08 (13) 0.16±0.07 (11) 0.05±0.04 (10) 0.24±0.07 (11)

(kHz) (0.05–0.20) (0.05–0.25) (0.10–0.40) (0.10–0.35) (0–0.10) (0.10–0.35) The presence of ventral markings clearly differentiates L. sabahmontanus from L. pictus, L. hamidi, and L. arayai. Furthermore, from L. pictus, the new species differs by having a smaller body size (male SVL 25.4–27.9 mm vs. 31.1–34.0 mm SVL in L. pictus), olive brown dorsum with black pattern without distinct light outlines (vs. dorsum pinkish brown with dark brown markings with conspicuous thin light outlines in L. pictus). From L. hamidi, L. sabahmontanus also differs by having a smaller body size (male SVL 25.4–27.9 mm vs. 28.4–28.8 mm in L. hamidi) and small dorsal markings without light outlines (vs. large dark brown dorsal markings with light outlines in L. hamidi). From L. arayai, L. sabahmontanus clearly differs by having a smaller body size (male SVL 25.4–27.9 mm vs. 29.2–32.0 mm in L. arayai), not strongly shagreened back, presence of dorsal markings, usually white venter, and absence of flush colour on ventral side of legs and groin (vs. dorsum tuberculated, without conspicuous markings, venter yellow, and groin and ventral sides of limbs orange in L. arayai). Finally, the new species is similar to L. maurus in body size (male SVL 25.4–27.9 mm vs. 25.0– 26.9 mm SVL in L. maurus), but differs from it by having an olive brown dorsum with black pattern, and maculated light-colored ventrum (vs. having a dark brown to black dorsum and ventrum in L. maurus).

The new species also differs from the known Bornean members acoustically. By lacking clear frequency modulation within a note, it differs from L. fritinniens, L. hamidi, and L. pictus, although the dominant frequency of the call of the new species (6.90–7.35 kHz at 17.2–17.7o C) overlaps (7.25–9.20 kHz at 24.3–24.9°C in L.

fritinniens, 6.70–7.30 kHz at 22.9–24.1°C in L. hamidi, and 6.80–7.15 kHz at 19–22°C in L. pictus). The new species is similar to other species without conspicuous frequency modulation, but the dominant frequency (6.90– 7.35 kHz) of the new species is much higher (6.05–6.40 kHz at unknown temperature in L. dringi; 5.40–5.90 kHz at 17.4°C in L. arayai; 5.15 kHz at unknown temperature in L. maurus; 2.60–2.80 kHz at 20.0–26.2°C in L. gracilis).

Range. The species appears to be restricted to Sabah, and has been found around the Headquarters (HQ) of KNP (Silau Silau trail, Pandanus trail, Bundu Tuhan view trail, and along Sg. Liwagu), Ranau District, and Sg. Wario, Sayap, Kota Belud District. It also occurs in CRNP, Tambunan District (Trails 4, 5, and 11 of UMS 2002 expedition to the Crocker Range, Ulu Kimanis, and along Sg. Mahua, Mahua). The known localities are all in mountain regions, ranging in altitude from 754 m to 1500 m a.s.l.

Natural history. Specimens for which data are available were caught in primary rain forest at night 2–50 (median = 5) m away from banks of streams with width of 1–12 (median = 5.5) m. Of the 29 frogs recorded, 20 were found on leaves of short grasses, two on stones at stream banks, two on the trail, three among litters on the forest floor, and two hidden under rotten log or among root of grasses. The height of the grass at which frogs perched is 10–100 (median = 30) cm from above the ground. Reproductive details are unknown, but males were actively calling from late July to mid-August and in mid-December, and these periods must be within the breeding season.

The new species is found sympatric with L. arayai around Headquarters of Kinabalu National Park (KNPHQ), L. pictus at Sayap, KNP, and Mahua, CRNP, and L. fritinniens at Trails of Ulu Kimanis, CRNP. The associated anuran species observed were: Leptobrachium cf. montanum Fischer (at KNPHQ), Leptobrachium cf. abbotti (Cochran) (at Ulu Kimanis), Leptobrachella baluensis Smith (Ulu Kimanis), Xenophrys dringi (Inger, Stuebing & Tan) (Ulu Kimanis), Megophrys nasuta (Schlegel) (Mahua), Leptophryne borbonica (Tshudi) (Ulu Kimanis), Ansonia hanitschi Inger (KNPHQ), A. platysoma Inger (Sayap, Ulu Kimanis, Mahua), A. longidigita Inger (Sayap, Ulu Kimanis, Mahua), Hylarana raniceps (Peters) (Ulu Kimanis), Staurois parvus Inger & Haile (Ulu Kimanis), S. guttatus (Günther) (Ulu Kimanis, Mahua), S. latopalmatus (Boulenger) (Ulu Kimanis), S. tuberilingus Boulenger (KNPHQ, Sayap, Ulu Kimanis), Meristogenys dyscritus Shimada, Matsui, Yambun & Sudin (Sayap), M. orphnocnemis (Matsui) (Ulu Kimanis, Mahua), M. whiteheadi (Boulenger) (Sayap), M. stigmachilus Shimada, Matsui, Yambun & Sudin (Mahua), M. kinabaluensis (Inger) (KNPHQ, Ulu Kimanis, Mahua), Huia cavitympanum (Boulenger) (Sayap), Occidozyga baluensis (Boulenger) (Ulu Kimanis), Ingerana baluensis (Boulenger) (Ulu Kimanis), Limnonectes palavanensis (Boulenger) (Ulu Kimanis), L. cf. kuhlii (Tschudi) (KNPHQ, Sayap, Ulu Kimanis), Fejervarya limnocharis (Gravenhorst) (Mahua), Nyctixalus pictus (Peters) (KNPHQ), Philautus mjobergi Smith (KNPHQ, Sayap, Ulu Kimanis), Ph. petersi (Boulenger) (Sayap, Ulu Kimanis, Mahua), Ph. aurantium Inger (Sayap, Ulu Kimanis, Mahua), Ph. bunitus Inger, Stuebing & Tan (Sayap, Ulu Kimanis), Ph. erythrophthalmus Stuebing & Wong (Ulu Kimanis), Ph. macroscelis (Boulenger) (KNPHQ, Ulu Kimanis), Rhacophorus angulirostris Ahl (KNPHQ, Ulu Kimanis, Mahua), Polypedates leucomystax (Gravenhorst) (Mahua), P. otilophus (Boulenger) (Ulu Kimanis), Kalophrynus heterochirus Boulenger (Ulu Kimanis), K. baluensis Kiew (KNPHQ), K. pleurostigma Tschudi (Crocker Trails), and Chaperina fusca Mocquard (Sayap, Ulu Kimanis, Mahua).