Limnonectes kinabaluensis, Dehling & Neokleous & Das & Grafe & Min & Hertwig, 2025

Dehling, Maximilian, Neokleous, Dario N., Das, Indraneil, Grafe, Ulmar, Min, Pui Yong & Hertwig, Stefan T., 2025, Cryptic radiation within the tadpole-carrying Guardian Frogs from Borneo, Limnonectes palavanensis and L. finchi (Anura: Dicroglossidae), with the description of eight new species, Zootaxa 5650 (1), pp. 1-80 : 21-23

publication ID	https://doi.org/10.11646/zootaxa.5650.1.1
publication LSID	lsid:zoobank.org:pub:F8B8158B-26F9-4E1A-A1CF-A20A72F2D875
persistent identifier	https://treatment.plazi.org/id/62199F50-FFF3-FFDB-FF34-FA9FFCE7F818
treatment provided by	Plazi
scientific name	Limnonectes kinabaluensis
status	sp. nov.

Treatment

Limnonectes kinabaluensis sp. nov.

Rana palavanensis (nec Rana palavanensis Boulenger, 1894 ): Boulenger 1897: 230 (partim); Boulenger 1920: 59 (partim); van

Kampen 1923: 182 (partim); Smith 1931: 30; Inger & Stuebing 1992: 46 (partim); Hoffman 1994: 223, 1995: 11; Inger et al. 1996: 363; Lakim et al. 2000: 32. Rana microdisca palavanensis (nec Rana palavanensis Boulenger, 1894 ): Inger 1966: 222 (partim); Matsui 1979: 333. Hylarana microdisca palavanensis (nec Rana palavanensis Boulenger, 1894 ): Manthey 1983: 22. Limnonectes palavanensis View in CoL (nec Rana palavanensis Boulenger, 1894 ): Malkmus 1994: 244; Hoffmann 2002: 31; Malkmus et al.

2002: 145 (partim).

Holotype. NMBE 1075310 View Materials , adult female, from Silau-Silau Trail (6.012741°, 116.539129°, 1,604 m), Gunung Kinabalu, Kinabalu National Park, Sabah, Malaysia, collected on 5 March 2017 by A. Haas, R. Hagmann, S. T. Hertwig and P. Yambun ( Fig. 3C View FIGURE 3 ).

Paratypes. SP 2076, adult male, from Silau-Silau Trail , Headquarters , Kinabalu National Park, Sabah, Malaysia, collected on 9April 1997 by “Paul, RFI” [= Paul Yambun and Robert F. Inger]. SP 2579, 2582–2584, one female, two males, one subadult, from Bundu Tuhan Trail, Headquarters, Kinabalu National Park, Sabah, Malaysia, collected on 23 December 1999 by “Maklarin” [bin Lakim], “Johny”, “Rashid”, David” [Sumpongul] and “Ben”[edict Butit] .

Referred material. ZFMK 79834 About ZFMK , adult male, from Sungai Wariu , Sayap , Sabah, collected on 16 June 1993 by P. Hoffmann. SP 1296, subadult, collected on 14 June 1995 by “Maklarin [bin Lakim], Alim et al.”; SP 1355, adult female, collected on 15 June by the Zoologi Unit of Sabah Parks ; both from Kota Belud , Sayap Park Substation , Kinabalu National Park , Sabah, Malaysia. SP 1395, adult female, collected in July 1995 by the Zoologi Unit ; SP 1545, juvenile, both from Sayap , Kinabalu National Park , Sabah, Malaysia. SP 1769, subadult female, collected on 23 March by the Zoologi Unit ; SP 27184, juvenile, collected on 10 October 2011 by “Paul” [Yambun], “Martinah” [Latim], “Dominik” [Tinggoh]; both from Lipasu Trail , Sayap Park Substation , Kinabalu National Park , Sabah, Malaysia. SP 558, adult of undetermined sex, from “Sungai (Bekalan Air)”, Poring, Kinabalu Park, Sabah, collected on 27 September 1980 by R. Stuebing. SP 2864, adult male, from Gunung Trusmadi , collected on 1 November 2001 by “Maklarim etc.” . UNIMAS 9061 View Materials , adult female, from Lipasu Trail , Sayap, Sabah, Malaysia, collected on 23 August 2007 by I. Das, A. Haas, K. B. Hee and C. Garrett . NMBE 1072214 View Materials , adult female, collected on 14 March 2015 ; NMBE 1072159 View Materials , juvenile, collected on 17 March 2015; both collected by S . T. Hertwig et al. from Mountain Hostel (4.4611°, 117.9230°; 900 m), Tawau Hills National Park, Sabah, Malaysia .

Diagnosis. Limnonectes kinabaluensis sp. nov. belongs to the L. palavanensis species group, showing the typical characters of the group, including small size (SVL <40 mm); odontoid processes in lower jaw low and inconspicuous in both males and females; dorsum finely shagreened, with prominent longitudinal dorsolateral glandular ridges; interorbital distance equal to or larger than upper eyelid width; toes not fully webbed; and horseshoe-shaped dermal ridge in middle of dorsum posterior to arm insertion. The species differs from all other species of the group by a unique combination of morphological characters, including toe webbing reduced; supratympanic fold subangular with its anterior part and posterior part about equal in length; pineal spot well discernible, at level of anterior upper-eyelid edge; vomer ridges short, very widely separated from each other; median ridge low, glandular, moderately distinct, only from horseshoe-shaped ridge to cloaca; postpalpebral and lumbar ridges absent; size relatively large with SVL of adult males 29.3–31.8 mm, of adult females 32.4–38.0 mm. The species differs from all other species of the group by at least 5.7% in the sequence of the 16S barcoding gene. It occurs in submontane and montane rainforest at elevations between 850 and 1,604 m.

Description of holotype. Adult female; SVL 35.5 mm; body sturdy, widest at temporal region, slightly tapering to groin ( Fig. 3C View FIGURE 3 ); head large (HL/SVL 0.38, HW/SVL 0.40), wider as long (HW/HL 1.06); snout moderately long (SL/HL 0.43), rounded in both dorsal view and lateral profile, slightly wider than long (SL/EE 0.95); canthus rostralis distinct between eye and nostril, weakly concave in dorsal view; loreal region oblique; nostrils rounded, directed laterally; situated slightly closer to tip of snout than to eye (EN/NS 1.06), separated from each other by distance larger than distance between eye and nostril (NN/EN 1.44); eye directed anterolaterally, moderately protruding, moderately large (ED/HL 0.33), its diameter much shorter than snout (ED/SL 0.76); interorbital distance greater than upper eyelid width (IO/EW 1.48) and smaller than internarial distance (IO/NN 0.83); pineal spot well discernible, at level of anterior upper-eyelid edge; tympanum and its annulus distinctly visible, its posterior fifth covered by thick skin; tympanum separated from eye by little less than half its diameter (ET/TD 0.44); tympanum diameter smaller than eye diameter (TD/ED 0.63); upper jaw with dentition; odontoid processes in lower jaw low, inconspicuous; choanae small, subtriangular, located far anterolaterally at margins of roof of mouth, fully visible in ventral view; vomer processes bearing teeth, short, separated from choana by distance about equal to length of individual process, from each other by 1.5 times length of individual process ( Fig. 4C View FIGURE 4 ); tongue moderately long and narrow, bilobed for about one-sixth of its length, free distally for about half its length; median lingual process absent.

Dorsal surfaces of head, trunk and limbs finely shagreened; lateral surfaces of trunk finely areolate with sparsely scattered small tubercles; dorsolateral ridge prominent, from posterior end of upper eyelid to groin; low, horseshoe-shaped dermal ridge distinct, in middle of back just behind level of arms; median ridge low, glandular, moderately distinct, only on posterior part of dorsum, from horseshoe-shaped ridge to cloaca; supratympanic fold thick and conspicuous, extending from posterior end of orbit to insertion of arm, subangular with its anterior part and posterior part about equal in length ( Fig. 5C View FIGURE 5 ); enlarged tubercles on lateral edge of upper eyelid; ventral side of head smooth with several weak wrinkles at lateral edge near mandible; transverse chest fold between arm insertions weakly distinct; ventral side of trunk weakly areolate, almost smooth; ventral side of limbs smooth; cloaca without dermal flap but with densely scattered small tubercles.

Forelimbs sturdy; hand relatively small (HND/SVL 0.26); tips of fingers rounded, slightly enlarged into disks; relative length of fingers: IV <II <I <III; subarticular tubercles rounded, well developed, numbering one on Fingers I and II, two on Fingers III and IV, proximal tubercles on Fingers III and IV larger and more prominent than distal ones; finger webbing absent; thenar tubercle distinct, oval, flat, about two-fifths length of metacarpal of Finger I; inner palmar tubercle rounded, weakly distinct; outer palmar tubercle elongate, about half length of metacarpal, moderately distinct.

Hindlimbs sturdy, very long (LEG /SVL 1.84); heel reaching beyond tip of snout when legs adpressed forwardly to body; tibiofibula long (TFL/SVL0.60), longer than thigh (TFL/THL1.15); heels overlapping each other considerably when knees flexed and thighs held perpendicularly to median plane; foot slightly shorter than tibiofibula (FOT/TFL 0.88); relative length of toes: I <II <V <III <IV; toe tips rounded, enlarged into disks; subarticular tubercles numbering one on Toes I and II, two on Toes III and V, and three on Toe IV; pedal webbing formula I 1.5/2+ II 1.25/3- III 2/3.25 IV 3.25/2 V ( Fig. 6 View FIGURE 6 ); narrow dermal flap on preaxial side of Toe I between metatarsal tubercle and disk and on postaxial side of Toe V, widest from proximal end of metacarpus to proximal subarticular tubercle, continued to disk; inner metatarsal tubercle very prominent, elongated, half as long as metatarsus of Toe I; outer metatarsal tubercle absent.

Colouration. In life, ( Fig. 7C View FIGURE 7 ), dorsum, limbs including fingers and toes light brown; upper arms without crossbands; lower arms, fingers, legs including feet with regular medium brown crossbands; interorbital bar dark brown; supratympanic fold and dorsolateral fold greyish dark brown; tympanum light brown; large light brown spots below eye on each side; horseshoe-shaped tubercle same colour as dorsum except dark brown posterior edge; four large dots arranged in rhombic pattern at level of pelvis, dark brown, each with large light grey tubercle in centre; area around cloaca black with whitish small tubercles; ventral side of head, chest, arms and legs orange; large dark brown spots in infralabial region; throat speckled with minute cream-coloured dots; abdomen yellow.

In preserved state ( Fig. 3C View FIGURE 3 ), dorsum greyish brown; limbs, fingers and toes light brown; regular crossbands on lower arms, fingers, legs, feet dark brown; interorbital bar dark brown; supratympanic fold and dorsolateral fold blackish; tympanum dark brown; large spots below eye dark brown; black posterior edge of horseshoe-shaped tubercle black; four large dots arranged in rhombic pattern at level of pelvis dark brown, each with large grey tubercle in centre; area around cloaca black with whitish small tubercles; ventral side of head, chest, arms and legs yellowish cream-white; large spots in infralabial region dark brown; throat speckled with minute dots; abdomen hardly pigmented, blueish white.

Variation. The paratypes match the holotype in general appearance and proportions. Males lack nuptial pads and have weak dermal folds parallel to posterior part of mandible on ventral side of head. The vocal sac aperture is slit-like, directed posterolaterally, situated at corner of mouth. SVL of paratypes is 30.2–31.8 mm in adult males and 36.8 mm in the adult female ( Table 2). Pedal webbing variation is I 1.5 [100] /2- [33],2 [33],2+ [33] II 1+ [66],1.25 [33] /2.5 [33],2.75 [33],3- [33] III 1.5 [66],2 [33] /3 [66],3.25 [33] IV 3 [66],3.25 [33] /1.5 [33],2- [33], 2 [33] V ( Fig. 6 View FIGURE 6 ). SVL of referred specimens from other localities is 29.3 mm in adult males and 32.4–38.0 mm in adult females.

Bioacoustics. The advertisement call of the species is unknown. The call description, including an audiospectrogram and a waveform, in Malkmus et al. (2002: 147, Fig. LXIV) is not based on a call of a specimen from Gunung Kinabalu but on the call recorded by J. Dring from Camp 3 in Gunung Mulu National Park that we refer to L. nephophilus sp. nov. (see below).

Distribution. The species is distributed around the headquarters of Kinabalu National Park Headquarters (Silau-Silau Trail, Bundu Tuhan View Trail) at about 1,600 m. Referred specimens have been collected at Sayap (850–900 m) on the western slope of Gunung Kinabalu; and we tentatively assign a badly preserved specimen (SP 558) from Poring on the eastern slope of Gunung Kinabalu and a specimen from Gunung Trusmadi (SP 2864) to the species. The species has a disjunct distribution and has also been collected at higher elevations of about 900 m in Tawau Hills National Park, Sabah, Malaysia, where it occurs parapatrically with Limnonectes phylax sp. nov. that is distributed at lower elevations in Tawau Hills National Park ( Figs. 8 View FIGURE 8 , 9 View FIGURE 9 ).

Ecology. The types were collected in leaf litter on the forest floor. The specimens from Sayap were collected under a log, another one on a rock, others on the ground and under leaves in leaf litter; both adults and juveniles were found on the ground in moist leaf litter in some distance from the nearest stream ( Hoffmann 1994). According to Malkmus et al. (2002), adults of the species feed on ants, termites, and other small terrestrial invertebrates. The number and size of the ripe ova of the females indicate small clutch sizes. A male was observed releasing tadpoles from its back into a shallow puddle on Silau-Silau Trail in the Headquarters of Kinabalu National Park on 7 July 2023 (P. Janzen, in litt., Fig. 10F View FIGURE 10 ).

Etymology: The species epithet is composed of the name of the type locality, Gunung Kinabalu, as an invariable noun and the Latin suffix -ensis (“from”); meaning “an inhabitant of Kinabalu”.

Suggested English name. Kinabalu Guardian Frog.