Limnonectes gunungensis, 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 : 19-20

publication ID	https://doi.org/10.11646/zootaxa.5650.1.1
publication LSID	lsid:zoobank.org:pub:F8B8158B-26F9-4E1A-A1CF-A20A72F2D875
DOI	https://doi.org/10.5281/zenodo.15820483
persistent identifier	https://treatment.plazi.org/id/62199F50-FFF5-FFDE-FF34-FF50FCE1F8FC
treatment provided by	Plazi
scientific name	Limnonectes gunungensis
status	sp. nov.

Treatment

Limnonectes gunungensis sp. nov.

Holotype. NMBE 1061576 View Materials , adult female, from Pa’ Lungan (3.808622°, 115.524576°; 1,100 m), Gunung Murud, Pulong Tau National Park, Sarawak, Malaysia, collected on 5 March 2012 by S. T. Hertwig, A. Jankowski and Y. M. Pui ( Fig. 3B View FIGURE 3 ).

Paratypes. NMBE 1061593 View Materials , juvenile, from the type locality, collected on 4 March 2012 by S. T. Hertwig, A. Jankowski and Y. M. Pui ; NMBE 1065994 View Materials , adult female, from Payeh Maga (4.4°, 115.5°), Sarawak, collected on 2 March 2013 by S. T. Hertwig, Y. M. Pui et al .; NMBE 1073882 View Materials , adult female, from “Old camp”, Payeh Maga, collected on 28 February 2016 ; NMBE 1073867 View Materials , adult male , NMBE 1073886–88 View Materials , 1073891 View Materials , four adult females, from a stream behind Camp 1 (4.438°, 115.538°; 960 m), Payeh Maga, Sarawak, Malaysia, collected on 29 February 2016 ; all collected by J. Flury, A. Haas, S. T. Hertwig, Y. M. Pui and N. Reichen . NMBE 1101226 View Materials , collected on 25 February 2019 ; NMBE 1101230 View Materials , collected on 26 February 2019 ; NMBE 1101231 View Materials , collected on 27 February 2019 , three adult males, from Kerangas Forest , Camp Balah (3.127907°, 114.278603°; 1,074 m), Gunung Dulit, Sarawak, Malaysia, collected by L. Etter, S . T. Hertwig and F. Heussler . NMBE 1101220–1101221 View Materials , 1101232 View Materials , three adult males, from Camp Koyan (3.342366°, 114.177573°; 822 m), High Plateau, Gunung Dulit, Sarawak, Malaysia, collected on 5 March 2019 by L. Etter, S. T. Hertwig and F. Heussler .

Referred specimens. BMNH 1978.213 , adult female, from Camp 3, Gunung Mulu, Gunung Mulu National Park, Sarawak, Malaysia, collected on 7–8 September 1977 by J. Dring ; NMBE 1101227–1101229 View Materials , three tadpoles from Kerangas Forest , Camp Balah (3.127907°, 114.278603°; 1,074 m), Gunung Dulit, Sarawak, Malaysia, collected with an adult male paratype ( NMBE 1101226 View Materials ) .

Diagnosis. Limnonectes gunungensis 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 extensive; supratympanic fold subangular; pineal spot well discernible, at level of anterior upper-eyelid edge; vomer ridges long, narrowly separated from each other; postpalpebral ridge moderately distinct, along anterior part of dorsolateral ridge to just behind level of arms; lumbar and median ridges absent; size relatively large with SVL of adult males 25.6–31.5 mm, of adult females 30.4–39.9 mm. The species differs from all other species of the group by at least 6.7% in the sequence of the 16S barcoding gene. The species occurs at mid-level elevations (1,000–1,600 m) in the transition between submontane rainforest and lower montane rainforest .

Description of holotype. Adult female; SVL 38.6 mm; body moderately sturdy, widest at temporal region, slightly tapering to groin ( Fig. 3B View FIGURE 3 ); head large (HL/SVL 0.37, HW/SVL 0.38), about as wide as long (HW/HL 1.01); snout moderately long (SL/HL 0.43), subacuminate in dorsal view, rounded and slightly protruding in lateral profile, as long as wide (SL/EE 0.98); canthus rostralis weakly expressed between eye and nostril, slightly concave from eye to nostril in dorsal view; loreal region oblique; nostrils rounded, directed laterally, situated about halfway between tip of snout and eye (EN/NS 1.08), separated from each other by distance much larger than distance between eye and nostril (NN/EN 1.34); eye directed anterolaterally, moderately protruding, large (ED/HL 0.32), its diameter shorter than snout (ED/SL 0.74); interorbital distance greater than upper eyelid width (IO/EW 1.23) 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 and fully visible, its posterior fifth obscured by thickened skin, its dorsal edge in contact with supratympanic fold; tympanum separated from eye by about half its diameter (ET/TD 0.53); tympanum diameter slightly more than half eye diameter (TD/ED 0.55); upper jaw with dentition; odontoid processes in lower jaw low, inconspicuous; choanae small, rounded, located far anterolaterally at margins of roof of mouth, lateral fifth covered by palatal shelf of maxilla in ventral view; vomer processes bearing teeth, long, separated from choana by distance about length of individual process and from each other by half length of individual process ( Fig. 4B View FIGURE 4 ); tongue moderately long and broad, bilobed for about one-sixth its length, free distally for about three-fourth its length; median lingual process absent.

Dorsal surfaces of head, trunk and limbs and lateral surfaces of trunk finely shagreened; dorsolateral ridge prominent, from shortly behind posterior end of upper eyelid to groin; postpalpebral ridge moderately distinct, only in anterior part of dorsum, from behind eyes to just behind level of arms; lumbar and median ridges absent; horseshoe-shaped dermal ridge low, indistinct, just behind level of arms; supratympanic fold thick and conspicuous, extending from posterior end of orbit to insertion of arm, subangular, with anterior and posterior part about equal in length ( Fig. 5B View FIGURE 5 ); ventral side of head smooth; weak transverse chest fold between arm insertions; ventral side of trunk weakly areolate; ventral side of limbs smooth; cloaca without dermal flap.

Forelimbs moderately sturdy; hand relatively small (HND/SVL 0.26); tips of fingers rounded, slightly enlarged into disks; relative length of fingers: II <I = IV <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, prominent, about one-third length of metacarpal of Finger I; inner palmar tubercle subcircular, about as long as narrow outer palmar tubercle; palmar tubercles fused proximally on proximal half of Fingers II–IV.

Hindlimbs sturdy, very long (LEG /SVL 1.85); heel reaching slightly beyond tip of snout when legs adpressed forwardly to body; tibiofibula long (TFL/SVL 0.59), longer than thigh (TFL/THL 1.12); heels overlapping each other considerably when knees flexed and thighs held perpendicularly to median plane; foot slightly shorter than tibiofibula (FOT/TFL 0.94); 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 1/2 II 1+/2+ III 1.25/2.5 IV 2.5/1+ V ( Fig. 6 View FIGURE 6 ); narrow dermal ridge on preaxial side of Toe I and on postaxial side of Toe V from proximal end of metacarpus to disk; inner metatarsal tubercle prominent, elongated, about half length of metatarsus of Toe I; outer metatarsal tubercle absent.

Colouration. In life, dorsum dark brown with narrow, whitish median band; limbs including fingers and toes somewhat lighter brown with regular medium brown crossbands; interorbital bar dark brown, interrupted by light median band; median band edged with dark brown on dorsal part of snout; dorsolateral fold blackish; horseshoe-shaped tubercle black laterally; fine line of black dots and speckling from posterior ends of horseshoe-shaped tubercle along median band to vent, much wider and conspicuous in posterior part; ventral side of head and chest cream-coloured with an orange tinge; limbs reddish orange; abdomen light yellow. See Fig. 7B View FIGURE 7 for a photograph of a male paratype in life.

In preserved state, dorsum dark brown with narrow, whitish median band ( Fig. 3B View FIGURE 3 ); crossbands on limbs, fingers and toes dark brown; interorbital bar black; median band edged with black on dorsal part of snout; dorsolateral fold blackish; horseshoe-shaped tubercle black laterally; fine line of black dots and speckling from posterior ends of horseshoe-shaped tubercle along median band to vent, much wider and conspicuous in posterior part; ventral side of head and chest cream-white; limbs yellowish, abdomen hardly pigmented, blueish white.

Variation. The paratypes match the holotype in general appearance. 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.SVLof adult males is 25.6–31.5 mm,of adult females 30.4–39.9mm ( Table 2). Pedal webbing variation is I 1 [40],1+ [60] /2 [90],2+ [10] II 1 +/2+ [20],2.25 [60],2.5 [20] III 1 + [10],1.25 [70],1.5 [20] /2.5 [30],2.75 [30],3- [40] IV 2.5 [10],2.75 [30],3- [20], 3 [40] /1+ [50],1.25 [50] V ( Fig. 6 View FIGURE 6 ). The median dorsal band is absent in most specimens .

Bioacoustics. The advertisement call and other vocalisations are unknown, but see account on bioacoustics of L. nephophilus sp. nov. below.

Distribution. The species is so far known from only a few places in eastern Sarawak between 1,000 and 1,600 m ( Figs. 8 View FIGURE 8 , 9 View FIGURE 9 ). Apart from the type locality, Pa’ Lungan, it has been recorded from other locations around Gunung Murud and from Payeh Maga, Gunung Dulit, and Gunung Mulu ( Fig. 8 View FIGURE 8 ). The species co-occurs sympatrically with L. sarawakensis sp. nov. on the High Plateau on Gunung Dulit, Sarawak, and with L. nephophilus sp. nov. around Camp 3 on Gunung Mulu, Sarawak ( Fig. 8 View FIGURE 8 ).

Ecology. Adult males and gravid females were collected in moist leaf litter close to small streams. One of the male paratypes ( NMBE 1101226 View Materials ) was carrying tadpoles ( NMBE 1101227–1101229 View Materials ) on its back ( Fig. 10E View FIGURE 10 ). The number and size of the ripe ova of the females indicate small clutch sizes .

Etymology. The species epithet refers to the distribution of the species on mountains in Sarawak (including Gunung Murud, Gunung Dulit, and Gunung Mulu) and is composed of the Malay word “gunung” (meaning “mountain”) as an invariable noun and the Latin suffix -ensis (“from”); meaning “inhabitant of the mountain”.

Suggested English name. Mountain Guardian Frog.