Limnonectes oreibates Dehling, Neokleous, Das, Grafe, Min & Hertwig, 2025, sp. nov.
Year: 2025
Type: other
Abstract: Limnonectes oreibates sp. nov. Rana palavanensis (nec Rana palavanensis Boulenger, 1894)— Boulenger 1920: 59 (partim); van Kampen 1923: 182 (partim); Smith 1925: 32. Rana microdisca palavanensis (nec Rana palavanensis Boulenger, 1894): Inger 1966: 222 (partim). Limnonectes palavanensis (nec Rana palavanensis Boulenger, 1894)— Zainudin et al. 2017: 106. Holotype. NMBE 1061519, adult female, from Borneo Highlands Resort (1.116667°, 110.216667°; 990 m), Gunung Penrissen, Sarawak, Malaysia, collected on 10 March 2012 by S. T. Hertwig, A. Jankowski, Y. M. Pui (Fig. 3E). Paratypes. BMNH 1928.11.4, adult female, from Mt. Penrissen, “ N. Borneo ” [= Sarawak], Malaysia, “pres. by M. Smith” (probably collected by Eric Mjöberg; Smith 1925). UNIMAS P1186, adult male, collected on 10 September 2015 by Y. M. Pui; UNIMAS P1193, juvenile, collected on 14 September 2015 by Y. M. Pui and I. Das, both from Summit Trail to Gunung Penrissen, below Batu Panggah, Sarawak, East Malaysia (Borneo). UNIMAS P1192, adult male, from an unnamed forest trail within Borneo Highlands Resort area, Gunung Penrissen, Sarawak, East Malaysia (Borneo), collected on 14 September 2015 by Y. M. Pui and I. Das (Fig. 7E). Referred specimen. UNIMAS 9737, adult male, from the edge of an intermittent stream at Batu Panggah, Borneo Highlands Resort, collected by I. Das on 27 August 2021. Diagnosis. Limnonectes oreibates 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 weakly curved; pineal spot distinctly discernible, anterior to level of anterior upper-eyelid edge; vomer ridges short, widely separated from each other; postpalpebral ridge weakly developed; lumbar and median ridges absent; size relatively large with SVL of adult males 32.5–33.2 mm, of adult females 35.9–37.1 mm. The species differs from all other species of the group by at least 5.8% in the sequence of the 16S barcoding gene. The advertisement call is a slow chirp, 174–317 ms in duration with a dominant frequency of 1.4–1.6 kHz with weak frequency modulation, given in call bouts of up to 11 calls with an intercall interval of 381–775 ms. The species occurs in montane rainforest at around 1,000 m. Description of holotype. Adult female; SVL 35.9 mm; body sturdy, widest at temporal region, slightly tapering to groin (Fig. 3E); head large (HL/SVL 0.38, HW/SVL 0.39), slightly wider than long (HW/HL 1.04); snout moderately long (SL/HL 0.45), rounded in both dorsal view and lateral profile, wider than long (SL/EE 0.94); canthus rostralis distinct between eye and nostril, weakly concave between eye and nostril in dorsal view; loreal region oblique; nostrils oval, directed laterally; situated much closer to tip of snout than to eye (EN/NS 1.21), separated from each other by distance larger than distance between eye and nostril (NN/EN 1.33); eye directed anterolaterally, protruding, moderately large (ED/HL 0.32), its diameter much shorter than snout (ED/SL 0.71); interorbital distance greater than upper eyelid width (IO/EW 1.17) and smaller than internarial distance (IO/NN 0.74); pineal spot distinctly discernible, anterior to level of anterior upper-eyelid edge; tympanum and its annulus distinctly visible; tympanum separated from eye by little more than half its diameter (ET/TD 0.57); tympanum diameter smaller than 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, their lateral half covered by palatal shelf of maxilla in ventral view; vomer processes bearing teeth, short, separated from choana by two-thirds length of individual process, from each other by distance subequal to length of individual process (Fig. 4E); tongue moderately long and narrow, bilobed for about one-seventh of its length, free distally for about two-thirds 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; postpalpebral ridge weakly developed; lumbar and median ridges absent; horseshoe-shaped dermal ridge low, in middle of back just behind level of arms; supratympanic fold thick and conspicuous, extending from posterior end of orbit to insertion of arm, weakly curved (Fig. 5E); few enlarged tubercles on lateral edge of upper eyelid; ventral side of head smooth; transverse chest fold between arm insertions distinct; ventral side of trunk weakly areolate, almost smooth; ventral side of limbs smooth; cloaca without dermal flap. Forelimbs sturdy; hand relatively small (HND/SVL 0.24); tips of fingers rounded, slightly enlarged into disks; relative length of fingers: II <IV <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 and outer palmar tubercles fused proximally, bipartite for about one-fifth of its length on distal end, otherwise rounded, distinct, covering proximal one-third of metacarpals of Fingers II–IV. Hindlimbs sturdy, very long (LEG /SVL 1.80); heel reaching beyond tip of snout when legs adpressed forwardly to body; tibiofibula long (TFL/SVL 0.57), slightly longer than thigh (TFL/THL 1.06); 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 <III <V
Authors: Dehling, Maximilian, Neokleous, Dario N., Das, Indraneil, Grafe, Ulmar, Min, Pui Yong, Hertwig, Stefan T.
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6893405387
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