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| Leptobrachium widianai Fauzan, Smith, Amarasinghe, Farajallah, Racho, Matsui & Hamidy, 2026 Widiana’s Litter Frog | Katak Serasah Widiana || |
Abstract
The fauna of Indonesia's Lesser Sunda and eastern Java areas harbour lineages of Leptobrachium that have been historically assigned to L. hasseltii Tschudi, 1838. Here, using an integrative dataset—mtDNA (12S–tRNA^Val–16S; 1,979 bp), adult and larval morphology, and advertisement calls—we delimit and describe a new species from Buleleng (Bali) and Kediri (East Java). Phylogenetic analyses (ML/Bayesian) recover two well-supported clades within L. hasseltii sensu lato: (1) West–Central Java and southern Sumatra (true L. hasseltii) and (2) Bali–East Java (new species), with 16S uncorrected p-distance 3.2–5.2% to L. hasseltii. Morphologically, the new species differs from L. hasseltii by the combination of brown iris with a light-blue scleral arc (eye fully open), very large oval femoral glands (dark edged), no vomerine teeth and rictal glands, distinctive dorsal pattern (dark blotches with paired transverse bars) and ventral patterning, and tadpoles having LTRF 7(1–6)/5(1–4) versus 5(1–4)/5(1–4) in L. hasseltii. The advertisement call is an elongated series of short barks followed by low-frequency squawks and differs markedly in temporal structure from L. hasseltii. We discuss biogeographic implications and provide an IUCN preliminary assessment following current guidelines.
Key words. Amphibia, bioacoustics, Leptobrachium hasseltii, morphology, phylogeny
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| Two species of Bali and Javan Leptobrachium in life. (A, B) Adult male Leptobrachium widianai, new species, from Buleleng, Bali (MZB Amph. 33320, 32734); (C) adult male from Kediri, East Java (MZB Amph. 26959); (D) juvenile (MZB Amph. 32735); (E) adult male L. hasseltii from Mt. Slamet, Central Java (MZB Amph. 32743); (F) adult male L. hasseltii from Cisarua, West Java (MZB Amph. 32735). |
Leptobrachium widianai, new species
Diagnosis. A medium-sized Leptobrachium (adult male SVL 36.2 mm; adult female SVL to 54.1 mm) assigned to the Leptobrachium hasseltii group (subgenus Leptobrachium sensu Matsui et al., 2010) based on iris colour pattern, femoral gland morphology, and absence of upper lip spines. Distinguished from all congeners by the following combination of characters: (1) Iris and sclera: iris uniformly brown in adults with a narrow light blue scleral arc visible when the eye is fully open (juveniles with distinctive white spot-ring on iris); (2) Femoral glands: very large, oval (occasionally circular), conspicuous, with dark surrounding pigmentation; (3) Humeral glands: present, circular, flat; (4) Dentition and projections: vomerine teeth absent; snout without projections; no dermal palpebral projection; no rictal glands; ventrolateral glandular ridges absent; no upper lip spines. (5) Digital morphology: inner palmar tubercle circular, not extending along first metacarpal; subarticular tubercles reduced, replaced by low callous pads; fingers and toes with rounded, swollen tips, lacking circummarginal grooves; toe webbing poorly developed (I 0–2+, II 0–3+, III 2+–4, IV 4–2 V); (6) Dorsal pattern: typically dark brown with large irregular blotches and paired transverse bars; sometimes with orange vertebral line or orange dots; interorbital–parietal region with darker markings; (7) Lateral and ventral pattern: lateral surfaces dark grey with scattered white granules and a distinct black spot between axilla and groin; ventrum grey to light grey, throat darker, chest densely granular with white spots; (8) Call structure: elongated series of short “barks” followed by low-frequency “squawks,” temporally and structurally distinct from L. hasseltii; (9) Larvae: LTRF 7(1–6)/5(1–4) (vs. 5(1–4)/5(1–4) in L. hasseltii), marginal papillae conical and acute.
Etymology. The specific epithet honours Mr. I Made Widiana Darma Santosa, Director of the Bali Reptile Park, whose longstanding dedication to the conservation of Indonesian reptiles and amphibians — particularly those of Bali — has significantly advanced both in-situ and ex-situ conservation awareness. The name is formed as a genitive singular noun.
Proposed English name: Widiana’s Litter Frog;
Proposed Indonesian name: Katak Serasah Widiana.
Muhammad F. FAUZAN, Eric N. SMITH, A. A. Thasun AMARASINGHE, Achmad FARAJALLAH, Asrael RACHO, Masafumi MATSUI and Amir HAMIDY. 2026. A New Species of Leptobrachium Tschudi, 1838 (Anura: Megophryidae) from Bali and East Java, Indonesia. RAFFLES BULLETIN OF ZOOLOGY. 74; 62–86.