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Frogs of Borneo

Frogs of Borneo

Frogs of Borneo

Frogs of Borneo

Frogs of Borneo

Frogs of Borneo

Frogs of Borneo

Frogs of Borneo

Frogs of Borneo

Frogs of Borneo

Frogs of Borneo

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Leptobrachella itiokai

This species occurs in clear streams of montane forests at the higher elevations of Gunung Mulu. Tadpoles inhabit interstitial spaces in gravel and under rocks. Their feeding ecology is unknown.
  • Family:
    Megophryidae
  • Genus:
    Leptobrachella
  • Ecomorph:
    exotrophic, fossorial, gravel-interstice specialist, lotic
  • Waterbody Type:
    flowing
  • Water Column:
    fossorial
  • Feeding Type:
    feeding, generalist, leaf litter
  • Size:
    47 mm
  • Development:
    larva, tadpole
  • Adult:
    Leptobrachella
    itiokai

Coloration

Early larval stages are lightly pigmented and appear yellowish; advanced stages are uniformly brown dorsally. Silvery iridophores are absent. The skin has a hatched texture, reminiscent of fabric, with bluish iridescence in life. The ventral side, including the oral disc, is unpigmented, cream-colored, and semitranslucent. Gut coils and gills are faintly visible through the abdominal skin, while the heart and gill region appear reddish. The brown dorsal coloration continues onto the muscular part of the tail. Tail fins are pigmented at their base and clear toward their edges. Myosepta are visible in the distal part of the tail.

Snout

In dorsal view, the snout is broadly rounded, blunt, and moderately long relative to the head. In lateral view, the head is bluntly conical. A small bulge supports the nostril in lateral view.

Oral Disc

Oral disc positioned anteroventrally, approximately half the body width. Funnel-shaped, protruding from the body. Emarginations and infoldings present in the midline of the upper and lower lips. Both lips bear short, numerous marginal papillae in a continuous row. At the base of the oral funnel, irregular rows of papillae occur. Keratodonts are absent (LTRF 0/0). Beaks are strong, well keratinized, black, with sharp serrations, deeply recessed in the funnel-shaped oral disc and partly obscured by transverse ridges.

Body

Midsized, eel-like, very elongate. In lateral view, head and trunk are slightly depressed; trunk subcylindrical. In dorsal view, body slender, only slightly wider than the base of the tail. Body-tail transition smooth. Trunk elongate; head much shorter than trunk. Body widest at the trunk. Spiracle sinistral, opening posterodorsally. Spiracular orifice positioned above the longitudinal body axis in lateral view, free from the body wall; spiracular tube long. Lateral line organs visible as a series of light dots on the head, along the flanks, and along the side of the tail.

Eyes & Nostrils

Eyes dorsolateral, tiny and nonprotruding in early stages; increasing in size and bulging during metamorphosis. Eye orbits unpigmented, whitish. Iris black, with a faint silvery circle around the pupil in late larval stages. Nostril closer to the snout than to the eye, oriented anterolaterally. Dorsal rim of nostril bears a triangular projection.

Tail

Long, approximately 70% of total length. Muscular part strong, almost as high as the body in lateral view. Upper fin starts well posterior to trunk-tail junction, low in the proximal half of the tail and increasing in height in the posterior half. Lower fin maintains constant low height in the proximal half and increases slightly posteriorly. Tail tip triangular, narrowly rounded and acuminate. Skin glands absent.

Similar Species

Leptobrachella itiokai tadpoles are morphologically similar to other species in the genus. Few known specimens and the lack of distinctive features (absence of distinct color pattern and keratodonts) require DNA analysis for reliable identification, especially in cases where different species occur in sympatry or syntopy. See also comments for Leptobrachella mjobergi. Before the discovery of L. itiokai, its tadpoles had been assigned to L. brevicrus (Oberhummer et al. 2014). This description is preliminary, as few specimens have ever been found. Larvae are interstice specialists in clear montane streams.

Literature

Males typically call on leaves or branches 20–60 cm above the ground at steep montane streams. The call of males consists of series of chirps.
Oberhummer, E., Barten, C., Schweizer, M., Das, I., Haas, A., Hertwig, S.T. (2014) Description of the tadpoles of three rare species of megophryid frogs (Amphibia: Anura: Megophryidae) from Gunung Mulu, Sarawak, Malaysia. Zootaxa 3835: 59–79.

Eto, K., Matsui, M., Nishikawa, K. (2016) A new highland species of dwarf litter frog genus Leptobrachella (Amphibia: Anura: Megophryidae) from Sarawak. The Raffles Bulletin of Zoology 64: 194–203.