Overview
The Smooth Bug-eyed Frog (Theloderma licin) is an arboreal rhacophorid frog native to the primary dipterocarp rainforests of Sundaland. Unlike the heavily tuberculated and moss-like species that characterize most of the genus Theloderma, Theloderma licin stands apart due to its remarkably smooth dorsal skin, lustrous jade-to-olive coloration, and prominent bulging eyes, thriving in pristine tree-hole microhabitats across the Malay Peninsula and Borneo.
Biology and Physical Characteristics
Measuring under two inches in body length, Theloderma licin features sleek, waxy skin devoid of the rough, bark-like warts typical of other moss frogs. Its specific epithet licin is the Malay word for ‘smooth’ or ‘slippery.’ The dorsal coloration is a rich olive-green, emerald, or warm russet-brown with subtle darker reticulations, while its flanks display delicate creamy spotting. Its bulbous, protuberant dark eyes are set high upon a broad, flattened head, flanked by expansive adhesive digital discs on its toes.
Behavior and Ecology
This secretive nocturnal amphibian spends daylight hours tucked deep within water-filled tree crevices, bamboo internodes, and hollowed rot holes along steep rainforest stream banks. At night, it emerges onto low foliage to hunt small soft-bodied invertebrates. Breeding occurs inside water-retaining tree cavities, where females deposit small clutches of eggs along the damp wall just above the water level; upon hatching, the aquatic tadpoles drop directly into the pool below to feed on decaying organic detritus.
Conservation and Human Impact
Classified as Least Concern by the IUCN, Theloderma licin is widely distributed across protected national reserves in Peninsular Malaysia and Malaysian Borneo. However, because it relies strictly on primary rainforest with mature, hollow-bearing timber, it is highly sensitive to commercial logging and deforestation for oil palm plantations. Protecting extensive contiguous tracts of intact dipterocarp forest remains fundamental to its preservation.
Interesting Factoid
While almost all members of the mossy frog family look like rough, bumpy clumps of tree bark or lichen, Theloderma licin is the smooth rebel of the family—its name ‘licin’ is literally the Malay word for ‘slippery smooth’!
Last updated: October 2026