The Australian waterfall frog or torrent treefrog (''Ranoidea nannotis'') is a species of

tree frog A tree frog (or treefrog) is any species of frog that spends a major portion of its lifespan in trees, known as an arboreal state. Several lineages of frogs among the Neobatrachia have given rise to treefrogs, although they are not closely rela ...

native to

Far North Queensland Far North Queensland (FNQ) is the northernmost part of the Australian state of Queensland. Its largest city is Cairns and it is dominated geographically by Cape York Peninsula, which stretches north to the Torres Strait, and west to the Gulf ...

, Australia. The common name "waterfall frog" is indicative of its habitat of moist, rocky streams, and is often found along waterfalls within its range.

Taxonomy

The waterfall frog is one of the four species of Australian torrent treefrogs that comprise the '' Ranoidea nannotis'' species group. The other species are the mountain mist frog,

common mist frog The common mist frog (''Ranoidea rheocola'') is a species of tree frog native to north-eastern Queensland, Australia. It is a medium-sized frog and a member of the Australian torrent treefrog group.Cunningham, M. (n.d.). Memoirs of the Queenslan ...

, and the

armoured mist frog The armoured frog (''Ranoidea lorica''), or armoured mist frog, is a species of tree frog in the torrent frog complex, a group restricted to north-eastern Queensland, Australia. Taxonomy The armoured mist frog is one of the four species of A ...

Description

The waterfall frog is large in size, reaching 5.5 cm in length. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

surface is mottled with puck brown. The patterning on the back is similar to its habitat, allowing for effective

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

against

granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies und ...

. The

ventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

surface is bright orange, green, and pink in colour, and granular. The posterior ventral surface is translucent, showing internal parts. The toe pads of ''R. nannotis'' are very large in comparison to toe width, to aid in gripping to rocks in the rapids. The

nuptial pad A nuptial pad (also known as thumb pad, or nuptial excrescence) is a secondary sex characteristic present on some mature male frogs and salamanders. Triggered by androgen hormones, this breeding gland (a type of mucous gland) appears as a sp ...

s of breeding males are also large, covering the entire inner surface of the thumb, with spines also present on the arms and chest. The tympanum is not visible, the fingers are partially webbed, and the toes are completely webbed. Like the stoney creek frog ('' Litoria wilcoxi''), and many other stream-dwelling frogs, waterfall frogs lack

vocal sac The vocal sac is the flexible membrane of skin possessed by most male frogs and toads. The purpose of the vocal sac is usually as an amplification of their mating or advertisement call. The presence or development of the vocal sac is one way o ...

s. This may be because the sound of a running stream drowns out any calls, and it becomes a waste of energy.

Ecology and behavior

The waterfall frog is a stream-dwelling frog native to tropical north Queensland, from Paluma to

Cooktown Cooktown is a coastal town and locality in the Shire of Cook, Queensland, Australia. Cooktown is at the mouth of the Endeavour River, on Cape York Peninsula in Far North Queensland where James Cook beached his ship, the Endeavour, for repai ...

, notable in the Mt. Carbine uplands. It is found at altitudes between . It has undergone large declines in high-altitude areas (likely from

chytridiomycosis Chytridiomycosis ( ) is an infectious disease in amphibians, caused by the chytrid fungi '' Batrachochytrium dendrobatidis'' and '' Batrachochytrium salamandrivorans''. Chytridiomycosis has been linked to dramatic population declines or exti ...

), with many populations completely extinct. It is, however, stable in lowland areas.

Conservation status

It is listed as Least concern under both the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

References

*Cunningham, M. 2002. ''Identification and evolution of Australian torrent treefrogs''. Memoirs of the Queensland Museum. 48(1):93-102. Brisbane, Qld. * *

External links

Litoria nannotis
at

CalPhotos CalPhotos is an online database of natural history photographs, including many useful for identifying wildlife. It is maintained by the University of California, Berkeley. Its images are used by many universities, government agencies, websites, an ...