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Huia (genus)
Encyclopedia
Huia is a group of true frog
s found in Southeast Asia
. Many are commonly known as "torrent frog
s" after their favorite habitat
- small rapid-flowing mountain and hill streams -, but this name is used for many similar-looking frogs regardless of whether they are closely related. A seemingly less ambiguous name is huia frogs; however, the supposed genus
seems actually to be a polyphyletic "wastebin taxon
" and might contain only a fraction of the dozens of species
placed here by some authors.
Several species
of Amolops
and Odorrana
are highly convergent
with Huia. O. absita for example is highly similar in habitus
to the completely allopatric H. masonii. Though the latter might not be a member of Huia in the strictest sense, it is at least a very close relative.
In another incidence of convergent evolution yielding adaptation
to habitat, the tadpole
s of Amolops, Huia, Meristogenys as well as Rana sauteri
have a raised and usually well-developed sucker on their belly. This is useful in keeping in place in rocky torrents, where these frogs grow up. But as Odorrana and Staurois
from comparable habitat
prove, this sucker is by no means a necessity and other means of adaptation to torrent habitat exist.
are sometimes placed in Huia, including some originally placed into the genera Odorrana
and Eburana, which formed a paraphyletic cluster; indeed these two genera are sometimes treated as junior synonyms of Huia. The Long-snout Torrent Frog
on the other hand – formerly Huia nasica – is now in Odorrana. But many of the moves to Huia seem to be premature and it is better to treat Odorrana as valid, in a more comprehensive way and including Eburana, than expanding Huia.
For as it seems, even in the revised delimitation the genus is still paraphyletic with Meristogenys
. Either the latter genus is included here, or Huia is restricted to the type species
(the Hole-in-the-head Frog
, H. cavitympanum) and what might be its closest living relatives (e.g. an undescribed species from Sumatra
), or some species of Huia - e.g. the Sumatran Torrent Frog
(H. sumatrana) - are split off again. The former alternatives seem to be more advisable as long as the interrelationships of Huia and Meristogenys species as well as the closely related Clinotarsus
are as badly resolved as they are at present. Meristogenys tadpole
s are furthermore characterized by a split and ridged upper lip not found in the Hole-in-the-head Frog, indicating that the genera ought to be kept separate.
New species are being discovered regularly, exacerbating the taxonomic uncertainties.
Sumatran Torrent Frog group
Relationships undetermined
True frog
The true frogs, family Ranidae, have the widest distribution of any frog family. They are abundant throughout most of the world, occurring on most continents except Antarctica...
s found in Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
. Many are commonly known as "torrent frog
Torrent frog
Torrent frogs are a number of unrelated frogs that prefer to inhabit small rapid-flowing mountain or hill streams with a lot of torrents. They are generally smallish neobatrachians with a greyish-brown and usually darkly mottled back, giving them excellent camouflage among wet rocks overgrown with...
s" after their favorite habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
- small rapid-flowing mountain and hill streams -, but this name is used for many similar-looking frogs regardless of whether they are closely related. A seemingly less ambiguous name is huia frogs; however, the supposed genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
seems actually to be a polyphyletic "wastebin taxon
Wastebin taxon
Wastebasket taxon is a term used in some taxonomic circles to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined by their lack of one or more distinct character states or by their not belonging to one or more other taxa...
" and might contain only a fraction of the dozens of species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
placed here by some authors.
Several species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of Amolops
Amolops
Amolops is a quite large genus of true frogs native mainly to eastern and southeastern Asia. These frogs are quite closely related to such genera as Huia, Meristogenys, Odorrana, Pelohylax and Rana, but still form a distinct lineage among the core radiation of true frogs...
and Odorrana
Odorrana
Odorrana is a genus of true frogs from East Asia and surrounding regions. Many of these frogs inhabit fast-flowing mountain streams, and they typically have a remarkably pointed snout, as evidenced by common names like "long-snout" or "tip-nosed frog" and scientific names like nasica or nasutus...
are highly convergent
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
with Huia. O. absita for example is highly similar in habitus
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
to the completely allopatric H. masonii. Though the latter might not be a member of Huia in the strictest sense, it is at least a very close relative.
In another incidence of convergent evolution yielding adaptation
Adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....
to habitat, the tadpole
Tadpole
A tadpole or polliwog is the wholly aquatic larval stage in the life cycle of an amphibian, particularly that of a frog or toad.- Appellation :...
s of Amolops, Huia, Meristogenys as well as Rana sauteri
Rana sauteri
Rana sauteri is a species of frog in the genus Rana from Taiwan.-Taxonomy:Rana sauteri was first described in 1909 by George Albert Boulenger on the basis of specimens collected on Taiwan by one H. Sauter...
have a raised and usually well-developed sucker on their belly. This is useful in keeping in place in rocky torrents, where these frogs grow up. But as Odorrana and Staurois
Staurois
Staurois is a small genus of true frogs. They occur from Borneo via Palawan to the Philippines.This genus is a quite ancient member of the true frog family, Ranidae.-Selected species:The Staurois natator complex is in need of revision....
from comparable habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
prove, this sucker is by no means a necessity and other means of adaptation to torrent habitat exist.
Systematics and taxonomy
Up to some 55 speciesSpecies
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
are sometimes placed in Huia, including some originally placed into the genera Odorrana
Odorrana
Odorrana is a genus of true frogs from East Asia and surrounding regions. Many of these frogs inhabit fast-flowing mountain streams, and they typically have a remarkably pointed snout, as evidenced by common names like "long-snout" or "tip-nosed frog" and scientific names like nasica or nasutus...
and Eburana, which formed a paraphyletic cluster; indeed these two genera are sometimes treated as junior synonyms of Huia. The Long-snout Torrent Frog
Long-snout Torrent Frog
The Long-snout Torrent Frog is a species of frog in the Ranidae family.It is found in China, Laos, Thailand, Vietnam, and possibly Myanmar....
on the other hand – formerly Huia nasica – is now in Odorrana. But many of the moves to Huia seem to be premature and it is better to treat Odorrana as valid, in a more comprehensive way and including Eburana, than expanding Huia.
For as it seems, even in the revised delimitation the genus is still paraphyletic with Meristogenys
Meristogenys
Meristogenys is a genus of true frogs from Borneo. Its tadpoles are easily recognizable by their divided upper lip with ribs on the outside....
. Either the latter genus is included here, or Huia is restricted to the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
(the Hole-in-the-head Frog
Hole-in-the-head Frog
The Hole-in-the-head frog is a species of frog in the Ranidae family.It is found on the island of Borneo. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montanes, and torrential rivers. It is threatened by habitat loss.-Vocalization:H...
, H. cavitympanum) and what might be its closest living relatives (e.g. an undescribed species from Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
), or some species of Huia - e.g. the Sumatran Torrent Frog
Sumatran Torrent Frog
The Sumatran Torrent Frog is a species of frog in the Ranidae family.It is endemic to Indonesia.Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montanes, and rivers....
(H. sumatrana) - are split off again. The former alternatives seem to be more advisable as long as the interrelationships of Huia and Meristogenys species as well as the closely related Clinotarsus
Clinotarsus
Clinotarsus is genus of Ranid frogs containing at least two species. This genus was originally part of Rana. Members of this genus are found in India and Southeast Asia....
are as badly resolved as they are at present. Meristogenys tadpole
Tadpole
A tadpole or polliwog is the wholly aquatic larval stage in the life cycle of an amphibian, particularly that of a frog or toad.- Appellation :...
s are furthermore characterized by a split and ridged upper lip not found in the Hole-in-the-head Frog, indicating that the genera ought to be kept separate.
New species are being discovered regularly, exacerbating the taxonomic uncertainties.
Selected species
Huia core group- Huia cavitympanum – Hole-in-the-head FrogHole-in-the-head FrogThe Hole-in-the-head frog is a species of frog in the Ranidae family.It is found on the island of Borneo. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montanes, and torrential rivers. It is threatened by habitat loss.-Vocalization:H...
- Huia sp. 'Sumatra'
Sumatran Torrent Frog group
- Huia masonii – Javan Torrent FrogJavan Torrent FrogThe Javan Torrent Frog is a species of frog in the Ranidae family.It is endemic to Indonesia.Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montanes, and rivers.-Source:...
- Huia melasmaHuia melasmaHuia melasma is a species of frog in the Ranidae family. It is sometimes placed in the genus Odorrana, but actually seems to belong neither there nor in Huia, at least if the latter genus is defined in the strict sense. It is found in Thailand and possibly Myanmar.Its natural habitats are...
- Huia sumatrana – Sumatran Torrent FrogSumatran Torrent FrogThe Sumatran Torrent Frog is a species of frog in the Ranidae family.It is endemic to Indonesia.Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montanes, and rivers....
Relationships undetermined
- Huia aureolaHuia aureolaThe Phu Luang Cliff Frog is a newly discovered true frog species from northern Thailand. It is most notable for its ability to change color between green and brown...
– Phu Luang Cliff Frog (sometimes in Odorrana) - Huia modiglianiiHuia modiglianiiHuia modiglianii is a species of frog in the Ranidae family.It is endemic to Indonesia.Its natural habitats are subtropical or tropical moist lowland forests and rivers.It is threatened by habitat loss.-Source:...