''Megaelosia goeldii'', also known as the Rio big-tooth frog, is a species of

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

in the family

Hylodidae Hylodidae, commonly known as giant Neotropical torrent frogs, is a family of frogs native to Brazil and northern Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the souther ...

. It is the only member of the genus ''Megaelosia.'' It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Southeast Brazil The Southeast Region of Brazil ( pt, Região Sudeste do Brasil; ) is composed of the states of Espírito Santo, Minas Gerais, Rio de Janeiro and São Paulo. It is the richest region of the country, responsible for approximately 60% of the Brazilian ...

and occurs in

São Paulo São Paulo (, ; Portuguese for 'Saint Paul') is the most populous city in Brazil, and is the capital of the state of São Paulo, the most populous and wealthiest Brazilian state, located in the country's Southeast Region. Listed by the GaWC a ...

and

Rio de Janeiro Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...

states. It is named after

Émil Goeldi Émil August Goeldi (var. Göldi, Portuguese language, Portuguese var. Emílio Augusto Goeldi) (28 August 1859 – 5 July 1917 in Bern), was a Swiss-Brazilian natural history, naturalist and zoologist. He was the father of Oswaldo Goeldi, a no ...

, a Swiss zoologist who worked in Brazil.

Taxonomy

The genus ''Megaelosia'' formerly contained several other species, but all of these were reclassified in a new genus, ''

Phantasmarana ''Phantasmarana'' is a genus of frogs in the family Hylodidae. The genus is endemic to the Atlantic Forest of southeastern Brazil. Members of this genus are associated with fast-flowing rivers. They are difficult to collect because they are easi ...

'', in 2021 based on a phylogenetic study, leaving ''M. goeldii'' as the only remaining member of ''Megaelosia''.

Description

Males measure and females in snout–vent length (based on 2 males and 3 females only). The dorsolateral skin is granular. The snout is subacuminate in dorsal view and protruding in profile. The

canthus rostralis In snakes and amphibians, the canthus, canthal ridge or ''canthus rostralis'',Spawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. . is the angle between the flat crown of the head and the ...

is evident and straight. Males have neither vocal sacs nor vocal slits.

Diet

Stomach contents have been found to contain insects (cockroaches, Coleoptera, lepidopteran caterpillars), earthworms, and plant material. In experiments, ''Megaelosia goeldii'' have consumed other frogs.

Habitat and conservation

Its natural

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s are rivers in primary forest. During the day, they can be found on emergent rocks in shallow places.

Tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...

s have been collected under large rocks in a moderate-sized forest stream. ''Megaelosia goeldii'' is a common species, but very difficult to catch. It is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

caused by forest clearance and infrastructure development, and by pollution.

References

{{Taxonbar, from=Q2239267 Hylodidae Endemic fauna of Brazil Amphibians of Brazil Taxonomy articles created by Polbot Taxa named by Alípio de Miranda-Ribeiro Monotypic amphibian genera