The Bornean flat-headed frog (''Barbourula kalimantanensis'') 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

Bombinatoridae Bombinatoridae is a family of toads found in Eurasia. Species of the family have flattened bodies and some are highly toxic. Taxonomy and systematics Fossil specimens of the genus ''Bombina'' are known from the Pliocene to the Pleistocene. The ...

. Although many

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

s are lungless, the Bornean flat-headed frog is the first frog known to have no

lung The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of ...

Djoko Iskandar Djoko Tjahjono Iskandar (born 1950) is an Indonesian herpetologist who studies the amphibians of Southeast Asia and Australasia. He is a professor of biosystematics and ecology at Bandung Institute of Technology in West Java, Indonesia. Iskandar h ...

, an Indonesian zoologist, first described the Bornean flat-headed frog based on a single specimen. However, he did not know the frog was lungless until he was in the field with David Bickford's expedition. Bickford ''et al.'' were able to dissect some of the specimens and discovered for the first time that the frogs had no lungs. The frog breathes entirely through its skin, and its internal organs (the stomach, spleen and the liver) take up much of the space which normally would be filled by the lungs. By retaining the lunglessness of their

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 ...

stage, the frogs are much flatter than typical frogs, which might help absorb oxygen and avoid being swept away in fast streams.

Description

This frog grows to a snout-to-vent length of for females and males are slightly smaller. It has a dorsoventrally flattened body with a broad head with a rounded snout. The limbs are robust and both hands and feet are fully webbed. The dorsal skin is smooth with small

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projection ...

s on the posterior end and the hind legs and the ventral skin is smooth. Its general colour is brown with black mottling.

Distribution and habitat

This aquatic frog lives in cold, clear, and fast rivers in remote areas of the rain forests of

Kalimantan Kalimantan () is the Indonesian portion of the island of Borneo. It constitutes 73% of the island's area. The non-Indonesian parts of Borneo are Brunei and East Malaysia. In Indonesia, "Kalimantan" refers to the whole island of Borneo. In 2019, ...

, the

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Gui ...

n part of the island of

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and e ...

. It is known from only two localities, both in the

Kapuas River The Kapuas River (or Kapoeas River) is a river in the Indonesian part of Borneo island, at the geographic center of Maritime Southeast Asia. At in length, it is the longest river in the island of Borneo and the longest river of IndonesiaMacK ...

basin.

Status

The Bornean flat-headed frog is listed as

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

. 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 ...

from severe degradation of the river habitats because of increased turbidity and toxic metals used in mining and other negative consequences of development on the island.

References

External links

CBC: Gasp! Scientists find first lungless frog
* http://calphotos.berkeley.edu/imgs/512x768/1111_1111/1111/7442.jpeg

Science Daily article

New Scientist article {{Taxonbar, from=Q369695 Barbourula Amphibians of Indonesia Endemic fauna of Borneo Endemic fauna of Indonesia Taxonomy articles created by Polbot Amphibians described in 1978 Amphibians of Borneo

Description

Distribution and habitat

Status

See also

References

External links