The hairy frog (''Trichobatrachus robustus'') also known as the horror frog or Wolverine frog, is a

Central Africa Central Africa is a subregion of the African continent comprising various countries according to different definitions. Angola, Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, the Republic of the Congo, ...

n 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

Arthroleptidae The Arthroleptidae are a family of frogs found in sub-Saharan Africa. This group includes African treefrogs in the genus ''Leptopelis'' along with the terrestrial breeding squeakers '' Arthroleptis'', and several genera restricted to the Guinea ...

. It is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

within the genus ''Trichobatrachus''. Its

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

refers to the somewhat hair-like structures on the body and thighs of the breeding male.

Description

Males are about long from snout to vent, while females are . The large head is broader than long, with a short rounded snout. The former have a paired internal vocal sac and three short ridges of small black spines along the inner surface of the first manual digit. Breeding males also develop hair-like dermal papillae that extend along the flanks and thighs. These contain arteries and are thought to increase the surface area for the purpose of absorbing oxygen (comparably to

external gills External gills are the gills of an animal, most typically an amphibian, that are exposed to the environment, rather than set inside the pharynx and covered by gill slits, as they are in most fishes. Instead, the respiratory organs are set on a frill ...

of the aquatic stage), which is useful as the male stays with his eggs for an extended period of time after they have been laid in the water by the female. The species is terrestrial, but returns to the water for breeding, where egg masses are laid onto rocks in streams. The quite muscular

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 are

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

and feature several rows of horned teeth. Adults feed on

slug Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a smal ...

s, myriapods,

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

s, and

grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are among what is possibly the most ancient living group of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grasshopp ...

s. The hairy frog is also notable in possessing retractable "claws", which it may project through the skin, apparently by intentionally breaking the bones of the toe. These are not true claws, as they are made of bone, not

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...

. In addition, there is a small bony nodule nestled in the tissue just beyond the frog's fingertip. When sheathed, each claw is anchored to the nodule with tough strands of collagen. When the frog is grabbed or attacked, it breaks the nodule connection and forces the sharpened bones through the skin. Although a retraction mechanism is not known, it has been hypothesized that the claws later retract passively, while the damaged tissue is regenerated. This type of natural weaponry appears to be unique in the animal kingdom, although the

Otton frog The Otton frog (''Babina subaspera''), is a species of frog in the family Ranidae. It is endemic to the islands of Amami Ōshima and Kakeromajima in the Ryukyu Islands, Japan. Its natural habitats are subtropical or tropical moist lowland fores ...

possesses a similar "spike" in its thumb. An alternative hypothesis is that the broken bones could provide a better grip on rocks.

Distribution

It is found in

Cameroon Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the C ...

Democratic Republic of the Congo The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...

Equatorial Guinea Equatorial Guinea ( es, Guinea Ecuatorial; french: Guinée équatoriale; pt, Guiné Equatorial), officially the Republic of Equatorial Guinea ( es, link=no, República de Guinea Ecuatorial, french: link=no, République de Guinée équatoria ...

Gabon Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north ...

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

, and possibly

Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

. 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 subtropical or tropical moist lowland

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

arable land Arable land (from the la, arabilis, "able to be ploughed") is any land capable of being ploughed and used to grow crops.''Oxford English Dictionary'', "arable, ''adj''. and ''n.''" Oxford University Press (Oxford), 2013. Alternatively, for the ...

plantation A plantation is an agricultural estate, generally centered on a plantation house, meant for farming that specializes in cash crops, usually mainly planted with a single crop, with perhaps ancillary areas for vegetables for eating and so on. The ...

s, and heavily degraded former forest.

Conservation status

''T. robustus'' 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 ...

, but is not considered endangered.

Relation with humans

This species is roasted and eaten in Cameroon. They are hunted with long

spear A spear is a pole weapon consisting of a shaft, usually of wood, with a pointed head. The head may be simply the sharpened end of the shaft itself, as is the case with fire hardened spears, or it may be made of a more durable material fasten ...

s or machetes. The

Bakossi people The Bakossi people are a Bantu ethnic group that live on the western and eastern slopes of Mount Mwanenguba and Mount Kupe in the Bakossi Mountains of Cameroon. They number about 200,000, mostly engaged in subsistence farming but also producing ...

traditionally believed that the frogs fall from the sky and, when eaten, it would help childless couples become fertile.

References

External links

* *
Hairy Frog – ''Trichobatrachus robustus''
The BioFresh Cabinet of Freshwater Curiosities. * {{Taxonbar, from=Q1028620 Arthroleptidae Amphibians described in 1900 Taxa named by George Albert Boulenger Frogs of Africa Amphibians of Cameroon Amphibians of the Democratic Republic of the Congo Amphibians of Equatorial Guinea Amphibians of Gabon Amphibians of West Africa Taxonomy articles created by Polbot