''Acanthixalus spinosus'', commonly known as the African wart 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

Hyperoliidae The Hyperoliidae, or sedge frogs and bush frogs, are a large family of small to medium-sized, brightly colored frogs which contains more than 250 species in 19 genera. Seventeen genera are native to sub-Saharan Africa. In addition, the monotypic ...

, the sedge and bush frogs. It is native to Africa, where it can be found from south-eastern Nigeria to Gabon and the Democratic Republic of the Congo.

Description

Males measure and females in snout–vent length. The dorsum is warty, black or brownish to olive in color, and bears an hourglass pattern consisting of very irregular transverse bands on dorsum and limbs. Males have no vocal sac or vocal sac openings and are believed to be mute. Males also have strong spines on the tarsus, and they have larger digital discs than females. The

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 grow to in total length. Newly

metamorphosed Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causin ...

juveniles are brightly colored: they are dorsally orange, with the top of the head and bars across the middle of the back and in the lumbar region deep maroon.

Habitat and conservation

This frog lives in lowland

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

. It is mostly aquatic, living in water-filled holes in trees. Apparently, they leave the tree holes only during night to forage. The eggs are deposited a few centimeters above the water surface. Upon hatching, the

s fall into the water. The development takes approximately three months. They are

detritivore Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...

s. Because this species depends on large trees with holes that collect rainwater, it is vulnerable to ongoing forest loss.

Ecological interactions

This frog is host to the

commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...

protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exc ...

s ''Opalina proteus'' and ''Cepedea couillardi''.

References

{{Taxonbar, from=Q1943776 Spinosus Frogs of Africa Amphibians of West Africa Amphibians of Cameroon Amphibians of the Democratic Republic of the Congo Amphibians of Gabon Fauna of Nigeria Amphibians of the Republic of the Congo Amphibians described in 1875 Taxa named by Reinhold Wilhelm Buchholz Taxa named by Wilhelm Peters Taxonomy articles created by Polbot