Description
A medium-sized arboreal treefrog (both sexes up to 36 mm). Dorsum warty, black or brownish to olive with an hourglass pattern consisting of very irregular transverse bands on dorsum and limbs. The male has no vocal sac or vocal sac openings, but has a pair of sub-mandibular glands, 4 x 2,5 mm. They are apparently mute. The male also has strong spines on tarsus. The digital discs of males are larger than those of the females.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Cameroon, Congo, the Democratic Republic of the, Gabon, Nigeria

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (5 records).

Rainforest from south-eastern Nigeria to Mayombe and to north-eastern Democratic Republic of the Congo (Kivu).

Life History, Abundance, Activity, and Special Behaviors
Based on observations in captivity, Perret (1961) suggests that the sexes may be attracted to each other by smell.
Acanthixalus spinosus is arboreal and apparently mainly aquatic. It spends its days and breeds in the small bodies of water which accumulate in cavities in living and dead trees. The frogs sit submerged with only the tip of the snout above water. Presumably they leave their refuge at night to hunt. A strange defence mechanism is described by Perret: the frog half-closes its eyes, keeps its limbs immovable close to the body and extends its orange tongue.

Development: The eggs are laid in a small hemispherical mass of jelly, 3–4 cm in diameter. The egg mass contains only 8–10 yellow eggs with a diameter of 2 mm, deposited a few centimetres above the water surface in the water-bodies in trees. The hatching larvae fall into the water where they spend approximately three months, feeding on the debris and algae in their little basin. Newly metamorphosed juveniles are orange above with the top of the head, a broad bar across the middle of the back and another in the lumbar region deep maroon.

Larva
The tadpole attains a maximum length of 60 mm and has a tooth formula of 1,3+3/3.

Comments
This account was taken from "Treefrogs of Africa" by Arne Schiøtz with kind permission from Edition Chimaira publishers, Frankfurt am Main.

References

Amiet, J.L. (1975). ''Ecologie et distribution des amphibiens anoures de la région de Nkongsamba (Cameroun).'' Annales de la Faculté des Sciences de Yaoundé, 20, 33-107.

Schiøtz, A. (1999). Treefrogs of Africa. Edition Chimaira, Frankfurt am Main.

Species Account Citation: AmphibiaWeb 2022 Acanthixalus spinosus: Central African Spiny Frog <https://amphibiaweb.org/species/441> University of California, Berkeley, CA, USA. Accessed Nov 27, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 27 Nov 2024.

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