Arthroleptis species are small to medium-sized brown frogs that live and breed in the leaf litter of the forest floor. Their eggs are laid in moist soil or leaves and develop directly into small frogs without passing through a free-swimming tadpole stage. Males in breeding condition typically have a distinctly elongated third finger. The genus Leptopelis includes species that are morphologically and ecologically quite different from the Arthroleptis species. Leptopelis species are medium to large-sized tree frogs with vertical pupils. Until recently they were included in the family Hyperoliidae. Females of some Leptopelis species are known to lay their eggs in mud cavities and the tadpoles move into water after hatching (Text from Harper et al., 2010).
Evolution and Systematics
Discussion of Phylogenetic Relationships
The Arthroleptidae // are a family of frogs found in sub-Saharan Africa. They are also known as squeakers because of their high-pitched calls. They are small, less than 4 cm (1.6 in) in length, terrestrial frogs found mostly in leaf litter on the forest floor. They completely bypass any aquatic stage, so do not have tadpoles. They lay their eggs on the ground, in crevices or in leaf litter, and the offspring undergo direct development. Some species hatch already completely metamorphosed into the adult form, while others still have tails when they hatch.
This family contains a unique frog, the hairy frog (Trichobatrachus robustus). Breeding male hairy frogs develop highly vascularised, hair-like projections on their thighs and flanks. They will sit on their eggs for long periods of time, and the hairs are thought to assist in respiration through the skin, while they cannot use their lungs in the water. The hairy frog is also notable in possessing retractable "claws" (though unlike true claws, they are made of bone, not keratin), which it may project through the skin, apparently by intentionally breaking the bones of the toe . In addition, the researchers found 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, but when the frog is grabbed or attacked, the frog breaks the nodule connection and forces its sharpened bones through the skin.
Amphibian researcher and biologist David Wake of the University of California, Berkeley, says this type of weaponry appears to be unique in the animal kingdom. But David Cannatella, a herpetologist at the University of Texas, Austin, questions whether the bony protrusions are meant for fighting. They could allow a frog's feet "to get a better grip on whatever rocky habitat they might be in", he says.
The Arthroleptidae ares separated into three subfamilies: Arthroleptinae, Astylosterninae and Leptopelinae. Some consider these to be separate families, while others do not recognize any subfamilies.
The three subfamilies consist of these genera:
|Subfamilia||Species||Common name||Scientific name|
|47||Screeching frogs||Arthroleptis Smith, 1849|
|16||Long-fingered frogs||Cardioglossa Boulenger, 1900|
|12||Night frogs||Astylosternus Werner, 1898|
|15||Egg frogs||Leptodactylodon Andersson, 1903|
|1||Southern night frog||Nyctibates Boulenger, 1904|
|1||Gaboon forest frog||Scotobleps Boulenger, 1900|
|1||Hairy frog||Trichobatrachus Boulenger, 1900|
|52||Forest treefrogs||Leptopelis Günther, 1859|
- Frost, Darrel R. (2014). "Arthroleptidae Mivart, 1869". Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History. Retrieved 4 July 2014.
- Zweifel, Robert G. (1998). Cogger, H.G. & Zweifel, R.G., ed. Encyclopedia of Reptiles and Amphibians. San Diego: Academic Press. p. 101. ISBN 0-12-178560-2.
- Blackburn, D.C.; Wake, D.B. (2011). "Class Amphibia Gray, 1825. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness". Zootaxa 3148: 39–55.
- ADW: Arthroleptidae: Information
- Cogger, H.G.; R.G. Zweifel, and D. Kirschner (2004). Encyclopedia of Reptiles & Amphibians Second Edition. Fog City Press. ISBN 1-877019-69-0.
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