African clawed frog

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African clawed frog
Xenopus laevis 02.jpg
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Pipidae
Genus: Xenopus
Species: X. laevis
Binomial name
Xenopus laevis
Daudin, 1802

The African clawed frog (Xenopus laevis, also known as the xenopus, African clawed toad, African claw-toed frog or the platanna) is a species of African aquatic frog of the Pipidae family. Its name is derived from the three short claws on each hind foot, which it uses to tear apart its food. The word Xenopus means "strange foot" and laevis means "smooth".

African clawed frogs can grow up to a length of 5 in (13 cm). They have a flattened head and body, but no tongue or external ears.

The species is found throughout much of Sub-Saharan Africa (Nigeria and Sudan to South Africa),[2] and in isolated, introduced populations in North America, South America, and Europe.[1] All species of the Pipidae family are tongueless, toothless and completely aquatic. They use their hands to shove food in their mouths and down their throats and a hyobranchial pump to draw or suck things in their mouth. Pipidae have powerful legs for swimming and lunging after food. They also use the claws on their feet to tear pieces of large food. They lack true ears but have lateral lines running down the length of the body and underside, which is how they can sense movements and vibrations in the water. They use their sensitive fingers, sense of smell, and lateral line system to find food. Pipidae are scavengers and will eat almost anything living, dying or dead and any type of organic waste.


These frogs are plentiful in ponds and rivers within the south-eastern portion of Sub-Saharan Africa. They are aquatic and are often greenish-grey in color. Albino varieties are commonly sold as pets. “Wild type" African Clawed Frogs are also frequently sold as pets, and often incorrectly labeled as a Congo Frog or African Dwarf Frog because of similar colorings. They are easily distinguished from African Dwarf Frogs because African Clawed Frogs have webbing only on their hind feet while African Dwarf Frogs have webbing on all four feet. They reproduce by laying eggs (see frog reproduction). Also, the clawed frogs are the only amphibians to have actual (though small) claws used to shred foods like fish or tadpoles. They lay their eggs from winter till spring during wet rainy seasons they will travel to other ponds or paddles of water to search for food.[3]

The average life-span of these frogs ranges from 5–15 years with some individuals recorded to have lived for 20–25 years.[4] They shed their skin every season, and eat their own shedded skin.

Although lacking a vocal sac, the males make a mating call of alternating long and short trills, by contracting the intrinsic laryngeal muscles. Females also answer vocally, signaling either acceptance (a rapping sound) or rejection (slow ticking) of the male.[5][6] This frog has smooth slippery skin which is multicolored on its back with blotches of olive gray or brown. The underside is creamy white with a yellow tinge.



In the wild[edit]

The monogenean Protopolystoma xenopodis,[8] a parasite of the urinary bladder of Xenopus laevis

In the wild, Xenopus laevis are native to wetlands, ponds, and lakes across arid/semiarid regions of Sub-Saharan Africa.[2][9] Xenopus laevis and Xenopus muelleri occur along the western boundary of the Great African Rift. The people of the sub-Saharan are generally very familiar with this frog, and some cultures use it as a source of protein, an aphrodisiac, or as fertility medicine. Two historic outbreaks of priapism have been linked to consumption of frog legs from frogs that ate insects containing cantharidin.[10] Wild Xenopus are much larger than their captive bred counterparts.[citation needed]
Xenopus laevis in the wild are commonly infected by various parasites,[8] including monogeneans in the urinary bladder.

Use in research[edit]

Xenopus embryos and eggs are a popular model system for a wide variety of biological studies.[11][12] This animal is widely used because of its powerful combination of experimental tractability and close evolutionary relationship with humans, at least compared to many model organisms.[11][12] For a more comprehensive discussion of the use of these frogs in biomedical research, see the Wikipedia entry for Xenopus.

Xenopus has long been an important tool for in vivo studies in molecular, cell, and developmental biology of vertebrate animals. However, the wide breadth of Xenopus research stems from the additional fact that cell-free extracts made from Xenopus are a premier in vitro system for studies of fundamental aspects of cell and molecular biology. Thus, Xenopus is the only vertebrate model system that allows for high-throughput in vivo analyses of gene function and high-throughput biochemistry. Finally, Xenopus oocytes are a leading system for studies of ion transport and channel physiology.[11]

Although X. laevis does not have the short generation time and genetic simplicity generally desired in genetic model organisms, it is an important model organism in developmental biology, cell biology, toxicology and neurobiology. X. laevis takes 1 to 2 years to reach sexual maturity and, like most of its genus, it is tetraploid. It does have a large and easily manipulated embryo, however. The ease of manipulation in amphibian embryos has given them an important place in historical and modern developmental biology. A related species, Xenopus tropicalis, is now being promoted as a more viable model for genetics.




The first vertebrate ever to be cloned was an African clawed frog, an experiment for which Sir John Gurdon was awarded the Lasker award.



The community-maintained model organism database for Xenopus is Xenbase [18]

As pets[edit]




They are as easy to take care of as fish.

As a pest[edit]

African Clawed Frogs are voracious predators and easily adapt to many habitats.[20] For this reason, they can easily become a harmful invasive species. They can travel short distances to other bodies of water, and some have even been documented to survive mild freezes. They have been shown to devastate native populations of frogs and other creatures by eating their young.

In 2003, Xenopus laevis frogs were discovered in a pond at San Francisco's Golden Gate Park. Much debate now exists in the area on how to exterminate these creatures and keep them from spreading.[21][22] It is unknown if these frogs entered the San Francisco ecosystem through intentional release or escape into the wild. San Francisco officials recently drained Lily Pond and fenced off the area to prevent the frogs from escaping to other ponds in the hopes they starve to death.

Due to incidences in which these frogs were released and allowed to escape into the wild, African Clawed Frogs are illegal to own, transport or sell without a permit in the following US states: Arizona, California, Kentucky, Louisiana, New Jersey, North Carolina, Oregon, Virginia, Hawaii,[23] Nevada, and Washington state. However, it is legal to own Xenopus laevis in New Brunswick and Ohio.[24][25]

Known feral colonies of Xenopus laevis do also exist in South Wales, United Kingdom.[26]

The African clawed frog may be an important vector and the initial source of Batrachochytrium dendrobatidis, a chytrid fungus that has been implicated in the drastic decline in amphibian populations in many parts of the world.[2] Unlike in many other amphibian species (including the closely related western clawed frog) where this chytrid fungus causes the disease Chytridiomycosis, it does not appear to affect the African clawed frog, making it an effective carrier.[2]


  1. ^ a b Tinsley, R., Minter, L., Measey, J., Howell, K., Veloso, A., Núñez, H. & Romano, A. (2009). "Xenopus laevis". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 4 May 2014. 
  2. ^ a b c d Weldon; du Preez; Hyatt; Muller; and Speare (2004). Origin of the Amphibian Chytrid Fungus. Emerging Infectious Disease 10(12).
  3. ^ Maddin HC, Eckhart L, Jaeger K, Russell AP, Ghannadan M (April 2009). "The anatomy and development of the claws of Xenopus laevis (Lissamphibia: Anura) reveal alternate pathways of structural evolution in the integument of tetrapods". Journal of Anatomy 214 (4): 607–19. doi:10.1111/j.1469-7580.2009.01052.x. PMC 2736125. PMID 19422431. 
  4. ^ Garvey, Nathan. "ADW: Xenopus laevis: INFORMATION". Retrieved 2013-06-08. 
  5. ^ Garvey, Nathan. "ADW: Xenopus Laevis: Information". Retrieved 2013-06-08. 
  6. ^ Talk of the Nation. "ADW: NPR: Listening To Love Songs of African Clawed Frogs". NPR. Retrieved 2013-06-08. 
  8. ^ a b Theunissen, M., Tiedt, L. & Du Preez, L. H. 2014: The morphology and attachment of Protopolystoma xenopodis (Monogenea: Polystomatidae) infecting the African clawed frog Xenopus laevis. Parasite, 21, 20. doi:10.1051/parasite/2014020
  9. ^ John Measey. "Ecology of Xenopus Laevis". Retrieved 2013-06-08. 
  10. ^
  11. ^ a b c Wallingford, J., Liu, K., and Zheng, Y. 2010. Current Biology v. 20, p. R263-4
  12. ^ a b Harland, R.M. and Grainger, R.M. 2011. Trends in Genetics v. 27, p 507-15
  13. ^ Nutt, S. L.; Bronchain, O. J.; Hartley, K. O.; Amaya, E. (2001). "Comparison of morpholino based translational inhibition during the development ofXenopus laevis andXenopus tropicalis". Genesis 30 (3): 110–113. doi:10.1002/gene.1042. PMID 11477685.  edit
  14. ^ Blow JJ, Laskey RA (November 1986). "Initiation of DNA replication in nuclei and purified DNA by a cell-free extract of Xenopus eggs". Cell 47 (4): 577–87. doi:10.1016/0092-8674(86)90622-7. PMID 3779837. 
  15. ^ "Ludington Daily News - Sep 14, 1992, p. 7". 1992-09-14. Retrieved 2013-06-08. 
  16. ^ "Reading Eagle - Sep 11, 1992, p. A8". 1992-09-11. Retrieved 2013-06-08. 
  18. ^ "". 2010-04-26. Retrieved 2013-06-08. 
  19. ^ "NPR December 22, 2007". 2007-12-22. Retrieved 2013-06-08. 
  20. ^ Dr. James A. Danoff-Burg. "ADW: Columbia: Introduced Species Summary Project". Retrieved 2013-06-08. 
  21. ^ "Killer Meat-Eating Frogs Terrorize San Francisco". FoxNews. 2007-03-14. 
  22. ^ "The Killer Frogs of Lily Pond:San Francisco poised to checkmate amphibious African predators of Golden Gate Park". San Francisco Chronicle. [dead link]
  23. ^ "ADW: Honolulu Star-Bulletin Wednesday, July 3, 2002". 2002-07-03. Retrieved 2013-06-08. 
  24. ^ ADW: New Brunswick Regulation 92-74[dead link]
  25. ^ "ADW: New Brunswick Acts and regulations". Retrieved 2013-06-08. 
  26. ^ John Measey. "Feral Xenopus laevis in South Wales, UK". Retrieved 2013-06-08. 

External links[edit]