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Xenopus laevis varies in size; males (45.6 to 97.5 mm) tend to be be smaller than females (57 to 147 mm). Their heads and bodies are depressed and flattened and they have small round eyes on the top of their heads. The skin is smooth and the hind limbs are long and robust. The three inner toes of the large fully webbed feet have small black claws on them. The body color is usually dark-gray to greenish-brown dorsally, and pale ventrally (Trueb 2003).Despite the genomic revolution, the first complete genome of a frog, Xenopus tropicalis, was sequenced only in 2010. Session et al. (2016) have sequenced the genome of Xenopus laevis. Because X. tropicalis is diploid and X. laevis is tetraploid, important inferences can be made about genome evolution. Based on analysis of the rate of synonymous mutations in protein-coding genes, they estimated that the two species diverged from each other about 48 mya, a date is remarkably close to the estimate based on phylogenetic analysis of fossils, morphology, and other genomic sequences. They also calculated that the lineage of tetraploid Xenopus species originated 17–18 mya from two now extinct diploid ancestors.This species was featured as News of the Week on 21 November 2016: Despite the genomic revolution, the first complete genome of a frog, Xenopus tropicalis, was sequenced only in 2010. Session et al. (2016) have sequenced the genome of another species, Xenopus laevis. Because X. tropicalis is diploid and the X. laevis is tetraploid, important inferences can be made about genome evolution. Based on analysis of the rate of synonymous mutations in protein-coding genes, they estimated that the two species diverged from each other about 48 mya, a date is remarkably close to the estimate based on phylogenetic analysis of fossils, morphology, and other genomic sequences. They also calculated that the lineage of tetraploid Xenopus species originated 17–18 mya from two now extinct diploid ancestors (Written by David Cannatella).This species was featured as News of the Week on 29 May 2017:Often conservationists lack information critical to developing recovery strategies for endangered species. The Cape Platanna, Xenopus gilli, is restricted in distribution to a few sites in southwestern Cape, South Africa, always in sympatry with Xenopus laevis, an invasive species. Vogt et al. (2017 PeerJ) assessed niche differentiation at two sites. The diet of X. gilli is much more diverse than that of X. laevis. Both consume large numbers of tadpoles of different amphibian species (reaching as high as 45% of prey), including congeners, but X. laevis, which is about three times as common as its congener, also consumes adult X. gilli and is thus a direct predator as well as a dominant competitor. Furthermore, dietary overlap is greater between smaller members of each species. An effective conservation strategy for X. gilli is likely to require removal of X. laevis (Written by David B. Wake).Its role as possible vector control agent was highlighted in News of the Week on 19 November 2018:As a disease vector, it is important to control mosquito populations. However, biological control with introduced mosquitofish (Gambusia affinis) has the unintended consequence of altering ecosystems. Watters et al. (2018) explored the effectiveness of using native amphibian larvae in Missouri instead. They found that Leopard frogs (Rana sphenocephala), while consuming a large number of mosquito larvae, ate fewer mosquitos than mosquitofish. The Spotted Salamander (Ambystoma maculatum), on the other hand, consumed as much mosquitos as mosquitofish. Moreover, there was a positive relationship between mosquito consumption and salamander larvae body size providing encouragement to assess more native amphibians for mosquito control. However Thorpe et al. (2018) indicate other considerations. They found a body size-dependent response to varying prey densities. With small African Clawed frog (Xenopus laevis) tadpoles, a type II functional feeding response is shown, increasing feeding rates with prey density until a threshold when the predator cannot keep up with the prey, while larger tadpoles exhibit type III response, characterized by lower than expected feeding rates at low and high densities but increasing feeding rates at increasing intermediate densities. This suggests a need for size diversity in biological control (Written by Ann T. Chang).This species was featured as News of the Week on 17 June 2019:Amphibians are unique among tetrapods in their ability to regenerate their appendages, like arms or tails, when removed. The particular mechanisms underlying appendage regeneration, however, are poorly known. A recent study (Aztekin et al. 2019) combined tail amputation experiments in tadpoles of the African clawed frog (Xenopus laevis) with single-cell RNA sequencing, allowing researchers to study how different genes work in individual cells of various cell types during tail regeneration. This study discovered a previously unknown cell type named the regeneration-organizing cell (ROC). Removing ROCs from severed tails demonstrated that ROCs are necessary for tadpoles to regrow their tails. Transplanting these cells to other areas of the embryo demonstrated these cells are sufficient to grow tail-like structures elsewhere in tadpoles. ROCs are normally found in the epidermis and migrate to the wound site after tadpole tails are amputated, secreting similar regenerative compounds that are produced when salamanders regrow limbs. The discovery of a new cell type that enables amphibian larvae to regrow appendages has exciting implications for tissue and organ transplant procedures and is an important reminder that we have much yet to learn about the amazing biology of amphibians (Written by Max Lambert).

This species occurs in savannas of the Republic of South Africa, Kenya, Uganda, Democratic Republic of Congo, and Cameroon. This frog has high tolerance to change in its environment and will survive in nearly any body of water. It can be found in water bodies ranging from ice-covered lakes to desert oases. Unlike most frogs, the African clawed frog can also survive in water with high salinity (Trueb 2003).

These frogs spend most of their life-cycle in the water, only to leave when there is a drought. When a drought occurs, they will burrow into the drying mud. They can survive up to a year without food. Their diet consists of a wide range of animals including fish, crustaceans, insects, and other frogs. They will also scavenge on dead frogs, fish, birds, and small mammals (Trueb 2003).

Not threatened.

This is one of the most-studied species of frogs, considered one of the model systems of developmental biology. It is hardy and breeding can be easily induced in the laboratory. Xenopus laevis early development has been studied by developmental biologists for decades and its genome has been fully sequenced. Because it makes a hardy and popular pet, it can also be found in aquariums worldwide. This species has been used as food in African countries (Trueb 2003).