Male and female frogs can be easily distinguished through the following differences. Male frogs are usually about 20% smaller than females, with slim bodies and legs. Males make mating calls to attract females, sounding very much like a cricket calling underwater. Females are larger than the males, appearing far more plump with hip-like bulges above their rear legs (where their eggs are internally located).
A gravel substrate can be used, but avoid small gravel to prevent accidental ingestion. Use rocks, wood and flower pots to decorate the tank and provide hiding places; frogs with no place to hide may be stressed. Artificial plants can also be used, but the frogs will dig up and generally destroy live plants.
Clawed frogs often become quite tame over time, taking food directly from owners' fingers. They do sometimes accidentally nibble on fingers, but they lack teeth so this is not an issue. These frogs also lack tongues and feed by stuffing food into their mouths with their front legs. They can be quite messy as a result!
The average life-span of these frogs ranges from 5–15 years with some individuals recorded to have lived for 20–25 years. They shed their skin every season, and eat their own shed skin.
The clawed frogs are the only amphibians to have actual claws used to climb and 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 puddles of water to search for food.
They reproduce by ferilizing eggs outside of the female's body (see frog reproduction). Of the seven amplexus modes (positions in which frogs mate), these frogs are found breeding in inguinal amplexus, where the male clasps the female in front of the female's back legs and squeezes until eggs come out. The eggs are then fertilized.
Feral colonies of Xenopus laevis exist in South Wales, United Kingdom.
African Clawed Frogs are frequently mislabeled as African Dwarf Frogs in pet stores. The astute pet owner will recognize the difference, however, because of the following characteristics:
Extracts from the eggs of X. laevis frogs are also commonly used for biochemical studies of DNA replication and repair, as these extracts fully support DNA replication and other related processes in a cell-free environment which allows easier manipulation.
The first vertebrate ever to be cloned was an African clawed frog, an experiment for which Sir John Gurdon was awarded the Nobel Prize in Physiology or Medicine 2012 "for the discovery that mature cells can be reprogrammed to become pluripotent".
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".
Additionally, several African clawed frogs were present on the space shuttle Endeavour (which was launched into space on September 12, 1992) so that scientists could test whether reproduction and development could occur normally in zero gravity.
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. 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.
Feed the amount they will clear from the water in 10-15 minutes daily. Some sources say fully grown frogs only need to feed 3-4 times a week. In general, overfeeding is more of a problem than under feeding, so feed daily and keep an eye on the body shape of your frog--if it seems to be getting overweight, then cut back a bit.
Xenopus laevis have been kept as pets and research subjects since as early as the 1950s. They are extremely hardy and long lived, having been known to live up to 20 or even 30 years in captivity.
Due to incidents 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, Nevada, and Washington state. However, it is legal to own Xenopus laevis in New Brunswick (Canada) and Ohio.
Both males and females have a cloaca, which is a chamber through which digestive and urinary wastes pass and through which the reproductive systems also empty. The cloaca empties by way of the vent which in reptiles and amphibians is a single opening for all three systems.
The tank can be kept at room temperature: 68-75 F. No special lighting is required; indirect lighting is fine and may be preferred). Use a 12 hour light to 12 hour dark light cycle.
Amphibian frog Xenopus laevis also serves as an ideal model system for the study of the mechanisms of apoptosis. In fact, iodine and thyroxine stimulate the spectacular apoptosis of the cells of the larval gills, tail and fins in amphibians metamorphosis, and stimulate the evolution of their nervous system transforming the aquatic, vegetarian tadpole into the terrestrial, carnivorous frog.
X. laevis is also notable for its use in the first well-documented method of pregnancy testing when it was discovered that the urine from pregnant women induced X. laevis oocyte production. Human chorionic gonadotropin (HCG) is a hormone found in substantial quantities in the urine of pregnant women. Today, commercially available HCG is injected into Xenopus males and females to induce mating behavior and to breed these frogs in captivity at any time of the year.
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. It is unknown if these frogs entered the San Francisco ecosystem through intentional release or escape into the wild. San Francisco officials drained Lily Pond and fenced off the area to prevent the frogs from escaping to other ponds in the hopes they starve to death.
Xenopus embryos and eggs are a popular model system for a wide variety of biological studies. 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. For a more comprehensive discussion of the use of these frogs in biomedical research, see Xenopus.
Xenbase is the Model Organism Database (MOD) with the full details and release information regarding the current Xenopus laevis genome (9.1).
The water in the tank must be dechlorinated using a product from the pet store designed to remove chorine (and chloramine, if necessary). These frogs can also be very sensitive to the toxic effects of metal ions in the water, so ensure that their water does not come in contact with metal (e.g. on the tank cover).
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. 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.
African Clawed Frog
Roger Wolcott Sperry used X. laevis for his famous experiments describing the development of the visual system. These experiments led to the formulation of the Chemoaffinity hypothesis.
African Clawed Frogs are voracious predators and easily adapt to many habitats. 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.