Archives of The Cold Blooded News

The Newsletter of the Colorado Herpetological Society

Volume 30, Number 6;   June, 2003

African Clawed Frog

by Katrina Smith

Description:
Adult - 3-6 inches long, with an egg-shaped, slightly flattened body. Four slender front fingers and huge, webbed, five-toed hind feet with the first three toes ending in short, black claws. Organs designed to detect motion look like stretch marks or stitches on the sides. Slimy, slick skin. Color is light to dark gray or brown, with light cream bellies. Albinos do exist in the pet trade. Tongueless and toothless. Females are larger than males, with a longer cloacal opening.
Tadpoles - Transparent skin with heart and intestines visible. Catfish-like barbs on either side of the face. Tails constantly in motion. Filter feeders, taking 6-10 weeks or more to metamorphasize.
Froglets - Newly morphed froglets are roughly the size of a nickel.

Housing:
For one frog, a ten gallon aquarium is the absolute minimum size acceptable, although a larger tank is appreciated. Twenty gallon long aquariums provide excellent housing for a single animal or a pair. Although totally aquatic, the ACF CAN BE AN ESCAPE ARTIST. One would have to see it to believe it. Hoods or covers of some sort are essential for aquariums. With their large appetites, these frogs are best kept only with other members of the same species and same size. Although they can tolerate temperatures between 60-80F, the preferred temperature is 68-76F. Xenopus can live in a very Spartan habitat, but if providing a substrate, use large, smooth river stones, such as those found in plant nurseries. The frogs can accidentally swallow small gravel, so never use this with ACF. The large feet easily uproot aquatic plants, but plastic plants may be used for decoration if they are weighted down. These frogs prefer something to hide in as well. A clean piece of PVC pipe will work, or pet stores sell natural-looking plastic or ceramic logs and caves.

Filtration should be kept as unobtrusive as possible. Too much turbulence acts as the equivalent of a jack-hammer, since the motion will continually bother the motion detecting organs on the frog's sides. Partial water changes are done every week if not using filtration. If using filtration, it is still advisable to change the water every other week. Canister filters, though expensive, are excellent filtration systems, and can be set up so that they cause little turbulence. Even if the water looks clean, change it regularly. These frogs are especially sensitive to metals, so ensure that no metal comes into contact with the water.
(NOTE: Other authors made this last claim. My frogs are kept in an older style aquarium with exterior metal reinforced corners, and they have shown no ill effects for five years.) If using tap water when doing water change, use a water conditioner that removes chlorine.

Food:
Adults - Offer insects, such as crickets (available from a pet store), small fish (feeder guppies, rosy reds), chopped earthworms, freeze-dried Tubifex worms, turtle pellets, and/or trout chow pellets. Feed adults every other day. One or two crickets or one square of Tubifex worms seems to be an appropriate amount.
Froglets - finely ground dried shrimp pellets, frozen glassworms (sold as "Fish Gum Drops"), bloodworms, fish flakes, or freeze-dried tubifex worms. Feed small amounts twice daily. As they grow older (about 4 months) feed once a day.
Tadpoles - strained pea baby food or fry fish food for egg layers, 1/8 - 1/4 tsp. twice a day, depending on number in tank.

Mating:
In the wild, this frog mates when spring rains produce rapid flooding. Stagnant, nearly dry pools of warm water will quickly rise with fresh, cooler water, inducing the frogs to breed. Males can vocalize with an almost metallic sound. Mating occurs at night, with hundreds of eggs deposited singly among rocks and plants. In captivity, the adults will eat eggs and tadpoles, so they must be separated from the frogs after mating, if one is trying to raise tadpoles. Tadpoles not much larger than the head of a pin emerge after 3 days.

In captivity, mating seems to occur at the drop of a hat, with no rhyme or reason. Water changes often bring about breeding. You will usually hear the male vocalizing in the night, then wake up to a tank full of small, white eggs.

Special concerns:
Adult animals can be left alone over the weekend without worry. For short vacation trips of no more than 4 days, they may be left alone in the house. When changing water, try to ensure that the tap water is nearly the same temperature as the aquarium water. You may want to check the pH of your water, although these frogs appear to tolerate a wide pH range. Should your frog escape its tank, try to find it immediately. Despite their aquatic nature, they can travel quite far in the house, and crawl under doorways. If found within a few hours and placed immediately back into their tank, they should be fine. Females prefer to hunt near the water surface, while males prefer to hunt at the bottom of a pond or aquarium. As with all reptiles and amphibians, they will shed their skin, and may eat the shed.

Helpful frog-related terminology:
Aestivation: Essentially a summer hibernation, used when the environment becomes too hot or too dry.
Amplexus: The mating stance of frogs, in which the male uses his front legs to grab the female from behind.
Cloaca: A common passage used for eliminating fecal, urinary, and reproductive discharges.
Pica: Ingestion of inedible objects such as gravel or wood. Often results in death.

Xenopus: Latin for "strange foot".

Bibliography:
http://www.sonic.net/~melissk/xenophus.html
http://www.abcnews.com/sections/science/DailyNews/frogs0216.html
http://gto.ncsa.uiuc.edu/pingleto/xenopus.html
Coborn, John. The Proper Care of Amphibians, T.F.H. Publications, Inc., NJ: 1992 pp. 198-201.
Frank, Norman. "Xenopus The African Clawed Frog," Reptile & Amphibian Magazine, Sept./Oct. 1990 pp. 34,36,60.
Halliday, Tim R. & Adler, Kraig, eds. The Encyclopedia of Reptiles and Amphibians, New York: Facts On File, 1986. pp. 43-44, 52.