Raising African Clawed Frogs

Although African Clawed frogs, or Xenopus laevis, (Xenopus - peculiar foot, Laevis - smooth) are commonly seen in captivity, many don't know how to properly take care of these unusual Anuras.

These frogs could make an ideal pet for experts and novices alike, if their unique needs are appropriately met.

Xenopi are grouped in Family Pipidae, all of whose members are wholly aquatic and tongueless. In addition, all Pipids embody a number of other exceptional characteristics: a wedge-shaped body which is dorsoventrally flattened, small, upward-gazing eyes, no visible eardrums, unique vocalizing apparatus requiring no inflatable sacs, no teeth, and very slippery skin. Xenopus laevis also have enormous webbed, five-toed, three-clawed rear feet.

Xenopus laevis is perhaps the best known of the 14 species in Genus Xenopus. All are native only to sub-Saharan Africa.

To obtain a feeling for Xenopus husbandry, one must understand how they live in the wild. The Clawed Frog is a creature of stagnant pools and backwaters arising on a substrate of deep mud. Its highly-developed lungs enable it to obtain practically all necessary oxygen at the surface; indeed, without constant access to air it will quickly succumb.

Their incredibly sensitive fingertips, four on each hand, and sophisticated lateral line systems allow them to locate living prey easily, even when it is concealed in mud and detritus. Given these inhospitable conditions, however, they have also evolved the ability to locate by smell and efficiently consume nonliving food items--a rare adaptation in anurans and one which often gives the Xenopus a significant advantage when inadvertently transplanted to other parts of the globe.
Captive Clawed Frogs can live 15 years, but typical life spans for wild and feral Xenopi, including those which aestivate, have not been ascertained. While Clawed Frogs are not known to be toxic to any animal, they possess chemical defenses which give protection against both predators and diseases. The mildly fishy smell they exude repels many vertebrate predators, especially those found outside of the Xenopus' native range. In addition, they generate organic compounds called magainins which have powerful antibiotic, antifungal, antiparasitic, and antiviral actions. Ongoing research on magainins and other substances produced by Clawed Frogs has already given rise to some useful pharmaceuticals, with many more in the offing.

Housing

These are strictly aquatic anurans. At least 1 gallon of water per animal, with the depth no more than 12 inches and no less than six. Do not use distilled water. Bottles of tap water should stand open for at least 1 day before being poured into the tank to outgas chlorine and related chemicals. Alternatively, you can use anti chlorine, which could be bought in any fish carrying pet store.

African Clawed frogs are specifically adapted for stagnant water conditions. Although aesthetically pleasing to the keeper mechanical and/or electrical filtration invariably produces adverse long-term effects on the frogs. Constant water movement no matter how slight is sensed through the highly developed lateral-line system and results in severe stress. The effect is insidious and can be compared to what would happen to a human if (s)he were compelled to live where sandblasters and jackhammers were in use 24 hours a day.

99 % of the water should be changed by siphon and/or spigots every 3-4 days, or whenever it becomes extremely cloudy. use a towel to remove any algae and accumulated exudate which form on the tank walls, but do not use any type of algae-inhibiting or water-purifying chemicals other than the minuscule amount of sodium thiosulfate mentioned above.
Metal ions are toxic to Xenopi, lowering their resistance to infection. Make absolutely certain there is no metal of any kind in or on the tank or upon which water can splash and drip back into the tank, e.g. from a screen or light fixture. Never clean the tank with soaps or caustics or allow such compounds to come in contact with the water. Do not use pest-strips or insecticides in the vicinity of the tank. The Clawed Frog is quite comfortable in ascetic surroundings, provided they are suitably spacious. Do not use a substrate of small stones, as these can be accidentally ingested. Avoid living plants, as the frogs uproot them quickly. A few sterilized medium-to-large rocks are sufficient to break up the physical monotony of a plain tank.
Adult Xenopi may be gently handled, although they're notoriously slippery, so handling is recommended inside the water only. They must never be netted, however, because their thin fingers may be inadvertently entangled and amputated by even the finest mesh. Since they desiccate easily they must never be kept in a dry situation for more than a few minutes.

Lighting & Temperature

Avoid extremes. In particular, do not expose the tank to any
direct sunlight, very bright artificial light, or temperatures above 90
degrees or below 40 degrees F. The frogs are most comfortable with indirect lighting during regular daylight hours and a temperature range of from 60 to 80 degrees F., i.e. customary indoor temperature. As a rule of thumb, if you're comfortable in the environment where the tank is located, Xenopi will be too. Clawed frogs have no special ultraviolet lighting requirements.

Food

Xenopi should be fed once a day with as much food as they will consume in 15 minutes. Avoid overfeeding; it only clouds the water. Content African Frogs will often take food from their keeper's fingers. They'll nibble the keeper too, but their toothless mouths can't do any damage. In the wild, Clawed Frogs are happy to dine on living, dead, and dying arthropods, bits of organic garbage, and loose material from putrefying corpses of miscellaneous vertebrates. For captive specimens, Reptomin sticks are excellent basic fare as are many other heavily proteinaceous foods compounded primarily for aquatic turtles.

Pieces of lean raw beef, meet of fish, insects and larvae, shrimp, worms, etc. may be offered. Supplementation with calcium or vitamins is unnecessary if professionally balanced formula foods are used as a dietary staple.

Tadpoles

In captivity, adult frogs and tadpoles must be kept completely
separate; even freshly metamorphosed Xenopi will quickly make a
meal of sibling tads if given the chance.
Powdered egg is an ideal food for the tadpoles, but goldfish flakes ground extremely fine with mortar and pestle may be used as an alternative. Each tad should receive only enough powder per day to lightly cover a 14-point capital letter O. Overfeeding tads poses a real danger to the animals, as their gills cannot process needed oxygen when the water is clogged with particulate food. 98 % of tadpole water must be changed once a day, even if it appears to be perfectly clear. Clawed Frog tads are extremely delicate and should not be touched or netted.

Mating

Xenopi are sexually mature at 10 months to 1 year. At that time sexing is easy. Males vocalize frequently during evening hours, have a smooth rump, are 1/2 the size of females, relatively skinny, and develop dark mating pads on the undersides of their hands and forearms. Females are chubby, almost entirely silent, and possess a cloacal extension; they range between 3 and 6 inches snout-to-vent.

Mating can take place at any time but is more common during the spring; up to four matings per year have been reported for compatible couples. the frogs must be given substantially more room than usual. For 2 males and 2 females, 5 to 50 gallons of water at a depth of 8 to 9 inches is adequate. Water should be kept as clean as possible, and its temperature should be around 70 degrees F. Mating often takes place late at night when the frogs detect no other activity, so it is challenging to observe. Sticky eggs are cast loose singly, with hundreds extruded during a 3 to 4 hour period. Within obviously
narrow limits, the speed of metamorphosis is directly proportional to the water temperature. The average interval from egg to froglet is about 6 to 8 weeks. Metamorphosis is a critical event, since the entire circulatory, digestive, and nervous systems are reorganized in a short space of time. The keeper must be particularly concerned about the radical change in eating habits: while Clawed Frog tadpoles must filter-feed, the short gut of newly transformed juveniles (and subsequent adults) can only accommodate visible solid food.
To insure only appropriate fare is offered, the following should be carefully observed. Massive morphological changes will be noted soon after the front limbs appear, and the tail's energetic vibrations will slow and finally stop. During this period, feeding with powdered food should continue as usual. However, when the tail clearly begins to degenerate the frog is deriving nourishment from it alone, and feeding is not necessary. In this very brief interim, lasting on the average of 4-5 days, when the animal is balanced on a developmental edge between tadpole and frog, no external nourishment can be absorbed. Soon, the tail shrinks to nothing but a small stump. At this point adult food should be offered. The newly metamorphosed frog's first regular meal should be particularly appetizing: a few small slivers of lean, raw beef are good. The period between formation of the front legs and first acceptance of solid food is around 10 days.