That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

For as long as I can recall, distinguishing between young African clawed frogs (Xenopus laevis) and adult dwarf clawed frogs (Hymenochirus boettgeri or H. curtipes) has been problematical for many frog keepers (and pet store employees!). The question is more than academic, because both are exceedingly common and popular in the pet trade, and their care differs radically.

Distinguishing the Species

Both are members of the frog family Pipidae, a group of 32 species of aquatic, tongue-less and thoroughly engaging creatures. Included the Pipidae is the bizarre, back-brooding Surinam toad (Pipa pipa) and its 5 relatives.

The two can be easily distinguished by closely examining the front feet. If the fingers are webbed, then the frog is a dwarf clawed frog. If they are not webbed, then it is a baby African clawed frog. Both have webbed feet.

There are subtle differences as well – dwarf frogs are even more flattened in shape than their larger cousins, and have somewhat pointed (as opposed the African clawed frog’s rounded) heads.

Lifestyle and Care Differences

African clawed frogs are boisterous, hardy beasts that eat most anything, prepared foods included, and are easily trained to feed from the hand. Captive longevity approaches 30 years.

Dwarf clawed frogs are live food specialists. Tiny and slow moving, they incessantly search the substrate for worms and other invertebrates, and do best in warm, densely-planted aquariums. A breeding group makes for an enchanting display.

Frogs and Fish?

Unfortunately, both are often sold as “oddities” for tropical fish aquariums. This situation rarely works out…African clawed frogs consume all but the largest of fishes, and dwarf frogs are inevitably out-competed for food and perish in short order.

There are major differences in the care of both species, which I’ll cover in detail in the future. Until then, please write in with your questions and comments. Thanks, Frank Indiviglio.

Further Reading

I’ve long been fascinated by aquatic frogs, and have bred a number of species. Please see my article African Clawed Frog Behavior  for some unusual observations upon which I’m seeking the comments of other frog enthusiasts.

Both frogs can be bred in captivity, and their tadpoles have a most unusual feeding strategy. For more information and a video clip, please see Suction Feeding in H. boettgeri.

Dwarf Clawed Frog Image referenced from Wikipedia and originally posted by Mwatro

As you may know, the African clawed frog is entirely aquatic but may travel overland in search of water, but only when forced to do so – when its habitat dries out or poison is introduced to its pond. Many years ago I kept an adult pair that would lie out on a rock which protruded above the water, directly under an incandescent bulb. This only occurred in winter, when the water temperature in their tank averaged 66 F, so I thought they might be seeking warmth. However, others I’ve kept at that temperature have not left the water, despite being provided with a basking light as well.

The second observation involves a female clawed frog that laid eggs in absence of a male. That in itself is unusual, as most frogs utilize amplexus (the male grasps the female just behind the front legs or, in Xenopus, just above the rear legs) to induce egg laying. Odder still, however, was the fact that a male placed in the tank with the eggs (and without the female) on the following day fertilized the eggs. He was in breeding condition, as evidenced by the rough “nuptial pads” along his forearms, and perhaps was responding to pheromones or scents in the water, but still should have (according to me, not him, it seems!) required a female to stimulate sperm release. I have spoken with a number of herpetologists about this, and none can recall a similar incident.

Further information on this frog’s mating behavior and ability to travel overland is available at:
http://animaldiversity.ummz.umich.edu/site/accounts/information/Xenopus_laevis.html