African bullfrog

African bullfrog
File:Pyxicephalus adspersus, Boston Aquarium.jpg
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Family:	Pyxicephalidae
Genus:	Pyxicephalus
Species:	P. adspersus
Binomial name
Pyxicephalus adspersus Tschudi, 1838

The African bullfrog (Pyxicephalus adspersus) is a species of frog in the Pyxicephalidae family. It is also known as the pixie frog due to its Latin name. It is found in Angola, Botswana, Kenya, Malawi, Mozambique, Namibia, South Africa, Swaziland, Tanzania, Zambia, Zimbabwe, and possibly Democratic Republic of the Congo.

Its natural habitats are dry savanna, moist savanna, subtropical or tropical dry shrubland, intermittent freshwater lakes, intermittent freshwater marshes, arable land, pastureland, and canals and ditches. This is a large frog, with males weighing 1.4 kg (3.1 lb), though can easily exceed 2 kg (4.4 lb); females are half the size, making it unique among frogs, as in most amphibians females are usually larger than males. Males can reach 23 cm (9 inches) while females are much smaller.

Feeding and habits

The African bullfrog is carnivorous and a voracious eater, eating insects, small rodents, reptiles, small birds and other amphibians. It is also a cannibalistic species — the male African bullfrog is known for occasionally eating the tadpoles he guards. This frog is also aggressive and has been known to bite when provoked. An African bullfrog kept at the Pretoria Zoo in South Africa once ate 17 Juvenile Rinkhals Snakes (Hemachatus haemachatus). They emit a loud croaking and a bleating sound when stressed or handled. Like the Pacman frogs and the Budgett's Frogs, African Bullfrogs also bite when they are provoked. It is one of three frog species that have sharp teeth and bite humans when they are provoked or handled by humans (when they are getting picked up by humans using their hands to lift them up).

Reproduction

Breeding starts after heavy rain (initiated by 65 mm of rain over the previous day or two). They breed in shallow, temporary water bodies, such as pools, pans and ditches. Eggs are laid in the shallow edge of the pond, but fertilization takes place above water level.

The African bullfrog males call out during the rainy season. The call lasts about a second and can be described as a deep low-pitched whoop. Males have two breeding strategies, depending on their age. Young males congregate in a small area, perhaps only 1 or 2 square meters of shallow water. The larger males occupy the center of these breeding arenas or leks and attempt to chase off other males. Often they fight, causing injury and even killing one another. The dominant male attempts to prevent other males from breeding. A female approaches the group of males by swimming along at the surface until she is within a few meters of the group. Then the female dives to avoid the smaller males and surfaces in the defended area of a larger male in the middle of the group. This helps to ensure that she mates with the dominant male.

The female lays about 3,000 to 4,000 eggs at a time. The tadpoles hatch and after two days start feasting on vegetation, small fish, invertebrates and even each other. Defending males will continue to watch over the tadpoles, which will metamorphose within three weeks. During the tadpole's development, the father guards his young. He will pounce and bite anything that he views as a threat. If the pool is in danger of drying out, the father will use his legs and head to dig a canal from the drying pond to a bigger pond. He will continue to guard the tadpoles until they are old enough to fend for themselves, although he may also eat some of them.

In pet trade

The African bullfrog is an exotic pet in many countries around the world, and owning it is not prohibited by any laws. Animals sold are generally bred in captivity. It is not unusual for pet African Bullfrogs to live for 35 years in captivity.

In popular culture

• In the film Jurassic Park, dinosaurs are cloned for a theme park and are kept from breeding because each one is cloned to be a female. Dr. Grant said that in a same sex environment, certain kinds of West African frogs can change their sex. The genetic coding of the dinosaur DNA is completed with the DNA of a frog and as a result, the dinosaurs change their sex in order to breed. Whether West African Bullfrogs can actually do this is not as yet known.
• In My Gym Partner's a Monkey, Principal Pixiefrog is an African bullfrog.

External links

• The Natural History of the African Bullfrog, copyright 2002 by Terry Gampper.
• Natural History, Care and Breeding Information for African Bullfrogs / Pyxie frogs