The African bullfrog is one of the largest frogs on Earth, with the Goliath Frog being the biggest. Also known as the Giant African Bullfrog, the male of the species can grow to 10 inches long and weigh more than 4 pounds. This bullfrog primarily lives in the central part of sub-Saharan Africa. It is a voracious eater and will swallow anything it can, but is also popular as a pet. One notable characteristic of the bullfrog is the sound it makes when it is annoyed, which has been described as croaking, roaring, or bleating.
4 Incredible African Bullfrog Facts!
- Interestingly, the frog is also called the pixie frog. This, of course, has nothing to do with the animal’s size. “Pixie” comes from its scientific name of Pyxicephalus adspersus.
- As belligerent as he can sometimes be, the male African bullfrog is a doting father, to a point. If he sees that the pool that holds his tadpoles is running out of water, he’ll use his back legs to dig a channel into a larger pool to both replenish the smaller pool and allow the tadpoles to escape. On the other hand, he’ll sometimes eat his young.
- African bullfrogs shed their skin in its entirety occasionally, splitting down the back first then across its belly so the frog can pull its arms and legs out then work the skin off its head. Not to waste any food source, the frog then eats the old skin.
- After burrowing underground, some African bullfrogs keep just their noses above ground, the better to grab any unsuspecting prey.
Scientific Name
The African bullfrog’s scientific name is Pyxicephalus adspersus. It is a member of the Pyxicephalidae family of sub-Saharan frogs and belongs to the Pyxicephalus genus, which comes from the Greek for “round box head.”
The African bullfrog is the largest of the four species that belong to Pyxicephalus, with the other species being the edible bullfrog (Pyxicephalus edulis), Calabresi’s bullfrog (Pyxicephalus obbianus), and Pyxicephalus angusticeps.
Evolution and History
The African bullfrog has evolved in several ways to adapt to its environment.
As the biggest threat to these frog is habitat destruction, they have developed adaptations that allow them to thrive in a range of climates from hot deserts to velds, high open lands that reach below-freezing in the winter. One of the adaptations the frog has developed to stay alive in a hostile environment is when it estivates (becomes dormant), it sloughs off its skin one layer at a time to form a cocoon around itself for protection and to reduce evaporative water loss from its body. While cocooned, the frog decreases its metabolic rate. All of this allows the bullfrog to withstand the African dry season, which can last 7-8 months.
Another adaptation is its odontodes, tooth-like features on its jaw that it uses to grab onto prey and fight off predators. While many frogs have “pedicel” teeth divided into three sections, African bullfrogs have non-pedicellate teeth composed of dentin, with an enamel tip on the crown.
Appearance and Behavior
Male African bullfrogs are almost 10 inches long, while females are about 4.5 inches long. The males of this big frog can weigh a little over 4 pounds, and the females weigh about half that, as they are half the size. This is unusual because in most frog species the females are bigger than the males.
A fully grown male African bullfrog is olive green, has a throat in shades of yellow or orange, and can be as big as a dinner plate. The female is much smaller and olive green to light brown with a white or cream throat. Younger bullfrogs are more brightly colored, with mottled skin and white or yellow lines that run down their back. The colors fade to the adult coloring as the frog gets older, though some females do retain the lines. Adult frogs have a knob on their hind foot shaped like a shovel that helps them dig. Their back toes have some webbing while the stubby front toes do not.
The African bullfrog has a similar body to most other frogs. Its powerful legs help it jump away from predators and threats, and its skin protects its internal organs, helps it take in oxygen, and absorbs water. The skin is also full of glands. Many of these glands are located on the back and head and secrete a solution that keeps the skin moist and protects it against pathogens. Since it’s slick, it also helps the frog escape predators.
The African bullfrog is noted for having a huge skull and robust skeleton, and though they do not have teeth, their bottom jaw has three structures called odontodes. These are growths that are similar to teeth but grow on the top of the skin. Odontodes are adaptations used to grab and hang on to prey. The African bullfrog is one of only three species of frog that have “teeth.”
African bullfrogs are solitary save the breeding season, which happens after a heavy rain that allows shallow, temporary pools of water to form. A group of frogs is called an army or a knot.
Habitat
The bullfrog can be found in a wide variety of habitats in sub-Saharan Africa. It’s found as far east as Somalia, as far west as Nigeria, and south into South Africa.
Though they are amphibians, African bullfrogs can live in climates that stay dry for years. They can live in the mountains but are probably happiest near bodies of water. The secret to their adaptability is that they dig chambers in the soil when the climate becomes too harsh, enter the chambers and become dormant until conditions are more favorable.
