The goliath frog is the largest of the world’s frog species. They can measure up to 32cm (12.5in) long and weigh up to 3.3kg (7.2lbs). The male is larger in size than the female.
Their skin is a dark or orangey green colour and features dark spots. On the underside they are yellowish orange. Their skin is slippery and smooth with a granular texture. Their toes are webbed. They have a large yellowish-green eye with a horizontal black pupil. This may be up to 2.5cm (1in) in diameter. Their back legs are long while the front legs are short and stout.
During their larval stage when they are a tadpole the goliath frog is a herbivore whose sole food source is a plant that can be found in streams or near waterfalls.
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Africa is the native home of the goliath frog. Here they have a small range in Cameroon and Equatorial Guinea. A population may potentially exist in Gabon though this has not been confirmed.
They are found in forests and wetlands where they live near fast flowing rivers and streams that have a rocky or sandy base. They have been seen surviving in areas of secondary forest but are unable to live in heavily degraded regions.
Breeding takes place during the rainy season.
Recently it has been discovered that these frogs build a nest pond in which to lay their eggs. These vary from simply clearing the leaves and sediment from an existing pool through to digging a hole in the riverbank and then pushing rocks which may weigh half as much as the frog to the edges to create their own pond.
This behavior is suggested as one reason for their large size.
They will lay their eggs in to this nest. Males build their nest and fight other males for breeding rights with a female. Once the male and female mate she will deposit her eggs in to the nest. A single clutch may consist of 1000s of eggs. These eggs are attached to vegetation or stones. They will spend up to 3 months in the egg.
Eggs may be preyed upon by shrimp.
While it was previously believed that the parents had no involvement in raising their young new studies suggest that the female may watch over the eggs and chase predators away.
At hatching the tadpoles are similar in size to a normal frog. They will simply continue growing to a larger size. They spend up to a year as a tadpole swimming in a waterway before they undergo metamorphosis and begin to turn in to an adult frog.
Previously it was believed the goliath frog did not call due to their lack of a vocal sac. Recent research has found that they do indeed make whistles and chirps.
Much of their time is spent in the water though they occasionally emerge from the water to bask.
They can travel up to 3m (10ft) in a single jump.
Predators and Threats
Humans affect the population of the goliath frog through collection for both trade and food along with habitat destruction or pollution. Construction in their habitat affects them as it can fill up the streams where they live.
They are often collected for export to be used in ‘frog races.’ As the largest frogs are most desirable for sale some areas are left with no adults and as such no breeding takes place there meaning a whole generation could be lost.
When threatened they will often dive back below the water’s surface.
The goliath frog has existed for 270 million years making them one of the few frogs who live on Earth before the dinosaurs.
They are also known as the giant slippery frog.
Jordiferrer / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)
Ryan Somma / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.0)
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