Goliath Frog vs African Bullfrog: Understanding the Differences Between Two Amphibians

Goliath and African bullfrogs are both gigantic among frog species. They’re similar in many aspects. Despite that, they differ in that they are worth exploring. 

So, Goliath frog vs African bullfrog: What are the differences? Well, Goliath frogs hold the title “largest” frog species, but African bullfrog is comparatively smaller. Gigantic Goliaths make nests of large rocks, but they lack vocal sacs. On the contrary, African bullfrogs make loud, deep sounds during mating. Their distribution, habitat, and reproduction also vary. 

Want to explore these two wandering creatures? Come with us as we will put both species apart.  

Taxonomy of Goliath Frogs and African Bullfrogs

Before we go into a long discussion, let’s start with their taxonomy. E

Taxonomy of Goliath Frog 

• Common name: Goliath Frog, Giant Slippery Frog, Goliath Bullfrog
• Scientific Name: Conraua goliath
• Kingdom: Animalia
• Phylum: Chordata
• Class: Amphibia
• Order: Anura
• Family: Conrauidae
• Genus: Conraua

Taxonomy of African Bullfrog 

• Common name: African Bullfrog, Giant Bullfrog, South African Burrowing Frog
• Scientific Name: Pyxicephalus adspersus
• Kingdom: Animalia
• Phylum: Chordata
• Class: Mammalia
• Order: Anura
• Family: Pyxicephalidae
• Genus: Pyxicephalus

Goliath Frog Vs. African Bullfrog: Key Distinctions 

You want a quick start to the differences between the Goliath frog and the African bullfrog, right? Here you go! 

Characteristics	Goliath frog	African bullfrog
Size and Weight	Largest frog; 12. 6 inches long, maximum weight is 3.25 kg	The second largest frog in Africa. It can be 9.4 inches long and weigh 1.4 kg
Coloration	Brown, green, yellow, orange	Olive green body
Distribution	Central and West African countries	Southern African countries
Diet	Carnivores, insectivores, molluscivora	Voracious carnivores
Social Behavior	Solitary	Territorial
Reproduction	Polygamous, litter size: 3000 eggs, gestation period 85 to 95 days	Polygamous, litter size: 4000 eggs, gestation period: 2 days
Lifespan	Wild: 10-15 years, Captivity: 21 years	Wild: 20 years, Captivity: 45+ years

Goliath Frog vs African Bullfrog: Physical Characteristics

Goliath frogs and African bullfrogs are two different amphibians. Let’s see their physical distinction. 

Weight and Size

The Goliath Frog (Conraua goliath) holds the title of the world’s largest frog species. Adult specimens can reach an impressive length of up to 32 centimeters (12.6 inches) and exceed a weight of 3.25 kg ( 7.17 lb). Can you imagine how heavy it is? It’s like a newborn human baby (average weight 2.5-4 kg). 

On the contrary, the African Bullfrog (Pyxicephalus adspersus) exhibits a more modest size. Adults generally range from 9 to 24 centimeters (9.4 inches) in length, with weights reaching up to 1.4 kg. 

Though these are smaller than the Goliath frogs, they’re the second largest frog in Africa. However, they’re the largest frog in the southern hemisphere. 

Coloration

The color of the Goliath frog varies from upside down. The upper side (Dorsal part) of the body is usually a brownish-green color with various spots. At the same time, the lower side (Ventral part) is yellow mixed with green or orange. 

Their color provides effective camouflage amidst the lush vegetation of the rainforest. Plus, this coloration serves as a protective adaptation, aiding in their concealment from potential predators. 

African bullfrogs show diverse colors, unlike Goliath frogs. Their bodies are primarily olive green in color. But their throats are yellow-orange in males, whereas they are cream-colored in females. 

Other Physical Characteristics

The most interesting fact about Goliath frogs is that they lack vocal sacs. Therefore, they can’t produce sound like others. At the same time, African bullfrogs make powerful sounds. 

Goliaths have long, powerful hind legs. Their legs help them jump longer than 3m in a single leap. On the contrary, African bullfrogs comprise short and sturdy legs. They use their legs for digging and burrowing. 

Goliath Frog vs African Bullfrog: Ecological Characteristics

To comprehend these species’ ecological roles in the ecosystem, you must be aware of their distribution and habitat.

Goliath Frog

• Distribution: The Goliath Frog is native to Central and West African countries, including Cameroon and Equatorial Guinea. Its distribution is primarily concentrated within the dense rainforests of these regions.
• Habitat: These frogs thrive in lush, tropical rainforest environments characterized by high humidity and abundant vegetation. Goliath Frogs are often found near slow-flowing rivers and streams, preferring habitats with ample aquatic and terrestrial features.

African Bullfrog

• Distribution: The African Bullfrog is indigenous to various southern African countries, such as South Africa, Namibia, and Botswana. Its distribution preference varies, encompassing both savannas and semi-arid regions.
• Habitat: African Bullfrogs are strategically distributed across a range of landscapes, adapting to environments that include grasslands, open woodlands, and arid areas. Their versatile habitat selection aligns with their burrowing behavior and seasonal migration patterns.

Goliath frog vs African Bullfrog: Lifestyle

Goliath frogs and African bullfrogs show some distinctions in behavior, too. 

1. Social Behavior 

• Goliath Frogs: These animals live isolated. They’re kind of shy and solitary. These frogs are excellent swimmers. They can live underwater for up to 30 minutes. Whenever they’re at risk, they jump into the water.  
• African Bullfrogs: Unlike Goliath, these species are territorial. They can become aggressive, especially during the breeding season. 

2. Eating Habits

• Goliath Frogs: Adult Goliaths are carnivores, insectivores, and molluscivora. They feed on insects, spiders, worms, small fishes or snakes, mollusks, crabs, and other crustaceans. However, tadpoles are herbivorous only. They feed on a single acoustic plant named Podostemaceae. 
• African Bullfrogs: Similarly, African bullfrogs are also voracious carnivores. They feed on insects, frogs, small mammals, and reptiles like snakes. Even they prey on birds, too!

3. Sleeping Patterns

Both of these frogs have interesting facts about sleep. 

• Goliath Frogs: Goliaths don’t have a sleep cycle. However, they rest during the day and become active during the night. Their eyes remain closed while taking rest. 
• African Bullfrogs: African bullfrogs also don’t go into a complete sleep state. However, they rest throughout the whole day. During rest, they relax their bodies with their eyes closed. 

Goliath Frog vs African Bullfrog: Reproduction Strategies and Lifecycle

The reproductive strategies and life cycles of African bullfrogs and Goliath frogs differ. These are some of the main distinctions between the two species:

Mating Season

Goliath frogs usually breed when the environment is dry, say July and August. They also breed during the short dry season of December and January. 

In contrast, African bullfrogs hibernate during the dry season for almost ten months. When rainfall occurs,  they emerge and breed. 

Mating Ritual 

Goliaths are the largest frogs and have unique mating behavior. Previously, people believed that they didn’t produce mating sounds at all. However, now scientists claim Goliath can also make small sounds like whistles or chirps. 

Male Goliaths create nests of large rocks beside rivers for their offspring. Then, the couple will enter their house, and the male will grasp the female in an amplexus position. Then, the lady frog will lay eggs, and the male will fertilize them. 

On the other hand, male African bullfrog make their territories in water bodies when they emerge during the rainy season. Then, they make loud sounds to attract their mates. This sound can be heard from several kilometers away, too. The female frog chooses the one who makes the loudest call. 

Female frogs enter the home, are intimate in the amplexus position, and lay eggs. Male sperm fertilize the egg on the external water surface. Both frogs are polygamous in terms of behavior. 

Gestation Period 

Goliath frogs have much longer gestation periods than African bullfrogs. Goliath passes 85-95 days in incubation, while the latter passes only two days to the hatching of tadpoles after fertilization of eggs. 

Litter Size 

Here, African bullfrog females win the game. Their litter size is about 4000 eggs. However, Goliath female frogs lay 3000 eggs in a single breeding event. Anyway, both of these frogs comprise larger litter sizes compared to other amphibians. 

Lifecycle Stage 

Both frogs develop through the following stages: eggs to larva to adults. However, the transition from larva to adult (metamorphosis) takes only 21 days in Goliath. African bullfrogs take a much longer time, approximately 14 to 16 weeks. 

Lifespan 

In the wild, Goliath Frogs often live between 10 and 15 years, depending on the environment and potential predators. In captivity, these species may live up to 21 years. 

Giant bullfrogs live longer. They have an average lifespan of 20 years in the wild and may celebrate 45+ birthdays in captivity. 

FAQs 

Let’s now investigate a few relevant queries regarding these enormous amphibians. 

Final Words

Both African bullfrogs and Goliath frogs are amazing creatures with distinctive traits and ways of behaving. Despite sharing the same classification as amphibians, they differ greatly in terms of their preferred environments, social behaviors, reproductive cycles, and morphological characteristics.