Amphibians · Anura · Ranidae

American Bullfrog

Lithobates catesbeianus

Least Concern

The species is abundant and widely distributed; it faces no significant short-term risk. See full glossary

The American bullfrog is a species of anuran amphibian belonging to the family Ranidae. It is large, measuring between 10 and 20 cm from snout to vent and weighing between 60 and 900 g. Its larvae are exceptionally large, measuring between 15 and 18 cm. Its dorsal colour ranges from pale or olive green to greenish brown, usually with green or brown blotches. The head is broad and flat with a fold of skin running behind each eye to the eardrum and around it. The belly is whitish with grey markings. The hind legs have dark bars or blotches. The toes of the hind feet, except the fourth, are webbed. In males the eardrum is larger in diameter than the eye and has a dark rim; in females it is the same size as the eye.

Weight

300 g – 800 g

Size

9 cm – 20 cm

Lifespan

10 years

Diet

Carnivore

Feeds mainly on other animals.

Activity

Nocturnal

Active mainly at night.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Easy

FreshwaterCarnivore Nocturnal Solitary Amphibian Freshwater

35countries 29parks 7dive sites11same family

Fun facts

It is on the IUCN list of the hundred most damaging invasive alien species in the world: it has become established in more than forty countries and preys on or displaces the native amphibians wherever it arrives.
It is a healthy carrier of the chytrid fungus responsible for the global decline of amphibians: the species tolerates it without falling ill and spreads it to native populations that have no defences, a role as vector that greatly worsens its impact.
In Spain there are isolated feral populations and it is on the catalogue of invasive alien species, with protocols for immediate eradication whenever it is detected.

Life cycle & biology

Skeleton type: Vertebrate - internal bony skeleton (amphibian)
Habitat & environment: Lagoons, reservoirs, slow rivers and permanent wetlands; native to eastern North America
Sexual maturity: 3.5 years
Gestation / incubation: 4 days
Litter / clutch size: 20000 eggs

Sources consulted: https://es.wikipedia.org/wiki/Aquarana_catesbeiana