American Bullfrog

(Lithobates catesbeianus) or the American Bullfrog as it is more commonly known is a member of the true frog family found natively in Eastern North America. With its large size compared to other frog species the species is able to inhabit a wide variety of aquatic environments with relative success. The American Bullfrog gets its name from the male call during breeding season resembling a bulls bellow.

Scientific Classification

image = North-American-bullfrog1.jpg
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Family:	Ranidea
Genus:	Lithobates
Species:	L. catesbeianus
Source: Integrated Taxonomic Information System

Description

The American Bullfrog has an olive-green coloring on the dorsal surface (backside) which may also include dull brown mottling or banding patterns ending at the top lip. The ventral surface (belly) typically appears as an off-white color with gray or yellow blotchy patches that end at the bottom lip. American Bullfrogs possess extremely small teeth that only functions to grasp objects. The eyes notably have horizontal pupils and a brownish iris. The hind legs possess webbing between the toes while frontal toes are un-webbed.

Habitat

While the American Bullfrog's natural habitat consists along the American Atlantic coast, it has also been introduced to western states such as Colorado and Nebraska, Nevada, California, Oregon, Washington, Hawaii, Arizona, and Utah and is considered an invasive species there. The American Bullfrog can also be found in other countries such as Dominican Republic, Jamaica, Italy, the Netherlands, Belgium, France, Cuba, and Mexico. [3]

Diet

The Bullfrog is known to eat a variety of organisms most typically being invertebrates including species of snail, worm, and insect. However due to the opportunistic behavior of the American Bullfrog the species has been dissected and found to eat species of rodents, small snakes and birds, and are even found to be cannibalistic. This feeding behavior is a major factor into the American Bullfrog being observed as invasive due to the introduction of the species affecting native species of salamanders and other smaller amphibians.

Feeding

American Bullfrogs are observed to be ambush and opportunistic predators, feeding on a variety of animals unsuspecting of their presence. Once its prey has been located it moves towards the prey using a series of hops to sneak up on its meal. Using its tongue and strong bite from the jaw smaller prey are consumed and engulphed using its mouth. Larger prey that are not able to fit in the American Bullfrogs mouth have been observed to be assisted using its hands, with larger prey observed to be asphyxiated after a successful catch as a defense mechanism. This behavior mimics other forms of feeding from other frogs, most notably a wood frog .

Ecology

American Bullfrogs are an essential prey item for many birds, predatory fish, otters, and other amphibians. American Bullfrog eggs are famously bad-tasting to many predators that typically consume frog and fish eggs as part of their diet. However, those that aren't deterred by the taste tend to have an easier time spotting out Bullfrog young as tadpoles due to their activity. Bullfrogs tend to be loud when attacked by a predator, warning other bullfrogs in the area to the potential danger where many will retreat to deeper waters.

References

[3] Crayon, John J. (2009-12-03). "Lithobates catesbeianus (=Rana catesbeiana) (amphibian)". Global Invasive Species Database. Invasive Species Specialist Group