|
Background Information
The North American Bullfrog (Rana catesbeiana) is the largest frog native to North America. Its natural range is
the Eastern and Central United States. With its large, meaty legs, it has been introduced to many other areas as a food
source.
|
| A bullfrog tadpole |
Size
|
| An adult bullfrog |
During its tadpole stage , the bullfrog can grow to be between 4 to 6.7 inches (10.2 to 17.1 cm.) long.
Bullfrogs can grow to enormous proportions. An adult can grow to a length of between 3.5 to 8 inches (9 to 20 cm.)
in length. The legs of this frog can add another 7 to 10 inches (17 to 25 cm.). The bullfrog can also grow to
a size of up to 1 pound (0.5kg.). Bullfrogs can jump from 3 to 6 feet in a single leap.
Lifespan
The bullfrog will spend between 1 to 3 years in its larval (tadpole) stage. It will grow to be around 4
or 5 years old. There are records that indicate that the frog can survive to be up to 6 or even 7
years old.
| Male bullfrog |
|
Identification
| Bullfrog caught by little girl. |
|
| It is clear from this picture that bullfrogs can grow to enormous proportions |
Other than its large size, there are several traits that can assist you in identifying the bullfrog and determining its
sex.
To identify the bullfrog, look at the ridge over its eardrum (tympanic membrane). On the bullfrog, it goes
straight over the tympanum and then curves down, around the membrane. Click here to open a picture that points out the identifying marks. You can see in this picture that the ridge forms a distinctive
curve that is characteristic of the bullfrog.
| Female Bullfrog |
|
To determine the sex of a bullfrog, there are two main indicators. First and most obvious is the tympanic membrane. In
the female, this mambrane is aproximately the same size as the frogs eye. In the male, this membrane is usually larger than
its eye.
The second method of sexing bullfrogs is less relyable and more difficult to use. This method uses the color under the
frogs chin. In the male, this area is usually a light yellow while in the female, it is not. This method is not only less
relyable (due to normal skin variation and algae growth) but the frog usually needs to be captured before the underside of
its chin can be observed. The tympanum method can not only be used at a distance but it is also possible to use it when the
frog is in the water.
A link to some other interesting stuff.
|
