BiologyCoachOnlineBlog

In honor of national Save the Frogs Day, we would like to shine the spotlight on the bullfrog.

The American bullfrog (Lithobates catesbeianus) is member of the family Ranidae (e.g. “true frogs”;). The bullfrog has an olive green back, brownish-blotched sides, and a white underside spotted with yellow or grey. The bullfrog has a characteristic bright green upper lip and males have yellow throats.Bullfrogs inhabit the edges of large, permanent water bodies including swamps, ponds, and lakes. Males defend territories during the breeding season and his call is reminiscent of the roar of a bull (hence its common name). Bullfrogs are native to the southern and eastern parts of the United States and Canada. However, they have been introduced across other parts of North, Central, and South America, Western Europe, and parts of Asia. In fact, the bullfrog is harvested for use as food in many areas (including North America).

Bullfrogs are sexually dimorphic with males being smaller than females and having yellow throats. The tympanic membranes of males is larger than their eyes while the tympani of females are about the same size as the eyes. Bullfrogs measure about 3.6 to 6 in (9 to 15 cm) from snout to vent. They grow fast and large mature individuals can weigh more than a pound (500 grams). Further, some large bullfrogs have weighed in at as much as 1.8-pounds (800 grams) and have measured up to 8-inches (20 cm) in length.

Bullfrogs have a prolonged breeding season with males engaging continuosly while the receptivity of females is sporadic throughout the breeding season. The sex ratio is generally skewed toward males. These behaviors cause male-to-male competition to be high within the bullfrog population and sexual selection for females to be quite intensive.