The eye color is … These are much bigger in diameter than their eyes.
Both male and female bullfrogs have large tympanums relative to other species, but those of males are much larger than those of females. Both male and female bullfrogs can reach a body length of 6 to 8 inches. They have large eyes with almond shaped pupils. The top of a bullfrog is green, and the belly is cream or yellow colored. Upon reaching maturity, male bullfrogs develop yellow and gray markings on their throats.
The rear feet have webbing between most of the toes, but the front feet have no webbing. A bullfrog's head is broad and flat. The bullfrog is a powerful swimmer, with strong, long back legs that may measure from seven to ten inches and having very large webbed feet. Bullfrogs have short front legs, and long, muscular rear legs. The female's throat is white, whereas the male's throat is yellow.
The chins of males are darkly pigmented, with a distinctive yellow mottle. They are easily distinguished from females by the very large tympanic membranes that cover their ears. In females, the tympanic membrane is about the same diameter as the eyes.
Male Bullfrogs. The male's eardrums are larger than the female's …
Male bullfrogs are smaller than females, and have bright yellow throats. Female bullfrogs are larger in size than males are, and males' heads are more narrow.
Another anatomical difference between the sexes relates to the frogs’ tympanums, which are akin to human eardrums. Adult male bullfrogs are large, muscular and vocal.
A bullfrog's round eardrums, called tympanums, are on the outside of his body, behind his eyes.