Southern Bullfrog

Rana grylio Stejneger

Colour: Head and shoulders usually vividly green; olive posteriorly, with many irregular black spots. The whole frog may be olive or rich dark brown. Ear orange-brown, with green centre. Middle and posterior back may have four longitudinal bands of bright orange-brown, alternating with bands of olive. Small black spots on legs. Underparts light, unspotted, except posteriorly. Throat of male bright yellow. Undersurfaces of legs may be mottled and reticulated in coarse pattern with black and yellow.
Measurements: Size large, i. e. length 4 to 5 inches. Head long, its length contained little more than two and one-half times in the total length. Legs medium in length; length to heel equals length of frog forward to a point anterior to the eye. Tibia same length as femur.
Structure: Skin smooth on the head, slightly rougher elsewhere on upper parts; when examined closely, seen to be everywhere finely pitted. Head with pointed outlines, gradually diverging backward to the widest part of the head in the region of the middle point of the ear. Eyes greatly elevated and unusually large. Space between the eyes narrow. Ear of male greatly larger than the eye (twice the diameter) that of the female about equals the eye in diameter. Nostrils prominent, near together; slightly nearer to the muzzle than to the eye. Elevated fold of skin over the ear to the shoulder. A groove runs along the midline of the back. Arms and legs very muscular. Fingers long. Foot broad; webs large, extending fully to ends of toes (all except fourth toe relatively longer than corresponding toes of Rana catesbiana). No outer sole tubercle; inner sole tubercle small. Palm tubercles and all subarticular tubercles small.
Range: Reported from Florida (Pensacola, Kissimmee, Ozona) and Mississippi (Bay St. Louis).

This frog was first found in 1900 at Bay St. Louis, Mississippi, but was not recognised as a distinct species until more material was obtained some time later from Kissimmee, Florida. The frog might be unknown now, if it had not been for the persistent reports of its voice. The sounds produced are said to resemble the grunting of a herd of pigs, thus differing entirely from the familiar bass notes of the Common Bullfrog.

The frog is really very different in appearance from the Common Bullfrog, not resembling it in shape, porportions of body, or colouring. The long, narrow, pointed head, with its large eyes set close together, tell the story at once. But other evidences lie in the ratio of the lengths of head and body in the greater length of toes (except the fourth) and in the finely pitted texture of the skin. In addition to all these points, there is that of colouration. Rana grylio, in its brilliant phases of colouring, furnishes one of the most charming studies in blended shades of yellow, green, and brown, all of these colours showing metallic lustre. Especially beautiful is the colouring of the undersurfaces. This species shows great power of changing colour. It may be brilliant or dull, light or dark, green or brown. There may be green as vivid as that of the anterior head region on the breast, at each side, about the arm insertion.

The frog is shy and wary, and is seldom seen, except by those who are looking for it. It lives in deep water, among pond-lilies and other vegetation of the lake. It seldom leaps; its strong instinct, when frightened, is to dive and hide.

Rana grylio shows close relationship to Rana virgatipes of New Jersey in shape and proportion, metallic colouring, texture of skin, large size of eyes and ears, in lacking the lateral folds, and in aquatic habits.