Banded Rubber Frog

Phrynomatis bifasciatus is a medium-sized frog that can grow up to 75 mm. It has a moderately robust body, more elongated and depressed than many frogs. The body is carried high on its slender limbs when moving, which is generally by walking, or occasionally running, but not hopping. The head is mobile and able to move somewhat laterally. Eyes are relatively small and have circular pupils. Digit tips are expanded into truncated discs. Fingers lack webbing completely and toes have vestigial webbing (Wager, 1986; Passmore and Carruthers, 2005). The common name derives from the rubber-like appearance and texture of the frog's smooth and shiny skin, which feels dry when handled. This frog has shiny black or dark brown skin with continuous or interrupted vivid red or orange bands extending from the snout over the eyelids to the back of the body. There is also a large red or orange spot on the posterior dorsum, in the caudal region. Limbs have red bars or spots. Ventrally this frog is light brown or gray with dense, distinct white spotting (Wager, 1986; Passmore and Carruthers, 2005). Males have a black throat. (Wager, 1986; Zweifel, 2003). The tadpole of P. bifasciatus reaches 37 mm in total length, with a body length of 12 mm and tail length of 25 mm (Wager, 1986). It has a tail that narrows to a thin, whiplike flagellum (Wager, 1986). Eyes are at the sides of the head (Zweifel, 2003). Both external gills and suckers are present at hatching. The tadpole's appearance is unusual, with a pointed head and slit-like terminal mouth that lacks keratinized jaws, teeth, and papillae. The upper lip is straight and flat, while the lower lip is spatulate, shaped like a V and projecting slightly (Donnelly et al., 1990). No flaps are present on the lips, unlike the related species P. annectens, which has labial flaps on either side of the lower lip, adjacent to the infralabial prominence, and P. microps, which has a large flap on the upper lip (Donnelly et al., 1990). The spiracle is medial and opens near the vent (Donnelly et al., 1990) and is somewhat enlarged, at 2 mm wide (Wager, 1986). The body is mostly transparent, except for the coiled intestine, and has tiny black dots on the mid-back (Wager, 1986). Tail fins have black, sometimes red, narrow bands along the outside edges (Wager, 1986).This frog is collected for the pet trade (IUCN, 2006). The specific name "bifasciatus" refers to the two red stripes running down the back (Wager, 1986).

This frog occurs in a broad swath from southern Somalia southeastward to Angola, and extending southward into Namibia, Botswana, and South Africa. It inhabits open country grassland or savanna (Zweifel, 2003), up to 1450 m above sea level, and is also found in agricultural areas (IUCN, 2006). It can be found in loose sand under large rocks on dry hillsides, miles from the nearest water, in cavities of dead trees, and in holes in the ground or in a bank (Wager, 1986).

This species is nocturnal but may occasionally be seen in the daytime following a period of precipitation. Although it has expanded discs on the fingertips, it is generally found at or near ground level (Passmore and Carruthers, 1995). However, it is also an adept climber of trees and rocky walls (Wager, 1986). During the dry season it shelters underground in burrows in loose sand or earth, in termite mounds, or in cavities within dead trees (Wager, 1986; Passmore and Carruthers, 2005). Phrynomantis bifasciatus digs backwards to make its burrow, although it does not have specialized digging "spades" on the hind feet (Wager, 1986). This frog prefers to walk slowly rather than take long hops (Wager, 1986). Ants and possibly termites form a large part of the diet in this genus (Passmore and Carruthers, 2005). During the mating season, P. bifasciatus breeds in temporary rain pools (Zweifel, 2003). These frogs will gather in a large chorus, which may sometimes consist only of this species (rather than a multi-species group) to breed soon after a rainstorm (Wager, 1986). While swimming, they inflate and float, with all four legs kicking over short distances; in contrast, over long swimming distances they kick only with the back legs (Wager, 1986). Males call from shallow water or the water's edge, remaining exposed while calling (Passmore and Carruthers, 2005). The call is loud and audible for over a kilometer, and consists of a melodious high-pitched "porreeeee," or a slightly lower "perrooooo" with a duration of about 2 seconds and a pause of about 5 seconds in between calls (Wager, 1986). Amplexus is axillary (Zweifel, 2003). Females deposit a clutch of about 600 eggs (Wager, 1986) up to 1,500 eggs (Zweifel, 2003). The egg mass is attached to floating vegetation (Wager, 1986). Eggs have a diameter of 1.3 mm within jelly capsules of 5 mm, and the whole egg mass is about 75 mm in diameter (Wager, 1986). Tadpoles hatch after four days (Wager, 1986). The tadpole of P. bifasciatus is a midwater nektonic filter-feeder (Passmore and Carruthers, 2005). The V-shaped lower lip constantly moves in and out, to suction in water containing microorganisms such as unicellular algae, desmids, diatoms, and Volvox (Wager, 1986). Since a large amount of water needs to be suctioned, the spiracle through which the water enters is correspondingly enlarged at 2 mm in width (Wager, 1986). During filter-feeding, the tadpole suspends itself motionless at a steep angle in the water column, except for the tail tip vibration and sucking mouth (Wager, 1986). However, it is also capable of rapid and agile movement (Wager, 1986). Larval development takes approximately a month (Wager, 1986). Metamorphosis occurs at a body size of about 13 mm (0.5 inches) (Zweifel, 2003). The secretions from P. bifasciatus skins can cause skin irritation in humans (Jaeger, 1971), and are lethal to many other anurans, in addition to being highly toxic to mammalian heart cells (Passmore and Carruthers, 2005). The mechanism of toxin action appears to be through potassium channels (Passmore and Carruthers, 2005). Frogs of the families Microhylidae and Hemisotidae have the ability to aim their tongues laterally, independent of head or jaw movements, when shooting them out to capture prey. Phrynomantis bifasciatus shows the most extreme lateral aim of any frog known, extending its tongue over an arc of more than 200 degrees in the frontal plane. This means P. bifasciatus can extend its tongue to capture prey at an angle of greater than 90 degrees from the midline of the head (in other words, it can even aim slightly backwards). This lateral tongue aiming is controlled by a muscular hydrostatic mechanism (in common with other frogs of the families Microhylidae and Hemisotidae) (Meyers et al., 2003).

This species does not appear to be threatened and can tolerate a range of habitats (IUCN, 2006).

Maximum longevity: 10.3 years (captivity)

The banded rubber frog (Phrynomantis bifasciatus) is a species of frog in the family Microhylidae. It is found in central and southern Africa. Its natural habitats are dry savanna, moist savanna, subtropical or tropical dry shrubland, subtropical or tropical moist shrubland, subtropical or tropical dry lowland grassland, subtropical or tropical seasonally wet or flooded lowland grassland, subtropical or tropical high-altitude grassland, intermittent freshwater lakes, intermittent freshwater marshes, arable land, pastureland, water storage areas, ponds, and canals and ditches. The female can reach a maximum size of 65 mm whereas the tadpoles can reach a size of 37 mm. The maximum size of the male is yet unknown, but sizes differ from 45 mm to 68 mm.

Characteristics: Greyish underside with white spots (sometimes not apparent). Skin is smooth and rubbery. Arms and legs have reddish spots. To distinguish between gender, the male has a darker throat.