Allen's Slippery Frog

general

This species is named for Dr. Glover Allen, who first collected it on July 19, 1926 (Barbour and Loveridge, 1927).

African Amphibians

morphology

The head is rather short and broad and the eyes are positioned rather dorsolaterally (Barbour and Loveridge, 1927). The snout is rounded and is about 1.5 times longer than the diameter of the orbit. The tympanum is small and indistinct, and its diameter is about one third that of the orbit. The vomerine teeth in Conraua alleni form two oblique rows; anteriorly, they touch the inner posterior edge of the choanae, and they converge posteriorly (Loveridge, 1941). The species exhibits a strongly developed fringe on the third finger and no dermal fold on the forearm (Parker, 1936). A conspicuous groove runs from the posterior border of the eye to the insertion of hind limb. The body is strongly depressed and rather Xenopus -like. The fingers, four in number and of equal length, are long, slender and poorly developed. The fingers have sharp apices that are probably tactile, another Xenopus -like feature. The thighs and tibia are expanded and depressed. The feet are large and completely webbed. The toes are long and slender and the tibio-tarsal articulation of the adpressed hind limb reaches the posterior border of the eye (Barbour and Loveridge, 1927). The tips of the toes are dilat

African Amphibians

morphology

In dorsal view, the sphenethmoid is visible between the nasals and frontoparietals. The nasals do not meet medially, and the zygomatic ramus of the squamosal does not project anteriorly to meet the postorbital process of the maxilla. An otic flange projects medially from the corpus of the squamosal and dorsally invests the crista parotica. The articulation between the maxilla and premaxilla is typical of most neobatrachians in that the articulation does not seem to be ossified and probably allows a relatively high degree of motion of the premaxilla. The cartilaginous plate of the Y-shaped omosternum is expanded distally, achieving a width equal to that of the proximal heads. The metasternum is approximately twice as long as it is wide. The sternal plate is bilobed and projects posteriorly. The scapula is robust, nearly twice as wide as it is long (Sheil, 1999). The distal ends of the terminal phalanges of the fingers and toes are rounded, but with lateral extensions, making the outline of the distal phalanx mushroom-shaped in appearance (there is no median notch) (Clarke, 1981).

African Amphibians

biology

Conraua alleni lives in the vicinity of fast-flowing streams within rainforests, ranging from northern Sierra Leone, through southern Guinea and Liberia to southwestern Côte d'Ivoire. The species exhibits vomerine teeth in two oblique rows, a small and somewhat indistinct tympanum, and a strongly developed fringe on the third finger. No dermal fold is present on the forearm. The dorsum is ashy gray with five slighly darker areas, the limbs are mottled and irregularly cross-barred with dark gray on the light gray field, and the venter is immaculate white.

African Amphibians