Phrynobatrachus cornutus (Boulenger, 1906)
The specific name is derived from 'cornutus' (Latin) meaning horned and refers to the prominent eyelid spine of this species.
Phrynobatrachus cornutus is a small sized (snout–vent length < 20 mm) species of puddle frog distributed across parts of Cameroon, Gabon, Congo, the Central African Republic, and Bioko Island (Equatorial Guinea). Members of this genus are identified by the presence of a midtarsal tubercle, elongate inner metatarsal tubercle, and outer metatarsal tubercle. In this species, there is a narrow ridge connecting the tarsal and inner metatarsal tubercles. This species also exhibits a prominent eyelid spine, absent or rudimentary pedal webbing (3.75-4 phalanges free on digit IV), an indistinct tympanum, and digits expanded into small discs. The venter is white with large, round spots.
The IUCN Red List (2009) categorizes this species as Least Concern in view of its wide distribution, tolerance of a degree of habitat modification, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category (Amiet and Burger, 2004).
It occurs in Korup National Park (Cameroon), Lope-Okanda Faunal Reserve within the Petit Loango National Park (Gabon), and presumably in several other protected areas (Amiet and Burger, 2004).
It is presumably adversely affected by the loss of forest habitat for agriculture, logging and human settlements (Amiet and Burger, 2004).
Populations of this species are decreasing (Amiet and Burger, 2004).
This small-sized species exhibits a prominent eyelid spine, rudimentary pedal webbing (3.75-4 phalanges free on digit IV), an indistinct tympanum, digital discs, and a narrow ridge connecting the tarsal and inner metatarsal tubercle. The venter is white with large, round spots.
This species is morphologically most similar to those small species exhibiting an eyelid spine, including P. annulatus, P. calcaratus, P. taiensis and P. villiersi. All these species can be considered small in size and have absent or rudimentary webbing. Digital discs are absent in P. calcaratus and P. taiensis. The throat in male P. calcaratus is also dark in color. Digital discs are present in P. annulatus and P. villiersi, as well as P. cornutus. The venter of P. annulatus is white with dark rings with white interiors. The ventral pattern of P. villiersi includes two longitudinal, thick and parallel dark brown to black bands across the throat, and large spots on the belly. The cream-colored background often forms a cross on the chest where the spots are absent.
This species has a moderate-sized head, approximately as long as it is broad. The snout is rounded with an obtuse canthus rostralis and a concave loreal region. The nostril is slightly closer to the snout tip than the eye. The interorbital space is narrower than the upper eyelid. The typanum is indistinct. The fingers are rather short; finger I and II are approximately equal in length. Manual webbing is absent; pedal webbing is absent or rudimentary with 3.75-4 phalanges free on digit IV. Tips of both fingers and toes dilated into small discs. A midtarsal tubercle, elongate inner metatarsal tubercle, and metatarsal tubercle are present with the former two connected by a narrow ridge. The distance between the two metatarsal tubercles equals the distance between the inner and outer tubercles. The tibio-tarsal articulation reaches the eye. Dorsum has prominent warts of unequal size. A prominent spine is present on the posterior eyelid. A conical median papilla is present on the tongue.
The dorsum is grey with darker spots, and more or less distinct cross-bars on the limbs. A light vertebral stripe may be present. The posterior thighs with a more or les distinct whitish dark-edged stripe. The upper and lower mandible are white. The venter is white with large, round spots.
Boulenger (1906) reports that the snout-vent length of the holotype is 20 mm. Perret (1988) reports SVLs ranging from 14–16 mm in males and 18–20 mm in females.
This species occurs from southwestern Cameroon south through Gabon to southwestern Congo, inland as far as southwestern Central African Republic, and on the island of Bioko (Equatorial Guinea). It is presumed to occur in mainland Equatorial Guinea in the Rio Muni region (Amiet and Burger, 2004).
It is a species of lowland rainforest, surviving to some limited extent in degraded forest. It is often found by tracks and small marshes in the forest. It breeds in small pools (Amiet and Burger, 2004).
It is a common species (Amiet and Burger, 2004).