A small slender ranid frog with a pointed head, very long hind legs and reduced webbing. Males reach 37–41 mm (SVL), females 42 to 48 mm. The head length is 1.5 times the head width. The distance snout tip–nostril equals the distance nostril–eye. The distance snout-eye is up to two times the eye diameter. The tympanum reaches 0.66–0.75 of the eye diameter. Males have paired lateral vocal sacs whose slits point below the bases of the forearms. Below the eye, a glandular ridge stretches to the shoulder. Up to five pairs of longitudinal ridges are found on the back. One of them emerges at the posterior borders of the eye-covers, covering about 3/4 of the body length and extending further in a more or less discontinuous way. Between these ridges, a second pair runs from the vent to the center of the back. Another pair starts behind the eyes; this one stretches to the end of the body. A shorter pair is situated laterally to the above ridges, and all ridges are bordered by the proper dorsolateral ridges. The latter also emerge behind the eyes and stretch to the groin, but often they are less distinct or interrupted. The thigh bears 3–5 ridges, and additional ones are found on the shank which reaches 0.75 of the SVL. The foot, incl. the longest toe may surpass the SVL. 30–50% of the very long and slender toes are webbed. The inner metatarsal tubercle is distinct. A very small outer metatarsal tubercle may be present. Additional subdigital tubercles occasionally appear on the fourth toes, but they are not always distinct (Boulenger 1901, Perret 1979b).
Coloration: In alcohol, the basic color of the back is dark gray to olive brown. The dorsum shows at most several narrow black spots or lines. Large circular or square patches are absent. The area between the ridges is usually uniform dark. A black line runs from the snout tip across the eyes and ends on the flanks. An orange vertebral band or line is present. The dorsolateral ridges and the upper lip are yellow. The flanks above the said black line are light colored. On the thigh, a brown line runs from the groin to the knee. An irregular light line with dark borders runs along the posterior part of the thigh. Below this line, a less distinct light line is contrasted by several dark patches of variable size. 5–6 dark oval patches are present on the thighs. Bar-shaped markings are lacking. Similar patches appear on the inner and outer parts of the shanks. They tend to fuse into a continuous longitudinal line. A light longitudinal line may be present on the shanks, too. The anterior part of the vocal sac is black, the rest somewhat brighter. The throat is light colored. A black line stretches from the upper arm to the central part of the mouth, without reaching the latter. The remaining venter is yellowish white (Schmidt & Inger 1959, Perret 1979b).
Voice: The call has been described by Amiet (1974) under the name P. tournieri. 10–12 calls per second are uttered. Perret (1979b) describes the call as a nasal "kik" or "djitt".
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Angola, Cameroon, Cote d'Ivoire, Ghana, Guinea, Guinea-Bissau, Senegal, Sierra Leone, Uganda
Range: This species does not occur at Comoé National Park. As the first reliable revision has been published by Perret (1979b), it is rather difficult to evaluate older data. Frost (1985) only cites records from Guinea, Cameroon and Uganda. However, it has certainly been collected in other countries, too. The revision of the genus Ptychadena by Guibé & Lamotte’s (1957) has caused considerable confusion. In this study, the species is termed P. bibroni, a name that for a long period designated the West African subspecies of P. mascareniensis (refer to the P. bibroni and P. mascareniensis accounts). This species is treated separately in Guibé & Lamotte (1957). They, however, illustrate a syntype of P. stenocephala. In some older studies, detailed descriptions made it possible to decide which species were actually meant. Other authors are likely to have used the publications of Guibé & Lamotte then available which caused them to apply those erroneous names. In doubtful cases, I have preferred to mark the respective data by means of a "?". In particular, the following countries have been quoted: ?Senegal, ?Guinea Bissau, Guinea, ?Sierra Leone, Ivory Coast, ?Ghana, Cameroon, Uganda, ?Angola (Boulenger 1901, ?Barbour & Loveridge 1930a, Loveridge 1930, 1940, ?Parker 1936a, ?Mertens 1940, ?Monard 1940, Laurent 1952e, 1964b, Perret & Mertens 1957, ?Taylor & Weyer 1958, ?Schiøtz 1964a, b, Lamotte 1967b, Amiet 1973b, 1974b, Miles et al. 1978, Perret 1979b).
Habitats: Guibé & Lamotte (1957, 1958a) describe this frog, as P. bibroni, both as a forest–dweller (1957) and as a savanna species (1958a). According to Amiet (1973b, 1974b) and Perret (1979b), it inhabits marshy flooded grassland. High grass savannas are avoided. These authors expressly characterize this frog as a savanna species. Lamotte (1967b) quotes savanna regions adjacent to forests.
Life History, Abundance, Activity, and Special Behaviors
Biology: In Cameroon, P. stenocephala reproduces throughout the rainy season (May-October). The males call towards the end of the night (5–8 h a.m.) and almost to the afternoon during periods of heavy rainfall. However, single males reported to call at full moon in the early hours of the night do not match the above-mentioned observations (Amiet 1974b). In an earlier paper, Amiet (1973b) writes that these frogs are diurnal, calling from dawn till noon. The males are said to sit under vegetation near the water. Breeding habitats are temporary ponds (Amiet 1974b). According to Paulian & Vilardebo (1946), the diet includes young frogs and various arthropods.
This account was taken from Rödel, M.-O. (2000), Herpetofauna of West Africa vol. I. Amphibians of the West African Savanna, with kind permission from Edition Chimaira publishers, Frankfurt am Main.
For references in the text, see here
Rödel, M. O. (2000). Herpetofauna of West Africa, Vol. I. Amphibians of the West African Savanna. Edition Chimaira, Frankfurt, Germany.
Written by M.O. Roedel (roedel AT biozentrum.uri-wuerzburg.de), Post-Doc at the University of Wurzburg, Department of Animal Ecology and Tropical Biology, Wurzburg, Germany
First submitted 2001-05-07
Edited by Arie van der Meijden (2002-02-08)
Species Account Citation: AmphibiaWeb 2002 Ptychadena stenocephala <http://amphibiaweb.org/species/4955> University of California, Berkeley, CA, USA. Accessed Jul 11, 2020.
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Citation: AmphibiaWeb. 2020. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 11 Jul 2020.
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