A small ranid with a moderately pointed snout. Adult males measure 25–32 mm (SVL), females 25.5–36 mm. Four pairs of symmetrically arranged longitudinal ridges on the back. The third pair, counted from the vertebra, covers just half of the back length, whereas the rest stretch from the eye to the end of the body. All these ridges are continuous. On the flanks, some warts form a short ridge. A short supratympanal fold is present. The tympanum is clearly visible, reaching 0.7–0.9 of the eye diameter and appearing slightly concave. Males with paired lateral vocal sacs, enlarged thenar tubercles and swollen first fingers. The end of the slits of the vocal sacs are situated beneath the armpit. Sturdy, moderately long hind limbs. The thighs and shanks reach 0.4–0.6 of the SVL, and the foot, incl. the longest toe, 0.7–0.8 of the SVL. The inner metatarsal tubercle reaches 0.3-0.5 of the length of the shortest toe. Webbing formula of the hind limbs: 1 (0.5) or (0), 2 i/e (1–0.5) or (1–0), 3 i/e (1–0.5) or (1–0), 4 i/e (1), 5 (0,5) or (0). Toe-tips and finger-tips not enlarged.
Lamotte (1967a) gives up to 36 mm (SVL) for males and up to 40 mm for females. Poynton (1964a) even gives 41 mm for females. Passmore & Carruthers (1995) figure a specimen with three free phalanges on the fourth toe.
Voucher specimens: SMNS 8950 1–7; SMF 78633 + numerous specimens without number.
Coloration: Besides animals showing a dark brown basic color, against which other markings hardly contrast, there are also frogs with clear green basic color and any kind of transitional coloration. A fine line or a broad vertebral band, lined by two ridges, often runs along the vertebra. Both the line and the band may be yellow to red. Most animals bear a dark orange line. On green frogs, the vertebral band, the lateral ridges and the upper arms are often colored red orange. The respective animals were exclusively breeding males. The six median dorsal ridges bear numerous dark patches which may equally expand to the areas between the ridges. The lateral ridges are paler or even white. These light markings partially continue across the part of the iris situated above the pupil, ending at the nostril. A pale patch which forms an extension of the above-mentioned markings adorns the groin and the inner border of the thigh. The posterior part of the outer face of the thigh shows a continuous, partially undulating yellow line with broad dark brown borders. The basic color of the extremities, snout and temple is similar to that of the back. Several dark olive to black transverse bands are present on the extremities. The upper arm is usually paler and lacks bands. The upper lip is either white or dark. Hands and flanks are dirty gray. Dark spots may be present on the flanks. The line on the flank composed of numerous warts is black or at least bordered black. Single males have some black spots near the slits of their vocal sacs. The webs are usually dark, with only very few individuals lacking this coloration. According to Passmore & Carruthers (1995), 2–3 parallel pale lines adorn the outer parts of the thighs. In alcohol the markings generally turn somewhat less conspicuous, but they are still discernible. Yellow parts turn white, and the other colors are replaced by various shades of brown.
Voice: I have recorded two different calls uttered by P. pumilio. The first is a simple creaking sound uttered exclusively by solitary animals. It lasts 0.17–0.19 sec, the dominant frequency ranging from 2.6 to 4.8 kHz. Like the second call, it comprises numerous short pulses which might initially be produced at shorter intervals (0.02 sec) than later on. The second call, a dry rattling sound, is supposed to be the real advertisement call which usually can be heard where many males have formed a chorus. It may develop from the former call and consists of two different elements which are repeated alternately. The shorter one lasts 0.26 sec, frequency: 3.6–4.3 kHz, and the second lasts 0.29 sec, frequency: 2.2–4.6 kHz. The pauses between these call elements last about 0.1 sec.
The call published by Amiet (1974b) lasts approx. 0.3 sec, its dominant frequency being 2 kHz. Passmore & Carruthers (1995) figures a call lasting approx. 0.2 sec at a frequency of 0.8–3.8 kHz. A short creaking sound which may turn into a very intensive call has been described by Passmore (1977) for Ptychadena oxyrhynchus. This author supposes that this call is meant to "check" the presence of other males and to "assign" calling sites to those males who arrive later.
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Angola, Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Congo, the Democratic Republic of the, Cote d'Ivoire, Ethiopia, Gambia, Ghana, Guinea, Guinea-Bissau, Mali, Niger, Nigeria, Senegal, Sierra Leone, South Sudan
Range: According to Frost (1985, incl. P. taenioscelis), from Senegal to Ethiopia, stretching southward across eastern R.D. Congo to Mozambique, Zimbabwe and Zambia. In particular, the species has been recorded from the following countries: Senegal, Sierra Leone, Mali, Ivory Coast, Benin, Nigeria, Cameroon, Congo, R.D. Congo, Central African Republic, Ethiopia, Tanzania, Malawi, Zambia, Botswana, Mozambique, South Africa, Angola, Namibia (Guibé & Lamotte 1957, Schmidt & Inger 1959, Schiøtz, 1963, 1964b, Laurent 1964b, Poynton 1964a, c, 1966, 1970, 1991, Perret 1966, 1979b, Barbault 1967, 1974d, Lamotte 1967b, 1969, Stewart 1967, Walker 1968, Broadley 1971, 1991, Mertens 1971, Amiet 1973a, Stevens 1974, Böhme 1978, Miles et al. 1978, Joger 1981, 1982, 1990, Poynton & Broadley 1985b, Branch 1988, Lambiris 1988, Channing 1989, Largen & Dowsett-Lemaire 1991, Channing & Griffin 1993, Poynton & Haacke 1993, Simbotwe & Mubemba 1993, Bourgat et al. 1996, Rödel 1996, 1998b, Joger & Lambert 1997, Largen 1998). Hughes (1988) does not quote this species for Ghana, nor does Lambiris (1989) quote it for Zimbabwe.
Habitats: At Comoé National Park, this species has particularly been found in some ponds on the Gansé plain. The spawning sites are usually shallow ponds and ditches which are densely vegetated. During the dry season, this species is also encountered on the river banks. At least the borders of rainforest are inhabited, too. The habitats mentioned in the literature comprise savannas, grassland, humid and dry forests, gallery forests and the banks of all sorts of waters (Schiøtz 1963, 1964b, Perret 1966, Lamotte 1967b, Walker 1968, Poynton 1970, Amiet 1973a, Joger 1981, 1982, Poynton & Broadley 1985b, Böhme & Schneider 1987, Lambiris 1988).
Life History, Abundance, Activity, and Special Behaviors
Spawn: So far unknown; most probably similar to that of Ptychadena bibroni. Passmore & Carruthers (1995) report that Ptychadena species generally split up their clutches. The eggs either float at the surface or sink to the bottom.
Tadpoles: Unknown from Comoé National Park. The tadpoles found in a tyre at the fringe of the Tai National Park presumably belong to this species, as adult frogs were heard calling from that tire every night. The larvae were still very tiny and most similar to those of P. bibroni. Lamotte et al. (1995) described tadpoles of this species as P. taenioscelis. It is a typical Ptychadena larva with an ovoid body. The length of the tail almost doubles that of the body. The tail fin is unpigmented and rather narrow, its dorsal part being somewhat broader than the ventral one. Its borders converge evenly towards the tip. The said authors give the following keratodont formula: 1 / 1+1 // 2. The TL of the largest tadpole, whose hind limbs had already developed, was 43.5 mm (BL: 15 mm). Metamorphosed frogs measure about 12 mm.
Biology: I observed P. pumilio during the rainy season, particularly in the above-mentioned region. Like P. bibroni, this species spends the dry season on the river banks. As it always occurs together with the latter species, the identification of its eggs and tadpoles has proved to be very difficult. Adult frogs never spawned in captivity. The males call from shallow water or from the banks in the dusk after rainfall. They usually hide under vegetation. However, some males also call while they are floating at the water surface. A case of mismating with a female P. bibroni was observed once. Passmore & carruthers (1995) give a interesting observation: P. pumilio calls between 3 p.m. and 10 p.m., whereas P. oxyrhynchus is heard between 11 p.m. and 4 a.m. so that the two species don’t overlap acoustically. Whereas P. bibroni dominates in large parts of the national park, where P. pumilio has been observed very rarely, it is outnumbered by the smaller species in the ponds of the Gansé plain. At Lamto, the diet of this frog comprises mainly spiders and orthoperans (Barbault 1974d).
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 2001-05-02
Edited by Arie van der Meijden (2002-02-08)
Species Account Citation: AmphibiaWeb 2002 Ptychadena pumilio <http://amphibiaweb.org/species/4951> University of California, Berkeley, CA, USA. Accessed Dec 17, 2018.
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Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 17 Dec 2018.
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