A ranid with a pointed head and very long hind legs. The SVL of males is 43–50 mm, whereas females measure 51 to 56mm. The tympanum is well defined, reaching 0.8–1.3 of the eye diameter. A clearly visible supratympanal fold is present. Males with paired lateral vocal sacs. Rather flat dorsal ridges are always present, yet often discontinuous. If continuous ridges are present, these form three pairs emerging behind the eyes. The two outer pairs fuse on the last third of the back. The remaining four ridges stretch further to the end of the body. Additional short ridges may appear on the flanks. Small warts occasionally form short ridges. The rest of the skin is usually smooth. The small inner metatarsal tubercle reaches just 0.3–0.4 of the shortest toe length. Thighs reach 0.6 of the SVL; shanks 0.7; the foot, including the longest toe, 0.9 of the SVL. Toe-tips and fingertips are not expanded. Webbing formula: 1 (0), 2 i (0.5) or (1), 3 i (1), 4 i/e (0.5) or (0), 5 (0).
Loveridge (1955a) and Perret (1966) give 43–55 mm (SVL) for males and 53–63 mm for females. Chabanaud (1921) quotes a male measuring 55 mm.
Voucher specimens: The one specimen collected in the Comoé National Park was lost. Additional examined specimens: ZFMK 42263 Azagny National Park, 42162–164 Tai National Park, both Ivory Coast, specimens from Tai National Park without number.
Coloration: Snout and back are bright brown and are scattered with numerous, but inconspicuous, dark spots. A dark brown marking, resembling an hour-glass, extends from the eyes to the vent. However, this marking is not always well-defined. On the flat ridges, some red warts are often discernible. The latter may also appear on the eyelids and shanks. Dark patches occasionally present next to the ridges. The upper border of the iris is silver, the rest is black, similar to the lateral snout and temporal regions. The black band of the snout and temporal region is bordered dorsally by a somewhat brighter line. The black lateral line stretches to the groin, showing a slight incision at the base of the arm. Some dark patches appear on the gray brown extremities. Five distinct black bars are usually present on the thighs and shanks. The venter is white or yellow. The borders of the lower jaw bear some dark patches. The webs are darkly pigmented. Juveniles have a bright yellow venter.
Loveridge (1955a) quotes green vocal sacs, a pale yellow throat and a yellow venter. A similar description was published by Chabanaud (1920), but this author quotes a white venter and a yellow iris. In alcohol, the colors of animals from southern Ivory Coast appeared just a little faded.
Voice: Unknown at Comoé National Park. At Tai National Park, it is similar to that of P. bibroni. The call seems to be somewhat shorter. Schiøtz (1964c) gives a sonagram that shows a sequence of single calls comprising two harmonies from 0.6–3.1 kHz. The call duration is approx. 0.2 sec.
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Cameroon, Congo, Gambia, Ghana, Guinea, Liberia, Nigeria, Senegal, Sierra Leone
Range: According to Frost (1985) and Perret (1986), the range stretches from Sierra Leone to Nigeria. Schiøtz (1967) even includes Congo. Reliable records has been published from the following countries: Sierra Leone, Guinea, Liberia, Ivory Coast, Ghana, Nigeria, ?Cameroon, ?Congo (Peters 1870, Chabanaud 1920, Loveridge 1941, 1955a, Paulian & Vilardebo 1946, Guibé & Lamotte 1957, 1958a, Schiøtz 1963, 1964a, b, c, 1968, 1967, Perret 1966, 1981, Barbault 1967, Euzet et al. 1969, Maeder 1969, Hoogmoed 1980, ?Murith 1981, Hughes 1988, Rödel 1996). I saw a photograph of this species, taken by Joger in Senegal. Perret (1966) mentioned this species as a forest dweller in Cameroon, as did Nieden (1903, 1910b) and Barbour (1911). However, Perret doesn’t cite it any longer for Cameroon in 1981. Other authors reporting on Cameroon (e.g. Amiet, Böhme, Joger) do not mention P. longirostris either. It is quoted for R.D. Congo by Laurent (1956a, 1958a). As Lamotte (1969) reports on a savanna morph (schubotzi?), but exclusively quotes P. longirostris, it is not quite clear whether he has found both species, or to which species his records must be actually assigned.
Habitats: So far, I have found only a single individual in the Comoé National Park at a savanna pond in close vicinity of gallery forest. Over the rest of its range, P. longirostris has mainly been found in the rainforest zone (Loveridge 1955a, Schiøtz 1964c, 1967, Perret 1966, 1981, pers. obs.) Loveridge (1955a) quotes a car track within a forest. Lamotte (1967b) quotes forest habitats, but single specimens collected in the savanna. It is not clear whether the latter are actually P. schubotzi. The latter species was subsequently quoted for this region by Barbault (1984). Schiøtz (1963) writes that P. longirostris also invades dry forests in Nigeria, whereas Hughes (1988) writes that it is found in any habitat in Ghana. Murith (1981) quotes car tracks and the water reservoir of a plantation. The habitats are said to lack a "canopy".
Life History, Abundance, Activity, and Special Behaviors
Tadpoles: The larvae collected at a rock-pool possibly belong to this species, as freshly metamorphosed frogs with the features of adult P. longirostris were found at this site, as well (but, see below). These tadpoles did not differ significantly from those of P. bibroni. Metamorphosed frogs measured 12–13 mm. Tadpoles from Tai National Park had the keratodont formula 1 / 1+1 // 2, one lateral and two caudal rows of papillae. The horny teeth were long and slender, their shovel ending in 5–6 tips. Nine examined specimens (stage 25) had a body length of 4.7 mm.
Biology: At Comoé National Park, only one subadult specimen has been found so far, so that a detailed comment on its biology is impossible. The small inner metatarsal tubercle possibly indicates that this frog cannot burrow itself into the ground. It is supposed to spend the dry season in refuges at the banks of rivers. I caught the above-mentioned individual in a shallow savanna pool with scanty vegetation containing just 50l of water.
The above mentioned young frogs (see "tadpoles" paragraph) were sitting at the border of a shallow rock-pool lacking any vegetation, situated on a granite Inselberg within the savanna. As this species is usually considered a rainforest dweller, these froglets possibly do not belong to P. longirostris. The only observations concerning the breeding sites of P. longirostris have been published by Murith (1981), so far. He says it breeds mainly during the dry season in Ivory Coast. It there appeared at the ponds just once or twice a year. However, the habitat description given by this author does not at all match my personal data. The frogs therefore are possibly not P. longirostris. In Tai National Park this species was found in secondary forests. It breeds in temporary waters on forest roads and clearings. Calling males and spawn were found nearly throughout the year (unpub. data).
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 (2002-01-22)
Species Account Citation: AmphibiaWeb 2002 Ptychadena longirostris <http://amphibiaweb.org/species/4938> University of California, Berkeley, CA, USA. Accessed Nov 14, 2018.
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Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 14 Nov 2018.
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