Werneria mertensiana Amiet, 1976

Rödel, Mark-Oliver, Schmitz, Andreas, Pauwels, Olivier S. G. & Böhme, Wolfgang, 2004, Revision of the genus Werneria Poche, 1903, including the descriptions of two new species from Cameroon and Gabon (Amphibia: Anura: Bufonidae), Zootaxa 720, pp. 1-28 : 15-17

publication ID	https://doi.org/ 10.5281/zenodo.158599
DOI	https://doi.org/10.5281/zenodo.5610963
persistent identifier	https://treatment.plazi.org/id/7B388787-E256-FFF9-FEE4-312E8EB0FDEC
treatment provided by	Plazi
scientific name	Werneria mertensiana Amiet, 1976
status

Treatment

Werneria mertensiana Amiet, 1976 View in CoL

Figs. 1 View FIGURE 1 e, 2e, 3e, 4e, 8c, 10b

Holotype.— MHNG 1253.91 (formerly JLA 70.380), male, Mt. Nlonako, surroundings of Nkongsamba, 1,000 m, Cameroon, 21.III.1970, J.L. Amiet.

Additional material studied.— MHNG 1453.23, female, Kala river, under stone, ca. 800 m a.s.l., Yaoundé, Cameroon, 13.V.1969; MHNG 1453.24–25, two males, Nkolodou, Lékié valley, Yaoundé, Cameroon, III.1969, J.L. Perret & J.L. Amiet; ZFMK 69127144, 72040041, four males, seven females, nine juveniles, Mt. Nlonako, above Nguengué, 1,100–1,200 m a.s.l., Cameroon, 23.VI.–6.VII.1998, H.W. Herrmann & A. Schmitz; ZFMK 75396397, 75414, two males, one juvenile, Mt. Nlonako, Nguengué, ca. 1,100m a.s.l., Cameroon, 18.–21.I.2000, H.W. Herrmann & A. Schmitz; ZFMK 78242243, 78251252, female and juveniles, Mt. Nlonako, Nguengué, 1,000–1,100 m a.s.l., Cameroon, 25.III.2001, H.W. Herrmann et al.; IRSNB 13072.1–2, male and female, 75 km W of Yaoundé, Cameroon, 10.X.1975, M. Lamotte.

Diagnosis.— Large Werneria with short, nearly truncate snout; back dark with clear dorsolateral lines; urostyle bordered by a pair of longitudinal black lines; flanks uniform black; belly with large clear spots; throat black or with only minute clear points; skin of throat smooth; hind legs and feet with distinct black bars; moderate webbing more or less reduced to bases of toes.

Description.— Median sized, compact toad with very short, nearly truncate snout ( Figs. 4 View FIGURE 4 e, 10b); males reach 31.8–41.0 SVL, females 39.6–47.7 mm; greyish brown to reddish brown back; flanks are uniform black; white dorsolateral lines (about 1 mm broad) on the snout or just anterior to eye extend above the eye to the groins ( Fig. 4 View FIGURE 4 e, 8c); dorsolateral line well delimitated against flanks, less conspicuously against back; urostyle bordered by a pair of longitudinal black lines; thighs, lower legs and feet usually with two (rarely three) distinct black bars ( Fig. 1 View FIGURE 1 e), otherwise same colour as back; basic colour of venter dark black, between the forearm bases the venter is covered with irregular large white spots that range from 4–20 mm and cover the ventral sides of body and extremities ( Fig. 2 View FIGURE 2 e), throat and anterior part of breast are more or less black, but may show some small white points; hind legs with granulated skin, especially in females; moderate webbing more or less reduced to bases of toes ( Fig. 3 View FIGURE 3 e); males with nuptial pads on first finger. Even very small juveniles (e.g. ZFMK 75483, SVL 10.4 mm) exhibit the same coloration as adults. White spots on the belly are always larger than in similarsized specimens of the new Werneria species from the Bakossi Mts. and Mt. Kupe (see below).

Natural history.— W. mertensiana is a widespread, rockloving, submontane species that is restricted to mountain bases and foothills ( Gartshore 1984). Most, but not all, specimens have been found above 800 m a.s.l. ( Amiet 1975). At Mt. Manengouba W. mertensiana is replaced at higher altitudes by W. tandyi and W. bambutensis ( Amiet 1975) . It lives in small streams with waterfalls ( Amiet 1972, 1976b; Gartshore 1984). Amiet and Perret (1969) and Amiet (1986) report W. mertensiana (as Bufo preussi or as Werneria p. mertensiana ) from the Yaoundé region at about 800 m. There it lives in primary rainforest in small rivers with clear, turbulent water and a sandy or stony bed. Specimens have been found hiding under stones during the day, sometimes within the splash zone of waterfalls. Lawson (1993) reported W. mertensiana from the lower limit of the submontane zone (850–1,050 m). In early September he collected three active toads in leaf litter, far from streams, around midday. He also collected an unidentified Werneria tadpole, probably belonging to this species, in the Rumpi Hills near Dikome Balue. W. mertensiana is said to utter a call similar to that of W. tandyi ( Amiet 1976a) .

Distribution.— W. mertensiana was described from the Mt. Nlonako in the vicinity of Nkongsamba at 1,000 m a.s.l. ( Amiet 1972). It also occurs at Abang on Mt. Manengouba at 950 m, 40 km north of Kumba on the KumbaMamfe road at Fotabong at 900–1,000 m, and around Yaoundé including Mt. Kala and MbamMinkoum at 800 m ( Amiet 1972; Joger 1982; Gartshore 1984; Fig. 5 View FIGURE 5 ). It may occur on the southern and western slopes of the Bamiléké Plateau, and perhaps on the Obudu Plateau ( Amiet 1972, 1975). Records from Mt. Kupe (e.g. Hofer et al. 2000) and the Bakossi Mts. most likely belong to a new species (described below). However, as vouchers were not accessible to us, this could not be confirmed. Mt. Kupe records might be also based on W. preussi (see above) or toads that are intermediate between W. preussi and W. mertensiana (as suggested by J.L. Amiet pers. comm.). However, we never recorded any intermediate looking Werneria on Mt. Kupe. Other W. mertensiana records are known from Mt. Nta Ali massif, Cameroon ( Lawson 1993) and Monte Alén in Equatorial Guinea (de la Riva 1994). However, the latter record probably does not refer to W. mertensiana (see discussion).

Taxonomic remarks.— The species was described in 1972 by Amiet as Bufo mertensi . Because this name was a junior homonym of Bufo ictericus mertensi Cochran, 1950 , Amiet proposed the replacement name W. mertensiana ( Amiet 1976b) . Later Amiet (1986, 1987) treated this taxon as a subspecies of W. preussi , a decision that was followed by de la Riva (1994), but not in the most recent list of "Amphibian species of the World" ( Frost 2002). The disjunct records of W. preussi from Buëa and Mt. Kupé, and the clear morphological distinctiveness of W. preussi and W. mertensiana are strong arguments against a subspecific relationship of these two taxa. Hence, we agree with Frost (2002) in treating W. mertensiana as a full species.