Petropedetes juliawurstnerae, Barej, Michael F., Rödel, Mark-Oliver, Gonwouo, Legrand Nono, Pauwels, Olivier S. G., Böhme, Wolfgang & Schmitz, Andreas, 2010

Barej, Michael F., Rödel, Mark-Oliver, Gonwouo, Legrand Nono, Pauwels, Olivier S. G., Böhme, Wolfgang & Schmitz, Andreas, 2010, Review of the genus Petropedetes Reichenow, 1874 in Central Africa with the description of three new species (Amphibia: Anura: Petropedetidae), Zootaxa 2340, pp. 1-49 : 35-39

Petropedetes juliawurstnerae sp. nov.

Figs. 4 , 6 c, 7d, 8c, 9c, 10b, 14, 15

Holotype. ZFMK 67360 (adult male), Cameroon, Mt. Kupe: Nyasoso, 4°49’42N, 9°40’55E, app. 920 m a.s.l., 19.XII.1997, coll. O. Euskirchen.

Paratypes. IRSNB-KBIN 1989 (female), IRSNB-KBIN 1990 (male), Cameroon, Mt. Kupe, Nyasoso app. 950 m a.s.l., 4°49’42N, 9°40’55E, 6.VII.2009, coll. A Schmitz & M.F. Barej; MHNG 2713.12 (male), 5.VII.2009, other data as IRSNB-KBIN 1989; MHNG 2713.13 (female), same data as IRSNB-KBIN 1989); ZFMK 67357 (female), 2.I.1998, other data as holotype; ZFMK 67359 (female), 67987-990, 68170 (4 males), Cameroon, Mt. Kupe, NW-slope, app. 910 m a.s.l., 18.XII.1997 - 3.I.1998, coll. A. Schmitz; ZFMK 68131 (male), 68134-136 (3 females), app. 950 m a.s.l., other data as ZFMK 67987; ZFMK 75590 (female), 75591 (male), Cameroon, Mt. Kupe: Nyasoso, 4°49’42N, 9°40’55E, 15.I.2000, coll. H.-W. Herrmann & A. Schmitz; ZFMK 88866 (female), data as IRSNB-KBIN 1989; ZMB 73694 (male), ZMB (73695) (female), data as IRSNB-KBIN 1989.

Additional material. ZFMK 67355 (male), Cameroon, Bakossi Mts., Meked, app. 625 m a.s.l., no date, coll. O. Euskirchen.

Diagnosis. Medium sized Petropedetes ; slender body shape; tympanum round and distinct, smaller than eye diameter; characters of breeding males: tympanic papilla present, situated in the centre of the tympanum; forearm hypertrophy only weakly developed; carpal spike present; femoral glands long and narrow, not round; a typical dorsal marking of light spots in the form of a flower with five petals recognizable in many specimens ( Fig. 14 ); webbing moderate: 1 (0) 2 (0-0) 3 (1-1) 4 (2-2) 5 (0.5) ( Fig. 10 b).

Description of the holotype. The holotype is an adult male with a slender body shape; 32.7 mm SUL; snout in lateral view rounded; head width 13.8 mm; eye diameter 4.8 mm; interorbital distance 3.2 mm; naris closer to snout (1.9 mm) than to eye (3.2 mm); canthus rostralis distinct but rounded; loreal region deeply concave; throat without spinosities ( Fig. 6 c); femur length 18.1 mm; tibia length 19.8 mm; foot (incl. longest toe) 24.4 mm; femoral glands large, long and narrow (length x width: 6.8 x 1.9 mm / 6.6 x 2.0 mm); relation femoral gland length to femur length 0.37; spinosity hardly developed on upper forearms; webbing of feet: 1 (0) 2 (0-0) 3 (1-0.5) 4 (2-2) 5 (0.5); coloration in preservation: overall colour brown-grey; white marking in shape of a 5-petal flower (indistinct); white warts on flanks, hind limbs and abdomen; upper hind limbs with white transversal bars, continuing on lower legs; ventral side whitish and pale, throat of same coloration with minuscule darker pigmented points; ventral surfaces of femora whitish with darker marbling, which covers in parts the femoral glands; lower leg ventrally with little marbling.

Variation. Medium sized Petropedetes with slender body; females being slightly larger (SUL in males: 29.5–38.9 mm, in females: 39.1–42.6 mm); mean head width in males 40% of SUL in females 39%; snout in lateral view rounded; canthus rostralis distinct but rounded; loreal region deeply concave; eye diameter about 1.8 times eye-narial distance; nose closer to snout tip than eye; distinct round tympanum, smaller than eye in both sexes (tympanum / eye in males: 0.66–0.8%, in females: 0.47–0.60); slender tympanic papilla situated in centre of tympanum ( Fig. 8 c); supratympanic fold distinct; fingers slender, with typically T-shaped fingertips; relative length of fingers: III> IV> II> I; manual subarticular tubercles single; manual webbing absent; palmar tubercle and thenar tubercle present, palmar tubercle sometimes indistinct; forearm hypertrophy weakly developed in males; carpal spike present in males (well visible on X-rays; Fig. 15 ); spinosities in males weakly developed on upper forearms; dorsal skin heterogeneous with larger warts on flanks; dorsum with prolonged warts, less distinctly developed than in other species; ventral skin smooth; mean femur length in males 54% of SUL, in females 52%, mean tibia length in males 60% of SUL, in females 57%; mean foot length in males 76% of SUL, in females 75%; upper hind limbs of moderate size, lower hind limbs slender; femoral glands line-shaped, long and narrow, of almost similar length in both sexes (femoral gland / femur length in males: 0.36–0.51, in females: 0.32–0.41); relative length of toes: IV> III> V> II> I; half-webbed species, different webbing usually 3 (1-1), sometimes 3 (0.5-0) running along the 3rd toe, 4 (1.5-1.5) up to 4 (2-2) and 5 (0) or 5 (0.5); webbing of ZFMK 68170 (paratype) 1 (0) 2 (0-0) 3 (1-0) 4 (2-2) 5 (0).

Females of P. juliawurstnerae sp. nov. possess long femoral glands, which may make sex determination difficult. Females are best recognizable by their smaller tympana and more slender femoral glands ( Fig. 9 c).

Coloration. Dorsum brown with large greenish spots on head, or back dark brown without lighter spots, only light warts ( Fig. 8 c); iris golden; flanks with white warts; legs coloured as dorsum with greenish transversal bars; femoral glands pale orange or brownish; coloration in preservation: dorsum predominantly uniform grey or brown with few light, small spots; typical pattern of pale spots, resembling a flower with five petals, in most specimens recognizable; legs with thin white transverse lines.

Natural history. The species has been found at a water reservoir and close to small, fast flowing creeks at Mt. Kupe. The streambed was stony and the surrounding vegetation was a transition between primary and secondary rainforest. The frogs were sitting on slippery stones, overgrown by algae, or in the riverine vegetation at heights of 10–20 cm. On Mt. Kupe P. juliawurstnerae sp. nov. occurs in syntopy with P. euskircheni sp. nov.

Distribution. At present the species is only known from its type locality at Mt. Kupe and Meked on the adjacent Bakossi Mountains ( Fig. 4 ).

Genetics. The genetic comparison for the uncorrected p-distances of the mitochondrial 16S rRNAfragment (Table 4) gave the following results for Petropedetes juliawurstnerae sp. nov.: interspecific comparison between P. juliawurstnerae sp. nov. and all other Central African Petropedetes taxa ranged between 2.84%-12.39%, while the intraspecific variation within P. juliawurstnerae sp. nov. was much lower at 0.00%-0.90% (N= 5). The lowest interspecific difference has been detected between P. p e r re t i and P. juliawurstnerae sp. nov. ranging between 2.84%-3.59%, but species can be clearly differentiated on the morphological basis alone (see below).

Systematic remarks. Mostly closely P. juliawurstnerae sp. nov. resembles P. p e r re t i and P. cameronensis . It shares a tympanic papilla in the centre of the tympanum and a similar shape with P. perreti ( Figs. 8 a, 8c), and similar webbing with P. cameronensis ( Figs. 10 b, 10c). From the other species P. juliawurstnerae sp. nov. is distinctly different by its half-webbed toes; i.e. fully webbed in P. palmipes (additionally lacking the tympanal papilla) and rudimentary-webbed in P. euskircheni sp. nov., P. johnstoni , P. parkeri , and P. vulpiae sp. nov. Breeding males of P. juliawurstnerae sp. nov. can be distinguished from other species with a tympanic papilla by the position of the papilla. Only P. juliawurstnerae sp. nov. and P. perreti have papillae in the centre of the tympanum. In all other species this papilla is positioned closer to the dorsal edge of the tympanum. The papilla of P. juliawurstnerae sp. nov. is broad at the end, when not shrivelled after preservation.

From the most similar two species, P. p e r re t i and P. cameronensis , P. juliawurstnerae sp. nov. can be distinguished by the following characters: P. juliawurstnerae sp. nov. is smaller than P. p e r re t i (SUL in males: N juliawurstnerae = 12, N perreti = 13, p <0.001; in females: N juliawurstnerae = 10, N perreti = 15, p <0.01). The tympanum diameter / eye diameter ratio is smaller in male P. juliawurstnerae sp. nov. (tympanum diameter / eye diameter in males: N juliawurstnerae = 12, N perreti = 13, p <0.001), but does not differ significantly in females (p = 0.23). The webbing is less developed than in P. p e r re t i ( Figs. 10 a, 10b): 1) webbing deeper notched in P. juliawurstnerae sp. nov., 2) webbing always less developed on the fourth toe, where it usually leaves 1.5–2 phalanges free in P. juliawurstnerae sp. nov.; but only 0 or 1 free phalange in P. perreti . The femoral gland of P. juliawurstnerae sp. nov. is long and narrow (stripe-like) in males and females. The femoral glands of P. perreti are more oval. The gland length / gland width ratio in P. juliawurstnerae sp. nov. is significantly larger (gland length / gland width in males: N juliawurstnerae = 12, N perreti = 13, p <0.001; in females: N juliawurstnerae = 10, N perreti = 15, p <0.001).

In contrast, P. c a m e ro n e n s i s and P. juliawurstnerae sp. nov. do not differ in their size (males p= 0.19; females p =0.29). Petropedetes juliawurstnerae sp. nov. can be distinguished from P. cameronensis by the size of the tympanum which is distinct in P. juliawurstnerae sp. nov., but only rudimentary or even indistinctly developed in P. cameronensis (tympanum diameter / eye diameter in males: N juliawurstnerae = 12, N cameronensis = 16, p <0.001; in females: N juliawurstnerae = 10, N cameronensis = 17, p <0.001). P. c a m e ro n e n s i s males lack the tympanic papillae present in breeding P. juliawurstnerae sp. nov. males. Especially in females, which do not carry a tympanic papilla, the similar webbing makes it difficult distinguishing the new species from P. cameronensis . In this case the shape of the femoral gland is the character best suited for species identification. The femoral glands are oval shaped in P. cameronensis ; the gland length / gland width ratio in P. juliawurstnerae sp. nov. is significantly larger (gland length / gland width in males: N juliawurstnerae = 12, N cameronensis = 16, p <0.001; in females: N juliawurstnerae = 10, N cameronensis = 17, p <0.001).

Spinosities in examined specimens of P. juliawurstnerae sp. nov. seem not to be fully developed, therefore spines could be developed on the throat and more developed on upper forelimbs as well, as in other species ( Fig. 6 c).

Etymology. The specific epithet juliawurstnerae is a matronym. The name is dedicated to Mrs. Julia Anna Maria Wurstner (Bad Neuenahr-Ahrweiler, Germany), who accompanied the senior author during fieldwork in 2007 and supported his work from the beginning.

Figures

FIGURE 4. Distribution of known Petropedetes species; compare with text. Specimens from localities marked with an asterisk (*) were not available and are added from literature.

FIGURE 6. Portraits of holotypes showing spinosity: a) Petropedetes vulpiae sp. nov. (ZFMK 81623), b) P. euskircheni sp. nov. (ZFMK 75582), c) P. juliawurstnerae sp. nov. (ZFMK 67360).

FIGURE 8. Life coloration of Central African Petropedetes with developed webbing: a) Petropedetes perreti (male: Mt. Manengouba, Cameroon; female: Nguengue, Mt. Nlonako, Cameroon), b) P. cameronensis (left: Limbe, Cameroon; right: Rhoko-forest, Nigeria), c) P. juliawurstnerae sp. nov. (male and female: Nyasoso, Mt. Kupe, Cameroon, d) P. palmipes (left male: Monte Alen, Equatorial Guinea; photo: I. de la Riva; right male: Bipindi, Cameroon; photo: H. - W. Herrmann).

FIGURE 9. Relation of femoral gland to femur and shape of femoral gland in Central African Petropedetes with developed webbing: a) Petropedetes perreti (male: ZFMK 69215; female: ZFMK 69211), b) P. cameronensis (male: ZFMK 81616; female: ZFMK 81555), c) P. juliawurstnerae sp. nov. (male: ZFMK 67360; female: ZFMK 68134), d) P. palmipes (male: MHNG 1033.28; female: MHNG 1033.5).

FIGURE 10. Development of webbing of a) Petropedetes perreti (ZFMK 69217), b) P. juliawurstnerae sp. nov. (ZFMK 68170), c) P. cameronensis (ZFMK 81555).

FIGURE 14. Typical dorsal pattern in Petropedetes juliawurstnerae sp. nov. (ZFMK 68170):

FIGURE 15. X-rays of the holotype of Petropedetes juliawurstnerae sp. nov. (ZFMK 67360) with a developing bony carpal spike, not yet protruding the skin; right hand enlarged (scale 10 mm).