Amietophrynus superciliaris chevalieri ( Mocquard, 1908 )

Barej, Michael F., Schmitz, Andreas, Menegon, Michele, Hillers, Annika, Hinkel, Harald, Böhme, Wolfgang & Rödel, Mark-Oliver, 2011, Dusted off — the African Amietophrynus superciliaris - species complex of giant toads, Zootaxa 2772, pp. 1-32 : 9-18

Amietophrynus superciliaris chevalieri ( Mocquard, 1908)

Figs. 1 , 2 a, 4a, 6a–d, 7a, 8a–d, 9a–h.

Bufo chevalieri Mocquard, 1908 , Bull. Mus. Natl. Hist. Nat. Paris 14: 262 Type locality. “ Ivory Coast ”.

Material examined. MNHN 1908.0033 (holotype, juvenile) Ivory Coast, locality unknown; MNHN 1979.6148-50 (male + 2 females) Guinea, Nimba; MNHN 1980.1277 (female) Ivory Coast, locality unknown; MNHN 1989.4045 (female) Liberia, Mt. Tocadeh; MNHN 9026 (female) Guinea, locality unknown; ZFMK 31801 (male) Ghana, locality unknown; ZFMK 56292 (juvenile) Guinea, Sérédou, Forêt de Ziama; ZFMK 60724 (juvenile) Guinea, Sérédou, Forêt de Ziama; ZFMK 66282 (juvenile) Guinea, Sérédou, Forêt de Ziama; ZMB 74320 (juvenile) Guinea, Déré Classified Forest; ZMB 74321 (juvenile) Guinea, Diécké Classified Forest; ZMB 74322 (juvenile) Guinea, Mont Béro Classified Forest.

Holotype. The holotype of Amietophrynus s. chevalieri ( MNHN 1908.0033) is a juvenile (SUL: 35.8 mm) in poor condition. The skin is bleached and thinned, eyes and eyelids sunken, colouration not recognizable (neither on flanks nor on dorsum any visible pattern) and a long cut on the right flank opened the guts ( Figs. 8 a, b). Nonetheless, the shape of the eyelid is recognizable. The eyelids are rounded in dorsal view and not thickened medially, thus not forming a triangular prolongation ( Fig. 7 a). Skin on hand and feet are shrunken, hence, webbing between toes hardly visible ( Figs. 8 c, d). Measures of characters which are accessible: head width 13.6 mm; parotid length 8.8 mm and 9.6 mm; length of first finger 4.0 mm; length of third finger 4.9 mm; femur length 12.8 mm; tibia length 12.9 mm; length of shortest toe 1.6 mm, length of inner metatarsal tubercle 0.9 mm.

Diagnosis. Genetically the taxon belongs to the African toad genus Amietophrynus ( Frost et al. 2006) . As part of the Amietophrynus superciliaris -species complex, the taxon differs from all other members of the genus by a smooth dorsal skin in adult specimens, straight loreal region and large size.

Large toad; dorsal skin smooth in adults, granular in juveniles; body shape very broad, ovoid; tympanum distinct, drop-shaped, smaller than eye diameter; parotids prominent, shape of parotids like broad drop, width of parotid glands slightly reduced posteriorly, posterior part of parotid glands rounded; eyelid rounded in dorsal view, slender in lateral view, triangular prolongation absent; posterior part of back with dark colouration, thus different from anterior part; pair of spots on posterior part of back absent; extremities slender; males with nuptial swellings on fingers I and II.

A. s. chevalieri can be distinguished from the nominal subspecies by the following characters: shape of the eyelid (with the exception of few juveniles) being rounded and of equal width along the eye in A. s. chevalieri and of triangular shape and prolonged in the middle in A. s. superciliaris ( Figs. 2 a, b); the eyelid width / eye diameter ratio is significantly higher in the nominal subspecies (Kruskal-Wallis-test; p <0.01, N A.s.c.= 7, 0.20–0.33, x= 0.24 ± 0.05 sd; N A.s.s.= 28, 0.24–0.39, x= 0.32 ± 0.04; H= 12.28); palmar tubercles being more prominent in A. s. chevalieri than in A. s. superciliaris ; parotid glands being usually rounded at the posterior tip in A. s. chevalieri and pointed in A. s. superciliaris ; posterior part of the back in A. s. chevalieri coloured darker (a triangular shaped figure, pointing cranially) than the anterior part of the dorsum, in A. s. superciliaris back of uniform colouration (generally pale yellowish); in addition, a pair of abdominal spots present in A. s. superciliaris (exceptionally lacking one or even both) and absent in A. s. chevalieri .

For characters distinguishing A. s. chevalieri and A. channingi sp. nov. see below.

Description. Large Amietophrynus with very broad body shape; females being larger than males (SUL in males: 116.4–137.6 mm, in females: 130.6–156.0 mm); mean head width similar in both sexes, in males 41% of SUL, in females 40%; snout in lateral view straight or marginally rounded; head without bony ridges; canthus rostralis distinct, angular; loreal region slightly concave; distance eye-snout similar to eye diameter; nares closer to snout tip than eye; eyelid in adult specimens rounded in dorsal view; eyelid of almost identical width along the eye in lateral view, without a process in the middle (only MNHN 9026 possesses a very slight angular shaped eyelid; see also Fig. 9 d); tympanum more or less distinct, positioned at the concave cheek region; tympanum vertically prolonged and drop shaped, its horizontal diameter smaller than eye-diameter; dorsal skin smooth in adults, warty in juveniles; parotid glands very prominent, drop or bean shaped, width slightly diminishing backwards, usually with rounded posterior tip (mean parotid length / parotid width ratio in males: 2.86, in females: 3.00); parotid pattern bicoloured, ventral part coloured like flanks, dorsal part like back, both colours separated by sharp angle; parotid gland openings on upper part, sometimes reaching parotid angle; fingers and toes simple, not enlarged at the end; subarticular tubercles simple; relative length of fingers: III> I> II ≥ IV (mean length of finger I / length of finger III ratio in both sexes 96%); manual webbing absent; extremities slender in comparison to body; mean tibia length 39% of SUL in males, 37% in females; inner and outer metatarsal tubercle present; relative toe length: IV> III> V> II> I; webbing rudimentary: 1 (0.5) or 1 (0), 2 (1-0.5) or 2 (1-0), 3 (2-1), 4 (2.75-2.75) or 4 (3-3), 5 (1); tarsal fold absent; males in breeding condition with hypertrophied forearms and nuptial swellings on fingers I and II; juveniles with smaller and fewer warts on back than Central African specimens (Rödel et al. 2004).

Colouration. Dorsum pattern yellowish, extending from the tip of the snout, along the upper side of the parotids backwards to the vent region; posteriormost back region with darker marking, brownish or purple-blackish ( Fig. 9 ); lateral colouration ranging from tip of snout, below the canthus rostralis and along the flanks to the groins: dark purple, purple-brownish or intense red colour; ventral colouration reddish; extremities dark purple; inguinal region with small spots; gular region coloured like venter; anterior extremities dark purple below; juveniles orange or light brown on dorsum; flanks in juveniles generally reddish or purple, sometimes greyish ( Figs. 9 a–c, f); juveniles often with distinct white transversal bars on upper hind limbs and feet ( Figs. 9 c, h); juvenile interorbital marking a single V-shaped spot ( Fig. 4 a).

Colouration in preservation. Preserved specimens may loose their colouration, turning brownish. However, a clear differentiation between the lateral and dorsal colouration is usually still recognizable. The darker posterior part of the back is recognizable in only few preserved specimens, as the whole back turns dark.

Natural history. Amietophrynus s. chevalieri inhabits primary forests ( Guibé & Lamotte 1958; Böhme 1994; Rödel et al. 2004). In contrast to A. s. superciliaris male A. s. chevalieri are known to expel loud calls during the breeding season (I. Herbinger in Rödel et al. 2004). Unfortunately no recordings are available. Rödel et al. (2004) report on juveniles and subadults along large rivers in primary forests in November / December in Guinea (dry season). Böhme (1994) finds freshly metamorphosed and still smooth skinned juveniles in October, at the end of the rainy season in Guinea and Hillers & Rödel (2007) mention juveniles in December in Liberia.

Distribution. Amietophrynus s. chevalieri (formerly usually referred to as A. superciliaris ) is known from forests in Upper Guinea. At present the taxon is known from Liberia ( Hillers & Rödel 2007), Sierra Leone (this paper; Figs. 1 ; 9g); Guinea ( Guibé & Lamotte 1958; Böhme et al. 1994; Rödel & Bangoura 2004a, b; Rödel et al. 2004), Ivory Coast ( Mocquard 1908; Ernst et al. 2006) and Ghana ( Schiøtz 1964; Hughes 1988; Rödel & Agyei 2003).

Bailo et al. (2009) list A. s. chevalieri (as A. superciliaris ) for the Badiar National Park in northern Guinea. However, this area seems not suitable for the toad and the occurrence of the species is thus very unlikely. Other species names mentioned in this paper indicate further misidentifications. Hence, the locality has not been considered in the overall distribution ( Fig. 1 ). According to Segniagbeto et al. (2006) the species should be deleted from the list of possible species in Togo. Amietophrynus s. chevalieri is hence a strict endemic of the Upper Guinean forest region.

Taxonomy. Bufo chevalieri has been described by Mocquard (1908) from the Ivory Coast. According to Frost (2010) A. chevalieri has been synonymized with A. superciliaris by Tandy & Keith (1972) without comment. However, already Guibé & Lamotte (1958) report that their examination of the juvenile type of A. chevalieri revealed that it corresponds to a juvenile specimen of A. superciliaris . The type of A. s. chevalieri differs from typical A. superciliaris only by the lack of the palpebral process, which however is often lacking in juveniles of the A. superciliaris -species complex ( Guibé & Lamotte 1958; this paper). The synonymy of A. chevalieri with A. superciliaris has been accepted in later publications (e.g. Perret 1966; Tandy & Keith 1972). However, the two taxa are distinctly different in morphology (see Diagnosis section above).

Ethnozoology. According to Böhme (1994) locals believe the toad to be dangerous. This fear also exists in south-eastern Sierra Leone, where some people believe that this toad is evil and can kill people or at least cause disease to people who are close when it opens its mouth and exhales its evil breath. According to a widespread belief of non-related Upper Guinean ethnic groups the toad gives birth to the rainbow. These tales are known from Malinké people in Guinea, from Oubi and Gueré people in western Ivory Coast ( Rödel & Bangoura 2004b) and from different ethnic groups in Liberia and Sierra Leone. In the latter two countries the toad is also called “rainbow toad”.

Figures

FIGURE 1. Distribution of Amietophrynus channingi sp. nov. (red), A. superciliaris chevalieri (green) and A. s. superciliaris (blue, the purple spot refers to a specimen which was dried up, see text). Type localities are marked with a “ H ”, vouchers from localities marked with an asterisk (*) were not available and are added from literature. Locality symbols with an embedded question mark “? ” refer to imprecise recordings. I. West Africa: H = Ivory Coast (A. superciliaris chevalieri); II. western Central Africa: H 1 = Rio del Rey, Cameroons (A. s. superciliaris), H 2 = South Cameroon (A. laevissimus, synonym of A. s. superciliaris); III. eastern Central Africa: H = Democratic Republic of Congo, West Mwana (A. channingi sp. nov.).

FIGURE 2. Head in lateral view, showing shape of eyelid in adult specimens (insets show how to measure width of eyelid): Amietophrynus s. chevalieri (a; photo: C. Brede); A. s. superciliaris (b); A. channingi sp. nov. (c). Note the pointed eyelid in (b) and (c) forming a triangular eyelid process in lateral view.

FIGURE 4. Pattern of head markings in juvenile Amietophrynus s. chevalieri, A. s. superciliaris and A. channingi sp. nov. (specimens in lines from left to right; SUL in mm given in brackets). A. s. chevalieri (a): line 1: ZMB 74322 (22.3 mm); A. s. superciliaris (b): line 2: MHNG 757.61 (42.4 mm); MHNG 917.99 (46.2 mm); MHNG 955.89 (59.3 mm); MHNG 1018.88 (47.5 mm); line 3: MHNG 1018.91 (30.9 mm); MHNG 1390.97 (18.2 mm); ZFMK 67268 (17.0 mm); ZFMK 73192 (30.4 mm); line 4: ZMB 19924 (57.2 mm); ZMB 19971 (35.5 mm); ZMB 19972 (34.9 mm); ZMB 19973 (30.7 mm); line 5: ZMB 74319 (19.3 mm); ZMB 74522 (38.3 mm); A. channingi sp. nov. (c) line 6: MHNG 2520.25 (36.3 mm); ZFMK 34376; ZFMK 63895 (27.0 mm); ZFMK 63896 (21.3 mm); line 7: IRSNB-KBIN 1985, IRSNB-KBIN 11364 (2 juveniles).

FIGURE 7. Head in lateral view, showing shape of eyelid: a) holotype of Amietophrynus s. chevalieri (a: MNHN 1908.033); syntype of A. laevissimus (b: ZSM 148 - 1989.1); syntype of A. s. superciliaris (c: BM 1947.2.21.42; photo C. McCarthy).

FIGURE 8. Holotype of Amietophrynus s. chevalieri (Mocquard, 1908) MNHN 1908.033 in dorsal (a) and ventral view (b; scale bar: 10 mm.); details of hand (c) and foot (d).

FIGURE 9. Colour pattern in Amietophrynus s. chevalieri; subadult (a) and juvenile (b) from North Lorma National Park, Liberia; juveniles (c, f) and subadults (d, e), from Sérédou, Guinea (photos c, e, f: J. Köhler; photo d: P. Naskrecki); adult from Gola National Park, Sierra Leone (g); subadult from Taï National Park, Ivory Coast (h).