Odontobatrachus smithi Barej, Schmitz, Penner, Doumbia, Sandberger-Loua, Hirschfeld, Brede, Emmrich, Kouame , Hillers, Gonwouo, Nopper, Adeba, Bangoura, Gage, Anderson & Roedel

Barej, Michael F., Schmitz, Andreas, Penner, Johannes, Doumbia, Joseph, Sandberger-Loua, Laura, Hirschfeld, Mareike, Brede, Christian, Emmrich, Mike, Kouame, N'Goran Germain, Hillers, Annika, Gonwouo, Nono L., Nopper, Joachim, Adeba, Patrick Joel, Bangoura, Mohamed A., Gage, Ceri, Anderson, Gail & Roedel, Mark-Oliver, 2015, Life in the spray zone - overlooked diversity in West African torrent-frogs (Anura, Odontobatrachidae, Odontobatrachus), Zoosystematics and Evolution 91 (2), pp. 115-149 : 128-131

Taxon classification Animalia Anura Odontobatrachidae

Odontobatrachus smithi Barej, Schmitz, Penner, Doumbia, Sandberger-Loua, Hirschfeld, Brede, Emmrich, Kouame, Hillers, Gonwouo, Nopper, Adeba, Bangoura, Gage, Anderson & Roedel sp. n.

Odontobatrachus smithi OTU2 sensu Barej et al. (2015)

Holotype.

ZMB 78310 (male), Republic of Guinea, Fouta Djallon, Pita, Hörè Binti (Latitude: 10.83964; Longitude: -12.55572), 510 m a.s.l., 23 July 2010, coll. C. Brede and J. Doumbia.

Paratypes.

Guinea: MHNG 2731.47 (female), Mamou Region (10.85; -12.52), 664 m a.s.l., 22 July 2010; ZFMK 95466, ZMB 78306 (2 females), Kindia Region (10.81; -13.34), 314 m a.s.l., 3 October 2010; ZMB 78311 (female), same data as holotype.

Additional material.

Guinea: ZMB 78304-05 (2 juveniles), Kindia Region (10.83; -13.81), 253 m a.s.l.; ZMB 78307 (male), Kindia Region (10.81; -13.34), 314 m a.s.l.; ZMB 78308 (female), Kindia Region (10.96; -13.71), 312 m a.s.l.; ZMB 78309 (male), Kindia Region (10.00; -12.34), 92 m a.s.l.; ZMB 78312 (female), ZMB 78313 (juvenile), Mamou Region (10.85; -12.52), 664 m a.s.l.

Diagnosis.

Medium to large sized frogs, robust body shape; head narrow, smallest tympanum-eye ratio in the family, highest eye diameter/eye-naris-distance ratio in the family, webbing fully developed, leaving up to 0.5 of the distal phalange free at the inner side of toe II, leaving 0.5-0.75 of the distal phalange free at toe IV; belly pattern very variable, male femoral glands pale orange; glandular lines on tibia contain mean conic glands forming frequently interrupted lines. Genetically Odontobatrachus smithi differs by a minimum of 3.79% in the mitochondrial 16S gene from its congeners.

Differential diagnosis.

Odontobatrachus smithi can be distinguished from its congeners by a combination of characters (characters distinguishing Odontobatrachus smithi vs. Odontobatrachus ziama see above; for all significant differences see Table 5): growing larger than Odontobatrachus natator and Odontobatrachus arndti (Tables 1 and 2); male Odontobatrachus smithi differ from their congeners by the following ratios (Table 1): GL/GW larger than in Odontobatrachus natator and Odontobatrachus fouta but smaller than in Odontobatrachus arndti ; TD/O larger than in Odontobatrachus natator ; O/EN smaller than in Odontobatrachus natator and Odontobatrachus arndti ; ES/O smaller than in Odontobatrachus arndti ; female Odontobatrachus ziama differ from their congeners by the following ratios (Table 2): HW/SUL larger than in Odontobatrachus natator and Odontobatrachus arndti ; larger TD/O than in Odontobatrachus natator and Odontobatrachus arndti ; O/EN smaller than in Odontobatrachus natator and Odontobatrachus arndti ; TD/SUL larger than in Odontobatrachus arndti . Webbing formulae of Odontobatrachus smithi are similar to Odontobatrachus fouta and Odontobatrachus arndti ; however, Odontobatrachus smithi possesses less webbing on the inner side of toe II, and webbing in Odontobatrachus natator is more extensive (Table 7). Femoral glands are pale orange in Odontobatrachus smithi but rose-coloured in Odontobatrachus natator , dark orange in Odontobatrachus ziama and bright orange in Odontobatrachus fouta (Figs 4, 6, 8, 10). Glandular lines on tibia contain small to mean sized conic glands forming predominantly interrupted lines (Fig. 8a, b), while small to large glands form more or less interrupted lines in Odontobatrachus natator (Fig. 4 a–e), small to large glandular conic glands, rather interrupted lines in Odontobatrachus fouta (Fig. 10b, c) and small to mean glandular conic glands form hardly interrupted lines in Odontobatrachus arndti (Fig. 12b, c). Morphologically, the species is most similar in size and colour pattern to Odontobatrachus fouta . However, they differ in a few characters, namely colouration in male femoral glands and belly pattern with both taxa possessing a dark belly colouration, but only Odontobatrachus fouta specimens show a smeared pattern.

Genetics.

The species is genetically well differentiated from all congeners and known populations form a well-supported and monophyletic clade ( Barej et al. 2015). Uncorrected 16S p-distances between Odontobatrachus smithi and other Odontobatrachus species range from 3.79-5.55%, while maximum intrataxon differences of Odontobatrachus smithi add up to 0.54% (mean value 0.20%; N = 45; Appendix 1: Table A).

Holotype description.

The male holotype has been assigned to this taxon in the DCA analysis of ratios. The holotype is an adult male with a robust body (Fig. 7): snout-urostyle length of 60.4 mm; head width 21.9 mm; head slightly longer than broad; snout in lateral view short, flattened and slightly pointed at the snout tip; snout in dorsal view triangular, pointed; lower jaw with sharp tusk-like prolongations protruding the skin and single triangular knob at lower jaw symphysis, corresponding socket in between premaxillae weakly developed; upper premaxillae and maxillae with numerous teeth, posteriorly curved; vomerine teeth present, single prolongations; odontophores arranged in short lines, closer to each other than to choanae; tongue broadly heart shaped; horizontal eye diameter 7.9 mm; interorbital distance 5.6 mm; pupil horizontally elliptical; eye diameter distinctly larger than tympanum diameter; tympanum distinct (horizontal diameter 4.0 mm); nares closer to snout than to eye; snout as long as eye diameter; canthus rostralis rounded; loreal region concave; paired lateral vocal sacs; forelimbs robust, forearms hypertrophied, fingers slender; prepollex absent; relative finger lengths III>IV>II>I; velvety nuptial excrescences covering finger I; subarticular tubercles large, subconical; supernumerary tubercles absent; fingertips dilated, triangular, notched in the middle; femur length 29.9 mm; tibia length 30.4 mm; femoral glands large (length × width: left: 15.7 × 7.0 mm, right: 15.4 × 7.3 mm); femoral glands positioned on the posterior part of the ventral side of femur; relation femoral gland length to femur length: 0.52; minuscule circular glands running along upper side of tibia; foot length (incl. longest toe) 40.0 mm; relative toe lengths IV>III≥V>II>I; shortest toe (7.1 mm); inner metatarsal tubercle elliptical; toe tips broadened forming triangular dilated discs; inner metatarsal tubercle prominent (4.7 mm); number of subconical subarticular tubercles on toes I-V: 1, 1, 2, 3, 2; supernumerary tubercles absent; prominent skin fold on posterior side of feet; dorsal skin texture rough; dorsum and flanks covered with broad dorsal ridges of app. 3.0-4.0 mm (partially flattened, but recognisable as darker spots); venter somewhat rough and slightly granular; flank texture rough and granular as dorsum; webbing fully developed (0-1/0-1/0-1/1-0), skin fringe running along toe III, webbing between toes hardly concave. Damage to the male holotype: transverse cut at pectoral region (liver tissue sampled) and skin cut on throat; glandular dorsal ridges partially not recognisable due to preservation.

Colouration of holotype in alcohol

(Fig. 7). Dorsum dark brownish, few pale marblings recognisable; hind limbs with dark blotches on upper side; entire throat dark showing minuscule pale dots; venter dark; pale colouration between axillaries and elbows, femoral glands pale, clearly silhouetted from femora, with blurred minuscule dark dots; femora and tibia dark as belly.

Variation.

Females (Nfemales = 6) grow larger than males (Nmales = 3), mean SUL in females 54.1 mm and 48.9 mm in males and accordingly absolute values for extremities are larger too. However, ratios between the two sexes overlap in their range, and are very similar in their mean values showing only minor differences (Tables 1 and 2). Both sexes possess enlarged tusk-like prolongations in the lower jaw as well as the name-bearing ‘teeth’ on the upper jaw. Male secondary sexual characters are femoral glands, velvety nuptial excrescences on finger I and presence of vocal sacs. Male femoral glands are pale orange (Fig. 8d). Webbing formulae showed little variance in this character (Table 7). Dorsal ridges are usually elongated and slender (Fig. 8a, b). Number of distinct dorsal ridges (counted from spine to flank) ranges between four and seven, usually five to six ridges per body site. However, this character was not recognisable in all vouchers due to preservation artefacts. Glandular ridges on tibia usually are built of small to large conic glands and form more or less interrupted lines (Fig. 8a, b). Dorsal colouration (in life) ochre coloured with dark brown markings along dorsal glandular ridges or greenish with dark grey markings. Male femoral glands are pale orange (Fig. 8c). Belly colouration (in alcohol) is mainly uniform dark, only few specimens possess paler markings or show a dirty smeared colouration, showing no sex-dependant differentiation.

Distribution.

Distribution of Odontobatrachus smithi is restricted to localities in western Guinea on the western and southern edge of the Fouta Djallon Highlands and its western extensions to the Kindia region (Fig. 1). Its easternmost localities are in proximity of Odontobatrachus fouta . However, Odontobatrachus smithi seems to occupy lowland to mid-altitudes (app. 100-650 m a.s.l.) while Odontobatrachus fouta occurs in mid-altitudes (app. 650-900 m a.s.l.).

Etymology.

The species epithet smithi refers to Major F. Smith of the Royal Army Medical Corps (R.A.M.C.). In addition to his studies on blackwater fever he contributed to our knowledge on West African amphibians and collected the first specimens of Petropedetes natator Boulenger, 1905 in Sierra Leone during his military service in West Africa.

Common name.

We advise to use the term ‘‘Smith’s torrent-frog’’ in English and ‘‘ grenouilles des torrents de Smith" in French.

Conservation status.

The EOO of Odontobatrachus smithi is 12673 km2, placing the species in the category "Vulnerable (VU)" while the AOO of 40 km2 even classifies the species as "Endangered (EN)" ( Barej et al. 2015).