Tuesday, August 4, 2015

[Herpetology • 2015] Life in the Spray Zone – Overlooked Diversity in West African Torrent-Frogs (Anura, Odontobatrachidae, Odontobatrachus)


 Odontobatrachus arndti 
Barej, Schmitz, Penner, Doumbia, Sandberger-Loua, Emmrich, Adeba & Rödel, 2015
Odontobatrachus arndti sp. n. in life: a) and c) Nimba Mts, Guinea; b) Mt. Sangbé, Côte d’Ivoire. Non vouchered specimens. Note parasitic mites (minuscule red dots) close to the cloaca in (c).

Abstract
West African torrent-frogs of the genus Odontobatrachus currently belong to a single species: Odontobatrachus natator (Boulenger, 1905). Recently, molecular results and biogeographic separation led to the recognition of five Operational Taxonomic Units (OTUs) thus identifying a species-complex. Based on these insights, morphological analyses on more than 150 adult specimens, covering the entire distribution of the family and all OTUs, were carried out. Despite strong morphological congruence, combinations of morphological characters made the differentiation of OTUs successful and allowed the recognition of five distinct species: Odontobatrachus natator, and four species new to science: Odontobatrachus arndti sp. n., O. fouta sp. n., O. smithi sp. n. and O. ziama sp. n. All species occur in parapatry: Odontobatrachus natator is known from western Guinea to eastern Liberia, O. ziama sp. n. from eastern Guinea, O. smithi sp. n. and O. fouta sp. n. from western Guinea, O. arndti sp. n. from the border triangle Guinea-Liberia-Côte d’Ivoire. In addition, for the first time the advertisement call of a West African torrent-frog (O. arndti sp. n.) is described.

Key Words: Upper Guinea, biodiversity hotspot, rainforest, taxonomy, Amphibia, new species


Systematics of the Odontobatrachus natator-complex


Figure 4. Odontobatrachus natator in life: a) female ZMB 78303, Ziama Forest, Guinea; b) male ZMB 78214, N’Zérékoré Region, Guinea; c) Gola Rainforest National Park, Sierra Leone; d) Freetown Area (type locality of Petropedetes natator Boulenger, 1905), Sierra Leone; e) ZMB 80504, Nimba County, Liberia; f) colouration of male femoral glands hardly visible (male shown in d); g) colouration distinctly contrasted against the femur (male shown in e).
Odontobatrachus natator (Boulenger, 1905)

Distribution: Odontobatrachus natator has the widest distribution of all congeners (Fig. 1). The species is known from Sierra Leone, Liberia and Guinea. While the species distribution overlaps with O. ziama and O. arndti in eastern Guinea, westernmost localities reach extensions of the Fouta Djallon area, close to the range of O. fouta. Two distinct molecular clades have been uncovered in O. natator (Barej et al. 2015), one of them being restricted to the Freetown Peninsula in coastal Sierra Leone (FP sensu Barej et al. 2015) and the other covering all remaining localities (IL sensu Barej et al. 2015) of this taxon.

Conservation status: The EOO, combining both subclades of O. natator (Barej et al. 2015; therein natator) sums up to 180,231 km2, resulting in the IUCN Red List category “Least Concern (LC)”. However, due to the habitat requirements of this family the AOO is restricted to 224 km2 and thus classifies the species as “Endangered (EN)”. When considering the genetic subdivision of O. natator (see Barej et al. 2015), the distribution areas further diminish dramatically, especially for the Freetown Peninsula subclade. While IUCN categories remain constant for the widely distributed subclade, the Freetown Peninsula subclade possesses an AOO of only 20 km2 classifying it as EN and an EOO of 34 km2 placing it as “Critically Endangered (CR)” if treated as its own taxonomic unit.


Figure 6. Odontobatrachus ziama sp. n. in life: a) female paratype ZFMK 95465 Ziama Forest, Guinea; b) female paratype MHNG 2731.46, from Ziama Forest, Guinea; c) female ZMB 78267, Kankan Region, Guinea; d) female ZMB 78263, Kankan Region, Guinea; e) ventral view of ZFMK 95465; f) colouration of femoral glands in male ZMB 78269. Mind the variation in shape of snout in lateral view from rounded (b) to pointed (d) and the variation in shape of dorsal ridges ranging from sub-elliptical (a, b), elongated (c) to conic (d).

Odontobatrachus ziama Barej, Schmitz, Penner, Doumbia, Hirschfeld, Brede, Bangoura & Rödel, sp. n.

Distribution: Distribution of Odontobatrachus ziama is restricted to isolated mountains north of the Nimba Mts. in south-eastern Guinea (Fig. 1). Its range apparently overlaps with O. natator as the latter is found in proximity to the Simandou Mountain Range, Massif du Ziama or Mt. Going. However, no syntopic populations are known so far. At present no differing habitat requirements or ecological adaptations are known (Barej et al. 2015), which could explain their spatial separation. Presence of O. natator in lower altitudes (e.g. Liberia, Grand Gedeh 250-500 m a.s.l.) could be a factor but both species co-occur in altitudes of app. 500–1300 m a.s.l. in the distribution range of O. ziama.

Natural history remark: Odontobatrachus ziama is known as a host of the endoparasitic mite Endotrombicula pillersi, otherwise known from members of the family Phrynobatrachidae (Wohltmann et al. 2007).

Etymology: The species epithet ziama is a noun in apposition, therefore invariable, referring to the species' type locality, the Ziama Forest, in eastern Guinea.

Common name: We advise to use the term ‘‘Ziama torrent-frog’’ in English and ‘‘grenouilles des torrents de Ziama’’ in French.

Conservation status: The EOO of O. ziama is 7797 km2, placing the species in the category “Vulnerable (VU)” while the AOO of 104 km2 classifies the species as “Endangered (EN)” (Barej et al. 2015).


Figure 8. Odontobatrachus smithi sp. n. in life: a) male ZMB 78307, Kindia Region, Guinea; b) female paratype MHNG 2731.47, Fouta Djallon: Pita, Hörè Binti, Guinea); c) colouration of femoral glands in ZMB 78307; d) ventral view of female paratype MHNG 2731.47.

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


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 O. fouta. However, O. smithi seems to occupy lowland to mid-altitudes (app. 100–650 m a.s.l.) while O. 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).


Figure 10. Odontobatrachus fouta sp. n. in life: a) female paratype ZMB 78315, Fouta Djallon: Labé, Sala, Guinea; b) male holotype ZMB 78314, Fouta Djallon: Labé, Sala, Guinea; c) male Dalaba\Chute de Ditinn, Guinea; d) colouration of femoral glands in the male holotype ZMB 78314.

Odontobatrachus fouta 
Barej, Schmitz, Penner, Doumbia, Brede, Hillers & Rödel, sp. n.

Distribution: The distribution of Odontobatrachus fouta is restricted to isolated peaks in the central Fouta Djallon Highlands in western Guinea (Fig. 1). Localities of O. natator at the southern edge and of O. smithi close to western-central of the Fouta Djallon Highlands are in close proximity to O. fouta. However, O. fouta occurs in higher altitudes (southern edge: O. natator app. 500 m a.s.l. and O. smithi app. 92 m a.s.l. vs. O. fouta app. 650 m a.s.l.; western-central: O. smithi app. 510–650 m a.s.l. vs. O. fouta app. 750–900 m a.s.l.).

Etymology: The species epithet fouta is a noun in apposition, therefore invariable, referring to the species' type locality, the Fouta Djallon Highlands, in western Guinea.

Common name: We advise to use the term ‘‘Fouta Djallon torrent-frog’’ in English and ‘‘grenouilles des torrents de Fouta Djallon” in French.

Conservation status: Both, the EOO of 1318 km2 and the AOO of 20 km2 classify O. fouta as “Endangered (EN)” (Barej et al. 2015).


Figure 12. Odontobatrachus arndti sp. n. in life: a) and c) Nimba Mts, Guinea; b) Mt. Sangbé, Côte d’Ivoire. Non vouchered specimens. Note parasitic mites (minuscule red dots) close to the cloaca in (c).

Odontobatrachus arndti 
Barej, Schmitz, Penner, Doumbia, Sandberger-Loua, Emmrich, Adeba & Rödel, sp. n.

Distribution: Odontobatrachus arndti is known to occur on the Nimba Mts. in Guinea and Liberia, the adjacent areas at Mt. Gangra (Liberia) and Déré (Guinea), as well as the Mt. Sangbé in western Côte d’Ivoire (Fig. 1). This taxon represents the easternmost representative of the family. Localities at the southern end of the Nimba Mts. and along Mt. Gangra are in very close proximity to O. natator. Both species inhabit similar altitudes at the foot of the Nimba Mts. However, at present no differing habitat requirements or ecological adaptations are known (Barej et al. 2015), which could explain their spatial separation.

Etymology: The species epithet arndti was chosen in order to honour Prof. emerit. Dr. Rudolf G. Arndt, New Jersey USA, for his trust in young academics and his invaluable support of this study.

Common name: We advise to use the term ‘‘Arndt’s torrent-frog’’ in English and ‘‘grenouilles des torrents d’Arndt” in French.

Conservation status: Both, the EOO of 2595 km2 and the AOO of 156 km2 classify O. arndti as “Endangered (EN)” (Barej et al. 2015).


Michael F. Barej, Andreas Schmitz, Johannes Penner, Joseph Doumbia, Laura Sandberger-Loua, Mareike Hirschfeld, Christian Brede, Mike Emmrich, N’Goran Germain Kouamé, Annika Hillers, Nono Legrand Gonwouo, Joachim Nopper, Patrick Joel Adeba, Mohamed Alhassane Bangoura, Ceri Gage, Gail Anderson and Mark-Oliver Rödel. 2015. Life in the Spray Zone – Overlooked Diversity in West African Torrent-Frogs (Anura, Odontobatrachidae, Odontobatrachus). Zoosystematics and Evolution. 91(2): 115-149. DOI: 10.3897/zse.91.5127

Life in the fast spray zone: Four new endemic tooth-frog species in West African forests
http://phy.so/357196640 via @physorg_com

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