Afrotropic / Sub-Saharan Africa


Afrotropic ecozone or Sub-Saharan Africa is an area of our particular interest. We are focusing on patterns of diversity of amphibians and reptiles, studying species diversification mainly in forested regions of both lowland and mountain areas. We study phylogeography of Central and East African rainforests with special interests in the Congo Basin, Cameroon Volcanic Line (CVL) highlands, and Eastern Arc Mountains (EAM).

We did fieldworks in Cameroon, Republic of the Congo, Democratic Republic of the Congo, and Tanzania.

Projects

Amphibian species diversification across sky-island and lowland rainforests in a spatial and ecological context: genome-wide and continental transect

gacr_pic

 

 

Research highlights

Read our 2017 publications:

The Amphibians of Mount Oku, Cameroon: species diversity and conservation

Phrynobatrachus_njiomockMtOkuThe species diversity and conservation status of the amphibians of Mount Oku in Cameroon was assessed. Twenty-five species were recorded for the first time from the region, two species for the first time from Cameroon (Phrynobatrachus schioetzi and Ptychadena taenioscelis), and the proportion of threatened species was found to be 44–48% – that’s more than the global average of 33%. The natural habitats of Mt Oku are irreplaceable refuges for its endemic and restricted-range amphibians, which are under severe pressure elsewhere in their range.

However, it is alarming that some species are undergoing severe population declines, e.g. Phrynobatrachus njiomock (Fig.) has not been seen since 2010 (although formally described as late as in 2013 based on museum specimens), and thus, might be near extinction!

Doherty-Bone T.M., Gvoždík V., 2017: The Amphibians of Mount Oku, Cameroon: an updated species inventory and conservation review. ZooKeys 643: 109–139

Our study was presented by MONGABAY: Nearly half of Mount Oku frogs are in danger of croaking, study finds

 


Phylogeography of Africa and Madagascar:

Diversification of the Mascarene ridged frog (Ptychadena mascareniensis”), niche conservatism and divergence

Ptychadena_Lomie2The Mascarene ridged frog, Ptychadena mascareniensis”, is a species complex that includes numerous lineages occurring mostly in humid savannas and open forests of mainland Africa, Madagascar, the Seychelles, and the Mascarene Islands. Sampling across this broad distribution presents an opportunity to examine phylogeographic pattern across the continent and islands and to investigate how the evolution of bioclimatic niches may have shaped current biogeographic patterns. Twelve distinct lineages were detected including widespread P. nilotica and São Tomé endemic P. newtoni, which are also a part of the P. mascareniensis species complex. Most speciation events took place throughout the Miocene, including “out-of-Africa” overseas dispersal events to Madagascar in the east (sister lineage detected in Tanzania) and to São Tomé in the west (P. newtoni and P. nilotica are sister species). Bioclimatic niche was remarkably well conserved, with most species tolerating similar temperature and rainfall conditions common to the Central African region, while niche divergence shaped populations in West Africa and Madagascar. Central Africa, including the Albertine Rift region, has been a diversity hotspot for this species complex.

Ptychadena cf. mascareniensis (OTU 7) is known only from the north-western Congo Basin.

 

The research was led by Breda M. Zimkus, Museum of Comparative Zoology, Harvard University, Cambridge, USA.

Zimkus B.M., Lawson L.P., Barej M.F., Barratt C.D., Channing A., Dash K.M., Dehling J.M., Du Preez L.; Gehring P.-S., Greenbaum E., Gvoždík V., Harvey J., Kielgast J., Kusamba C., Nagy Z.T., Pabijan M., Penner J., Rödel M.-O., Vences M., Lötters S., 2017: Leapfrogging into new territory: How Mascarene ridged frogs diversified across Africa and Madagascar to maintain their ecological niche. Molecular Phylogenetics and Evolution 106: 254–269

 


Read our 2016 publications:

Diversification and life-history evolution of African true toads (Bufonidae)

The most complete molecular phylogeny of African bufonid anurans to date showed that Africa was colonized in two waves, and the first wave/radiation was studied in details as a model to understand diversification and life-history evolution during colonization of the African continent. Despite the wide morphological and life-history diversity of present species tests did not support the ecological-opportunity model for the bufonid radiation on this big geographical (continental) scale. A constant rate model of lineage and life-history trait (represented by clutch size and egg size) diversification over time was shown more appropriate. However, an analysis of generalist and specialist species showed a shift toward higher speciation rates associated with habitat specialization.

bufonids_tree

The research was led by Simon P. Loader and H. Christoph Liedtke, Department of Environmental Sciences (Biogeography), University of Basel, Switzerland (currently at the University of Roehampton, London, UK; and Estación Biológica de Doñana, Sevilla, Spain, respectively).

Liedtke H.C., Müller H., Rödel M.-O., Menegon M., Gonwouo L.N., Barej M.F., Gvoždík V., Schmitz A., Channing A., Nagel P., Loader S.P., 2016: No ecological opportunity signal on a continental scale? Diversification and life-history evolution of African true toads (Anura: Bufonidae). Evolution 70-8: 1717–1733

bufonids_photo

African bufonids represent a group with high morphological and life-history diversity. Sclerophrys regularis – a generalist species having larval development as free-swimming tadpoles (distribution: northern half of Sub-Saharan Africa; left); and Nectophrynoides pseudotornieri – a habitat specialist assumed to give birth to live young via lecithotrophic viviparity (endemic to the Uluguru Mts., Tanzania; right).

 


Read our 2015 publications:

African clawed frogs (Xenopus)

In cooperation with the McMaster University (The Laboratory of Ben Evans) in Hamilton, Canada, we contributed to the knowledge of the historical biogeography and systematics of African clawed frogs (Xenopus), including the model species widespread across experimental laboratories all around the world, Xenopus laevis. However, the evolutionary history of the X. laevis species group within its pan-African range had earlier been unknown. Population structure and evolutionarily diverged lineages were evidenced by analyses of molecular variation, and these results further contextualized the chronology and evolutionary relationships within this group. Beside others, our results shed also new light on the taxonomy and recognized four species within this species complex: X. laevis, X. petersii, X. victorianus, and revalidated X. poweri.

A thorough and multi-method review of the West and Central African Xenopus necessitated descriptions of six new species and a revalidation of one species in the subgenus Silurana: X. (S.) calcaratus, X. (S.) mellotropicalis; the X. amieti group: X. allofraseri, X. parafraseri, X. eysoole, X. kobeli; and the X. muelleri group: X. fischbergi.

 Gvozdik_Vaclav-Xenopus_calcaratus

 

 

Biafran clawed frog, Xenopus calcaratus, one of the new species occurring in the Gulf of Guinea region, Central Africa, is the closest tetraploid relative to the only known extant diploid clawed frog, X. tropicalis.

 

Furman B.L.S., Bewick A.J., Harrison T.L., Greenbaum E., Gvoždík V., Kusamba C., Evans B.J., 2015: Pan-African phylogeography of a model organism, the African clawed frog ‘Xenopus laevis’. Molecular Ecology 24: 909–925

Evans B.J., Carter T.F., Greenbaum E., Gvoždík V., Kelley D.B., McLaughlin P.J., Pauwels O.S.G., Portik D.M., Stanley E.L., Tinsley R.C., Tobias M.L., Blackburn D.C., 2015: Genetics, morphology, advertisement calls, and historical records distinguish six new polyploid species of African clawed frog (Xenopus, Pipidae) from West and Central Africa. PLoS ONE 10 (12): e0142823

 


Colonization history of the Gulf of Guinea islands

The colonization history of reed frog species endemic to the oceanic islands of São Tomé and Príncipe in the Gulf of Guinea, Hyperolius molleri and H. thomensis, was inferred based on the phylogeographical structure in the closely related H. cinnamomeoventris species complex, which is distributed across continental Central Africa. The analysis supported a single dispersal event from the Ogooué or Congo Basins to the island of São Tomé, with subsequent divergence within the island and dispersal to Príncipe.

The research was led by Rayna C. Bell, Cornell University, Ithaca, USA (currently at the University of California, Berkeley, USA).

Bell_paper

 

Bell R.C., Drewes R.C., Channing A., Gvoždík V., Kielgast J., Lötters S., Stuart B.L., Zamudio K.R., 2015: Overseas dispersal of Hyperolius reed frogs from Central Africa to the oceanic islands of São Tomé and Príncipe. Journal of Biogeography 42: 65–75

 

 

 

 

 


Read our 2014 publications:

Taxonomy of the tree-frog genus Leptopelis described from East Africa

A revision of the type material of montane-forest Leptopelis tree frogs from East Africa resulted in several taxonomic and nomenclatural acts, in the first place synonymization of L. barbouri with L. flavomaculatus and resurrection with redescription of L. grandiceps. This study serves as a stepping-stone for an ongoing thorough systematic and biogeographic assessment of the genus in East Africa.

Leptopelis_grandicepsThe research is being done in close cooperation with Simon P. Loader, University of Basel, Switzerland (currently at the University of Roehampton, London, UK).

 

 

Leptopelis grandiceps from Tanzania was resurrected and redescribed as a valid species.

 

Gvoždík V., Tillack F., Menegon M., Loader S.P., 2014: The status of Leptopelis barbouri Ahl, 1929 and eleven other nomina of the current tree-frog genus Leptopelis (Arthroleptidae) described from East Africa, with a redescription of Leptopelis grandiceps Ahl, 1929. Zootaxa 3793 (1): 165–187

 


Diversity of African torrent frogs of the family Petropedetidae

African torrent frogs have a disjunct distribution with species endemic to West (Odontobatrachus), Central (Petropedetes) and East Africa (Arthroleptides). A molecular phylogeny provided insights into their evolutionary and biogeographical histories and revealed several candidate undescribed species.

Petropedetes_DSC_0661

The research was led by Michael Barej, Museum für Naturkunde Berlin, Germany.

 

Barej M.F., Rödel M.-O., Loader S.P., Menegon M., Gonwouo N.L., Penner J., Gvoždík V., Günther R., Bell R.C., Nagel P., Schmitz A., 2014: Light shines through the spindrift – Phylogeny of African torrent frogs (Amphibia, Anura, Petropedetidae). Molecular Phylogenetics and Evolution 71: 261–273

 

We continue in research of the genus Petropedetes in the Cameroonian Highlands.

 


Enigmatic snake Helophis schoutedeni from the Congo

New data on the morphology, systematic position and distribution of an almost unknown colubrid snake, Helophis schoutedeni, from the Congo Basin was published based on both a study of museum specimens and new data from the field.

The research was done in close cooperation with Zoltán T. Nagy, Royal Belgian Institute of Natural Sciences, Brussels, Belgium, and all other co-authors.

Helophis

Helophis schoutedeni from the central Congo Basin was described in 1922 but first photographs of a live specimen and detailed data on morphology and distribution were published in 2014. Photo by Václav Gvoždík

 

Nagy Z.T., Gvoždík V., Meirte D., Collet M., Pauwels O.S.G., 2014: New data on the morphology and distribution of the enigmatic Schouteden’s sun snake, Helophis schoutedeni (de Witte, 1922) from the Congo Basin. Zootaxa 3755 (1): 96–100

 


Read our older publications:

Sky Islands of Cameroon: a diversification hotspot for puddle frogs (Phrynobatrachus)

The Cameroon Volcanic Line (CVL) highlands represent biological ‘sky islands’ with high levels of species richness and endemism. Relationships of puddle frogs (Phrynobatrachus) endemic to the CVL were reconstructed to examine the patterns and timing of puddle frog diversification. Our results highlighted the Bamenda-Banso Highlands, and specifically emphasize Mt. Oku, as a centre of diversification for puddle frogs, supporting the conservation importance of this region. In addition, two new species, P. jimzimkusi and P. njiomock were described. Based on the dated phylogeny most speciation events were significantly older (Miocene) and cannot be linked to Africa’s aridification in response to Pleistocene climate fluctuations.

The research was led by Breda M. Zimkus, Museum of Comparative Zoology, Harvard University, Cambridge, USA.

stein_DSC_0512LakeOku_PICT0235Phrynobatrachussteindachneri’ comprises a species complex with high genetic diversity in montane forests in the border area between Cameroon and Nigeria. Lake Oku is a crater lake at 2,219 m on Mt. Oku, and is surrounded by cloud forest.

Zimkus B.M., Gvoždík V., 2013: Sky Islands of the Cameroon Volcanic Line: a diversification hotspot for puddle frogs (Phrynobatrachidae: Phrynobatrachus). Zoologica Scripta 42 (6): 591–611

 


Arthroleptis palava, a new squeaker frog from the mountains of Cameroon and Nigeria

A new species of squeaker frog (genus Arthroleptis) was described from the mountains of the Cameroon Volcanic Line. This new species is associated with human-altered landscapes, including farms and grasslands. The taxonomy of this new species had proven problematic before our description because of morphological similarity to A. poecilonotus. Although resembling A. poecilonotus, the molecular phylogeny demonstrated that the new species is not closely related to this species and, instead, forms a clade with the A. variabilis clade. Therefore the new species was named A. palava with “palava” meaning “problem” in the pidgins of north-western Central Africa. The description of this new species further highlighted the Cameroonian mountains as an important region of endemism.

The research was led by David C. Blackburn, University of Kansas, Lawrence, USA (currently at the University of Florida, Gainesville, USA).

A_palava_PICT0253

 

Blackburn D.C., Gvoždík V., Leaché A.D., 2010: A new squeaker frog (Arthroleptidae: Arthroleptis) from the mountains of Cameroon and Nigeria. Herpetologica 66 (3): 335–348 [& Erratum: Herpetologica 66 (4): 487]

Václav Gvoždík, Research on the Evolutionary biology of amphibians & reptiles | Last updated July 2017