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  1. Article ; Online: Comparative phylogeography of West African amphibians and reptiles.

    Leaché, Adam D / Oaks, Jamie R / Ofori-Boateng, Caleb / Fujita, Matthew K

    Evolution; international journal of organic evolution

    2020  Volume 74, Issue 4, Page(s) 716–724

    Abstract: Comparative phylogeographic studies often support shared divergence times for co-distributed species with similar life histories and habitat specializations. During the late Holocene, West Africa experienced aridification and the turnover of rain forest ... ...

    Abstract Comparative phylogeographic studies often support shared divergence times for co-distributed species with similar life histories and habitat specializations. During the late Holocene, West Africa experienced aridification and the turnover of rain forest habitats into savannas. These fragmented rain forests harbor impressive numbers of endemic and threatened species. In this setting, populations of co-distributed rain forest species are expected to have diverged simultaneously, whereas divergence events for species adapted to savanna and forest-edge habitats should be absent or idiosyncratic. We conducted a Bayesian analysis of shared evolutionary events to test models of population divergence for 20 species of anurans (frogs) and squamates (lizards and snakes) that are distributed across the Dahomey Gap, a climate change-induced savanna barrier responsible for fragmenting previously contiguous rain forests of Ghana into two regions: the Togo-Volta Hills and the Southwestern Forests. A model of asynchronous diversification is supported for anurans and squamates, suggesting that drivers of diversification are not specifically related to ecological and life history associations with habitat types. Instead, the wide variability of genetic divergence histories exhibited by these species suggests that biodiversity in this region has been shaped by diversification events that extend beyond the Holocene. Comparisons of the genealogical divergence index, a measure of the genetic divergence between populations due to the combined effects of genetic isolation and gene flow, illustrate that these populations represent a broad sampling of the speciation continuum.
    MeSH term(s) Amphibians/genetics ; Amphibians/physiology ; Animal Distribution ; Animals ; Bayes Theorem ; Biodiversity ; Biological Evolution ; Genetic Variation ; Ghana ; Phylogeography ; Reptiles/genetics ; Reptiles/physiology
    Language English
    Publishing date 2020-02-26
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2036375-8
    ISSN 1558-5646 ; 0014-3820
    ISSN (online) 1558-5646
    ISSN 0014-3820
    DOI 10.1111/evo.13941
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: A new critically endangered slippery frog (Amphibia, Conrauidae, Conraua) from the Atewa Range, central Ghana.

    Neira-Salamea, Karla / Ofori-Boateng, Caleb / Kouam, N'goran G / Blackburn, David C / Segniagbeto, Gabriel H / Hillers, Annika / Barej, Michael F / Leach, Adam D / Rödel, Mark-Oliver

    Zootaxa

    2021  Volume 4995, Issue 1, Page(s) 71–95

    Abstract: Forty-nine years after the last description of a slippery frog, we describe a seventh species of the genus Conraua. The new Conraua is endemic to the Atewa Range Forest Reserve, central Ghana, and is described based on genetic, bioacoustics, and ... ...

    Abstract Forty-nine years after the last description of a slippery frog, we describe a seventh species of the genus Conraua. The new Conraua is endemic to the Atewa Range Forest Reserve, central Ghana, and is described based on genetic, bioacoustics, and morphological evidence. Recent molecular phylogenetic and species delimitation analyses support this population as distinct from nominotypical C. derooi in eastern Ghana and adjacent Togo. The new species is sister to C. derooi, from which it differs ~4% in the DNA sequence for mitochondrial ribosomal 16S. Genetic divergences in 16S to other species of Conraua range from 412%. The new species is distinguished morphologically from its congeners, including C. derooi, by the combination of the following characters: medium body size, robust limbs, lateral dermal fringing along edges of fingers, cream ventral color with brown mottling, the presence of a lateral line system, indistinct tympanum, the presence of inner, outer, and middle palmar tubercles, and two subarticular tubercles on fingers III and IV. We compare the advertisement calls of the new species with the calls from C. derooi and find that they differ by duration, frequency modulation, and dominant frequency. We discuss two potential drivers of speciation between C. derooi and the new species, including river barriers and fragmentation of previously more widespread forests in West Africa. Finally, we highlight the importance of the Atewa Range Forest Reserve as a critical conservation area within the Upper Guinean biodiversity hotspot.
    Language English
    Publishing date 2021-06-29
    Publishing country New Zealand
    Document type Journal Article
    ISSN 1175-5334
    ISSN (online) 1175-5334
    DOI 10.11646/zootaxa.4995.1.4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: A new Puddle Frog, genus Phrynobatrachus (Amphibia: Anura: Phrynobatrachidae), from the eastern part of the Upper Guinea biodiversity hotspot, West Africa.

    Kpan, Tokouaho Flora / KouamÉ, N'goran Germain / Barej, Michael F / Adeba, Patrick joËl / Emmrich, Mike / Ofori-Boateng, Caleb / RÖdel, Mark-Oliver

    Zootaxa

    2018  Volume 4388, Issue 2, Page(s) 221–237

    Abstract: We describe a new species of Phrynobatrachus from swamp forests in the southern border region of Ivory Coast and Ghana. The new species differs from all other known West African Phrynobatrachus by the combination of adult snout-vent-length being between ... ...

    Abstract We describe a new species of Phrynobatrachus from swamp forests in the southern border region of Ivory Coast and Ghana. The new species differs from all other known West African Phrynobatrachus by the combination of adult snout-vent-length being between 20 and 30 mm; absence of a spiny tubercle on the eyelid; presence of a dark face mask; a black throat in adult males; narrow and partly indistinct scapular ridges or comma shaped warts; distinct spinulae on males' throats and dorsal surfaces; pronounced pedal webbing; round finger- and toe tips, not enlarged to discs; a white belly with small blackish spots in both sexes; more than one wide dark cross bar on hind legs; and rosé to reddish colour on ventral parts of hind legs in both sexes. It is further defined by its genetic and acoustic characters. It is morphologically and genetically most similar to P. liberiensis and P. intermedius.
    MeSH term(s) Animals ; Anura ; Biodiversity ; Cote d'Ivoire ; Female ; Ghana ; Guinea ; Male ; Phylogeny
    Language English
    Publishing date 2018-03-01
    Publishing country New Zealand
    Document type Journal Article
    ISSN 1175-5334
    ISSN (online) 1175-5334
    DOI 10.11646/zootaxa.4388.2.5
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: A new species of Puddle Frog, genus Phrynobatrachus (Amphibia: Anura: Phrynobatrachidae) from Ghana.

    Ofori-Boateng, Caleb / LeachÉ, Adam D / Obeng-Kankam, Bright / KouamÉ, N'goran Germain / Hillers, Annika / RÖdel, Mark-Oliver

    Zootaxa

    2018  Volume 4374, Issue 4, Page(s) 565–578

    Abstract: We describe a new species of Phrynobatrachus from the eastern part of the Upper Guinea forest region, Ghana, West Africa. Morphologically, the new species can be distinguished from all of its congeners by the combination of a slender body, short and ... ...

    Abstract We describe a new species of Phrynobatrachus from the eastern part of the Upper Guinea forest region, Ghana, West Africa. Morphologically, the new species can be distinguished from all of its congeners by the combination of a slender body, short and pointed snout, a relatively warty dorsum, a black-spotted throat in both sexes, a gular flap in males, a dark spotted chest, a white-greyish venter with occasional blackish spots, rudimentary pedal webbing, none to slightly dilated finger tips and strongly delated toe tips, presence of both inner and outer metatarsal tubercles and absence of a dark face mask, eyelid tubercles and longer dorsal ridges. We collected mitochondrial DNA (mtDNA) sequence data from the 16S rRNA gene to measure the genetic diversity of the new species, and to estimate phylogenetic relationships. The new species is a distinct and monophyletic evolutionary lineage most closely related to Phrynobatrachus gutturosus, P. fraterculus and P. maculiventris. The discovery of this new species highlights that the biodiversity of West African forests is still incompletely known and that the few remaining forests need urgent protection.
    MeSH term(s) Animals ; Anura ; Biodiversity ; Female ; Ghana ; Male ; Phylogeny ; RNA, Ribosomal, 16S
    Chemical Substances RNA, Ribosomal, 16S
    Language English
    Publishing date 2018-01-21
    Publishing country New Zealand
    Document type Journal Article
    ISSN 1175-5334
    ISSN (online) 1175-5334
    DOI 10.11646/zootaxa.4374.4.6
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: A frog with three sex chromosomes that co-mingle together in nature: Xenopus tropicalis has a degenerate W and a Y that evolved from a Z chromosome.

    Furman, Benjamin L S / Cauret, Caroline M S / Knytl, Martin / Song, Xue-Ying / Premachandra, Tharindu / Ofori-Boateng, Caleb / Jordan, Danielle C / Horb, Marko E / Evans, Ben J

    PLoS genetics

    2020  Volume 16, Issue 11, Page(s) e1009121

    Abstract: In many species, sexual differentiation is a vital prelude to reproduction, and disruption of this process can have severe fitness effects, including sterility. It is thus interesting that genetic systems governing sexual differentiation vary among-and ... ...

    Abstract In many species, sexual differentiation is a vital prelude to reproduction, and disruption of this process can have severe fitness effects, including sterility. It is thus interesting that genetic systems governing sexual differentiation vary among-and even within-species. To understand these systems more, we investigated a rare example of a frog with three sex chromosomes: the Western clawed frog, Xenopus tropicalis. We demonstrate that natural populations from the western and eastern edges of Ghana have a young Y chromosome, and that a male-determining factor on this Y chromosome is in a very similar genomic location as a previously known female-determining factor on the W chromosome. Nucleotide polymorphism of expressed transcripts suggests genetic degeneration on the W chromosome, emergence of a new Y chromosome from an ancestral Z chromosome, and natural co-mingling of the W, Z, and Y chromosomes in the same population. Compared to the rest of the genome, a small sex-associated portion of the sex chromosomes has a 50-fold enrichment of transcripts with male-biased expression during early gonadal differentiation. Additionally, X. tropicalis has sex-differences in the rates and genomic locations of recombination events during gametogenesis that are similar to at least two other Xenopus species, which suggests that sex differences in recombination are genus-wide. These findings are consistent with theoretical expectations associated with recombination suppression on sex chromosomes, demonstrate that several characteristics of old and established sex chromosomes (e.g., nucleotide divergence, sex biased expression) can arise well before sex chromosomes become cytogenetically distinguished, and show how these characteristics can have lingering consequences that are carried forward through sex chromosome turnovers.
    MeSH term(s) Animals ; Female ; Genetic Fitness ; Ghana ; Male ; Recombination, Genetic ; Sex Chromosomes/genetics ; Sex Determination Processes/genetics ; Sex Differentiation/genetics ; Xenopus/genetics
    Language English
    Publishing date 2020-11-09
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2186725-2
    ISSN 1553-7404 ; 1553-7390
    ISSN (online) 1553-7404
    ISSN 1553-7390
    DOI 10.1371/journal.pgen.1009121
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Exploring rain forest diversification using demographic model testing in the African foam‐nest treefrog Chiromantis rufescens

    Leaché, Adam D / Portik, Daniel M / Rivera, Danielle / Rödel, Mark‐Oliver / Penner, Johannes / Gvoždík, Václav / Greenbaum, Eli / Jongsma, Gregory F. M / Ofori‐Boateng, Caleb / Burger, Marius / Eniang, Edem A / Bell, Rayna C / Fujita, Matthew K

    Journal of biogeography. 2019 Dec., v. 46, no. 12

    2019  

    Abstract: AIM: Species with wide distributions spanning the African Guinean and Congolian rain forests are often composed of genetically distinct populations or cryptic species with geographic distributions that mirror the locations of the remaining forest ... ...

    Abstract AIM: Species with wide distributions spanning the African Guinean and Congolian rain forests are often composed of genetically distinct populations or cryptic species with geographic distributions that mirror the locations of the remaining forest habitats. We used phylogeographic inference and demographic model testing to evaluate diversification models in a widespread rain forest species, the African foam‐nest treefrog Chiromantis rufescens. LOCATION: Guinean and Congolian rain forests, West and Central Africa. TAXON: Chiromantis rufescens. METHODS: We collected mitochondrial DNA (mtDNA) and single‐nucleotide polymorphism (SNP) data for 130 samples of C. rufescens. After estimating population structure and inferring species trees using coalescent methods, we tested demographic models to evaluate alternative population divergence histories that varied with respect to gene flow, population size change and periods of isolation and secondary contact. Species distribution models were used to identify the regions of climatic stability that could have served as forest refugia since the last interglacial. RESULTS: Population structure within C. rufescens resembles the major biogeographic regions of the Guinean and Congolian forests. Coalescent‐based phylogenetic analyses provide strong support for an early divergence between the western Upper Guinean forest and the remaining populations. Demographic inferences support diversification models with gene flow and population size changes even in cases where contemporary populations are currently allopatric, which provides support for forest refugia and barrier models. Species distribution models suggest that forest refugia were available for each of the populations throughout the Pleistocene. MAIN CONCLUSIONS: Considering historical demography is essential for understanding population diversification, especially in complex landscapes such as those found in the Guineo–Congolian forest. Population demographic inferences help connect the patterns of genetic variation to diversification model predictions. The diversification history of C. rufescens was shaped by a variety of processes, including vicariance from river barriers, forest fragmentation and adaptive evolution along environmental gradients.
    Keywords Hylidae ; Pleistocene epoch ; allopatry ; cryptic species ; demography ; evolutionary adaptation ; gene flow ; genetic variation ; geographical distribution ; habitat fragmentation ; mitochondrial DNA ; models ; phylogeny ; phylogeography ; population size ; population structure ; rain ; rain forests ; refuge habitats ; rivers ; secondary contact ; single nucleotide polymorphism ; Central Africa
    Language English
    Dates of publication 2019-12
    Size p. 2706-2721.
    Publishing place John Wiley & Sons, Ltd
    Document type Article
    Note NAL-AP-2-clean ; JOURNAL ARTICLE
    ZDB-ID 188963-1
    ISSN 0305-0270
    ISSN 0305-0270
    DOI 10.1111/jbi.13716
    Database NAL-Catalogue (AGRICOLA)

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  7. Article ; Online: Xenopus fraseri: Mr. Fraser, where did your frog come from?

    Evans, Ben J / Gansauge, Marie-Theres / Stanley, Edward L / Furman, Benjamin L S / Cauret, Caroline M S / Ofori-Boateng, Caleb / Gvoždík, Václav / Streicher, Jeffrey W / Greenbaum, Eli / Tinsley, Richard C / Meyer, Matthias / Blackburn, David C

    PloS one

    2019  Volume 14, Issue 9, Page(s) e0220892

    Abstract: A comprehensive, accurate, and revisable alpha taxonomy is crucial for biodiversity studies, but is challenging when data from reference specimens are difficult to collect or observe. However, recent technological advances can overcome some of these ... ...

    Abstract A comprehensive, accurate, and revisable alpha taxonomy is crucial for biodiversity studies, but is challenging when data from reference specimens are difficult to collect or observe. However, recent technological advances can overcome some of these challenges. To illustrate this, we used modern approaches to tackle a centuries-old taxonomic enigma presented by Fraser's Clawed Frog, Xenopus fraseri, including whether X. fraseri is different from other species, and if so, where it is situated geographically and phylogenetically. To facilitate these inferences, we used high-resolution techniques to examine morphological variation, and we generated and analyzed complete mitochondrial genome sequences from all Xenopus species, including >150-year-old type specimens. Our results demonstrate that X. fraseri is indeed distinct from other species, firmly place this species within a phylogenetic context, and identify its minimal geographic distribution in northern Ghana and northern Cameroon. These data also permit novel phylogenetic resolution into this intensively studied and biomedically important group. Xenopus fraseri was formerly thought to be a rainforest endemic placed alongside species in the amieti species group; in fact this species occurs in arid habitat on the borderlands of the Sahel, and is the smallest member of the muelleri species group. This study illustrates that the taxonomic enigma of Fraser's frog was a combined consequence of sparse collection records, interspecies conservation and intraspecific polymorphism in external anatomy, and type specimens with unusual morphology.
    MeSH term(s) Animals ; Biodiversity ; Conserved Sequence ; DNA Barcoding, Taxonomic ; Evolution, Molecular ; Genome, Mitochondrial ; Genomics/methods ; High-Throughput Nucleotide Sequencing ; Models, Anatomic ; Phylogeny ; X-Ray Microtomography ; Xenopus/anatomy & histology ; Xenopus/classification
    Language English
    Publishing date 2019-09-11
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ISSN 1932-6203
    ISSN (online) 1932-6203
    DOI 10.1371/journal.pone.0220892
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Two-stage recovery of amphibian assemblages following selective logging of tropical forests.

    Adum, Gilbert Baase / Eichhorn, Markus Peter / Oduro, William / Ofori-Boateng, Caleb / Rödel, Mark-Oliver

    Conservation biology : the journal of the Society for Conservation Biology

    2013  Volume 27, Issue 2, Page(s) 354–363

    Abstract: There is a lack of quantitative information on the effectiveness of selective-logging practices in ameliorating effects of logging on faunal communities. We conducted a large-scale replicated field study in 3 selectively logged moist semideciduous ... ...

    Abstract There is a lack of quantitative information on the effectiveness of selective-logging practices in ameliorating effects of logging on faunal communities. We conducted a large-scale replicated field study in 3 selectively logged moist semideciduous forests in West Africa at varying times after timber extraction to assess post logging effects on amphibian assemblages. Specifically, we assessed whether the diversity, abundance, and assemblage composition of amphibians changed over time for forest-dependent species and those tolerant of forest disturbance. In 2009, we sampled amphibians in 3 forests (total of 48 study plots, each 2 ha) in southwestern Ghana. In each forest, we established plots in undisturbed forest, recently logged forest, and forest logged 10 and 20 years previously. Logging intensity was constant across sites with 3 trees/ha removed. Recently logged forests supported substantially more species than unlogged forests. This was due to an influx of disturbance-tolerant species after logging. Simultaneously Simpson's index decreased, with increased in dominance of a few species. As time since logging increased richness of disturbance-tolerant species decreased until 10 years after logging when their composition was indistinguishable from unlogged forests. Simpson's index increased with time since logging and was indistinguishable from unlogged forest 20 years after logging. Forest specialists decreased after logging and recovered slowly. However, after 20 years amphibian assemblages had returned to a state indistinguishable from that of undisturbed forest in both abundance and composition. These results demonstrate that even with low-intensity logging (≤3 trees/ha) a minimum 20-year rotation of logging is required for effective conservation of amphibian assemblages in moist semideciduous forests. Furthermore, remnant patches of intact forests retained in the landscape and the presence of permanent brooks may aid in the effective recovery of amphibian assemblages.
    MeSH term(s) Amphibians/physiology ; Animals ; Biodiversity ; Ecosystem ; Forestry ; Ghana ; Microclimate ; Population Density ; Seasons ; Tropical Climate
    Language English
    Publishing date 2013-04
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 58735-7
    ISSN 1523-1739 ; 0888-8892
    ISSN (online) 1523-1739
    ISSN 0888-8892
    DOI 10.1111/cobi.12006
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: Two-Stage Recovery of Amphibian Assemblages Following Selective Logging of Tropical Forests

    Baase Adum, Gilbert / Eichhorn, Markus Peter / Oduro, William / Ofori-Boateng, Caleb / Rödel, Mark-Oliver

    Conservation biology

    2013  Volume 27, Issue 2, Page(s) 354

    Language English
    Document type Article
    ZDB-ID 58735-7
    ISSN 0888-8892
    Database Current Contents Nutrition, Environment, Agriculture

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  10. Article: Differences in the Effects of Selective Logging on Amphibian Assemblages in Three West African Forest Types

    Ofori‐Boateng, Caleb / Oduro, William / Hillers, Annika / Norris, Ken / Oppong, Samuel K / Adum, Gilbert B / Rödel, Mark‐Oliver

    Biotropica. 2013 Jan., v. 45, no. 1

    2013  

    Abstract: Making generalizations about the impact of commercial selective logging on biodiversity has so far remained elusive. Species responses to logging depend on a number of factors, many of which have not been studied in detail. These factors may include the ... ...

    Abstract Making generalizations about the impact of commercial selective logging on biodiversity has so far remained elusive. Species responses to logging depend on a number of factors, many of which have not been studied in detail. These factors may include the natural forest conditions (forest types) under which logging impacts are investigated; but this question has so far remained unexamined. In a large‐scale replicate study we aimed at clarifying the relationship between logging and forest types on leaf litter frogs. We contrast three distinct and naturally occurring forest types, including wet evergreen, moist evergreen and semi‐deciduous forests. Selectively logged sites were compared with primary forest sites for each forest type. We found that the response of frog communities to logging varies in different forest types. In the wet evergreen forest, richness was higher in logged forest than primary forest, while diversity measures were not different between logged and primary forest habitats. In the moist evergreen, richness and diversity were higher in selectively logged areas compared with primary forest habitats. In the semi‐deciduous, logged forests were characterized by drastic loss of forest specialists, reduced richness, and diversity. These results indicate that the net effect of logging varies with respect to forest type. Forest types that are characterized by adverse climatic conditions (i.e., low rainfall and protracted dry seasons) are more likely to produce negative effects on leaf litter anuran communities. For comparisons of the impact of logging on species to be effective, future research must endeavor to include details of forest type.
    Keywords Anura ; biodiversity ; climatic factors ; forest habitats ; forest types ; frogs ; logging ; plant litter ; rain
    Language English
    Dates of publication 2013-01
    Size p. 94-101.
    Publishing place Association for Tropical Biology
    Document type Article
    ZDB-ID 2052061-X
    ISSN 1744-7429 ; 0006-3606
    ISSN (online) 1744-7429
    ISSN 0006-3606
    DOI 10.1111/j.1744-7429.2012.00887.x
    Database NAL-Catalogue (AGRICOLA)

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