A new species of Potamonautes from Sao Tome Island, Central Africa, with redescriptions of P. margaritarius (A. Milne-Edwards, 1869) from Sao Tome, and P. principe Cumberlidge, Clark and Baillie, 2002, from Principe (Decapoda: Potamonautidae)

CITATION: Cumberlidge, N. & Daniels, S. R. 2018. A new species of Potamonautes from Sao Tome Island, Central Africa, with redescriptions of P. margaritarius (A. Milne-Edwards, 1869) from Sao Tome, and P. principe Cumberlidge, Clark and Baillie, 2002, from Principe (Decapoda: Potamonautidae). Contributions to Zoology, 87(4):287-303, doi:10.1163/18759866-08704005 .The original publication is available at https://brill.comSurveys of the freshwater crabs of two islands in the Gulf of Guinea, Central Africa, allowed a revision of the taxonomy of two little-known island endemic species, based for the first time on adult males: Potamonautes margaritarius (A. Milne-Edwards, 1869) from São Tomé, and of P. principe Cumberlidge, Clark and Baillie, 2002, from Príncipe (Brachyura; Potamonautidae). A new species of Potamonautes from southern São Tomé (Potamonautes saotome sp. nov.) is also described that is genetically distinct and has a clearly separate geographic distribution from P. margaritarius from northern São Tomé. The new species from southern São Tomé can be recognized by a suite of characters of the carapace, thoracic sternum, and gonopods. The taxonomy of P. margaritarius (A. Milne-Edwards, 1869) is stabilized by selecting a neotype from northern São Tomé. Potamonautes principe from Príncipe is the most distinct of the three taxa, with a more swollen carapace that has smooth anterolateral margins, and a shorter, straighter male first gonopod. All three taxa are morphologically distinct species that have also been clearly distinguished as evolutionarily separate lineages by mtDNA analysis and haplotyping in an earlier study. Previous phylogenetic evidence supports two separate island colonization events at different times in the past from different ancestral populations, one to São Tomé and another to Príncipe that resulted in the establishment of the endemic freshwater crab faunas of these two islands.https://brill.com/view/journals/ctoz/87/4/article-p287_5.xml?lang=enPublisher's versio

Multilocus phylogenetics in a widespread African anuran lineage (Brevicipitidae: Breviceps) reveals patterns of diversity reflecting geoclimatic change

AimTo investigate models assessing the influence of geomorphology and climatic shifts on species diversification in sub‐Saharan Africa by reconstructing the pattern and timing of phylogenetic relationships of rain frogs (Brevicipitidae: Breviceps).LocationSub‐Saharan Africa, south of the Congo Basin.MethodsMultilocus sequence data were generated for near complete species‐level sampling of the genus Breviceps. Phylogenetic relationships were inferred via Bayesian inference and maximum likelihood analyses on both concatenated and single‐gene datasets. Network analyses identified locus‐specific reticulate relationships among taxa. Bayesian methods were used to infer dates of divergence among Breviceps lineages, and niche modelling was used to identify possible adaptive divergence.ResultsBreviceps is monophyletic and comprised of two major, largely allopatric subclades. Diversity within each subclade is concentrated in two areas with contrasting geologic and climatic histories: the arid/semiarid winter rainfall zone in the south‐western (SW) Cape, and the semitropical East Coast that receives predominantly summer rainfall. Recognized species diversity in the SW Cape based on phenotypic variation is consistent with observed genetic patterns whereas the East Coast is shown to harbour unexpectedly high genetic diversity and up to seven putative, cryptic species. Niche models show significant overlap between closely related species.Main conclusionsDating analyses indicate that diversification of Breviceps occurred rapidly within the Miocene, with only a moderate decline over the Plio‐Pleistocene, suggesting that this process might be slowed but ongoing. Our findings suggest that a combination of two models, a landscape barrier model and climate fluctuation model, can explain patterns of diversification in Breviceps. This demonstrates that Miocene epeirogenic events and climatic shifts may have had a considerable influence on contemporary patterns of biodiversity. Topographic complexity and relative geoclimatic stability in the East have promoted cryptic diversification in allopatry, and this area clearly harbours numerous undescribed taxa and is in need of detailed biotic investigation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145569/1/jbi13394.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145569/2/jbi13394_am.pd

Three dispersal routes out of Africa: A puzzling biogeographical history in freshwater planarians

Aim Freshwater planarians may have a wide geographical range despite their assumed low vagility. Found across four continents, Dugesia may have either an ancient origin on a large palaeo landmass, followed by colonisation in different regions before continental fragmentation, or a more recent origin and subsequent transoceanic dispersal. We seek to resolve between these two hypotheses. Location Africa, Eurasia and Australasia. Taxon Genus Dugesia (Platyhelminthes: Tricladida: Dugesiidae). Methods We used data from the sequencing of six gene fragments and comprehensive taxonomic sampling of Dugesia from across its distribution range to reconstruct the phylogeny of this genus using maximum likelihood and bayesian inference methods. We conducted two phylogenetic dating analyses using Platyhelminthes fossils and palaeogeological events. Basing on the time-calibrated molecular phylogenetic framework we evaluated the contribution of vicariance and dispersal to the biogeographical evolution of Dugesia. By reconstructing the ancestral areas and present-day potential distribution using BioGeoBEARS and niche modelling, we elucidated the biogeographical history of the genus. Results The present-day distribution of Dugesia is a result of different vicariance and dispersal events. However, we also found evidence of transoceanic dispersal. Consistent with previous hypotheses, Dugesia dates to the Upper Jurassic in the Afro-Malagasy Gondwana region. We unveiled a novel biogeographical scenario for the genus, involving multiple events of colonisation in Eurasia from continental Africa via at least three dispersal routes. Main conclusions Dugesia is an ancient genus having reached its present distribution through a complex history of dispersal and vicariant events following its origin in southern Gondwana. Despite the low vagility of Dugesia, we found evidence of their overseas dispersal