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

Synthesis, Crystal Structure, and Antimicrobial Properties of a Novel 1-D Cobalt Coordination Polymer with Dicyanamide and 2-Aminopyridine

A novel one-dimensional coordination polymer bis(2-aminopyridine)-μ-bis(dicyanamido) cobaltate(II) has been synthesized and characterized by elemental analyses and infrared and ultraviolet visible spectroscopies and the structure has been determined by single crystal X-ray diffraction. Co(II) ion in the complex is coordinated to two axial 2-aminopyridine ligands through the pyridine N-atom and four equatorial dicyanamide ligands to give a CoN6 slightly distorted octahedral coordination environment around the metal ion. The amino N-atom forms intrachain hydrogen bonds. Antimicrobial screening of the complex against eight pathogenic microorganisms (four bacteria and four fungi) isolated from humans, indicates that the complex is moderately active

BILKO and African capacity development in coastal and marine remote sensing

In much of Africa barriers still exist to the effective use of Earth observation in marine and coastal research and management. To remedy this, the development of data access and processing capacity must go hand in hand with hands-on training in the use of satellite data. The Bilko project has been providing training resources suitable for this for 25 years. In recent years marine scientists from Africa and Europe have been using Bilko to develop lessons based on African examples taken from image data disseminated via GEONETCast in two EC funded projects. The work is part of current efforts to develop MSc level and professional training courses for use in Africa, and shows how the contribution of African experts in the development of new lessons contributes to making these more relevant

PCA (left plot) and DAPC (right plot) obtained from using a full set of SNPs (N = 1,814).

PCA–principal component analysis; DAPC–discriminant analysis of principal components. M_ch–M. chevalieri;M_dx–M. dux;M_fe–M. felicinum; M_ma–M. macrobrachion; M_so–M. sollaudii; M_sp–M. sp; M_vo–M. vollenhovenii.</p

Cluster membership classification of <i>Macrobrachium</i> species and the Bayesian information criterion (BIC) plot obtained from the full set SNPs (N = 1,814) using the Adegenet package assuming four (K = 4) and five (K = 5) populations.

Each bar in the admixture plot (left) represents an individual: M.ch–M. chevalieri; M.dx–M. dux; M.so–M. sollaudii; M.fe–M. felicinum; M.sp–M. sp; M.ma–M. macrobrachion; M.vo–M. vollenhovenii.</p

Distribution of minor allele frequency (MAF) for different <i>Macrobrachium</i> species: <i>M</i>. <i>dux</i>, <i>M</i>. <i>macrobrachion</i>, <i>M</i>. <i>sollaudii</i>, <i>M</i>. <i>vollenhovenii</i>, <i>M</i>. <i>chevalieri; M</i>. <i>felicinum</i>, and <i>M</i>. <i>sp</i>.

Distribution of minor allele frequency (MAF) for different Macrobrachium species: M. dux, M. macrobrachion, M. sollaudii, M. vollenhovenii, M. chevalieri; M. felicinum, and M. sp.</p

PCA (left plot) and DAPC (right plot) obtained from using the reduced set of ‘private SNPs’ (N = 72 SNPs, called ‘private SNPs80’ panel; see Methods).

PCA–principal component analysis; DAPC–discriminant analysis of the principal components. M_ch–M. chevalieri; M_dx–M. dux; M_fe–M. felicinum; M_ma–M. macrobrachion; M_so–M. sollaudii; M_sp–M. sp; M_vo–M. vollenhovenii.</p

Admixture results obtained from using 174 ’private SNPs’ based on the ADMIXTURE software.

(TIF)</p

Pictures of seven <i>Macrobrachium</i> species in the coastal area of Cameroon identified based on morphological analysis using [10, 31] keys.

Pictures of seven Macrobrachium species in the coastal area of Cameroon identified based on morphological analysis using [10, 31] keys.</p