Abstract: Genetic variation is generally considered a prerequisite for adaptation to new environmental conditions. Thus the discovery of genetically depauperate but geographically widespread species is unexpected. We used 12 paternally inherited chloroplast microsatellites to estimate population genetic variation across the full range of an emblematic circum-Mediterranean conifer, stone pine (Pinus pinea L.). The same chloroplast DNA haplotype is fixed in nearly all of the 34 investigated populations. Such a low level of variation is consistent with a previous report of very low levels of diversity at nuclear loci in this species. Stone pine appears to have passed through a severe and prolonged demographic bottleneck, followed by subsequent natural- and human-mediated dispersal across the Mediterranean Basin. No other abundant and widespread plant species has as little genetic diversity as P. pinea at both chloroplast and nuclear markers. However, the species harbors a nonnegligible amount of variation at adaptive traits. Thus a causal relationship between genetic diversity, as measured by marker loci, and the evolutionary precariousness of a species, cannot be taken for granted.

Abstract: The need for an updated list of spiders found in French Guiana rose recently due to many upcoming studies planned. In this paper, we list spiders from French Guiana from existing literature (with corrected nomenclature when necessary) and from 2142 spiders sampled in 12 sites for this baseline study. Three hundred and sixty four validated species names of spider were found in the literature and previous authors' works. Additional sampling, conducted for this study added another 89 identified species and 62 other species with only a genus name for now. The total species of spiders sampled in French Guiana is currently 515. Many other Morphospecies were found but not described as species yet. An accumulation curve was drawn with seven of the sampling sites and shows no plateau yet. Therefore, the number of species inhabiting French Guiana cannot yet be determined. As the very large number of singletons found in the collected materials suggests, the accumulation curve indicates nevertheless that more sampling is necessary to discover the many unknown spider species living in French Guiana, with a focus on specific periods (dry season and wet season) and on specific and poorly studied habitats such as canopy, inselberg and cambrouze (local bamboo monospecific forest). © 2013 Vedel et al.

Abstract: To obtain a reliable description of spider communities, robust sampling protocols are crucial. However, it remains unclear if descriptions of spider communities in tropical habitats require both day and night sampling. Here we tested whether sampling both day and night in high and low vegetation strata would lead to better diversity estimates of spider communities than sampling at only one period of the day. We determined spider taxonomic diversity in a network of 12 plots in French Guiana along a vegetation gradient. We found high alpha diversity of spiders as expected for a tropical area at every site. We showed strong differences in spider alpha and beta diversity between high and low vegetation strata, while they were similar between day and night sampling. Our results suggest that collecting spiders at only one period is sufficient to describe the diversity of spider communities across land use types in the neotropics. © The American Arachnological Society.

Abstract: For many kinds of ecological, evolutionary and developmental study, it is important to be able to describe the life-history of the individuals of a particular species/population. In the case of myriapods and other arthropods, this involves separating the different life-history stages (or stadia or instars) that are separated by moults. However, it has recently been pointed out that in the earliest post-embryonic stages the cuticle is still quite flexible; this means that visible external developmental changes can occur between moults as well as during them. Here, we provide evidence for such inter-moult changes in the coastal geophilomorph centipede Strigamia maritima. The character states studied enable finer-scale resolution of early post-embryonic forms than was hitherto possible. Specifically, we describe five transitional forms during a period in which just two (Peripatoid and Foetus) have traditionally been recognized

Abstract: In this study, the corrosion of S355 carbon steel was monitored for 50 days in equatorial environment. The experiments were conducted under three complementary approaches in a natural environment: (i) bacterial diversity was assessed with Miseq sequencing, (ii) observations of the surface and identifications of deposit compounds were realised with scanning electron microscopy (SEM), Raman spectrometry and EDX analyses, (iii) electrochemical measurements were used to calculate corrosion rate and to identify the phenomena which control corrosion. The results showed that the bacterial population had changed over immersion time from a dominance of β-proteobacteria to α-proteobacteria. This evolution decreased charge transfer resistance at the metal/deposit from 41.6 to 20.8 Ω/cm2 in 50 days, caused an increase in the corrosion rate by a factor of 2, from 0.13 to 0.27 mm/year. Surface analyses showed a progressive appearance of MIC markers in the deposit such as iron sulphide and manganese oxides that were detected after 30 days of immersion in the natural environment. In conclusion, this study describes in detail, the first stage of MIC activity on carbon steel surface in an equatorial brackish water, under aerobic conditions. © 2016 Elsevier Ltd.