Coral reef fishes reveal strong divergence in the prevalence of traits along the global diversity gradient.

Coral reefs are experiencing declines due to climate change and local human impacts. While at a local scale these impacts induce biodiversity loss and shifts in community structure, previous biogeographical analyses recorded consistent taxonomic structure of fish communities across global coral reefs. This suggests that regional communities represent a random subset of the global species and traits pool, whatever their species richness. Using distributional data on 3586 fish species and latest advances in species distribution models, we show marked gradients in the prevalence of size classes and diet categories across the biodiversity gradient. This divergence in trait structure is best explained by reef isolation during past unfavourable climatic conditions, with large and piscivore fishes better represented in isolated areas. These results suggest the risk of a global community re-organization if the ongoing climate-induced reef fragmentation is not halted.

Accounting for intraspecific diversity when examining relationships between non-native species and functional diversity.

Quantifying changes in functional diversity, the facet of biodiversity accounting for the biological features of organisms, has been advocated as one of the most integrative ways to unravel how communities are affected by human-induced perturbations. The present study assessed how functional diversity patterns varied among communities that differed in the degree to which non-native species dominated the community in temperate lake fish communities and whether accounting for intraspecific functional variability could provide a better understanding of the variation of functional diversity across communities. Four functional diversity indices were computed for 18 temperate lake fish communities along a gradient of non-native fish dominance using morphological functional traits assessed for each life-stage within each species. First, we showed that intraspecific variability in functional traits was high and comparable to interspecific variability. Second, we found that non-native fish were functionally distinct from native fish. Finally, we demonstrated that there was a significant relationship between functional diversity and the degree to which non-native fish currently dominated the community and that this association could be better detected when accounting for intraspecific functional variability. These findings highlighted the importance of incorporating intraspecific variability to better quantify the variation of functional diversity patterns in communities facing human-induced perturbations.

Captive bottlenose dolphins and killer whales harbor a species-specific skin microbiota that varies among individuals.

Marine animals surfaces host diverse microbial communities, which play major roles for host's health. Most inventories of marine animal surface microbiota have focused on corals and fishes, while cetaceans remain overlooked. The few studies focused on wild cetaceans, making difficult to distinguish intrinsic inter- and/or intraspecific variability in skin microbiota from environmental effects. We used high-throughput sequencing to assess the skin microbiota from 4 body zones of 8 bottlenose dolphins (Tursiops truncatus) and killer whales (Orcinus orca), housed in captivity (Marineland park, France). Overall, cetacean skin microbiota is more diverse than planktonic communities and is dominated by different phylogenetic lineages and functions. In addition, the two cetacean species host different skin microbiotas. Within each species, variability was higher between individuals than between body parts, suggesting a high individuality of cetacean skin microbiota. Overall, the skin microbiota of the assessed cetaceans related more to the humpback whale and fishes' than to microbiotas of terrestrial mammals.

Global functional diversity of freshwater fish is concentrated in the Neotropics while functional vulnerability is widespread.

Worldwide biodiversity assessments have mainly focused on species richness but little is known about the diversity of species roles, i.e. functional diversity, while this is a key facet to understanding the consequences of global changes on the ecosystem services to human societies. Here, we report the world pattern of functional diversity of freshwater fish using a database encompassing morphological characteristics of more than 9,000 species. The Neotropical realm hosts more than 75% of global functional diversity while other realms each host less than 25%. This discrepancy is mediated by high functional uniqueness in some diversified Neotropical fish orders. Surprisingly, functional diversity patterns were weakly related to functional vulnerability. In the Neotropics the loss of threatened species will cause a limited loss of functional diversity (<10%) whereas in the Nearctic and Palearctic realms, decline of the functional diversity will reach 43% and 33%, respectively, conferring a high functional vulnerability to these realms. Conservation of the Neotropical fish diversity is a key target to maintain world fish functional diversity, but this should not hide the pressing need to conserve the vulnerable fish faunas of the rest of the world, in which functional diversity is to a large extent supported by threatened species.

Studies on antibacterial dressings obtained by fluorinated post-discharge plasma.

Surface modification of wool, polyamide 6 and cotton fabrics was investigated with an Ar-CF(4) post-discharge plasma. The radical F, as determined by optical emission spectroscopy, is considered to be the main active species acting on the fabrics and producing different effects as a function of the textile substrate. Fluorination of the surface is achieved on the three materials studied, but only wool and polyamide 6 fluorinated surfaces become hydrophobic at long treatment times, and show antibacterial properties. The treatment conditions used are mild enough so as not to alter surface topography, as confirmed by scanning electron and atomic force microscopy.

[Bacterial DNA alteration by plasma generated atomic nitrogen. Real-time PCR detection contribution]. / Dégradation de l'ADN bactérien par de l'azote atomique produit par plasma. Apport de la détection par PCR en temps réel.

AIMS: Bacterial sterilization by the technology of plasma in post-discharge shows a growing interest. The main appeal of this new process resides in its action at dry and low temperature (60 degrees C). This technology would be therefore useful for the complex medical equipment, sensitive to the oxidization, humidity and/or requiring a temperature lower than 60 degrees C. The objective of this survey is to demonstrate the activity of an atomic flux emanating a plasma of pure molecular nitrogen on the bacterial DNA: does the plasma of nitrogen damage the genetic material? MATERIALS AND METHODS: The bacteria tested (Bacillus stearothermophilus, Staphylococcus aureus MRSA and Helicobacter pylori) are cultivated on suitable agar, and the bacterial DNA is extracted from every CFU by the technique of the columns (High Pure PCR Template, Roche). Every quantity of DNA extracted is diluted in 1 ml pure water. Then, 50 microl of each of these solutions of DNA are laid down in sterile Nunclon's plates holes, which undergo an advanced emptiness cycle during 60 minutes. The DNA residues will be then introduced during 40 minutes in a plasma sterilization surrounding wall (Plasmalyse), Satelec) where the debit of nitrogen, the pressure and the temperature are adjusted respectively to 1 L x min(-1), 5 Torrs and 60 degrees C. The DNA so ''plasmalysé'', is recovered then by aspiration in 500 mul pure water and processed to undergo an amplification/detection by Real-Time PCR (LightCycler2.0, Roche). The DNA ''plasmalysé'' will be compared to the intact DNA control(1), to the DNA control control(2) having undergone the cycle of emptiness solely, as well as to the DNA control(3) solely heated to 60 degrees C during 40 min. RESULTS: The amplification curves demonstrated that the only advanced emptiness and the only heat don't have any activity on the bacterial DNA. On the other hand, the DNA ''plasmalysé'' shows a deterioration of the amplified sequences. CONCLUSION: The genomic bacterial DNA, once extracted, is damaged by the gaseous flux of nitrogen plasma. A new sterilization process of the medical material will presumably impose itself in medium-term.