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Audo D.,CNRS Biodiversity and Territory Management Laboratory | Audo D.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Williams M.,Bath Royal Literary and Scientific Institution | Charbonnier S.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Schweigert G.,Staatliches Museum fur Naturkunde
Journal of Systematic Palaeontology

Polychelidan lobsters are decapod crustaceans with a unique anatomy: a dorsoventrally flattened carapace, four to five pairs of chelate appendages and a completely reduced rostrum. These crustaceans, like most other malacostracans, are mostly preserved in outcrops in which exceptional preservation occurs, Fossil-Konservat-Lagerstätten. Unfortunately, Lagerstätten are rare, and therefore disjointed both geographically and stratigraphically. This study focuses on a new genus of polychelidan lobster, Gabaleryon gen. nov., with the description of two new Toarcian species, Gabaleryon coquelae sp. nov. from France and G. garassinoi sp. nov. from Italy. The long-standing question of the generic assignment of Eryon moorei (Toarcian, UK) is resolved and the species is ascribed to Gabaleryon. The occurrences of these three species and a fourth, Gabaleryon sp. 1 (Toarcian, Germany), provide a first palaeobiogeographical indication that the Fossil-Lagerstätten in which they occur were linked during Toarcian times. The occurrence of a possible fifth species of Gabaleryon in the late Bajocian–early Bathonian of France may extend the stratigraphical distribution of the new genus. Finally, these new species increase our knowledge of fossil polychelidans and place the Toarcian as their second peak of palaeobiodiversity, after that at the Kimmeridgian–Tithonian boundary. http://zoobank.org/urn:lsid:zoobank.org:pub:073513BD-A0D8-4A5B-B9DE-1C61781077DC © 2016 The Trustees of the Natural History Museum, London 2016. All Rights Reserved. Source

Laugier F.,French Natural History Museum | Feunteun E.,French Natural History Museum | Pecheyran C.,University of Pau and Pays de lAdour | Carpentier A.,CNRS Biodiversity and Territory Management Laboratory
Estuarine, Coastal and Shelf Science

Knowledge of life history and connectivity between essential ecological habitats are relevant for conservation and management of species and some natural tracers could be used to study the lifecycles of small or short-lived marine fishes. Although sandeels are central in marine food webs and are key species, there is incomplete knowledge about population mixing and migration patterns. For the first time the use of the otolith microchemistry on sandeel species is evaluated in the case of the Small Sandeel. Variations in microchemical fingerprints of 13 trace elements are performed with a Femtosecond LA-ICPM from the core to the margin of sagittal otolith and are compared within and between otoliths extracted from 34 fishes sampled in three different sites along the coast of the south-western English Channel in France. Firstly, preliminary investigations on the validity of the method revealed that Mg/Ca was the only ratio significantly dependant on fish ontogeny and sampling season. Secondly, the Mn/Ca, Zn/Ca, and Cu/Ca ratios enabled us to significantly discriminate among sampling sites. Thirdly, microchemical fingerprints of each life stage varied significantly among sampling sites but not within them, suggesting high site fidelity over relatively short distances. Finally, the fingerprints of all life stages were significantly different from those of the larval and metamorphosis stages. The otolith microchemistry could detect change of signature relative to the shift from a pelagic behaviour to a resident bentho-pelagic behaviour during the middle of the juvenile stage in Small Sandeels. Hence, analysis of trace element fingerprints in otoliths appears to be a valuable method to further studies on ontogenic habitat change, population mixing and variation of life history and be helpful for the management at local or regional scales of short-lived species such as those belonging to other Ammodytidae. © 2015 Elsevier Ltd. Source

Bellard C.,University Paris - Sud | Leclerc C.,University Paris - Sud | Leroy B.,University Paris - Sud | Leroy B.,CNRS Biodiversity and Territory Management Laboratory | And 4 more authors.
Global Ecology and Biogeography

Aim Global changes are predicted to have severe consequences for biodiversity; 34 biodiversity hotspots have become international priorities for conservation, with important efforts allocated to their preservation, but the potential effects of global changes on hotspots have so far received relatively little attention. We investigate whether hotspots are quantitatively and qualitatively threatened to the same order of magnitude by the combined effects of global changes. Location Worldwide, in 34 biodiversity hotspots. Methods We quantify (1) the exposure of hotspots to climate change, by estimating the novelty of future climates and the disappearance of extant climates using climate dissimilarity analyses, (2) each hotspot's vulnerability to land modification and degradation by quantifying changes in land-cover variables over the entire habitat, and (3) the future suitability of distribution ranges of '100 of the world's worst invasive alien species', by characterizing the combined effects of climate and land-use changes on the future distribution ranges of these species. Results Our findings show that hotspots may experience an average loss of 31% of their area under analogue climate, with some hotspots more affected than others (e.g. Polynesia-Micronesia). The greatest climate change was projected in lowlatitude hotspots. The hotspots were on average suitable for 17% of the considered invasive species. Hotspots that are mainly islands or groups of islands were disproportionally suitable for a high number of invasive species both currently and in the future. We also showed that hotspots will increase their area of pasture in the future. Finally, combining the three threats, we identified the Atlantic forest, Cape Floristic Region and Polynesia-Micronesia as particularly vulnerable to global changes. Main conclusions Given our estimates of hotspot vulnerability to changes, close monitoring is now required to evaluate the biodiversity responses to future changes and to test our projections against observations. © 2014 John Wiley & Sons Ltd. Source

Gallon R.K.,French Natural History Museum | Robuchon M.,CNRS Systematics, Biodiversity and Evolution Institute | Robuchon M.,French National Center for Scientific Research | Leroy B.,CNRS Biodiversity and Territory Management Laboratory | And 4 more authors.
Journal of Biogeography

Aim: To assess environmental changes within a marine biogeographical transition zone and how they have affected seaweed assemblages and distributions over the past two decades. Location: Brittany (western France, Europe) - a biogeographical transition zone between cold-temperate and warm-temperate regions. Methods: We assessed spatio-temporal variation for three environmental parameters [sea-surface temperature (SST), suspended inorganic matter and chlorophyll a] between 1992 and 2012 in five adjoining regions using generalized linear models. To investigate changes in assemblages and distributional patterns of red seaweeds based on sampling surveys conducted during two separate periods (1992-1998 and 2010-2012), we used two complementary approaches, multivariate data analysis and species distribution models (SDMs) with a set of modelling procedures. Results: Coastal water temperature in Brittany has increased by 0.7 °C on average over the past two decades (0.35 °C per decade). At a finer scale, changes in SST showed that Brittany constitutes a mosaic of contrasting conditions, with the western and north-western regions being colder and less affected by climate change than the other three regions. Our results suggest that increasing SST caused significant changes in subtidal red seaweed assemblages over the 20-year period. Between the two periods, SDMs predicted significant species shifts for seven out of ten representative species, and reductions in the distribution ranges of most species. Main conclusions: Our study confirmed important differences across the different regions of the studied biogeographical transition zone. Changes in abiotic parameters and red seaweed assemblages are expected to occur at varying extremes across these regions, with western and north-western Brittany representing the most stable zones that might constitute a potential refuge for certain species when responding to global changes. © 2014 John Wiley & Sons Ltd. Source

Jauvion C.,University Claude Bernard Lyon 1 | Jauvion C.,Ecole Normale Superieure de Lyon | Audo D.,CNRS Biodiversity and Territory Management Laboratory | Charbonnier S.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Vannier J.,University Claude Bernard Lyon 1
Arthropod Structure and Development

Polychelidan lobsters are fascinating crustaceans that were known as fossils before being discovered in the deep-sea. They differ from other crustaceans by having four to five pairs of claws. Although recent palaeontological studies have clarified the systematics and phylogeny of the group, the biology of extant polychelidans and - first of all - their anatomy are poorly documented. Numerous aspects of the evolutionary history of the group remain obscure, in particular, how and when polychelidans colonized the deep-sea and became restricted to it. Surprisingly, the biology of extant polychelidans and the anatomy of all species, fossil and recent, are poorly documented. Here, X-ray microtomography (XTM), applied to an exceptionally well-preserved specimen from the La Voulte Lagerstätte, reveals for the first time vital aspects of the external and internal morphology of Voulteryon parvulus (Eryonidae), a 165-million-year-old polychelidan: 1) its mouthparts (maxillae and maxillipeds), 2) its digestive tract and 3) its reproductive organs. Comparisons with dissected specimens clearly identify this specimen as a female with mature ovaries. This set of new information offers new insights into the feeding and reproductive habits of Mesozoic polychelidans. Contrasting with other Jurassic polychelidans that lived in shallow-water environments, V. parvulus spawned in, and probably inhabited, relatively deep-water environments, as do the survivors of the group. © 2015 Elsevier Ltd. Source

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