Éditeur(s) : HAL CCSD Magnolia Press
Résumé : International audience
A new species of wrasse, Macropharyngodon pakoko, is described from the Marquesas Islands, bringing the total number of species of the genus Macropharyngodon to 12. Macropharyngodon pakoko was found at depths from 0-42 m and is endemic to the Marquesas Islands. Macropharyngodon pakoko is similar to M. meleagris, which is widely distributed from the central and western Pacific to Cocos-Keeling in the Indian Ocean, but differs genetically and in several coloration characters: males with irregularly curved black humeral blotch with incomplete iridescent blue border; inverted irregular " U "-shaped band on the cheek; a small black spot at the upper base of the pectoral fin; and background color of the body greenish with faint bluish black spots on each scale. Females lack black pigment on the chest posterior to the ventral attachment of the gill membranes; reddish black blotches on the body are widely spaced, particularly on the head where they are more reddish and half the size of those on body; caudal fin with small, bright yellow spots arranged in narrow vertical bands with pale interspaces; pelvic fins pale with three reddish yellow cross-bands; a small black spot at the upper base of the pectoral fin; and small reddish spots along the base of the anal fin. Juveniles have irregular black blotches on the body, a small black spot instead of an ocellus posteriorly on the dorsal fin and lack large black spots and ocellus on the anal fin.
ISSN: 1175-5326

Droits : http://creativecommons.org/licenses/by/
hal-01333340
https://hal-univ-perp.archives-ouvertes.fr/hal-01333340
https://hal-univ-perp.archives-ouvertes.fr/hal-01333340/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01333340/file/7387-23089-2-PB.pdf
DOI : 10.11646/zootaxa.3857.3.6

Éditeur(s) : Natl Acad Sciences
Résumé : Most marine organisms disperse via ocean currents as larvae, so it is often assumed that larval-stage duration is the primary determinant of geographic range size. However, empirical tests of this relationship have yielded mixed results, and alternative hypotheses have rarely been considered. Here we assess the relative influence of adult and larval-traits on geographic range size using a global dataset encompassing 590 species of tropical reef fishes in 47 families, the largest compilation of such data to date for any marine group. We analyze this database using linear mixed-effect models to control for phylogeny and geographical limits on range size. Our analysis indicates that three adult traits likely to affect the capacity of new colonizers to survive and establish reproductive populations (body size, schooling behavior, and nocturnal activity) are equal or better predictors of geographic range size than pelagic larval duration. We conclude that adult life-history traits that affect the postdispersal persistence of new populations are primary determinants of successful range extension and, consequently, of geographic range size among tropical reef fishes.
Proceedings Of The National Academy Of Sciences Of The United States Of America (0027-8424) (Natl Acad Sciences), 2013-10 , Vol. 110 , N. 41 , P. 16498-16502

Droits : Freely available online through the PNAS open access option.
http://archimer.ifremer.fr/doc/00161/27240/25457.pdf
DOI:10.1073/pnas.1304074110
http://archimer.ifremer.fr/doc/00161/27240/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
B-type olivine fabrics are pervasive within highly depleted dunites of the small-sized Imono peridotite body located within the subduction-type Sanbagawa metamorphic belt of the southwest Japan arc. The dunites contain various microstructures, ranging from porphyroclastic to fine-grained intensely sheared textures. The Mg/(Mg+Fe) atomic ratios (Fo number) of olivine within these dunites are consistently around 0.9, as are the Cr/(Cr+Al) atomic ratios (Cr number) of chromian spinel, suggesting their evolution from a highly depleted magma (boninite). These data provide strong thermal constraints on the formation of the highly depleted dunites,as their formation requires hot, hydrous, shallow mantle (> 1250 degrees C at < 30 km depth) in the mantle wedge. Because the Sanbagawa metamorphic belt finally entrained these peridotites during progressive retrogression, B-type olivine fabrics probably developed in the fore-arc side of the subduction zone, above or along the subducting slab, possibly in association with dehydration fluids derived from the slab. The previously documented small magnitude of S-wave splitting can be explained by the seismic properties of B-type peridotites within an anisotropic layer of approximately several kilometers in thickness, oriented by flow parallel to the subducting slab, under maximum temperatures of 880-1030 degrees C depending on the flow stress. These findings indicate that such a B-type layer could constitute a dominant source of seismic S- and P-wave anisotropy in mantle wedge regions. (c) 2008 Elsevier B.V. All rights reserved.
ISSN: 0012-821X

hal-00412594
https://hal.archives-ouvertes.fr/hal-00412594
DOI : 10.1016/j.epsl.2008.06.014

Éditeur(s) : HAL CCSD Société géologique de France
Résumé : In the eastern Pyrenees, the lherzolites always outcrop as restricted bodies scattered across Mesozoic sedimentary units along the North Pyrenean fault. In this article, we focus on the sedimentary processes associated with the tectonic exhumation of the mantle rocks during the Lower Cretaceous and we provide a new detailed analysis of the ultramafic-bearing sedimentary sequences associated with the Lherz body. The Lherz body, 1.5 km long only, belongs to a series of ultramafic bodies of restricted size (a few m to some hundred of m), occurring within sedimentary formations composed mostly of carbonate breccias originating from the reworking of Mesozoic platform limestones and dolomites. The carbonate clasts include marbles displaying different evolutions in relation with the Cretaceous thermal metamorphic event. The clastic formations also include numerous layers of polymictic breccias reworking ultramafic clasts. These layers are found far from any peridotitic body, implying that ultramafic clasts have been transported far away from their sources by sedimentary processes after their disaggregation on the seafloor. In addition, clasts of ultramafic-rich breccias and sandstones are also observed which indicates rapid sedimentation and diagenesis within a tectonically active environment. We discuss the significance of these deposits and their bearing on our understanding of the tectono-sedimentary processes associated with mantle exhumation in a context of development of narrow intracontinental basins suffering extreme crustal thinning.
EISSN: 1777-5817

hal-00766884
https://hal.archives-ouvertes.fr/hal-00766884
DOI : 10.2113/gssgfbull.183.5.443

Éditeur(s) : Elsevier
Résumé : The New Caledonia blue shrimp Litopenaeus stylirostris is commercially produced under semi-intensive rearing conditions. The size of the farming earthen ponds (5–10 ha) and the subsequent production constraints make it difficult to use them as experimental units for random experiments. Moreover, since every pond has its own characteristics, ponds' effects cannot be ruled out, thus making it hard to define true replicates. In order to design future experiments under conditions resembling those used in production, we evaluated the possible use of floating cages as experimental units with the aim of assessing treatment effects with a reasonable statistical power. To this end, two sets of floating cages were placed respectively in two different ponds in a commercial farm. In both cases the zootechnical conditions in the cages were similar in post-larvae origin, management, and diet and feeding regime. The aim of the study was to evaluate on a technical basis the possibility of rearing shrimps in floating cages set up in earthen ponds and to assess this method from a statistical standpoint. Shrimps reared in and outside the cages showed comparable growth and survival rates. The variability in the zootechnical parameters between cages, expressed as the estimated coefficient of variation (CV) for survival rate, total final biomass (g), final body weight (g), daily increment in body weight (g day− 1) and FCR were 11.0, 13.7, 4.4, 5.4, and 7.0%, respectively. On the basis of these figures, we calculated for a given statistical power (80%) the number of replicates (cages) that would be required to reveal significant differences between two treatments, at a 5% level of significance. We found that for expected differences of 20% from the control mean, 3 and 6 floating cages per treatment would be reasonable to determine statistical differences for growth parameters and survival rate, respectively. Moreover, we showed a significant pond effect in regard to survival and growth between the two sets of cages. These results illustrated the within-farm variability among the ponds, and confirmed that the specific characteristics of each pond from the same farm make it difficult to use the ponds themselves as experimental units. The study demonstrates that rearing in floating cages is an economical, powerful and sensitive experimental tool for shrimp culture studies specifically carried out under conditions close to semi-intensive production.
Aquaculture (0044-8486) (Elsevier), 2008-07 , Vol. 279 , N. 1-4 , P. 63-69

Droits : 2008 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2008/publication-4363.pdf
DOI:10.1016/j.aquaculture.2008.03.053
http://archimer.ifremer.fr/doc/00000/4363/

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Climatic changes result in an increased in mean temperature and in a higher incidence of extreme weather events such as heat and cold waves. For ectotherms, such as insect parasitoids, the ability to remain active under extreme climatic conditions is a significant key to fitness. The body size of individuals, and in particular their surface to volume ratio, may play a role in their resistance to thermal conditions. The thermal tolerances are investigated of two closely-related sympatric parasitoid species [Aphidius avenae Haliday and Aphidius rhopalosiphi De Stefani-Perez (Hymenoptera: Aphidiinae)] that have a similar ecology but differ in body size and phenologies. The critical thermal limits of individuals are assessed in both sexes of each parasitoid species and the influence of surface-volume ratios on their thermal tolerances. Aphidius avenae is less resistant to low temperatures and more resistant to high temperatures than A. rhopalosiphi. The lower surface to volume ratio of A. avenae individuals may help them to remain active in summer when experiencing heat waves. However, body size is not the sole factor that plays a role in differences of thermal tolerance between species and body size may not be an adaptation to extreme temperatures but rather a by-product of developmental regulation. Closely related sympatric species from the same ecological guild can have different thermal tolerances that may allow them to occur within the same habitat. The present study also highlights the importance of clearly defining how to measure critical thermal limits to determine the thermal tolerance of a species.
ISSN: 0307-6962

hal-00589094
https://hal.archives-ouvertes.fr/hal-00589094
DOI : 10.1111/j.1365-3032.2010.00758.x

Éditeur(s) : HAL CCSD Oxford University Press (OUP): Policy B - Oxford Open Option D
Résumé : International audience
The aim was to compare the relationship between body composition and body size in two subgroups with different metabolic risk.Body-mass index z-scores (BMIZ), bicipital, tricipital, subscapular and iliac thicknesses were determined in 178 India-originatingGuadeloupian (IOG) adolescents and 481 controls of other origins. Various equations were tested in a regression approach to fit therelationship between BMIZ and iliac thickness, and BMIZ and sum of skinfold thickness. A shift towards higher iliac thickness for a givenBMIZ was observed in IOG adolescents. This supports the idea that the relationship between BMI and risk for non-communicable diseases isethnicity-dependant.
ISSN: 1101-1262

hal-01143534
https://hal.univ-antilles.fr/hal-01143534
DOI : 10.1093/eurpub/cks070

Éditeur(s) : HAL CCSD
Résumé : International audience
Mylonite bodies are exhumed extensions at depth of shallow structural level brittle faults. They are characterised by intense strain localisation involving large volumes of middle to lower continental crust. The analysis of shear zone geometry and microstructures is a useful tool to decipher deformation kinematics, though finite strain estimation is still relatively qualitative. Timing of the deformation has also been the focus of numerous studies using the complete spectrum of geochronometers. However, only rare examples provide geochronological data that can be unambiguously interpreted and cooling, recrystallisation and neocrystallisation are difficult to tell from each other. Thus, time-scales over which major mylonite zones develop and remain active under ductile conditions as well as their strain rate often remain poorly documented. We investigated two sections across the South-Armorican Shear Zone (SASZ), a crustal-scale pluri-km thick dextral shear zone active during a single tectonic event of late-Variscan age and associated with syntectonic granite emplacement.. Finite strain profiles on these cross-sections, quantified from average Quartz grain-size in 34 samples, show a strong deformation partitioning towards the center of the SASZ, with a decrease, for each section, from 150µm in slightly deformed zones to less than 7-5 µm in the core of the ultramylonite. Furthermore, toward the core of the SASZ, development of a penetrative shear band network progressively eliminates lenses of less deformed rocks and results in homogenisation of the Quartz grain sizes. In parallel, we performed in-situ UV-laser Ar/Ar dating on the fabric-forming white micas. White micas population can be decomposed into inherited muscovites carried by the folation and newly-formed, syn-tectonic substituted phengites located along the shear bands yielding 2 age groups for each sample. Along the profiles, the difference between these two ages evolves from 10-15 Ma in weakly deformed domains to zero toward the SASZ core. In addition, mylonite-forming phengites yielded the same age irrespectively of their position on the section or of the rock strain.. On the regional point of view, this study brings deformation-ages for the late-orogenic evolution of the South Armorican domain. Strain accumulated along the SASZ in a time-span extending to 300-298 Ma, i.e. contemporaneously with the activity of nearby major extensional shear zones. These results support a new model of crustal-scale shear zone activity, where the whole body of the shear zone is active throughout its history (defined as the largest age difference through the section), i.e. the actively deforming zone does not get progressively narrower. The strain distribution nevertheless evolves with time, with an increasingly large fraction partitioned in the ultramylonitic core.
EGU General Assembly
Vienne, Austria

insu-00839320
https://hal-insu.archives-ouvertes.fr/insu-00839320
BIBCODE : 2010EGUGA..12.9881A

Éditeur(s) : HAL CCSD AGU and the Geochemical Society
Résumé : International audience
In the Wadi Haymiliyah of the Oman ophiolite (Haylayn block), discordant wehrlite bodies ranging in size from tens to hundreds of meters intrude the lower crust at different levels. We combined investigations on natural wehrlites from the Wadi Haymiliyah section with an experimental study on the phase relations in a wehrlitic system in order to constrain the petrogenesis of the crustal wehrlites of the Oman ophiolite. Secondary ion mass spectrometry analyses of clinopyroxenes from different wehrlite bodies imply that the clinopyroxenes were crystallized from tholeiitic, mid-ocean ridge (MORB)-type melts. The presence of primary magmatic amphiboles in some wehrlites suggests a formation under hydrous conditions. Significantly enhanced Sr-87/Sr-86 isotope ratios of separates from these amphiboles imply that the source of the corresponding magmatic fluids was either seawater or subduction zone-related. The experiments revealed that under wet conditions at relatively low temperatures, a MORB magma has the potential to produce wehrlite in the ocean crust by accumulation of early olivine and clinopyroxene. These show typically high Mg# which is a consequence of the oxidizing effect of the prevailing high aH(2)O. First plagioclases crystallizing after clinopyroxene under wet conditions are high in An content, in contrast to the corresponding dry system. Trace element compositions of clinopyroxenes of those wehrlites from the Moho transition zone are too depleted in HREE to be in equilibrium with present-day MORB, implying a genetic relation to the V2 lavas of the Oman ophiolite, which are interpreted to be the result of fluid-enhanced melting of previously depleted mantle. We present a model on the petrogenesis of the crustal wehrlites in an upper mantle wedge above an initial, shallow subduction zone at the beginning of the intraoceanic thrusting.
ISSN: 1525-2027

hal-00429373
https://hal.archives-ouvertes.fr/hal-00429373
DOI : 10.1029/2009GC002488

Éditeur(s) : John Wiley & Sons
Résumé : 1. Transitional waters, described as critical transition zones because of their position at terrestrial, freshwater and marine interfaces, provide essential goods and services to the biosphere including human populations. These ecotones face increasing human influence mainly due to population density increase in coastal areas. 2. Transitional water bodies have, to date, received little attention in the development of ecological status indicators, this is a critical deficiency when trying to meet the Water Framework Directive objective of all significant water bodies achieving good ecological status by the year 2015. 3. In order to assess changes in transitional water communities many taxonomic-based indicators have already been proposed but there are a number of concerns for their use such as taxonomic classification difficulties, their unsuitability for multi-site comparisons and their inconsistent relationships with disturbance or stress. 4. Alternative methods based on body size, abundance distribution among functional groups, functional diversity and productivity descriptors are proposed. These methods offer the opportunity to compare sites with different taxonomic compositions and allow derivation of indicators related to ecological status of communities under scrutiny. 5. Finally, the suitability of these taxonomic-free descriptors to provide relevant information for each of the four main biotic compartments in coastal lagoons is discussed. The use of biomass distribution among functional groups for fish, benthos and macrophyte and to use body-size distribution for benthos and plankton is proposed. Copyright (c) 2006 John Wiley and Sons, Ltd.
Aquatic Conservation: Marine and Freshwater Ecosystems (1052-7613) (John Wiley & Sons), 2006-07 , Vol. 16 , N. 5 , P. 469-482

Droits : 2006 John Wiley & Sons, Ltd
http://archimer.ifremer.fr/doc/2006/publication-1849.pdf
DOI:10.1002/aqc.769
http://archimer.ifremer.fr/doc/00000/1849/

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
In the Pyrenees, the lherzolites nowhere occur as continuous units. Rather, they always outcrop as restricted bodies, never more than 3 km wide, scattered across Mesozoic sedimentary units along the North Pyrenean Fault. We report the results of a detailed analysis of the geological setting of the Lherz massif (central Pyrenees), the type-locality of lherzolites and one of the most studied occurrences of mantle rocks worldwide. The Lherz body is only 1.5 km long and belongs to a series of ultramafic bodies of restricted size (a few metres to some hundreds of metres), occurring within sedimentary formations composed mostly of carbonate breccias originating from the reworking of Mesozoic platform limestones and dolomites. The clastic formations also include numerous layers of polymictic breccias reworking lherzolitic clasts. These layers are found far from any lherzolitic body, implying that lherzolitic clasts cannot derive from the in situ fragmentation of an ultramafic body alone, but might also have been transported far away from their sources by sedimentary processes. A detailed analysis of the contacts between the Lherz ultramafic body and the surrounding limestones confirms that there is no fault contact and that sediments composed of ultramafic material have been emplaced into fissures within the brecciated carapace of the peridotites. These observations bear important constraints for the mode of emplacement of the lherzolite bodies. We infer that mantle exhumation may have occurred during Albian strike-slip deformation linked to the rotation of Iberia along the proto-North Pyrenean Fault.
ISSN: 0954-4879

hal-00412602
https://hal.archives-ouvertes.fr/hal-00412602

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
This study demonstrates that 20-100 GHz range can be used for spatially-accurate focusing of heating inside the skin achieved by varying frequency and exposure beam size, as well as by enforcing air convection. The latter is also used to reduce overheating of skin surface. Heating at different skin depths depending on these parameters is investigated in detail using the hybrid bio-heat equation. In particular, it is shown that decreasing frequency and/or increasing exposure beam size at forced airflow result in elevation of heating of deeper layers of tissue and decrease of skin surface temperature. Changes of water content within 15%, which exceed those due to aging and presence of tumors, only slightly affect heating. Exposure intensity necessary to reach a target temperature significantly increases in different areas of body with elevated blood flow. Dependence on exposure intensity and hyperthermia treatment duration is also investigated and discussed. Results of this study suggest that the lower part of the millimeter-wave range is an attractive alternative for non-invasive thermal treatment of skin cancer with a high spatial resolution. Bioelectromagnetics. 36:464-475, 2015. © 2015 Wiley Periodicals, Inc
ISSN: 0197-8462

hal-01187403
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01187403
DOI : 10.1002/bem.21929
PUBMED : 26179286

Éditeur(s) : Société Française d’Ichtyologie
Résumé : Following the volcanic eruption of April 2007 at Reunion Island, 12 specimens of the pomacentrid genus Chromis were collected at sea surface. One of these fishes was a C. chrysura known from the reef Island fauna. The others have enlarged eyes. Among them were one C. axillaris (Bennett, 1831), new for the Island fauna, and ten specimens of a new Chromis species, described here under the name C. durvillei. This new species of deep dwelling Chromis is distinguishable by large sized eyes 1.9 to 2.4 in the head length, D. XIII, 12-13, 25 to 26 gill-rakers on the first gill arch, three spiniform procurrent caudal rays, without black or dark brown spot or band on the body, pectorals or caudal peduncle. C. axillaris, C. woodsi, C. unipa, C. okamurai, C. struhsakeri and generally C. mirationis have 14 spinous dorsal rays. C. abyssicola and rarely C. mirationis have 13 spinous dorsal rays but two spiniform procurrent caudal rays and a dark axillary spot on pectorals.
Parmi les poissons récoltés en surface à l’île de la Réunion (océan Indien sud-ouest), après l’éruption volcanique d’avril 2007, se trouvaient 12 exemplaires du genre Chromis. Un C. chrysura connu de la faune récifale de l’île et 11 exemplaires présentant des yeux de grande taille : un C. axillaris (Bennett, 1831), nouveau pour la faune de l’île de La Réunion et 10 Chromis distinguables des autres espèces du genre par des yeux de grande taille (1,9 à 2,4 fois dans la longueur de la tête), D. XIII , 12-13, 25 à 26 branchicténies sur le premier arc branchial, trois rayons caudaux procurrents épineux et l’absence de tache ou de bande de couleur foncée sur le corps, les pectorales ou le pédoncule caudal. C. axillaris, C. woodsi, C. unipa, C. okamurai, C. struhsakeri et C. mirationis ont 14 rayons épineux à la dorsale, alors que C. abyssicola et rarement C. mirationis n’en ont que 13, mais deux rayons caudaux procurrents et une tache axillaire noire sur les pectorales. Cette espèce nouvelle de Chromis est décrite sous le nom de C. durvillei.
Cybium (0399-0974) (Société Française d’Ichtyologie), 2009-12 , Vol. 33 , N. 4 , P. 321-326

Droits : 2009 Société Française d’Ichtyologie
http://archimer.ifremer.fr/doc/00003/11382/8006.pdf
http://archimer.ifremer.fr/doc/00003/11382/

Éditeur(s) : Inter-research
Résumé : Chemical tracers (e. g. stable isotopes or trace metals) are increasingly used to study trophic ecology and feeding habits of marine organisms and various factors can affect their values. The aim of the present study was to provide information on ontogenic effects on stable carbon and nitrogen values (delta C-13 and delta N-15) and on cadmium (Cd) and mercury (Hg) concentrations in 5 cephalopod species from the Bay of Biscay (North-East Atlantic Ocean). To this end, individuals belonging to 3 species showing the widest range of sizes were analysed for muscle delta C-13 and delta N-15 values and muscle Hg, and digestive gland Cd concentrations. Results showed that stable isotope ratios allowed discrimination of specific feeding strategies during ontogenesis. Segregation between 5 cephalopod species in terms of trophic ecology was also evidenced (different isotopic niches). In contrast, Hg concentrations varied over the same order of magnitude in these 5 cephalopod species, despite higher levels in the benthic octopus Eledone cirrhosa. Consistently, Hg concentrations followed the same ontogenic pattern and increased with increasing body size/age of cephalopods. Finally, Cd concentrations varied over 3 orders of magnitude among the 5 species. Despite possible effects of physiology in terms of metal bioaccumulation, Cd concentrations were likely to reflect specific feeding preferences or feeding zones and ontogenic variability within a single species. Thus, ontogenic effects have to be taken into account when stable isotope ratios of carbon and nitrogen or trace metals are used as ecological tracers; the best recommendation being to focus on a given class age.
Marine Ecology Progress Series (0171-8630) (Inter-research), 2011 , Vol. 433 , P. 107-120

Droits : Inter-Research 2011 · www.int-res.com
http://archimer.ifremer.fr/doc/00166/27761/25938.pdf
DOI:10.3354/meps09159
http://archimer.ifremer.fr/doc/00166/27761/

Éditeur(s) : HAL CCSD American Geophysical Union (AGU)
Résumé : International audience
The Pyrenean peridotites (lherzolites) form numerous small bodies of subcontinental mantle, a few meters to 3 km across, exposed within the narrow north Pyrenean zone (NPZ) of Mesozoic sediments paralleling the north Pyrenean Fault. Recent studies have shown that mantle exhumation occurred along the future NPZ during the formation of the Albian-Cenomanian Pyrenean basins in relation with detachment tectonics. This paper reviews the geological setting of the Pyrenean lherzolite bodies and reports new detailed field data from key outcrops in the Bearn region. Only two types of geological settings have to be distinguished among the Pyrenean ultramafic bodies. In the first type (sedimented type or S type), the lherzolites occur as clasts of various sizes, ranging from millimetric grains to hectometric olistoliths, within monogenic or polymictic debris flow deposits of Cretaceous age, reworking Mesozoic sediments in dominant proportions as observed around the Lherz body. In the second type (tectonic type or T type), the mantle rocks form hectometric to kilometric slices associated with crustal tectonic lenses. Both crustal and mantle tectonic lenses are in turn systematically associated with large volumes of strongly deformed Triassic rocks and have fault contacts with units of deformed Jurassic and Lower Cretaceous sediments belonging to the cover of the NPZ. These deformed Mesozoic formations are not older that the Aptian-early Albian. They are unconformably overlain by the Albian-Cenomanian flysch formations and have experienced high temperature-low pressure mid-Cretaceous metamorphism at variable grades. Such a tectonic setting characterizes most of the lherzolite bodies exposed in the western Pyrenees. These geological data first provide evidence of detachment tectonics leading to manle exhumation and second emphasize the role of gravity sliding of the Mesozoic cover in the preorogenic evolution of the Pyrenean realm. In the light of such evidence, a simple model of basin development can be inferred, involving extreme thinning of the crust, and mantle uprising along a major detachment fault. We demonstrate coeval development of a crust-mantle detachment fault and generalized gravitational sliding of the Mesozoic cover along low-angle faults involving Triassic salt deposits as a tectonic sole. This model accounts for the basic characteristics of the precollisional rift evolution in the Pyrenean realm.
ISSN: 0278-7407

hal-00512818
https://hal.archives-ouvertes.fr/hal-00512818
DOI : 10.1029/2009TC002588

Éditeur(s) : EDP Sciences
Résumé : Batch fecundity and relative fecundity of swordfish (Xiphias gladius) in the southwestern Indian Ocean were estimated from seven gravid swordfish females (size range 127-225 cm lower jaw-to-fork length, LJFL) with unovulated, hydrated oocytes collected onboard Reunion-based (France) longline swordfish fishing vessels between December 1999 to January 2001. To investigate the spawning pattern of swordfish, we used data collected through a combination of two at sea sampling regimes. A total of 17 007 geo-located size data of swordfish were recorded during 8 years (1993-2001) and a total of 1727 (size range 75-289 cm, LJFL) swordfish gonads (1107 females and 620 males) were sampled from May 1998 to January 2001. The estimated batch fecundity ranged from 995 000 hydrated oocytes for the smallest ripe female to 4.3 millions for the largest female sampled measuring respectively 127 to 225 cm in curved length (LJFL). The relative fecundity ranged from 25 to 72 hydrated oocytes per gram of body weight. We found that batch fecundity was positively correlated with fish length and that the older/larger females have earlier and longer spawning seasons than younger/smaller females. These findings suggested that older/larger females which are seasonally migrating in this spawning ground seem to play a major role in reproductive success of the species in producing significantly more offspring than younger females during an extended spawning season. Examination of the length-frequency date from the fishery indicated that the young fish are resident around Reunion and around the seamounts off Reunion Island. Our results highlight the important role of the older/larger females in the reproductive capacity of southwestern Indian Ocean stock. We discuss the potential implications of fishing the older/larger females for this stock in terms of reproduction and recruitment.
La fécondité par acte de ponte et la fécondité relative chez l'espadon (Xiphias gladius) dans le sud-ouest de l'océan Indien sont estimées d'après sept femelles de taille comprise entre 127 et 225 cm (de l'extrémité de la mâchoire inférieure à la fourche caudale) ; celles-ci ayant atteint la maturité sexuelle, les ovaires contenant des ovocytes hydratés. Ces femelles ont été pêchées entre décembre 1999 et janvier 2001, par des palangriers ciblant l'espadon et basés à La Réunion. La stratégie de la reproduction chez l'espadon a été étudiée en utilisant des données collectées au cours de deux campagnes d'échantillonnages en mer : soit 17 007 mensurations géo-référencées d'espadons, de 75 à 289 cm, qui ont été enregistrées durant les 8 années d'étude (1993-2001) et 1727 gonades d'espadon (1107 femelles et 620 mâles) prélevées entre mai 1998 et juin 2001.La fécondité par acte de ponte estimée varie de 995 000 ovocytes hydratés, pour la plus petite femelle (127 cm), à 4,3 millions pour la plus grande femelle (225 cm). La fécondité par acte de ponte est corrélée positivement à la taille du poisson. La fécondité relative s'étend de 25 à 72 ovocytes hydratés par gramme de poids de corps. Les femelles les plus âgées/grandes pondent plus tôt et sur une période plus grande que les plus jeunes/petites femelles. Ainsi, les femelles plus âgées/grandes qui migrent de façon saisonnière vers cette aire de ponte, contribueraient plus largement au renouvellement de l'espèce en produisant de façon significative davantage de recrues que les femelles plus jeunes et ceci pendant une saison de ponte plus étendue. Par ailleurs, les jeunes individus semblent séjourner aux abords de l'île de La Réunion et des monts sous-marins situés au large. Nos résultats soulignent l'importance du rôle des femelles âgées/grandes dans la capacité reproductrice du stock d'espadon du sud-ouest de l'océan Indien. Les implications potentielles de la pêche : des femelles âgées et de grandes tailles sont discutées pour ce stock, du point de vue de la reproduction et du recrutement.
Aquatic Living Resources (0990-7440) (EDP Sciences), 2009 , Vol. 22 , N. 1 , P. 59-68

Droits : 2009 EDP Sciences
http://archimer.ifremer.fr/doc/2009/publication-6354.pdf
DOI:10.1051/alr/2009012
http://archimer.ifremer.fr/doc/00000/6354/

Résumé : In an effort to implement new fishing activities for the small scale fisheries of Reunion Island, a prospecting cruise targeting deep demersal fish (200 to 600 m) was set up on the west coast of Reunion Island in 2000. This project was carried out by the Regional Fishery Committee and the French Institute for the Exploration of the Sea (Ifremer). Large commercial stocks were identified, and numerous professional or recreational fishermen started employing electric winches to exploit these deep resources. However, the deep demersal species are a fragile resource due mainly to low growth rates and late sexual maturation. Due to the rapid increase in fishing pressure, Ifremer was asked to set up a new study and two scientific campaigns were carried out in 2011 (68 fishing trips being conducted with 559 dropline operations). The first cruise was conducted at the same sites, using the same types of fishing gear and methods used in 2000. A marked drop of greater than 90% was observed in the catches of commercial species, together with a decrease of most fish sizes, attesting the overexploitation of these stocks. Only, catches of the small non-commercial shark (Squalus megalops) remained important (50% in number and weight of total catches). The second cruise extended the prospection area to all waters surrounding Reunion Island . The overexploitation was confirmed in the west of Reunion Island, and in to a lesser degree in the north. Yields were better along the east and the south coasts. Concurrently, the efficiency of 2 hook sizes was compared : small hooks caught significantly more fish but of significantly smaller body sizes, resulting in comparable total weight of fish. We conclude that medium size hooks (i.e. type 7/0) have a significant selectivity on the fish size without loss in the global catch yield. Various types of baits were also tested with the flesh of small local pelagic fish species (Selar crumenophtalmus and Decapterus macarellus) appearing to be the most efficient. This study provides helpful indicators for the management of demersal fish stocks in Reunion island, which have been poorly surveyed and poorly regulated until now. However, the total fishing effort, especially from recreational fishermen, remains the most important factor to be quantified.
Dans la perspective de diversifier la Petite Pêche réunionnaise, une campagne de prospection des stocks de poissons démersaux profonds (200 à 600 m) avait été réalisée en 2000 par le Comité Régional des Pêches Maritimes (CRPM) et l'Institut Français de Recherche pour L'Exploitation de la Mer (Ifremer) dans l'ouest de l'île de La Réunion. Elle a montré l'existence de stocks commercialement intéressants et de nombreux pêcheurs, professionnels et plaisanciers se sont équipés en moulinets électriques pour exploiter ces ressources profondes. Cependant les poissons démersaux profonds représentent une ressource fragile du fait, notamment, de leur croissance lente et de leur maturité sexuelle tardive. Aussi, face à cette augmentation rapide de la pression de pêche, Ifremer a été sollicité pour mener une nouvelle étude ; et deux nouvelles campagnes expérimentales ont été réalisées en 2011 (68 marées ayant permis la réalisation de 559 filages). La première campagne a repris les mêmes sites de pêche, le même matériel et la même méthodologie qu’en 2000. Elle montre que les rendements en espèces commerciales ont diminué de façon très nette (plus de 90%) ainsi que la taille de certaines espèces, indicateurs caractéristiques d'une surexploitation des stocks. Seules les captures de requins zépines (Squalus megalops,) non commercialisées à La Réunion, restent comparables à celles de 2000 avec la moitié des captures totales. La 2e campagne a étendu la prospection à tout le tour de l'île. La surpêche (baisse des rendements et des tailles de poisson) est confirmée dans l'ouest et à un moindre degré sur la côte nord. Les rendements sont meilleurs dans l'est et le sud. Parallèlement, 2 tailles d'hameçons ont été comparées : les petits hameçons capturent un nombre significativement plus élevé de poissons par filage, mais de tailles plus petites, ce qui se traduit par un poids global comparable. Les hameçons de taille moyenne (type 7/0) ont donc une sélectivité significative sur la taille des poissons capturés sans nuire au rendement global. Des comparaisons ont aussi porté sur les types d'appât : Les laizes de petits pélagiques locaux (pêche-cavale et bancloche) se révèlent les plus efficaces et les plus sélectives vis-à-vis des espèces commerciales. Cette étude fournit des indicateurs utiles à la gestion des stocks démersaux jusqu'ici peu étudiés et peu encadrés. Mais la grande inconnue reste l'effort de pêche total sur cette ressource et notamment celui des pêcheurs plaisanciers.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00098/20902/18837.pdf
DOI:10.13155/20902
http://archimer.ifremer.fr/doc/00098/20902/

Éditeur(s) : Wiley-blackwell
Résumé : An ecomorphological method was developed, with a focus on predation functions, to define functional groups in the Celtic Sea fish community. Eleven functional traits, measured for 930 individuals from 33 species, led to 11 functional groups. Membership of functional groups was linked to body size and taxonomy. For seven species, there were ontogenetic changes in group membership. When diet composition, expressed as the proportions of different prey types recorded in stomachs, was compared among functional groups, morphology-based predictions accounted for 28-56% of the interindividual variance in prey type. This was larger than the 12-24% of variance that could be explained solely on the basis of body size. (C) 2013 The Fisheries Society of the British Isles
Journal Of Fish Biology (0022-1112) (Wiley-blackwell), 2013-08 , Vol. 83 , N. 2 , P. 355-377

Droits : 2013 The Fisheries Society of the British Isles
http://archimer.ifremer.fr/doc/00152/26294/24831.pdf
DOI:10.1111/jfb.12177
http://archimer.ifremer.fr/doc/00152/26294/

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
We provide new constraints on the modes of mantle exhumation and denudation in the pre-orogenic Pyrenees by investigating the poorly known peridotites located east of the Lherz body, in eastern Ariè ge (Vicdessos, Urs, Bestiac, Caussou and Prades main peridotitic bodies). We show that: (1) numerous peridotite bodies, not described so far, are constituted by decametric to sub-metric outcrops scattered between and around the main outcrops identified by Monchoux (1970); (2) most of the peridotites form blocks and lenses of various sizes, from millimetric monocrystalline grains to hectometric olistoliths, embedded in debris flows involving mainly Mesozoic metasediments; these peridotites can therefore be linked to the S-type peridotites of Lagabrielle et al. (2010), and share similarities with the peridotites of Lherz region (Clerc et al., 2012). All originated from tectono-sedimentary processes associated with mantle exhumation in relation with extreme thinning and breakoff of the continental basement; (3) the various petrographic characters of these peridotites and their heterogeneity in serpentinisation degree imply a peculiar mode of exhumation, which merges mantle fragments inherited from different structural levels; (4) the lack of tectonic structures such as faults and shear planes associated with the ultramafic-rich breccia formation and the presence of neoformation of metamorphic minerals within the matrix preclude their origin as cataclasites related to the Latest Cretaceous and Tertiary Pyrenean contractional deformation. The peridotites of eastern Ariè ge are indisputable witnesses of the presence of an inverted hyper-extended Cretaceous passive margin forming the current North Pyrenean zone. The geometry of the extensional system was complex and probably associated with strike-slip faults and transcurrent motion. ß 2016 The Authors. Published by Elsevier Masson SAS on behalf of Acadé mie des sciences. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).
ISSN: 1631-0713

Droits : http://creativecommons.org/licenses/by-nc-nd/
insu-01280502
https://hal-insu.archives-ouvertes.fr/insu-01280502
https://hal-insu.archives-ouvertes.fr/insu-01280502/document
https://hal-insu.archives-ouvertes.fr/insu-01280502/file/1-s2.0-S1631071316000043-main.pdf
DOI : 10.1016/j.crte.2015.12.003

Éditeur(s) : HAL CCSD
Résumé : International audience
Afro-­‐‑ Caribbean sprinters often reach high performance levels at an early age. Adolescence is a time of morphological and physiological changes. This study was designed to analyze the evolution in parameters of short sprint performance during adolescence in Afro-­‐‑ Caribbean boys, especially the stride number/body height ratio (SN/BH), which is at the interface of technical and morphological factors. Seventy-­‐‑ one 13-­‐‑ year-­‐‑ old boys performed vertical jumps and short sprint races. The races were filmed with a view to determine stride variables. Anthropometric parameters were also measured. The same tests were performed two years later. Body height and SN/BH were the main predictors of sprint performance. The delta of performance was principally explained by stride length and stride number. Although deterioration in technical parameters was expected, the parameters related to body size and stride length were the main sprint performance predictors rather than explosive force. These results could be useful in developing tests to detect sprint potential in youth.
Journal of Human Kinetics

hal-01163933
https://hal.univ-antilles.fr/hal-01163933