Éditeur(s) : HAL CCSD Station Biologique
Résumé : International audience
This study focuses on the diet of the eel Anguilla anguilla, sampled during one month of each of the four seasons from autumn 1998 to summer 1999 in the Languedocian Ingril Lagoon (Gulf ot Lion). The following feeding indices were calculated based on observations of 11 categories of prey found in the contents of full stomachs: coefficient of vacuity (CV), degree of fullness (DR), occurrence frequency (PP, in %), relative abundance (N, in %) and relative weight (P, in %). A parallel monitoring of the benthic macrofauna was conducted in autumn and spring. The interpretation of the results is based on the degree III of the scale of confinement established by Guélorget & Perthuisot (1983) and on the Costello et al. (1990) method, which combines PP and N. A. anguilla mainly feeds on benthic organisms, primarily amphipods crustaceans, polychaetes, insect larvae and small fish. The eel's feeding activity is very low in November and February and usually increases during May. The trophic quality available to the eel population in the Ingril Lagoon depends on its hydrodynamic variables, which are directly related to its close communication with the sea. Changes observed in the eel's diet over this year long study illustrate an opportunist type of feeding behaviour that reflects the typical composition of the macroinvertebrate species assemblage at a given point in time. Eels consume the type of benthic prey that is most available at a given moment without using a particular feeding strategy (e.g., specialisation or generalisation). The eels adapt by shifting their diet according to the energetic resources available in the ecosystem, which vary depending on hydrological regime. Thus, the facultative catadromous migrant species Anguilla anguilla could be used as a bioindicator of changes in the biological zonation and in the available food resources in the brackish ecosystem of Ingril Lagoon during its lagoon-resident ecophase.
ISSN: 0007-9723

hal-00753020
https://hal.univ-antilles.fr/hal-00753020

Éditeur(s) : HAL CCSD
Résumé : International audience
Wound healing is important for sharks from the earliest life stages, for example, as the 'umbilical scar' in viviparous species heals, and throughout adulthood, when sharks can incur a range of external injuries from natural and anthropogenic sources. Despite anecdotal accounts of rapid healing in elasmobranchs, data regarding recovery and survival of individuals from different wound or injury types has not been systematically collected. The present study documented: (i) 'umbilical scar' healing in wild-caught, neonatal blacktip reef sharks while being reared for 30 days in flow-through laboratory aquaria in French Polynesia; (ii) survival and recovery of free-swimming blacktip reef sharks in Australia and French Polynesia following a range of injuries; and (iii) long-term survival following suspected shark-finning activities. Laboratory monitoring, tag-recapture records, telemetry data and photo-identification records suggest that blacktip reef sharks have a high capacity to survive and recover from small or even large and severe wounds. Healing rates, recovery and survival are important factors to consider when assessing impacts of habitat degradation and fishing stress on shark populations. The present study suggests that individual survival may depend more on handling practices and physiological stress rather than the extent of physical injury. These observations also contribute to discussions regarding the ethics of tagging practices used in elasmobranch research and provide baseline healing rates that may increase the accuracy in estimating reproductive timing inferred from mating scars and birth dates for neonatal sharks based on umbilical scar healing status. Cite as: Chin A, Mourier J, Rummer JL (2015) Blacktip reef sharks (Carcharhinus melanopterus) show high capacity for wound healing and recovery following injury. Conserv Physiol 3: doi:10.1093/conphys/cov062.
Conservation physiology

Droits : http://creativecommons.org/licenses/by/
hal-01250745
https://hal-univ-perp.archives-ouvertes.fr/hal-01250745
https://hal-univ-perp.archives-ouvertes.fr/hal-01250745/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01250745/file/Conserv%20Physiol-2015-Chin-.pdf
DOI : 10.1093/conphys/cov062

Résumé : First results obtained on mussels introduced in the Goury harbour on 12 June 2002 and collected on 20 March 2003 enabling a first approach of living material non-active contamination level next to the Cogema plant in La Hague. As a conclusion, COGEMA's industrial activity could have an effect on living materials, with a slight rise in the cadmium, mercury and zinc concentrations observed in mussel flesh, but without exceeding sanitary norms.
Premiers résultats obtenus sur un lot de moules introduit au port de Goury le 12 juin 2002 et récolté le 20 mars 2003 permettant d'avoir une première approche du niveau des contaminations non actives de la matière vivante dans un secteur proche de l'usine de Cogema à La Hague. En conclusion, il se pourrait qu'il y ait un effet de l'activité industrielle de la COGEMA, avec une très légère augmentation des concentrations observées dans la chair des moules en cadmium, en mercure et en zinc, mais sans jamais générer des dépassements des normes sanitaires.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2003/rapport-3833.pdf
http://archimer.ifremer.fr/doc/00000/3833/

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
: Human exposure to xenobiotics is usually estimated by indirect methods. Biological monitoring has emerged during the last decade to improve assessment of exposure. However, biomonitoring is still an analytical challenge, because the amounts of sample available are often very small yet analysis must be as thorough and sensitive as possible. The purpose of this work was to develop an untargeted "exposomics" approach by using ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS), which was applied to the characterization of pesticide metabolites in urine from pregnant women from a French epidemiological cohort. An upgradable list of pesticides commonly used on different crops, with their metabolites (more than 400 substances) was produced. Raw MS data were then processed to extract signals from these substances. Metabolites were identified by tandem mass spectrometry; putative identifications were validated by comparison with standards and metabolites generated by experiments on animals. Finally, signals of identified compounds were statistically analyzed by use of multivariate methods. This enabled discrimination of exposure groups, defined by indirect methods, on the basis of four metabolites from two fungicides (azoxystrobin, fenpropimorph) used in cereal production. This original approach applied to pesticide exposure can be extended to a variety of contaminant families for upstream evaluation of exposure from food and the environment.
ISSN: 1618-2642

hal-00875889
https://hal.archives-ouvertes.fr/hal-00875889
DOI : 10.1007/s00216-013-7136-2
PUBMED : 23892877

Éditeur(s) : HAL CCSD
Résumé : International audience
Increasingly, health risk assessment is addressing multiple pathway exposures to multiple contaminants. We reviewed aggregated exposure and cumulative risk approaches for contemporary and ubiquitous semivolatile organic compounds (SVOC). We identified 22 studies aggregating exposure pathways, and 31 cumulating risk. Exposure aggregation is based on the addition of pathway-specific doses, using kinetic modeling where it exists, and classic external dose equations otherwise. In most cases, exposure is dominated by a single route or source of exposure - mainly the oral pathway - via dietary or non-dietary exposure. Preferential routes and sources of exposure are influenced by SVOC physical-chemical properties such as vapor pressure. The cumulative risk approach for contaminants is based on dose addition. Simple sum of hazard quotient (Hazard Index: HI) is the most commonly used cumulative risk assessment approach, while Relative Potency Factor (RPF) appeared to the best suited - although this calls for a level of toxicological information that limits the number of compounds that can be studied simultaneously. Where both were performed, moving from HI to more refined approach produced similar results. In conclusion, both approaches - exposure aggregation and cumulative risk - rely on simple assumptions. Nevertheless, they allow uncertainty to be reduced, in comparison with source-by-source or chemical-by-chemical approaches.
Environmental Research

hal-01579608
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01579608
DOI : 10.1016/j.envres.2017.06.022
PUBMED : 28732321

Éditeur(s) : HAL CCSD Royal Society
Résumé : Coral bleaching events are predicted to occur more frequently in the coming decades with global warming. The susceptibility of corals to bleaching during thermal stress episodes depends on many factors, including the magnitude of thermal stress and irradiance. The interactions among these two factors, and in particular with ultra-violet radiation (UVR), the most harmful component of light, are more complex than assumed, and are not yet well understood. This paper explores the individual and combined effects of temperature and UVR on the metabolism of Acropora muricata, one of the most abundant coral species worldwide. Particulate and dissolved organic matter (POM/DOM) fluxes and organic matter (OM) degradation by the mucus-associated bacteria were also monitored in all conditions. The results show that UVR exposure exacerbated the temperature-induced bleaching, but did not affect OM fluxes, which were only altered by seawater warming. Temperature increase induced a shift from POM release and DOM uptake in healthy corals to POM uptake and DOM release in stressed ones. POM uptake was linked to a significant grazing of pico- and nanoplankton particles during the incubation, to fulfil the energetic requirements of A. muricata in the absence of autotrophy. Finally, OM degradation by mucus-associated bacterial activity was unaffected by UVR exposure, but significantly increased under high temperature. Altogether, our results demonstrate that seawater warming and UVR not only affect coral physiology, but also the way corals interact with the surrounding seawater, with potential consequences for coral reef biogeochemical cycles and food webs.
ISSN: 2046-6390

hal-01606454
https://hal.archives-ouvertes.fr/hal-01606454
DOI : 10.1242/bio.026757
PRODINRA : 406580
PUBMED : 28811302

Éditeur(s) : HAL CCSD American Society for Biochemistry and Molecular Biology
Résumé : International audience
Chronic low grade inflammation is closely linked to obesity-associated insulin resistance. To examine how administration of the anti-inflammatory compound indomethacin, a general cyclooxygenase inhibitor, affected obesity development and insulin sensitivity, we fed obesity-prone male C57BL/6J mice a high fat/high sucrose (HF/HS) diet or a regular diet supplemented or not with indomethacin (±INDO) for 7 weeks. Development of obesity, insulin resistance, and glucose intolerance was monitored, and the effect of indomethacin on glucose-stimulated insulin secretion (GSIS) was measured in vivo and in vitro using MIN6 β-cells. We found that supplementation with indomethacin prevented HF/HS-induced obesity and diet-induced changes in systemic insulin sensitivity. Thus, HF/HS+INDO-fed mice remained insulin-sensitive. However, mice fed HF/HS+INDO exhibited pronounced glucose intolerance. Hepatic glucose output was significantly increased. Indomethacin had no effect on adipose tissue mass, glucose tolerance, or GSIS when included in a regular diet. Indomethacin administration to obese mice did not reduce adipose tissue mass, and the compensatory increase in GSIS observed in obese mice was not affected by treatment with indomethacin. We demonstrate that indomethacin did not inhibit GSIS per se, but activation of GPR40 in the presence of indomethacin inhibited glucose-dependent insulin secretion in MIN6 cells. We conclude that constitutive high hepatic glucose output combined with impaired GSIS in response to activation of GPR40-dependent signaling in the HF/HS+INDO-fed mice contributed to the impaired glucose clearance during a glucose challenge and that the resulting lower levels of plasma insulin prevented the obesogenic action of the HF/HS diet.
ISSN: 0021-9258

hal-01074835
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01074835
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01074835/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01074835/file/JBC-2013-525220v2-Kristiansen-POSTPRINT.pdf
DOI : 10.1074/jbc.M113.525220

Éditeur(s) : HAL CCSD PubMed
Résumé : International audience
The aim of this study was to measure the heart rate (HR) response of eight elite water polo players during the four 7-min quarters of the game and to check for relationships with the physiological parameters of performance ( ·VO2max, Th1vent, Th2vent). Each athlete performed a ·VO2max treadmill test and played a water polo game wearing a heart rate monitor. The game fatigue index was calculated as the ratio of the fourth-quarter HR to the first-quarter HR: HR4/HR1. The results showed a slight decrease in fourth-quarter HR compared with the first quarter, with the mean four-quarter HR equal to 79.9 ± 4.2% of HRmax. Stepwise multiple regression analysis showed ·VO2max to be the main explanatory factor of game intensity, i.e. game HR expressed in %HRreserve (R=0.88, P<0.01). We observed that higher aerobic capacity resulted in higher game intensity. We also observed a decrease in the playing intensity in the fourth quarter compared with the first, likely due to very high game involvement. We concluded that high aerobic capacity seems necessary to ensure high game intensity in water polo. This suggests that coaches should encourage their athletes to reach a minimum level of ·VO2max and that HR monitoring could be of great interest in the control of water polo training sessions.
ISSN: 0860-021X

hal-01158208
https://hal.univ-antilles.fr/hal-01158208
DOI : 10.5604/20831862.1083277

Éditeur(s) : HAL CCSD Sociedade Entomológica do Brasil
Résumé : Variations in diel activity among hyperdiverse tropical communities of moths, despite representing a key component of niche partitioning between species, have barely been studied so far. Using light trapping from dawn to sunset over a 1-year period in French Guiana, we investigated these variations within and between two families of moths (Sphingidae and Saturniidae). Our results revealed contrasting patterns in flight activity at night between Sphingidae and Saturniidae. Sphingidae reached their peak in species richness and abundance between 7:00 and 8:00 p.m., followed by a decrease around 11:00 p.m. to midnight, whereas Saturniidae were continuously present throughout the night, with a peak around midnight. In addition, we found changes in diel activity among some of the most common genera in each family, highlighting distinct behavioral, physiological, and functional traits among taxa. Given differences in flight activity at different taxonomic levels, it is strongly recommended to monitor by light trapping throughout the night to effectively sample saturniid and sphingid assemblages, even though the activity of Sphingidae sharply declines after midnight. These results improve the general natural history information of tropical moths and reinforce the need of further research on the ecological and taxonomic consequences of differences in diel activity.
ISSN: 1519-566X

hal-01536447
https://hal.archives-ouvertes.fr/hal-01536447
DOI : 10.1007/s13744-014-0264-3
PRODINRA : 320714

Éditeur(s) : HAL CCSD
Résumé : International audience
BACKGROUND: There is increasing evidence that reproductive abnormalities are increasing in frequency in both human population and among wild fauna. This increase is probably related to exposure to toxic contaminants in the environment. The use of sentinel species to raise alarms relating to human reproductive health has been strongly recommended. However, no simultaneous studies at the same site have been carried out in recent decades to evaluate the utility of wild animals for monitoring human reproductive disorders. We carried out a joint study in Guadeloupe assessing the reproductive function of workers exposed to pesticides in banana plantations and of male wild rats living in these plantations. METHODS: A cross-sectional study was performed to assess semen quality and reproductive hormones in banana workers and in men working in non-agricultural sectors. These reproductive parameters were also assessed in wild rats captured in the plantations and were compared with those in rats from areas not directly polluted by humans. RESULTS: No significant difference in sperm characteristics and/or hormones was found between workers exposed and not exposed to pesticide. By contrast, rats captured in the banana plantations had lower testosterone levels and gonadosomatic indices than control rats. CONCLUSION: Wild rats seem to be more sensitive than humans to the effects of pesticide exposure on reproductive health. We conclude that the concept of sentinel species must be carefully validated as the actual nature of exposure may varies between human and wild species as well as the vulnerable time period of exposure and various ecological factors.
Environmental health : a global access science source [electronic resource]

hal-00669505
https://hal.archives-ouvertes.fr/hal-00669505
DOI : 10.1186/1476-069X-7-40
PUBMED : 18667078

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : We conducted a rigorous test of tropical tree seedling microhabitat differentiation by examining microhabitat associations, survival and growth of established seedlings of ten tropical tree species representing a four-factor gradient in seed size. Eight microhabitat variables describing soil and light conditions were measured directly adjacent to each of 588 seedlings within twelve 10×100 m belt transects at Paracou, French Guiana, and at 264 reference points along the transects. From these measurements, we defined three principal components describing soil richness, soil softness and canopy openness. Six of ten species (in 9 of 30 total cases) were distributed non-randomly with respect to microhabitat along at least one principal component. However, few species demonstrated clear microhabitat specialization. All shifts in distribution relative to reference points were in the same direction (richer, softer soil). Furthermore, of 135 pairwise comparisons among the species, only 7 were significantly different. More than three-fourths of all seedlings (75.3%) survived over the 2-year monitoring period, but survival rates varied widely among species. In no case was the probability of survival influenced by any microhabitat parameter. Relative height growth rates for the seedlings over 2 years varied from -0.031 cm cm-1 year-1 (Dicorynia guianensis, Caesalpiniaceae) to 0.088 cm cm-1 year-1 (Virola michelii, Myristicaceae). In only 4 of 30 cases was height growth significantly associated with one of the three principal components. Because the conditions in this study were designed to maximize the chance of finding microhabitat differentiation among a group of species differing greatly in life history traits, the lack of microhabitat specialization it uncovered suggests that microhabitat partitioning among tropical tree species at the established seedling stage is unlikely to contribute greatly to coexistence among these species.
ISSN: 0029-8549

hal-01031928
https://hal.archives-ouvertes.fr/hal-01031928
DOI : 10.1007/s00442-004-1691-3

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
The only symbiotic Mediterranean gorgonian, Eunicella singularis, has faced several mortality events connected to abnormal high temperatures. Since thermotolerance data remain scarce, heat-induced necrosis was monitored in aquarium by morphometric analysis. Gorgonian tips were sampled at two sites: Medes (Spain) and Riou (France) Islands, and at two depths: 15 m and-35 m. Although coming from contrasting thermal regimes, seawater above 28 degrees C led to rapid and complete tissue necrosis for all four populations. However, at 27 degrees C, the time length leading to 50% tissue necrosis allowed us to classify samples within three classes of thermal sensitivity. Irrespectively of the depth, Medes specimens were either very sensitive or resistant, while Riou fragments presented a medium sensitivity. Microsatellite analysis revealed that host and symbiont were genetically differentiated between sites, but not between depths. Finally, these genetic differentiations were not directly correlated to a specific thermal sensitivity whose molecular bases remain to be discovered.
ISSN: 1631-0691

hal-01546168
https://hal.archives-ouvertes.fr/hal-01546168
DOI : 10.1016/j.crvi.2013.06.008

Éditeur(s) : HAL CCSD
Résumé : International audience
The Chromosome-Centric Human Proteome Project (C-HPP) aims to identify "missing" proteins in the neXtProt knowledgebase. We present an in-depth proteomics analysis of the human sperm proteome to identify testis-enriched missing proteins. Using protein extraction procedures and LC-MS/MS analysis, we detected 235 proteins (PE2-PE4) for which no previous evidence of protein expression was annotated. Through LC-MS/MS and LC-PRM analysis, data mining, and immunohistochemistry, we confirmed the expression of 206 missing proteins (PE2-PE4) in line with current HPP guidelines (version 2.0). Parallel reaction monitoring acquisition and sythetic heavy labeled peptides targeted 36 ≪one-hit wonder≫ candidates selected based on prior peptide spectrum match assessment. 24 were validated with additional predicted and specifically targeted peptides. Evidence was found for 16 more missing proteins using immunohistochemistry on human testis sections. The expression pattern for some of these proteins was specific to the testis, and they could possibly be valuable markers with fertility assessment applications. Strong evidence was also found of four "uncertain" proteins (PE5); their status should be re-examined. We show how using a range of sample preparation techniques combined with MS-based analysis, expert knowledge, and complementary antibody-based techniques can produce data of interest to the community. All MS/MS data are available via ProteomeXchange under identifier PXD003947. In addition to contributing to the C-HPP, we hope these data will stimulate continued exploration of the sperm proteome. © 2016 American Chemical Society.
Journal of Proteome Research

hal-01406074
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01406074
DOI : 10.1021/acs.jproteome.6b00400
PUBMED : 27444420