Éditeur(s) : Blackwell science
Résumé : The trophic level mean and variance, and the degree of omnivory for five Celtic Sea fish predators were estimated using a database of stomach content records characterized by a high level of taxonomic resolution. The predators occupied a high position in the food web, i.e. 4.75 for Atlantic cod Gadus morhua, 444 for haddock Melanogrammus aeglefinus, 4.88 for European hake Merluccius merluccius, 5.00 for megrim Lepidorhombus whiffiagonis and 5.27 for whiting Merlangius merlangus. The level of taxonomic resolution of the prey did not greatly affect mean T-L predator values; an effect on variance was evident, low resolution masking intra-population variability in T-L. Generalized additive models (GAM) were used to explain the variability of predator T-L caused by environmental variables (international Council for the Exploration of the Sea, ICES, division and season) and predator characteristics (total length, L-T). Significant year, location season and interaction effects were found for some species and with L-T, at the scale of ICES subdivision. The species-specific variability of T-L could be due to spatio-temporal variations in prey availability and in predator selectivity following ontogenetic changes. Omnivorous fish T-L. was less affected by spatio-temporal variations. In addition, results showed that the omnivory index and T-L variability provide dissimilar information on predator feeding strategy. Combining information on T-L. variability and omnivory allowed between within individual and between-individual components contributing to trophic niche width to be separated and the type of generalization of fish predators to be identified. (c) 2008 The Authors Journal compilation (c) 2008 The Fisheries Society of the British Isles.
Journal of Fish Biology (0022-1112) (Blackwell science), 2008-09 , Vol. 73 , N. 4 , P. 763-781

Droits : 2008 Wiley Blackwell Publishing, Inc. The Fisheries Society of the British Isles
http://archimer.ifremer.fr/doc/2008/publication-4699.pdf
DOI:10.1111/j.1095-8649.2008.01938.x
http://archimer.ifremer.fr/doc/00000/4699/

Éditeur(s) : HAL CCSD Station Biologique
Résumé : International audience
From fish samplings (rotenone: 6 February 2002 & 13 May 2003; boxtraps: January 2008 to July 2009) in amangrove lagoon, the demographic structure, reproductive period and diet of Lophogobius cyprinoides were studied.Individual fish were measured (< 1 mm), weighed (± 0.01 g), and sexed by observing the urogenital papilla, sex-ratios andtotal length (TL)-standard length and length-mass relationships were calculated. Five individuals per size class (2 mm) wereused to study sexual maturity by macroscopic observation of gonad structure with a sexual maturity scale, and diet byqualitative and quantitative examination of digestive tract contents and calculation of the following indices: levels offullness and vacuity; occurrence, number, and point frequencies of various food items, and quality of nutrition. Growth isisometric and sexual dimorphism in favor of males (78 vs. 64 mm), demographic structure (18 ≤ TL ≤ 78 mm) and conditionevolved over time, with a distinct femininization of the population. Sexual inversion appeared from 46 mm onward, andtotal masculinization at 72 mm. Protogynous hermaphrodism is advantageous in a sedentary, subcryptobenthic species thatis reproductively active almost throughout the year. The species has an omnivorous diet specialized in copepods and plants
ISSN: 0007-9723

hal-00746079
https://hal.univ-antilles.fr/hal-00746079

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Fish mucus has important biological and ecologicalroles such as defense against fish pathogens andchemical mediation among several species. A non-targetedliquid chromatography–mass spectrometry metabolomicapproach was developed to study gill mucus of eight butterflyfishspecies in Moorea (French Polynesia), and theinfluence of several fish traits (geographic site and reefhabitat, species taxonomy, phylogeny, diet and parasitismlevels) on the metabolic variability was investigated. Abiphasic extraction yielding two fractions (polar and apolar)was used. Fish diet (obligate corallivorous, facultativecorallivorous or omnivorous) arose as the main driver ofthe metabolic differences in the gill mucus in both fractions,accounting for 23% of the observed metabolic variabilityin the apolar fraction and 13% in the polar fraction.A partial least squares discriminant analysis allowed us toidentify the metabolites (variable important in projection,VIP) driving the differences between fish with differentdiets (obligate corallivores, facultative corallivores andomnivorous). Using accurate mass data and fragmentationdata, we identified some of these VIP as glycerophosphocholines,ceramides and fatty acids. Level of monogeneangill parasites was the second most important factor shapingthe gill mucus metabolome, and it explained 10% of themetabolic variability in the polar fraction and 5% in theapolar fraction. A multiple regression tree revealed that themetabolic variability due to parasitism in the polar fractionwas mainly due to differences between non-parasitized andparasitized fish. Phylogeny and butterflyfish species werefactors contributing significantly to the metabolic variabilityof the apolar fraction (10 and 3%, respectively) buthad a less pronounced effect in the polar fraction. Finally,geographic site and reef habitat of butterflyfish species didnot influence the gill mucus metabolome of butterflyfishes.
ISSN: 0722-4028

hal-01563312
https://hal-univ-perp.archives-ouvertes.fr/hal-01563312
DOI : 10.1007/s00338-017-1554-0

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : This paperdiscusses approaches to cultural alterity in the context of tourism, with an emphasis on food consumption.Tourism as a field of study is ideal for the observation and analysis of the strategies adopted by individuals facing the unknown, the other.Food consumption, although universal,is deeplycultural, and it anchors social norms in the body.Studyingfood inthe context of tourismallows us tohighlightthese normsas well ascertain individual identification processes. Roseau’s cruise port, Commonwealth of Dominica, serves as the empirical basis for my analysis. In 2006, 470 830 cruise passengers disembarked on the Island, which represented over 80% of visitors to the island, as well as more than six times the national population. In consideration of these impressive statistics, analyzing food strategies can give us insights into larger patterns of negotiation, between fear and attraction to the unknown.
Ce texte propose de développer la question de la relation à l’altérité culturelle en jeu dans la pratique touristique sous l’angle de l’alimentation. Le tourisme a l’avantage d’offrir un terrain d’étude privilégié pour observer les stratégies identitaires des individus face à l’inconnu. La consommation alimentaire, bien qu’universelle, est profondément culturelle, et ancre dans les corps des normes sociales. Etudier l’alimentation dans le contexte touristique donne l’occasion de mettre en évidence ces normes de même que certaines logiques identitaires des individus. Le port de croisière de Roseau, Commonwealth of Dominica, sert de base empirique au développement. En 2006, 470 830 passagers de croisières ont débarqués sur l’île, ce qui représentait plus de 80 % des visiteurs de l’île, de même que plus de six fois la population nationale. Face à ces impressionnantes statistiques, s’intéresser aux stratégies alimentaires permet de mettre en évidence des schémas plus larges : entre peur et attrait de l’inconnu.
Dominique

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5655
http://journals.openedition.org/etudescaribeennes/5655

Éditeur(s) : Soc Francaise D Ichtyologie
Résumé : The ichtyofauna of Geyser and Zelee coral banks (north of Mozambique canal) was investigated in 1996, this work being the first quantitative study on this area. Quantitative data were collected on 11 stations (mean depth 18 m) by visual observations along 50 m transect, widened to 2 m for small sedentary species, and to 5 m for commercial species with a large action range. The main descriptors of the fish communities (species richness, abundance per species) and the trophic structure (omnivorous, herbivorous, carnivorous, browsers of sessile invertebrates) were described and analysed.A total of 294 fish species, belonging to 43 families were recorded. The species richness varied from 45 to 83 species / station, and the abundance, from 292 to 1322 individuals / 100 m(2), the lower values being recorded on the inner slope and the higher ones on the outer slope. In terms of number of individuals, diurnal planktivores were highly represented at all sites (mean 63.7%). Pomacentridae and Caesionidae were the most abundant families, damselfishes being mainly represented by Chromis ternatensis (mean 73 ind., max, 148 ind. 100 m(2)), C. dimidiata (mean 33 ind., max. 151 ind. / 100 m(2)) and Dascyllus carneus (mean 38 ind., max. 92 ind. 100 m(2)), and fusiliers by Pterocaesio chrysozona (mean 19 ind., max. 128 ind. / 100 m(2)), P. tile (mean 12 ind., max. 38 ind. / 100 m(2)) and Caesio teres (mean 6 ind., max. 32 ind. / 100 m(2)). The high values recorded showed that small and isolated coral banks can support relatively rich fish faunas and substantial populations of individuals. This result may be explained by different factors such as the oceanographic circulation favourable to a localised enrichment of nutrients from surface water, the low human impact, a good coral cover and a high degree of self-recruitment associated with regional recruitment. Nevertheless, the main commercial species such as Lutjanus bohar and Variola louti, observed at each station, were represented at a low density (mean 0.8 ind., max. 6 ind. / 100 m(2) and mean 0.2 ind., max. 0.8 ind. / 100 m(2) respectively). This result may be due to the exploitation of these coral banks between 1990 and 1992, which was interrupted following the fast decreasing output.Such an experience shows us the fragility of these small coral banks and the necessity to establish a rational management of the resource.
Cybium (0399-0974) (Soc Francaise D Ichtyologie), 2002 , Vol. 26 , N. 1 , P. 11-26

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00000/10132/7687.pdf
http://archimer.ifremer.fr/doc/00000/10132/

Éditeur(s) : J.-J. SYMOENS
Résumé : Un modèle Ecopath de l'estuaire du Sine-Saloum (Sénégal) comportant au total 37 groupes fonctionnels a été appliqué dans la présente étude en vue de déterminer les faits essentiels de ce système aquatique. La grande biodiversité spécifique des poissons de l'écosystème peut y jouer un rôle en assurant son intégrité, spécialement en présence de facteurs de stress, bien qu'il ait été observé que ce n'est pas entièrement le cas. Les résultats montrent qu'un autre facteur de mitigation est le niveau des forces d'interaction entre les groupes fonctionnels. La stabilité est accrue par des relations plus faibles et des pyramides plus courtes et plus larges. Bien que différentes questions se posent concernant les facteurs conduisant à la stabilité d'un système, les méthodes et les façons de les approcher devraient envisager d'en situer les résultats dans le contexte d'une théorie écologique plus large.
An Ecopath model of the Sine Saloum estuary (Senegal) with a total of 37 functional groups is used in this study to determine the key features of this aquatic system. The high fish species biodiversity in the ecosystem may play a role of ensuring its integrity, especially in the presence of stress, though it was observed that this is not entirely the case. Results show that another mitigating factor is the level of interaction strengths between functional groups. Stability is improved by weaker connectance as well as shorter and fatter pyramids. Though differing issues arise with respect to questions driving a system's stability, methods and approaches should consider placing results in the context of a broader ecological theory.
Coastal Ecosystems of West-Africa Biological Diversity-Resources-Conservation (J.-J. SYMOENS), 2005 , P. 15-26

Droits : J.-J. SYMOENS
http://archimer.ifremer.fr/doc/2005/publication-2554.pdf
http://archimer.ifremer.fr/doc/00000/2554/