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Auteur Blasco, F.R.; McKenzie, D.J.; Taylor, E.W.; Rantin, F.T.
Titre The role of the autonomic nervous system in control of cardiac and air-breathing responses to sustained aerobic exercise in the African sharptooth catfish Clarias gariepinus Type Article scientifique
Année 2017 Publication Revue Abrégée Comp. Biochem. Physiol. A-Mol. Integr. Physiol.
Volume 203 Numéro Pages (down) 273-280
Mots-Clés Adrenergic tone; bass dicentrarchus-labrax; cardiorespiratory interactions; Cholinergic tone; Fishes; Heart rate; heart-rate; hoplerythrinus-unitaeniatus; Hypoxia; oxygen-tensions; rainbow-trout; salmo-gairdneri; Swimming; synbranchus-marmoratus
Résumé Clarias gariepinus is a facultative air-breathing catfish that exhibits changes in heart rate (f(H)) associated with air breaths (AB). A transient bradycardia prior to the AB is followed by sustained tachycardia during breath-hold. This study evaluated air-breathing and cardiac responses to sustained aerobic exercise in juveniles (total length similar to 20 cm), and how exercise influenced variations in f(H) associated with AB. In particular, it investigated the role of adrenergic and cholinergic control in cardiac responses, and effects of pharmacological abolition of this control on air-breathing responses. Sustained exercise at 15, 30 and 45 cm s(-1) in a swim tunnel caused significant increases in f(AB) and f(H), from approximately 5 breaths h(-1) and 60 heartbeats min(-1) at the lowest speed, to over 60 breaths h(-1) and 100 beats min(-1) at the highest, respectively. There was a progressive decline in the degree of variation in f(H), around each AB, as f(AB) increased with exercise intensity. Total autonomic blockade abolished all variation in fH during exercise, and around each AB, but f(AB) responses were the same as in untreated animals. Cardiac responses were exclusively due to modulation of inhibitory cholinergic tone, which varied from >100% at the lowest speed to <10% at the highest. Cholinergic blockade had no effect on f(AB) compared to untreated fish. Excitatory beta-adrenergic tone was approximately 20% and did not vary with swimming speed, but its blockade increased f(AB) at all speeds, compared to untreated animals. This reveals complex effects of autonomic control on air-breathing during exercise in C. gariepinus, which deserve further investigation. (C) 2016 Elsevier Inc. All rights reserved.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1095-6433 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1714
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Auteur Villon, S.; Mouillot, D.; Chaumont, M.; Darling, E.S.; Subsol, G.; Claverie, T.; Villeger, S.
Titre A Deep learning method for accurate and fast identification of coral reef fishes in underwater images Type Article scientifique
Année 2018 Publication Revue Abrégée Ecol. Inform.
Volume 48 Numéro Pages (down) 238-244
Mots-Clés Automated identification; Convolutional neural network; density; Machine learning; Marine fishes; neural-networks; system; temperate; Underwater pictures; video stations; visual census; vulnerability
Résumé Identifying and counting fish individuals on photos and videos is a crucial task to cost-effectively monitor marine biodiversity, yet it remains difficult and time-consuming. In this paper, we present a method to assist the identification of fish species on underwater images, and we compare our model performances to human ability in terms of speed and accuracy. We first tested the performance of a convolutional neural network (CNN) trained with different photographic databases while accounting for different post-processing decision rules to identify 20 fish species. Finally, we compared the performance of species identification of our best CNN model with that of humans on a test database of 1197 fish images representing nine species. The best CNN was the one trained with 900,000 images including (i) whole fish bodies, (ii) partial fish bodies and (iii) the environment (e.g. reef bottom or water). The rate of correct identification was 94.9%, greater than the rate of correct identification by humans (89.3%). The CNN was also able to identify fish individuals partially hidden behind corals or behind other fish and was more effective than humans to identify fish on smallest or blurry images while humans were better to identify fish individuals in unusual positions (e.g. twisted body). On average, each identification by our best CNN using a common hardware took 0.06 s. Deep Learning methods can thus perform efficient fish identification on underwater images and offer promises to build-up new video-based protocols for monitoring fish biodiversity cheaply and effectively.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1574-9541 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2475
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Auteur Durand, J.-D.; Hubert, N.; Shen, K.-N.; Borsa, P.
Titre DNA barcoding grey mullets Type Article scientifique
Année 2017 Publication Revue Abrégée Rev. Fish. Biol. Fish.
Volume 27 Numéro 1 Pages (down) 233-243
Mots-Clés coi; fish assemblages; genetics; identification; level; management; marine fishes; maximum-parsimony methods; mitochondrial phylogeny; Mugilidae; new-caledonia; south-america; species diversity; Taxonomy; teleostei mugilidae
Résumé Despite the ecological and commercial importance of grey mullets (fish family Mugilidae), their taxonomy and systematics are still much debated. Reasons for this are the low level of morphometric variability and the relatively poor phylogenetic information borne by the morpho-anatomical characters used thus far in diagnosing species. Here, we evaluate the potential of DNA barcoding to accurately delineate species and assign unknown specimens to taxa in the family Mugilidae. Our reference sample consists of 257 individuals from 91 lineages characterized by their nucleotide sequences at the COI, cytochrome b, and 16S rRNA loci. These lineages correspond to 55 species according to the current taxonomy, and 36 presumed cryptic species. All known and presumed cryptic species within the 'Mugil cephalus' (n = 15) and 'M. curema' (n = 6) species complexes, as well as within genera Chelon (n = 10), Crenimugil (n = 6), Osteomugil (n = 6), and Planiliza (n = 18) were successfully recovered as distinct lineages by COI gene sequences (598 bp), demonstrating the utility of this marker to delineate species in the family Mugilidae. Inconsistencies in the labeling of sequences deposited in GenBank were ascribed to species misidentification. A proportion of these misidentifications occurred in the course of dedicated barcoding surveys, further emphasizing the need for an accurate and exhaustive reference barcoding database for Mugilidae.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0960-3166 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2109
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Auteur Lucena-Fredou, F.; Kell, L.; Fredou, T.; Gaertner, D.; Potier, M.; Bach, P.; Travassos, P.; Hazin, F.; Menard, F.
Titre Vulnerability of teleosts caught by the pelagic tuna longline fleets in South Atlantic and Western Indian Oceans Type Article scientifique
Année 2017 Publication Revue Abrégée Deep-Sea Res. Part II-Top. Stud. Oceanogr.
Volume 140 Numéro Pages (down) 230-241
Mots-Clés Bycatch; climate-change; ecological risk-assessment; exploitation status; Fishery management; impact; life-history strategies; management; marine fishes; Productivity and Susceptibility Analysis; risk; Sustainability; trawl fishery
Résumé Productivity and Susceptibility Analysis (PSA) is a methodology for evaluating the vulnerability of a stock based on its biological productivity and susceptibility to fishing. In this study, we evaluated the vulnerability of 60 stocks of tuna, billfishes and other teleosts caught by the tuna longline fleets operating in the South Atlantic and Indian Ocean using a semi-quantitative PSA. We (a) evaluated the vulnerability of the species in the study areas; (b) compared the vulnerability of target and non-target species and oceans; (c) analyzed the sensitivity of data entry; and (d) compared the results of the PSA to other fully quantitative assessment methods. Istiophoridae exhibited the highest scores for vulnerability. The top 10 species at risk were: Atlantic Istiophorus albicans; Indian Ocean Istiompax indica; Atlantic Makaira nigricans and Thunnus alalunga; Indian Ocean Xiphias gladius; Atlantic T. albacares, Gempylus serpens, Ranzania laevis and X. gladius; and Indian Ocean T. alalunga. All species considered at high risk were targeted or were commercialized bycatch, except for the Atlantic G. serpens and R. laevis which.were discarded, and may be considered as a false positive. Those species and others at high risk should be prioritized for further assessment and/or data collection. Most species at moderate risk were bycatch species kept for sale. Conversely, species classified at low risk were mostly discarded. Overall, species at high risk were overfished and/or subjected to overfishing. Moreover, all species considered to be within extinction risk (Critically Endangered, Endangered and Vulnerable) were in the high risk category. The good concordance between approaches corroborates the results of our analysis. PSA is not a replacement for traditional stock assessments, where a stock is assessed at regular intervals to provide management advice. It is of importance, however, where there is uncertainty about catches and life history parameters, since it can identify species at risk, and where management action and data collection is required, e.g. for many species at high and most at moderate risk in the South Atlantic and Indian oceans.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0967-0645 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2179
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Auteur Trystram, C.; Rogers, K.M.; Soria, M.; Jaquemet, S.
Titre Feeding patterns of two sympatric shark predators in coastal ecosystems of an oceanic island Type Article scientifique
Année 2017 Publication Revue Abrégée Can. J. Fish. Aquat. Sci.
Volume 74 Numéro 2 Pages (down) 216-227
Mots-Clés Bull shark; carcharhinus-leucas; elasmobranch fishes; galeocerdo-cuvier; individual specialization; Reunion island; south-africa; stable-isotope analyses; tiger shark; western indian-ocean
Résumé Stomach contents and stable carbon and nitrogen isotope analyses (delta C-13 and delta N-15) were used to investigate the trophic ecology of two apex predators, tiger sharks (Galeocerdo cuvier) and bull sharks (Carcharhinus leucas), from Reunion Island to describe their dietary habits at both the population and individual levels. In this oceanic island, the tiger and bull sharks were more piscivorous and teutophagous than noted in previous research from other localities. The delta C-13 values suggested that bull sharks depended on more neritic organic matter sources than tiger sharks, confirming a coastal habitat preference for bull sharks. Moreover, the total length of the bull shark influenced delta C-13 values, with smaller individuals being more coastal than larger individuals. All indicators suggest that there is a higher degree of similarity between individual tiger sharks compared with the more heterogeneous bull shark population, which is composed of individuals who specialize on different prey. These results suggest that the two species have different functions in these coastal habitats, and thus, they must be considered independently in terms of conservation and management.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0706-652x ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2111
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