Evaluation du probiotique bactérien Pediococcus acidilactici MA18/5M chez la crevette pénéide Litopenaeus stylirostris en Nouvelle- Calédonie Auteur(s) : Castex, Mathieu Éditeur(s) : Agro Paris Tech Résumé : P. acidilactici MA 18/5M is a dietary probiotic (BACTOCELL®) which has shown its efficiency on several terrestrial and aquatic species. The present thesis aimed to investigate more fully the effects of this probiotic on cultured penaeid shrimps. For this study, we chose a global approach by replacing the problem studied in a model of interactions between three compartments: the shrimp, its intestinal microflora and the probiotic. Having first defined how the probiotic should be administrated, we studied its effects under controlled laboratory conditions at several levels of Litopenaeus stylirostris biology: (i) Nutritional status and growth, (ii) associated bacterial microflora, and (iii) health status with respect to oxidative stress. Then the probiotic improves the growth of the shrimps and the feed conversion ratio. Our study shows that these effects are partially due to a better use of the feed, particularly of dietary carbohydrates, but also suggest an action on the metabolism, andor on the growth via a contribution of essential nutrients. On the other hand, although the intestinal bacterial communities seems little affected, we show an antagonism effect of the probiotic toward total and vibrionacea intestinal flora, as well as a decrease in the level of infection of shrimps during challenge with pathogenic V. nigripulchritudo. Beside, our works highlight that infection by this pathogen, led to a reduction in antioxidant defences, to a rise in oxidative damages, and to a release of mortalities within 48 hours. This oxidative stress following bacterial infection was better controlled by animals receiving the probiotic diet, and resistance of the shrimps to infection was significant improved. A nutritional hypothesis is proposed to explain such result, hypothesis based on a link between carbohydrate metabolism and antioxidant status. As a conclusion of these works, we can propose a first explanatory scenario for the effects of P. acidilactici on a penaeid shrimp. Finally probiotic's effects were assessed under a pilot scale in a commercial farm from New Caledonia currently affected by the "summer syndrome ". We confirm the improvements brought in term of zootechnical results, with in particular, a better resistance to this syndrome. This work was made possible thanks to a breeding method in floating cages, developed during this thesis, and therefore transferred, as an experimental tool, to the shrimp industry of New Caledonia. Pediococcus acidilacticii MA18/5M est un probiotique bactérien (BACTOCELL®) qui a démontré son efficacité chez plusieurs espèces d'animaux terrestres et aquatiques. Cette thèse avait pour objectif d'investiguer plus en détails les effets de ce probiotique chez les crevettes pénéides d'élevage. Pour cette étude, nous avons choisi une approche globale replaçant la problématique dans un modèle d'interactions entre trois compartiments : la crevette, sa microflore intestinale et le probiotique. Après avoir défini les modalités d'administration, l'effet de P. acicilactici a été étudié, en conditions de laboratoire, chez la crevette Litopenaeus stylirostris, à différents niveaux: (i) statut nutritionnel et croissance, (ii) microflore bactérienne associée, et (iii) santé de l'animal à travers son statut antioxydant et son niveau de stress oxydant. Ainsi, le probiotique améliore la croissance des crevettes et l'indice de conversion de l'aliment. Notre étude montre que ces effets sont en partie liés à une meilleure utilisation de l'aliment, notamment des carbohydrates alimentaires, mais suggèrent aussi une action sur le métabolisme, et/ou sur la croissance via un apport de nutriments essentiels. D'autre part, bien que les communautés bactériennes intestinales semblent peu affectées, un effet d'antagonisme du probiotique vis-à-vis de la flore intestinale totale et vibrionacée a été montré, ainsi qu'une réduction du niveau d'infection des crevettes au cours de challenge avec le pathogène V. nigripulchritudo. Par ailleurs, nous mettons en évidence que l'infection par ce pathogène, conduit à un abaissement des défenses antioxydantes, à une élévation des dégâts oxydatifs, et au déclenchement de mortalités dans les 48 heures. Le probiotique atténue le niveau de ce stress oxydant, et améliore significativement la résistance des crevettes à l'infection. Une hypothèse nutritionnelle est proposée afin d'expliquer ce résultat, hypothèse reposant sur un lien entre le métabolisme des carbohydrates et le statut antioxydant. A l'issue de ces travaux, nous pouvons alors proposer un premier scénario explicatif des effets de P. acidilactici chez une crevette pénéide. Finalement le probiotique a été éprouvé à l'échelle pilote sur une ferme commerciale de Nouvelle-Calédonie affectée par le « syndrome d'été ». Nous confirmons les améliorations apportées en termes de résultats zootechniques, avec notamment une meilleure résistance au syndrome. Ce travail a été réalisé grâce une méthode d'élevage en cages flottantes, mis au point au cours de cette thèse, et qui a dés lors été transférée, comme outil expérimental, à la filière crevetticole Calédonienne. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/2009/these-6814.pdf http://archimer.ifremer.fr/doc/00000/6814/ | Partager |
Study of a clade of retrotransposon Copia : The GalEa, in eukaryotic genomes ; Etude d'un clade de rétrotransposons Copia : les GalEa, au sein des génomes eucaryotes Auteur(s) : Donnart, Tifenn Auteurs secondaires : Evolution Paris Seine ; Université des Antilles et de la Guyane (UAG) - Université Pierre et Marie Curie - Paris 6 (UPMC) - Université Nice Sophia Antipolis (UNS) ; Université Côte d'Azur (UCA) - Université Côte d'Azur (UCA) - Centre National de la Recherche Scientifique (CNRS) Université Pierre et Marie Curie - Paris VI Eric Bonnivard Éditeur(s) : HAL CCSD Résumé : Transposable elements play a major role in the evolution of eukaryotic genomes. Knowing the distribution of transposable elements between different species within the same taxon is essential to study their dynamics and to better understand their role in the evolution of species. Given their abundance, species diversity and living environment, crustaceans are an excellent model for studying comparative genomics of retrotransposons. It is notably in the squat lobsters that the GalEa clade of Superfamily Copia was defined. We studied the distribution of two well-known LTR retrotransposons superfamilies: Gypsy and Copia, in crustaceans. By combining PCRs with degenerate primers and in silico analysis, we identified 35 families of Copia retrotransposons and 46 families of Gypsy retrotransposons in 15 and 18 species of crustaceans (mainly Malacostraca: crabs, shrimp, krill ...). These elements have different distribution and diversity in crustaceans. Gypsy elements appear relatively commonly and diverse in all species. Conversely, the Copia elements seem rare, and consequently more difficult to detect, and are largely dominated by the elements of the clade GalEa. These results suggest two different dynamic strategies for retrotransposons Gypsy (the Red Queen theory) and retrotransposons GalEa (‘domino days spreading’ branching process). In addition, GalEa elements present a great evolutionary success being widely distributed in many branches of metazoans. They are also present in certain red algae and we have also detected them in Fungi. Taking advantage of the large amount of available genomic data, we have studied the distribution of GalEa elements of Fungi, in order to compare it with the results obtained in crustaceans. In fact, they appear only in a large phylum of Ascomycetes, in Pezizomycotina, and they form a monophyletic group within the GalEa. Finally, in the Fungi, the GalEa elements are not majority among Copia retrotransposons. We have therefore initiated a new study in molluscs, to define if the results obtained in crustaceans are a feature of GalEa elements, Malacostraca or metazoans. Les éléments transposables jouent un rôle majeur dans l’évolution des génomes eucaryotes. La connaissance de la distribution des éléments transposables entre différentes espèces au sein d’un même taxon est une condition essentielle pour étudier leur dynamique et mieux comprendre leur rôle dans l'évolution des espèces. Compte tenu de leur abondance, de leur diversité spécifique et de milieu de vie, les crustacés sont un excellent modèle pour étudier la génomique comparative des rétrotransposons. C’est notamment chez les Galathées qu’a été défini le clade GalEa des éléments de la superfamille des Copia. Nous avons étudié la distribution de deux superfamilles de rétrotransposons à LTR bien connus: les Gypsy et les Copia, au sein des crustacés. En combinant des PCRs avec amorces dégénérées et des analyses in silico, nous avons identifié 35 familles de rétrotransposons Copia et 46 familles de rétrotransposons Gypsy dans respectivement 15 et 18 espèces de crustacés (principalement des malacostracés : crabes, crevettes, krill...). Ces éléments présentent une distribution et une diversité différentes au sein des crustacés. Les éléments Gypsy apparaissent relativement fréquents et diversifiés dans toutes les espèces. A l’inverse, les éléments Copia semblent rares, donc difficilement détectables, et sont largement dominés par les éléments du clade GalEa. Ces résultats suggèrent deux stratégies différentes de dynamique pour les rétrotransposons Gypsy (théorie de la Reine Rouge) et les rétrotransposons GalEa (‘domino days spreading’ branching process). De plus, les éléments GalEa présentent un grand succès évolutif en étant largement distribués dans de nombreuses branches de métazoaires. Ils sont aussi présents chez quelques algues rouges et nous en avons également détecté chez des Fungi. Profitant des nombreuses données génomiques disponibles, nous avons donc étudié la distribution des éléments GalEa de Fungi, dans le but de comparer celle-ci aux résultats obtenus chez les crustacés. En fait, ils n’apparaissent qu’au sein d’un grand embranchement d’ascomycètes, les Pezizomycotina, et ils forment un groupe monophylétique au sein des GalEa. Enfin, chez les Fungi, les éléments GalEa ne sont pas majoritaire parmi les rétrotransposons Copia. Nous avons donc initié une nouvelle étude chez les mollusques, afin de définir si les résultats obtenus chez les crustacés sont une caractéristique des éléments GalEa, des malacostracés ou des métazoaires. https://tel.archives-ouvertes.fr/tel-01132413 NNT : 2015PA066017 tel-01132413 https://tel.archives-ouvertes.fr/tel-01132413 https://tel.archives-ouvertes.fr/tel-01132413/document https://tel.archives-ouvertes.fr/tel-01132413/file/these_archivage_2600252o.pdf | Partager |
La crevette profonde (pandalus borealis) dans la région du nord-ouest atlantique Auteur(s) : Fontaine, Bernard Éditeur(s) : ISTPM Résumé : Introduction. L'exploitation commerciale des crustacés, et en particulier des crevettes, a connu un développement considérable à partir de 1950. L'augmentation constante des apports est liée à une demande croissante sur les marchés et l'intérêt s'est porté vers de nombreuses espèces qui ne subissaient à l'origine qu'une exploitation locale. Parmi ces espèces, Pandalus borealis, caractérisée par sa vaste distribution dans l'Atlantique nord, a reçu plusieurs noms vernaculaires. Elle est appelée "pink shrimp" ou "crevette rose" aux Etats-Unis, alors que ce terme désigne aussi bien une grande crevette du golfe du Mexique et de Guyane qu'une espèce des fonds rocheux côtiers européens. L'appellation "northern shrimp" ou "crevette nordique" est quelquefois employée dans la littérature ; ce terme très vague pourrait s'appliquer à d'autres espèces, Le nom "deep-sea prawn" ou "crevette profonde" vient de la distribution bathymétrique. En réalité, les fonds fréquentés par cette crevette sont quelquefois peu profonds, mais ce nom généralisé dans le langage scientifique international sera employé dans ce texte. La crevette profonde se présente comme un animal de plus grande taille que la "crevette rose" ou "bouquet" des côtes rocheuses européennes. Elle est armée d'un long rostre épineux mesurant près de la moitié de la longueur du corps du crustacé et sa couleur varie du rose au rouge sombre. Le caractère qui permet de la distinguer très rapidement des autres crevettes de l'Atlantique nord, est situé sur le troisième segment de l'abdomen. Ce troisième segment qui détermine la courbure de la queue porte un tubercule très visible qui ressort sur le profil supérieur, cela est très net en contre-jour (fig. 1). Science et Pêche (0036-8350) (ISTPM), 1970-11 , Vol. 197 , P. 1-14 Droits : Ifremer http://archimer.ifremer.fr/doc/1970/publication-7003.pdf http://archimer.ifremer.fr/doc/00000/7003/ | Partager |
Révision des paramètres de croissance de la crevette Penaeus subtilis et étude de la faisabilité d'un modèle ECOPATH de l'écosystème littoral guyanais Auteur(s) : Doquin, Olivier Résumé : The brown shrimp Penaeus subtilis growth parameters has been studied by a lot of biologist since the fisheries of the three Guyana and Brazil has been created. The following through of the French Guyana’s fisheries had hallowed us to have an important database about shrimp boat lending. This atabase had permit us to fine the values used for predictive models helped by software like FISAT 2 in this case. This database had permit us to follow the evolution of the growth parameters along the fifteen last years.
This study had given us different results which are interesting. First, the L∞ values used by the COPACO workshop (Isaac et al, 1992) are under evaluated and the K values aren’t. in a second time, the K values of the female brown shrimp are decreasing in a significant way since 1989, this case is not the male’s one. At last, we haven’t fond a link between meteorological variation in French Guyana (rainfall, river’s flow, sunshine) or biological data (biomass, density) and the K variations.
A ecosystemic model feasibility study had been done for the French Guyana littoral. The data that are existing in the literature aren’t sufficient to build a model of this ecosystem. Future studies will perhaps provide the data that are missing to realize a first model Les paramètres de croissance de la crevette Penaeus subtilis ont été étudiés par de nombreux auteurs depuis la création de la pêcherie sur le bouclier des Guyanes. Cependant le suivi permanent de cette pêcherie a permis d’avoir une base de données importante sur les débarquements des crevettiers et ainsi de chercher à affiner les estimations utilisées dans les modèles d’évaluation avec l’aide de logiciel prévus à cet effet comme FISAT 2 utilisé ici. Ces données peuvent permettre aussi de suivre l’évolution de ces paramètres au fil des années.Il ressort de cette étude plusieurs résultats intéressants. En premier lieu, les valeurs de L∞utilisées par le groupe de travail de la COPACO (Isaac et al, 1992) sont sous-évaluées et les valeurs de K ne le sont pas forcément. En second lieu, le K des femelles présente une tendance à la diminution sur les quinze dernières années (1989 – 2003), ce qui ne semble pas être le cas des mâles. Enfin, nous ne pouvons rattacher facilement les variations de K enregistrées à aucune donnée météorologique ne concernant que la Guyane (pluviosité, débit des fleuves, insolation), ni à certaines données biologiques (biomasse, densité). La faisabilité d’un modèle écosystémique du littoral a aussi été étudiée. Il en ressort que dans l’état actuel des connaissances sur l’écosystème du littoral guyanais la réalisation d’un modèle n’est pas possible. Mais des campagnes d’études à venir pourraient permettre de recueillir suffisamment de données pour pouvoir dresser un premier modèle. Droits : 2004 Ifremer http://archimer.ifremer.fr/doc/00077/18859/16433.pdf http://archimer.ifremer.fr/doc/00077/18859/ | Partager |
Identification de marqueurs génétiques de la virulence chez Vibrio nigripulchritudo, un pathogène de crevettes pénéides en Nouvelle-Calédonie Auteur(s) : Reynaud, Yann Éditeur(s) : Université de Paris 6 Pierre et Marie Curie Résumé : Since 1997, a new pathology seasonally occurs in new caledonian shrimp farms during the warm season and was named Summer Syndrome. Diseased Litopenaeus stylirostris shrimp suffer from a septicemic vibriosis which was attributed to V. nigripulchritudo. Preliminary studies based on a collection of V. nigripulchritudo strains have brought to light different virulence levels according to experimental infections results; three virulence statuses were defined: highly (HP), moderately (MP) and non pathogenic (NP). The aim of this work was to genetically characterize virulent V. nigripulchritudo strains. In a first step the genetic diversity of 58 V. nigripulchritudo strains was analyzed by MLST and AP-PCR, revealing a cluster of HP and MP strains, characterized by a low genetic variability and that includes all Summer Syndrome-associated isolates. This confirms the emergence of one cluster of pathogenic V. nigripulchritudo simultaneously with the emergence of the Summer Syndrome ; in a second step, 368 genetic markers of virulence were identified by a Suppressive Subtractive Hybridization performed between the genomes of a HP strain and a genetically close, NP isolate; the distribution of the screened SSH fragments was studied in 58 V. nigripulchritudo isolates by macro-array: 78 DNA fragments were selected, allowing to characterize clusters identified and pathogenic statuses; 13 are specific of the HP strains involved in Summer Syndrome. Interestingly, 10 of these markers are carried by a plasmid pSFn1 that contains sequences highly similar to those of a plasmid pAK1, detected in Vibrio shilonii, a coral pathogen. The origin and consequences of this plasmid acquisition are discussed. Depuis 1997, les élevages de crevettes en Nouvelle-Calédonie sont confrontés à une nouvelle maladie, le Syndrome d'été, une vibriose septicémique dont l'agent étiologique est Vibrio nigripulchritudo. Les résultats d'infection expérimentale sur une collection de souches, ont montré l'existence de trois pathotypes distincts : hautement (HP), moyennement (MP) et non pathogène (NP). L'étude du polymorphisme génétique de 58 souches par typage moléculaire en MLST et AP-PCR, a mis en évidence un groupe phylogénétique particulier caractérisé par un très faible degré de variabilité génétique (confirmant l'émergence de ce groupe en parallèle à l'émergence du Syndrome d'été) et constitué uniquement de souches HP (dont toutes celles associées au Syndromed'été) et de souches MP. Afin d'identifier des marqueurs génétiques de la virulence des souches responsables du Syndrome d'été, et parmi ces marqueurs des gènes codant potentiellement pour des effecteurs de la virulence, une approche soustractive par SSH a été développée entre une souche HP de type Syndrome d'été et une souche NP : 368 marqueurs génétiques ont ainsi été mis en évidence ; la distribution de ces marqueurs a été étudiée chez les 58 souches de la collection par une approche en macroarray : 78 marqueurs ont été sélectionnés, qui permettent de caractériser les différents groupes phylogénétiques et les différents pathotypes, dont 13 fragments spécifiques des souches HP type Syndrome d'été. Parmi ces 13 fragments, 10 ont été localisés sur le plasmide pSFn1 qui a été entièrement séquencé. Ce même plasmide a été purifié uniquement des souches HP de type Syndrome d'été. Par ailleurs, une très forte homologie a été mise en évidence entre pSFn1 et pAK1, un autre plasmide également séquencé et retrouvé chez la souche V. shilonii AK1, responsable du blanchiment du corail Oculina patagonica en Méditerranée. Ces résultats ont ouvert la discussion sur le rôle de pSFn1 dans la virulence de V. nigripulchritudo. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/2008/these-3906.pdf http://archimer.ifremer.fr/doc/00000/3906/ | Partager Voir aussi plasmide SSH épidémiology virulence shrimp vibriosis Vibrio nigripulchritudo plasmide SSH épidémiologie Télécharger |
The impact of easily oxidized material (EOM) on the meiobenthos: Foraminifera abnormalities in shrimp ponds of New Caledonia; implications for environment and paleoenvironment survey Auteur(s) : Debenay, J.p. Della Patrona, Luc Herbland, Alain Goguenheim, H Éditeur(s) : Elsevier Résumé : This study was carried out in shrimp ponds from New Caledonia, in order to determine the cause of the exceptional proportion of abnormal tests (FAI) (often >50%, sometimes >80%). FAI was positively correlated to the quantity of easily oxidized material (EOM) deposited on the bottom of the ponds and to the sediment oxygen demand, and negatively correlated to redox. These results suggest that a very high FAI is a potential indicator for great accumulations of native organic matter, leading to a high sediment oxygen demand. When studying ancient sediments in core samples, exceptional abundances of abnormal tests may indicate periods of high accumulation of EOM, and therefore of oxygen depletion. This finding should help in better management of aquaculture ponds, but should also allow new insight into the interpretation of sedimentary records, providing a useful proxy for paleoenvironmental reconstructions. Marine Pollution Bulletin (0025-326X) (Elsevier), 2009-09 , Vol. 59 , N. 8-12 , P. 323-335 Droits : 2009 Elsevier Ltd All rights reserved. http://archimer.ifremer.fr/doc/2009/publication-6955.pdf DOI:10.1016/j.marpolbul.2009.08.012 http://archimer.ifremer.fr/doc/00000/6955/ | Partager |
Floating cages as an experimental tool for shrimp culture studies: first attempts to check their reliability Auteur(s) : Pham, Dominique Castex, Mathieu Wabete, Nelly Lemaire, Pierrette Brun, Pierre Éditeur(s) : Poster présenté au colloque Carribean & Latin American Aquaculture 2007, 6 - 9 novembre 2007, San Juan, Puerto Rico Résumé : The first aim of this study was to evaluate on a technical basis the rearing of shrimps in floating cages set up in earthen ponds. Shrimps reared in and outside the cages presented comparable growths and survival rates. Then it was concluded that shrimp culture in floating cages did not present zootechnical biases comparing to pond culture. The second objective of this study was to assess the present method as a statistical point of view. We found that for expected differences of 20% to the control mean, 3 and 6 floating cages per treatment will be reasonable to determined statistical differences for growth parameters and survival. Furthermore, we showed a significant pond effect as regard as survival and growth between both sets of cages. This results illustrated the within farm variability among the ponds, and confirmed that specific characteristics of each ponds from a same farm make difficult to use them as experimental unit. The study demonstrates that floating cages rearing is an economical, powerful, and sensitive experimental tool for shrimp culture studies specifically undertaken under close to semi-intensive production conditions. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/2007/acte-4100.pdf http://archimer.ifremer.fr/doc/00000/4100/ | Partager |
Eutrophication in a tropical pond: Understanding the bacterioplankton and phytoplankton dynamics during a vibriosis outbreak using flow cytometric analyses Auteur(s) : Lucas, Ronan Courties, C. Herbland, Alain Goulletquer, Philippe Marteau, Anne-laure Lemonnier, Hugues Éditeur(s) : Elsevier Science Bv Résumé : In tropical shrimp ponds, the increasing of feed input, concomitantly with the stocking shrimp biomass, induces an eutrophication of the ecosystem. Although difficult to maintain, its stability is required to guarantee the success of the culture. A 110-day period of phytoplankton and bacterioplankton stock and dynamics in an earthen pond (1.2 ha area, 1 m depth) was monitored using flow cytometry to provide baseline information on community characteristics and ecosystem instability. Seven autotrophic cell types were identified over the whole sampling period. Prokaryotic cells included Synechococcus sp., a group named UNK which presented an atypical new flow cytometric signature and picoeukaryotes (PEUK). Nanophytoplankton cells were represented by 4 groups: NAN1, NAN2, NAN3 and Cryptophytes. During the first part of the survey, picophytoplankton dominated the phytoplanktonic assemblage. The mean abundance of total cells (up to 8 x 10(6) cells mL(-1)) was among the highest recorded in marine and brackish waters. Bacterial abundance and production ranged from 0.8 to 5.1 x 10(7) cells mL(-1) and from 30 to 110 mu g C L-1 h(-1). A shift from pico to nanophytoplankton abundance was observed for a few days from d 96. During this period, heterotrophic bacteria production and abundance suddenly dropped, implying a change in the functioning of the microbial loop. This shift was concomitant with a significant shrimp mortality outbreak due to Vibrio penaeicida, the etiological agent of a disease known as Syndrome 93, which affects the shrimp industry in New Caledonia. This survey suggests that flow cytometric analysis could be used for the monitoring of aquaculture systems to improve our understanding of the complex phytoplankton and bacterial dynamics of these systems and its potential influence on disease development. (c) 2010 Elsevier B.V. All rights reserved. Aquaculture (0044-8486) (Elsevier Science Bv), 2010-12 , Vol. 310 , N. 1-2 , P. 112-121 Droits : 2010 Elsevier B.V. All rights reserved. http://archimer.ifremer.fr/doc/00029/14068/11312.pdf DOI:10.1016/j.aquaculture.2010.10.022 http://archimer.ifremer.fr/doc/00029/14068/ | Partager Voir aussi Tropical shrimp aquaculture Ecosystem shift Phytoplankton Bacterioplankton Vibrio Flow cytometry Télécharger |
Metal and metalloid bioaccumulation in the Pacific blue shrimp Litopenaeus stylirostris (Stimpson) from New Caledonia: Laboratory and field studies Auteur(s) : Metian, Marc Hedouin, Laetitia Eltayeb, Mohamed M. Lacoue-labarthe, Thomas Teyssie, Jean-louis Mugnier, Chantal Bustamante, Paco Warnau, Michel Éditeur(s) : Pergamon-elsevier Science Ltd Résumé : The present work aimed at better understanding metal and metalloid bioaccumulation in the edible Pacific blue shrimp Litopenaeus stylirostris, using both laboratory and field approaches. In the laboratory, the bioaccumulation kinetics of Ag, Cd, Co, Cr, and Zn have been investigated in shrimp exposed via seawater and food, using the corresponding gamma-emitting radiotracers (Ag-110m, Cd-109, Co-57, Cr-51, and Zn-65) and highly sensitive nuclear detection techniques. Results showed that hepatopancreas and intestine concentrated the metals to the highest extent among the blue shrimp organs and tissues. Moulting was found to play a non negligible detoxification role for Co, Cr and, to a lesser extent, Zn. Metal retention by L stylirostris widely varied (from a few days to several months), according to the element and exposure pathway considered (a given metal was usually less strongly retained when ingested with food than when it was taken up from the dissolved phase). In the field study, Ag, As, Cd, Co, Cr, Cu, Mn, Ni, and Zn were analysed in shrimp collected from a New Caledonian aquaculture pond. Metal concentrations in the shrimp muscles were generally relatively low and results confirmed the role played by the digestive organs and tissues in the bioaccumulation/storage/detoxification of metals in the Pacific blue shrimp. Preliminary risk considerations indicate that consumption of the shrimp farmed in New Caledonia is not of particular concern for human health. (C) 2010 Elsevier Ltd. All rights reserved. Marine Pollution Bulletin (0025-326X) (Pergamon-elsevier Science Ltd), 2010 , Vol. 61 , N. 7-12 , P. 576-584 Droits : 2010 Elsevier Ltd All rights reserved. http://archimer.ifremer.fr/doc/00014/12528/9869.pdf DOI:10.1016/j.marpolbul.2010.06.035 http://archimer.ifremer.fr/doc/00014/12528/ | Partager |
Les échanges internationaux de crevettes pénéidés vivantes entre les pays du Pacifique, de l'Atlantique et de l'Europe Auteur(s) : Michel, Alain Éditeur(s) : Office Int Epizooties Résumé : The tremendous development of penaeid shrimp culture across the world over the past twenty years has led to international trade in eggs, larvae and spawners of the best shrimp species for aquaculture. Trade has involved, in particular, the following species: - Penaeus japonicus from Japan to Europe, the Pacific Islands and South America - P. monodon from South-East Asia to almost all tropical countries - P. vannamei and P. stylirostris from countries along the Pacific coast of South and Central America to the United States of America, the islands of the South Pacific, countries along the Atlantic coast of the Americas and certain countries in Africa. In the 1980s, research conducted by American and French teams enabled the breeding of stocks of spawners in captivity. This resulted in the establishment of lines of captive broodstock outside natural areas of distribution, and the development of new breeding farms in previously unproductive regions. Trade related to movements of these species is facilitated by the absence of legislation in most countries; even when such legislation does exist, it is not always applied These practices have led to the rapid development of world shrimp production, but have also contributed to the dissemination of pathogens. In recent years, the occurrence of serious epizootics - occasioning heavy losses world-wide - has led to a more cautious approach involving trade of post-larvae obtained from captive broodstock in which thorough control measures have been implemented for known diseases. Trade in wild shrimp will probably be abandoned progressively, to avoid the risk of introducing new pathogens. The main challenges for research in the near future are the development of diagnostic tools, to enable continuous control of captive broodstock, and the selection of strains which are resistant to the principal pathogens affecting these species. Revue Scientifique Et Technique-office International Des Epizooties (0253-1933) (Office Int Epizooties), 1996-06 , Vol. 15 , N. 2 , P. 499-515 Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00091/20231/17883.pdf http://archimer.ifremer.fr/doc/00091/20231/ | Partager |
Sequence polymorphism-based identification and quantification of Vibrio nigripulchritudo at the species and subspecies level targeting an emerging pathogen for cultured shrimp in New Caledonia Auteur(s) : Goarant, Cyrille Reynaud, Yann Ansquer, Dominique De Decker, Sophie Merien, Fabrice Éditeur(s) : Elsevier Résumé : In a previous study, we demonstrated the existence of an emerging cluster of Vibrio nigripulchritudo that proved to be associated with shrimp mortality events in New Caledonia. Using sequence polymorphisms evidenced in this previous MultiLocus Sequence Typing study, we developed two new quantitative PCR assays permitting the detection and quantification of V. nigripulchritudo at the genospecies level using SYBR Green I chemistry and at the emerging cluster level using Fluorescence Resonance Energy Transfer technology with hybridization probes. The use of this molecular diagnostic tool evidenced the colonization of the shrimp pond ecosystem by the pathogenic cluster at least at the onset of the disease. This new tool will allow better investigation of the dynamics of this bacterial pathogen in the shrimp farm ecosystem. (C) 2007 Elsevier B.V. All rights reserved. Journal of Microbiological Methods (0167-7012) (Elsevier), 2007-07 , Vol. 70 , N. 1 , P. 30-38 Droits : 2007 Elsevier B.V. All rights reserved http://archimer.ifremer.fr/doc/2007/publication-2729.pdf DOI:10.1016/j.mimet.2007.03.007 http://archimer.ifremer.fr/doc/00000/2729/ | Partager |
A search-matching model of fisheries Auteur(s) : Sanz, Nicolas Diop, Bassirou Auteurs secondaires : Centre de Recherche en Economie, Gestion, Modélisation et Informatique Appliquée (CEREGMIA) ; Université des Antilles et de la Guyane (UAG) Éditeur(s) : HAL CCSD Résumé : This paper studies the implications of fi sh search activities on the working of fisheries. We develop a simple shery matching modelin which rms stochastic search for sh requires speci fic resources.The equilibrium level of anthropic pressure (number of empty ves-sels/conserved sh stock) exerted by rms on the sh stock is derivedfrom their individual pro t maximizing behavior. Anthropic pressuredetermines in turn the rate at which vessels fi nd fi sh i.e. catchability,which is therefore endogenous in our model, and the stock conserva-tion (uncaught sh) rate, through the dynamic equation of the latter.We then show that under open access, equilibrium anthropic pressure, fishing effort and the conservation rate heavily depend on search costs.An empirical study of the French Guiana shrimp shery con rms theability of the model to reproduce empirical data. https://hal.univ-antilles.fr/hal-01228851 Droits : info:eu-repo/semantics/OpenAccess hal-01228851 https://hal.univ-antilles.fr/hal-01228851 https://hal.univ-antilles.fr/hal-01228851/document https://hal.univ-antilles.fr/hal-01228851/file/Nicolas%20Sanz%20%26Bassirou%20Diop.pdf | Partager |
Non-specific activation of antiviral immunity and induction of RNA interference may engage the same pathway in the Pacific white leg shrimp Litopenaeus vannamei Auteur(s) : Labreuche, Yannick Veloso, Artur De La Vega, Enrique Gross, Paul S. Chapman, Robert W. Browdy, Craig L. Warr, Gregory W. Éditeur(s) : Elsevier Sci Ltd Résumé : Many questions remain unanswered regarding RNAi-based mechanisms and dsRNA-induced antiviral immune responses in penaeid shrimp. In this study, we report the characterization in the white leg shrimp Litopenaeus vannamei of RNAi pathway associated proteins Lv-Ago 1 and Lv-Ago 2, two members of the Argonaute family of proteins, as well as Lv-sid 1, the first shrimp homologue of Sid-1, a membrane channel-forming protein implicated in the cellular import of dsRNA. To decipher their functional implication in RNAi-related phenomena, we monitored their relative expression following stimulation by specific and non-specific RNA duplexes of diverse length. The findings show that the length of small RNA duplexes plays a critical role in the activation of both RNAi-related and innate antiviral responses. They also suggest that these two mechanisms of antiviral response may activate the same pathway, requiring Lv-Sid 1 and Lv-Ago 2 induction. (C) 2010 Elsevier Ltd. All rights reserved. Developmental And Comparative Immunology (0145-305X) (Elsevier Sci Ltd), 2010-11 , Vol. 34 , N. 11 , P. 1209-1218 Droits : 2010 Elsevier Ltd All rights reserved. http://archimer.ifremer.fr/doc/00015/12652/9587.pdf DOI:10.1016/j.dci.2010.06.017 http://archimer.ifremer.fr/doc/00015/12652/ | Partager |
Quantification of Vibrio penaeicida, the etiological agent of Syndrome 93 in New Caledonian shrimp, by real-time PCR using SYBR Green I chemistry Auteur(s) : Goarant, Cyrille Merien, F Éditeur(s) : Elsevier Résumé : Shrimp farming is a small but growing industry in New Caledonia. Since 1993, "Syndrome 93" has been affecting New Caledonian shrimp farming industry every cold season, causing severe epizootic mortalities in grow-out ponds and significant losses. Highly pathogenic strains of Vibrio penaeicida are considered the etiological agent of the disease in Litopenaeus stylirostris. On one hand, studies demonstrated that healthy shrimp may carry V penaeicida for weeks with a high overall prevalence, regardless of any seasonal pattern or temperature conditions. On the other hand, larvae are free of V penaeicida and are also resistant to experimental infection. V penaeicida is frequently detected in incoming water pumped from the bays, which was shown, by a molecular typing study, to be the infectious source. This particular epidemiological pattern highlights the major role of the factors that trigger and aggravate the disease in grow-out ponds, where shrimp populations carry the pathogen all year round. In order to gain a better understanding of "Syndrome 93" epidemiology, quantification of V penaeicida both in shrimp and the shrimp farm ecosystem is necessary. This article describes the steps in the successful development of a real-time PCR quantification assay of V penaeicida in shrimp haemolymph, seawater (from ponds or bays) and sediment pore water, including the choice of an accurate extraction technique. The entire detection method; including sample processing, DNA extraction and real-time PCR amplification, can be completed within 4 h. (c) 2006 Elsevier B.V All rights reserved. Journal of Microbiological Methods (0167-7012) (Elsevier), 2006-10 , Vol. 67 , N. 1 , P. 27-35 Droits : 2006 Elsevier http://archimer.ifremer.fr/doc/2006/publication-1903.pdf DOI:10.1016/j.mimet.2006.02.013 http://archimer.ifremer.fr/doc/00000/1903/ | Partager |
Traitement des crevettes contre le noircissement .Mise au point d'une ligne de traitement Auteur(s) : Chantreau, Patrick Résumé : Once fished, the shrimps must be cooled quickly in water cooled in order to slow down all chemical and bacteriological activities.
In addition, in order to avoid blackening (mélanose) shrimps (céphalothorax and legs) it is necessary to treat those with an antioxydant product.
The product currently used to inhibit this enzymatic change is the soda niétabisuifite (Na-> S7 O5), until now, after being fished. the shrimps were directly soaked in a cooled water tank, containing the pesticide.
The solution of treatment was progressively prepared needs. The concentration of this one was approximately 2 to 3% of métabisulfite, that is to say 6 to 9 G of SO2 per liter for a starting product containing 320 G of SO2 approximately.
In order to preserve a good quality of the liquid of treatment it was essential to often renew it (every 400 to 500 kg) what was not always the case, the métabisulfite being often added progressively with the liking of the appointed person with the treatment of shrimps.
In order to cure this delicate problem of renewal of vat and uniformity of the treatment, the SODACAL obtained the system of treatment by sprinkling. Une fois pêchées, les crevettes doivent être refroidies rapidement dans de l'eau réfrigérée afin de ralentir toutes activités chimiques et bactériologiques. D'autre part, afin d'éviter le noircissement (mélanose) des crevettes (céphalothorax et pattes) il est nécessaire de traiter celles-ci avec un produit anti-oxydant. Le produit actuellement utilisé pour inhiber cette altération enzymatique est le niétabisuifite de soude (Na-> S7 O5), jusqu'à maintenant, après avoir été pêchées. les crevettes étaient directement trempées dans une cuve d'eau réfrigérée, contenant le produit de traitement. La solution de traitement était préparée au fur et à mesure des besoins. La concentration de celle-ci était d'environ 2 à 3 % de métabisulfite, soit 6 à 9 g de SO2 par litre pour un produit de départ contenant 320 g de SO9 environ. Afin de conserver une bonne qualité du liquide de traitement il était indispensable de le renouveler souvent (tous les 400 à 500 kg) ce qui n'était pas toujours le cas, le métabisulfite étant souvent rajouté au fur et à mesure au gré de la personne préposée au traitement des crevettes. Afin de remédier à ce problème délicat de renouvellement de bac et d'uniformité du traitement, la SODACAL s'est dotée du système de traitement par aspersion. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1991/rapport-1648.pdf http://archimer.ifremer.fr/doc/00000/1648/ | Partager Voir aussi New Caledonia Blackening Treatment Penaeus stylirostris Shrimp Nouvelle Calédonie Noircissement Traitement Penaeus stylirostris Crevette Télécharger |
Response of the blue shrimp Litopenaeus stylirostris to temperature decrease and hypoxia in relation to molt stage Auteur(s) : Mugnier, Chantal Soyez, Claude Éditeur(s) : Elsevier Résumé : The effect of different levels of dissolved oxygen (DO) and a decreased temperature combined with severe hypoxia were studied in the blue shrimp Litopenaeus stylirostris in relation to molt stage. In the first experiment, shrimps were submitted to DO concentrations of 5 to 1 mg l(-1). Osmoregulatory capacity (OC) was measured in shrimps at molt stage C after 6, 24, or 48 h of exposure. No mortality was recorded but a significant negative effect of DO concentration on hypo-OC was observed for DO concentrations below 3 mg l(-1). Osmoregulation improved after 48 h exposure, compared to 6 and 24 h exposure. In a second experiment, temperature was decreased from 28 to 22 degreesC in 24 h, before a severe hypoxia of 0.5+/-0.1 mg O-2 l(-1) was applied. Mortality and OC were studied in relation to molt stages. Half of the shrimps died after respectively 100 min at 0.5 mg O-2 l(-1) at 28 degreesC and 153 min at 0.4 mg O-2 l(-1) at 22degreesC. Mortality was significantly higher in stages D-2 and B compared to stages C and Do. Control shrimps in stage D2 had a lower hypo-OC than shrimps in stages C and Do both at 28 and 22 degreesC. Temperature decrease had no effect on hypo-OC. Hypoxia reduced hypo-OC for all stages, whatever the temperature, but the effect was greater in stage C at 27 degreesC (68% decrease) compared to 22 degreesC (49%) and stage D-2 at both temperatures (respectively, 43% and 58% at 27 and 22 degreesC). Combination of temperature and hypoxia had a significant effect on hypo-OC. Low temperature reduced the effect of hypoxia presumably by slowing down the metabolism. Results are discussed in relation to pond observation. (C) 2004 Elsevier B.V. All rights reserved. Aquaculture (0044-8486) (Elsevier), 2005-02 , Vol. 244 , N. 1-4 , P. 315-322 Droits : 2004 Elsevier B.V. All rights reserved. http://archimer.ifremer.fr/doc/2005/publication-372.pdf DOI:10.1016/j.aquaculture.2004.11.010 http://archimer.ifremer.fr/doc/00000/372/ | Partager Voir aussi Temperature Stress Penaeid shrimp Osmoregulation Molt stage Litopenaeus stylirostris Hypoxia Télécharger |
LTR-Retrotransposons in R. exoculata and Other Crustaceans: The Outstanding Success of GalEa-Like Copia Elements Auteur(s) : Piednoel, Mathieu Donnart, Tifenn Esnault, Caroline Graca, Paula Higuet, Dominique Bonnivard, Eric Auteurs secondaires : Evolution des Génomes Eucaryotes (EGE) ; Systématique, adaptation, évolution (SAE) ; Université Pierre et Marie Curie - Paris 6 (UPMC) - Centre National de la Recherche Scientifique (CNRS) - Université Pierre et Marie Curie - Paris 6 (UPMC) - Centre National de la Recherche Scientifique (CNRS) - Evolution Paris Seine ; Université Nice Sophia Antipolis (UNS) ; Université Côte d'Azur (UCA) - Université Côte d'Azur (UCA) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Université Pierre et Marie Curie - Paris 6 (UPMC) - Université Nice Sophia Antipolis (UNS) ; Université Côte d'Azur (UCA) - Université Côte d'Azur (UCA) - Université des Antilles et de la Guyane (UAG) Éditeur(s) : HAL CCSD Public Library of Science Résumé : International audience Transposable elements are major constituents of eukaryote genomes and have a great impact on genome structure and stability. They can contribute to the genetic diversity and evolution of organisms. Knowledge of their distribution among several genomes is an essential condition to study their dynamics and to better understand their role in species evolution. LTR-retrotransposons have been reported in many diverse eukaryote species, describing a ubiquitous distribution. Given their abundance, diversity and their extended ranges in C-values, environment and life styles, crustaceans are a great taxon to investigate the genomic component of adaptation and its possible relationships with TEs. However, crustaceans have been greatly underrepresented in transposable element studies. Using both degenerate PCR and in silico approaches, we have identified 35 Copia and 46 Gypsy families in 15 and 18 crustacean species, respectively. In particular, we characterized several full-length elements from the shrimp Rimicaris exoculata that is listed as a model organism from hydrothermal vents. Phylogenic analyses show that Copia and Gypsy retrotransposons likely present two opposite dynamics within crustaceans. The Gypsy elements appear relatively frequent and diverse whereas Copia are much more homogeneous, as 29 of them belong to the single GalEa clade, and species-or lineage-dependent. Our results also support the hypothesis of the Copia retrotransposon scarcity in metazoans compared to Gypsy elements. In such a context, the GalEa-like elements present an outstanding wide distribution among eukaryotes, from fishes to red algae, and can be even highly predominant within a large taxon, such as Malacostraca. Their distribution among crustaceans suggests a dynamics that follows a ``domino days spreading'' branching process in which successive amplifications may interact positively. ISSN: 1932-6203 hal-01544761 https://hal.archives-ouvertes.fr/hal-01544761 DOI : 10.1371/journal.pone.0057675 | Partager |
Colonization of coastal environments by foraminifera: insight from shrimp ponds in New Caledonia (sw Pacific) Auteur(s) : Debenay, J. -p. Della Patrona, Luc Goguenheim, H. Éditeur(s) : Cushman Foundation for Foraminiferal Research Résumé : The objectives of this study were to observe foraminiferal colonization patterns and behavior in shrimp ponds in New Caledonia during a shrimp-growing (farming) cycle. Weekly collecting at 10 stations in 8 shrimp ponds yielded a total of 170 samples accompanied by environmental data. Seawater pumped from the nearby ocean filled the ponds at the beginning of the growth cycle and its daily renewal maintained salinity at 32-39, and supplied the ponds with influxes of smaller, mostly juvenile, foraminifera. A few days after initial filling, the pioneering species Ammonia tepida and Quinqueloculina seminula appeared, with A. tepida dominant. Their high reproduction rates increased both living and dead assemblage densities during the first 10 weeks. Populations of these two species then stabilized with higher oxygen demand (drop of redox) and consumption of living foraminifera by shrimp. Only a few colonizers subsequently appeared, which was attributed to the isolation of the pond, despite the high rate of water renewal. Only one pond had notably higher species richness, but it could not be distinguished from the others by its physicochemical parameters. The species that appeared in ponds initially barren of foraminifera also survived where there was water seepage between growing cycles, suggesting that the assemblages had already reached equilibrium with the environment. Despite the number of environmental parameters measured, only oxygen and reactive organic matter correlated with the microfauna on a weekly timescale. We assume that other parameters do not significantly affect foraminifera until they reach critical threshold. Consistent with previous studies, A. tepida was the species most tolerant of organic influx, but its relative abundance dropped once the organic matter flocculated and settled, leading to disoxic conditions in the sediment. Conversely, Q. seminula was able to climb through the floc and reach the oxygenated layer, where its relative abundance increased. Journal of Foraminiferal Research (0096-1191) (Cushman Foundation for Foraminiferal Research), 2009-10 , Vol. 39 , N. 4 , P. 249-266 Droits : 2009 Cushman Foundation for Foraminiferal Research http://archimer.ifremer.fr/doc/2009/publication-6954.pdf DOI:10.2113/gsjfr.39.4.249 http://archimer.ifremer.fr/doc/00000/6954/ | Partager |
Oxidative stress studies applied to the farmed shrimp Litopenaus stylirostris in new caledonia Auteur(s) : Chim, Liet Castex, Mathieu Lemaire, Pierrette Wabete, Nelly Éditeur(s) : PSIC 11 - 11th Pacific Science Inter-Congress : Pacific Countries and their Ocean: Facing Local and Global Changes / 2nd Symposium on French Research in the Pacific. March 2 - 6, 2009 Tahiti, French Polynesia. Résumé : The study of the antioxidant status and oxidative stress in shrimp L. stylirostris make it possible to assess risk factors (temperature, shrimp size, pathogen, ..) associated with shrimp farming. From a practical view, this research should lead to zootechnical and/or nutritional recommendations to improve the antioxidant status of the shrimp during their growout stage in farm. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00197/30875/29243.pdf http://archimer.ifremer.fr/doc/00197/30875/ | Partager |
Influence of sediment characteristics on shrimp physiology: pH as principal effect Auteur(s) : Lemonnier, Hugues Bernard, E Boglio, E Goarant, Cyrille Cochard, Jean-claude Éditeur(s) : Elsevier Résumé : Penaeid shrimp reared in earthen ponds are exposed to sediment, which can, in some instances, induce a stress. In seawater, the osmoregulatory capacity (hyporegulation) is a useful tool to compare the physiological condition of shrimp exposed to various stressors. By keeping some shrimp in cages at different locations of a single pond heterogeneous in terms of sediment quality, it was possible, using osmotic pressure (OP), to identify some locations where the stress was maximum and some others where it was minimum. Simultaneously, sediment samples were taken and analysed in order to evaluate some physico-chemical parameters that could be related to the stress observed in the shrimps kept in the cages. This approach allowed to show a significant positive correlation between the pH of the sediment surface and the shrimp osmotic pressure. This result was confirmed in a study carried out in experimental 70-1 tanks, where osmotic pressure decreased significantly as water pH decreased from 7.0 to 6.5. The methodology developed in this study may be useful to evaluate the stress caused by sediment in shrimp farms. (C) 2004 Elsevier B.V. All rights reserved. Aquaculture (0044-8486) (Elsevier), 2004-10 , Vol. 240 , N. 1-4 , P. 297-312 Droits : 2004 Elsevier http://archimer.ifremer.fr/doc/2004/publication-1866.pdf DOI:10.1016/j.aquaculture.2004.07.001 http://archimer.ifremer.fr/doc/00000/1866/ | Partager |