Éditeur(s) : Elsevier
Résumé : In New Caledonia, the "syndrome 93," which results in mass mortalities of farmed shrimp Penaeus stylirostris, occurs during the transitional and the cold seasons. The transitional season is characterized by an important fall in the average water temperature from 28 to 19 degreesC in 2 weeks. Besides this marked temperature fall, there are also nyctemeral temperature changes of up to 7 degreesC in 12 h. The cold season is characterized by an average water temperature of 19 degreesC with extreme lows of 14 degreesC. The objective of this study was to determine the effect of temperature and its variations on the osmoregulatory capacity of juvenile (7-10 g average weight) and subadult (25 g average weight) shrimps subjected to conditions of different salinity. A reduction in temperature level resulted in a decreased osmoregulatory capacity (OC) (defined as the difference between the osmolality of the haemolymph and that of sea water) at low salinity (hyper-CO) and at high salinity (hypo-CO), respectively, below and above the isoosmotic point (26.2 ppt). In subadult shrimps, the hyper-CO was affected when temperature dropped from 26 to 22 degreesC. The hypo-CO was modified only when temperature decreased down to 15 degreesC. Furthermore, the sensitiveness of osmoregulation to temperature changes was dependent on the developmental stage of the shrimp. Subadults were more sensitive than juvenile animals. The value of the isoosmotic point, which did not depend on the shrimp developmental stage, increased when temperature decreased to 17 or 15 degreesC. Our results provide an additional explanation of the "syndrome 93" and display the unfavourable influence of marked temperature drop on shrimp health. Our research could provide a possibility of seeking a nutritional and/or genetic solution to improve the capacity of the shrimps to maintain their homeostasis within a rearing medium with fluctuating temperatures.
Aquaculture (0044-8486) (Elsevier), 2002-06 , Vol. 209 , N. 1-4 , P. 307-317

Droits : 2002 Elsevier Science B.V. All rights reserved
http://archimer.ifremer.fr/doc/2002/publication-395.pdf
DOI:10.1016/S0044-8486(01)00756-6
http://archimer.ifremer.fr/doc/00000/395/

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

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

Résumé : Ce document constitue le bilan détaillé des résultats du projet DEDUCTION (2007-2010) , action par action. Le projet DEDUCTION "DEveloppement DUrable de la Crevetticulture, Traitement de l’Information et Observatoire du système en Nouvelle-Calédonie" est un projet de recherche et de développement en soutien à la filière crevetticole néo-calédonienne. C'est un programme très horizontal et pluridisciplinaire en poursuivant et développant les ouvertures scientifiques, techniques et thématiques établies à la faveur de DESANS. Son ossature s’articule autour de 4 actions : 3 actions de recherche et une action transversale devant faciliter les interfaces entre la recherche et sa finalité, entre les chercheurs et les partenaires locaux (GFA, Provinces, Gouvernement, Haut-Commissariat), en intégrant les résultats "ferme" à l'échelle de la filière. Une tâche de « Communication et de Transfert des connaissances » a été ajoutée en facteur commun des 4 actions scientifiques afin de répondre à la question fondamentale des échanges entre acteurs.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00199/31006/35663.pdf
http://archimer.ifremer.fr/doc/00199/31006/

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/

Éditeur(s) : Elsevier
Résumé : We studied the effects of a lactic acid bacterium, Pediococcus acidilactici (strain MA 18/5M, CNCM), as a dietary probiotic on growth performance and some nutritional and microbiological aspects of the shrimp Litopenaeus stylirostris. Experimental shrimp culture was carried out over 10 weeks, using floating cages of 14 m(2) each set in earthen ponds, in a New Caledonia farm affected by "Summer syndrome", a septicaemic vibriosis caused by Vibrio nigripulchritudo. The experiment design testing probiotic-coated pellets against control was replicated in two earthen ponds. High mortalities, characteristic of Summer syndrome, were observed during the first 2 weeks of the trial. The probiotic improved production in the treated cages from both ponds with increases in the survival rate (7% and 15% respectively) and final biomass (8% and 12% respectively). No differences were recorded among treatments on growth performances, but significant lower food conversion ratios were obtained with probiotic treatment. After 5 weeks of rearing, the Hepatosomatic Index and the adjusted dry weight of the digestive gland were significantly increased by 10% and by 9% respectively in shrimps treated with probiotic. In the meantime, the specific activities of alpha amylase and trypsin in the digestive gland showed a significant effect of the probiotic treatment with respective increases by 35% and 55%. The rise in total trypsin activity following morning feeding was also enhanced by the probiotic treatment (P < 0.001). The highest concentration of probiotic (between 10(4)-10(5) CFU g(-1) of fresh gut) in the shrimp gut was obtained 2 h after feeding. The concentration remained high for 4 h after feeding before decreasing until the next meal. Total bacterial counts on Marine agar and TCBS in the gut were significantly lowered by the probiotic treatment over the 10 weeks of the experiment. Additionally, during the first 2 weeks, prevalence and load of V nigripulchritudo strains in haemolymph was lower in animals fed with the probiotic diet. This study demonstrated, under pond conditions, that feeding shrimp with live terrestrial lactic acid bacteria can be an effective treatment for improving shrimp culture affected by vibriosis. (c) 2008 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier), 2008-03 , Vol. 275 , N. 1-4 , P. 182-193

Droits : 2008 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2008/publication-4079.pdf
DOI:10.1016/j.aquaculture.2008.01.011
http://archimer.ifremer.fr/doc/00000/4079/

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/

Résumé : Since 1993, the New Caledonian shrimp industry has been faced with cold season mortality outbreaks of multifactorial origin. This pathology called “Syndrome 93” affects as well animals in grow-out ponds as broodstock after their transfer in maturation room, with up to 35% of mortality in 48 hours. From literature data and physiological studies on Litopenaeus stylirostris, several combinations of three abiotic parameters (temperature, salinity and feeding) have been tested during the breeders stocking period. This research allowed us to lower stress factors impact and to propose a transfer protocol which leads to an optimal physiological comfort of the animal. Results showed that survival rate is improved and spawning rates are twice higher. These findings have come up with a routine protocol of carrying out any transfer in a tank with water at temperature of 26°C, salinity of 26 ppt and no food supply during 48 hours. The use of this protocol in a commercial hatchery led to a significant broodstock survival improvement.
Depuis 1993, la filière crevetticole calédonienne est confrontée aux mortalités de saison froide dont les causes sont multifactorielles. Cette pathologie appelé « Syndrome 93 » affecte non seulement les animaux dans les bassins de grossissement, mais elle touche également les géniteurs après leur transfert en salle de maturation, les pertes pouvant atteindre 35% en 48 heures. A partir de la littérature et d’études physiologiques de la Litopenaeus stylirostris, différentes combinaisons de trois paramètres abiotiques (température, salinité et alimentation) ont été testés lors de la stabulation des reproducteurs en salle de maturation. Ces recherches ont permis de diminuer l’impact des facteurs de stress et d’établir un protocole de transfert des animaux dans les conditions de confort physiologique optimale. Les résultats montrent que la survie est améliorée mais que le pourcentage de pontes est également doublé. Il est maintenant recommandé pour tout transfert, de prévoir des bacs de réception dans lesquels l’eau est à la température de 26°C, la salinité à 26 ppt et de ne fournir aucune alimentation pendant 48 heures. L’application de ce protocole dans une écloserie privée a démontré un gain substantiel sur la survie des géniteurs.

Droits : 2008 Ifremer
http://archimer.ifremer.fr/doc/00118/22970/20800.pdf
http://archimer.ifremer.fr/doc/00118/22970/

Éditeur(s) : Academic Press Ltd- Elsevier Science Ltd
Résumé : Antioxidant defences and induced oxidative stress tissue damage of the blue shrimp Litopenaeus stylirostris, under challenge with Vibrio nigriputchritudo, were investigated for a 72-h period. For this purpose, L stylirostris were first infected by immersion with pathogenic V. nigripulchritudo strain SFn1 and then antioxidant defences: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (Gpx), Total antioxidant status (TAS), glutathiones and induced tissue damage (MDA and carbonyl proteins) were determined in the digestive gland at 0, 12, 24, 48 and 72 h post-infection (h.p.i.). In the meantime, TAS was also measured in the blood. Infection level of the shrimps during the challenge was followed by determining V. nigripulchritudo prevalence and load in the haemolymph of the shrimps. Changes in all these parameters during the 72-h.p.i. period were recorded for control shrimps and shrimps previously fed for one month with probiotic Pediococcus aciditactici MA18/5M at 10(7) CFU g(-1) of feed. Our results showed that immersion with V nigripulchritudo led to maximal infection level in the haemolymph at 24 h.p.i. preceding the mortality peak recorded at 48 h.p.i. Significant decreases in the antioxidant defences were detected from 24 h.p.i. and beyond that time infection leaded to increases in oxidative stress level and tissue damage.. Compared to control group, shrimps fed the probiotic diet showed lower infection (20% instead of 45% at 24 h.p.i. in the control group) and mortality (25% instead of 41.7% in the control group) levels. Moreover, infected shrimp fed the probiotic compared to uninfected control shrimps exhibited very similar antioxidant status and oxidative stress level. Compared to the infected control group, shrimps fed the probiotic sustained higher antioxidant defences and lower oxidative stress level. This study shows that bacterial infection leads to oxidative stress in L. stylirostris and highlighted a beneficial effect of P. acidilactici, suggesting both a competitive exclusion effect leading to a reduction of the infection level and/or an enhancement of the antioxidant status of the shrimps. (C) 2010 Elsevier Ltd. All rights reserved.
Fish & Shellfish Immunology (1050-4648) (Academic Press Ltd- Elsevier Science Ltd), 2010-04 , Vol. 28 , N. 4 , P. 622-631

Droits : 2010 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/00003/11419/7984.pdf
DOI:10.1016/j.fsi.2009.12.024
http://archimer.ifremer.fr/doc/00003/11419/

Éditeur(s) : The 11th Pacific Science Inter-Congress : Pacific Countries and their Ocean: Facing Local and Global Changes. March 2 - 6, 2009 Tahiti, French Polynesia
Résumé : New Caledonian shrimp farming feasibility studies started in the mid-seventies. Today ca. 2000 tons of Litopenaeus stylirostris, introduced in 1978, are semi-intensively produced each year. Since fifteen years, production has been impacted by two seasonal vibriosis, the “Summer” syndrome caused by Vibrio nigripulchritudo in relation to pond bottom and water column quality, and the “Winter Syndrome” caused by Vibrio penaeicida in relation to drastic temperature drops . With the ambition of elucidating processes possibly leading to mortality outbreaks in ponds, Ifremer has been conducting a research program since 2003 under the DESANS project (2003-2006) and the present DEDUCTION project, equally funded by the South and North Provinces and by the Government of New Caledonia. This program has been designed in a multidisciplinary approach integrating the suspected multifactorial origin of shrimp mortalities. Environment quality in ponds (either sediment or water column) plays a major role in the shrimp ecophysiological status, influencing sensitivity to pathogens . DEDUCTION focuses on a better knowledge of phytoplankton composition and biogeochemical fluxes at the sediment-water interface in ponds. Impact of farm discharges is also investigated. In addition, a more fundamental work is conducted to understand the pathogenicity mechanisms of these two Vibrio species but also to prevent the occurrence of viral infections through a RNA interference approach. Markers of the ecophysiological status of broodstock, larvae, post-larvae and reared animals, such as enzymes testifying from an oxidative stress, are developed. Gain of performance (resistance to pathogens and growth) were obtained on hybrids of the New Caledonian and introduced Hawaiian strains. Finally the database Stylog is exploited in view of discriminating “good” from “bad” rearings on the basis of relevant indicators.
Les études de faisabilité de l'aquaculture de crevettes ont débuté en Nouvelle-Calédonie dans les années soixante dix. Aujourd'hui environ 2000 tonnes de Litopenaeus stylirostris, introduite en 1978, sont produites chaque année de façon semi-intensive. Depuis quinze ans la production a été impactée par deux vibrioses : le syndrome d'été provoqué par Vibrio nigripulchritudo en relation avec la qualité de la tranche d'eau et des fonds de bassins et le syndrome d'hiver provoqué par Vibrio penaeicida en relation avec des chutes rapides de température. Dans le but d'élucider les processus entrainant des mortalités dans les élevages, Ifremer a conduit un programme de recherche depuis 2003 dans le cadre du projet DESANS (2003-2006) puis du présent projet DEDUCTION co-financé par les provinces Nord et Sud et le Gouvernement de la Nouvelle-Calédonie. Ce programme se construit dans une démarche multidisciplinaire intégrant les origines supposées multifactorielles des mortalités de crevettes. La qualité environnementale dans les bassins (les fonds et la colonne d'eau) joue un rôle majeur dans l'état physiologique des animaux, influençant leur sensibilité aux pathogènes. DEDUCTION se focalise sur une meilleure compréhension de la composition phytoplanctonique et des flux bio-géochimiques à l'interface eau/sédiment dans les bassins.L'impact des rejets des fermes est également étudié. En outre, un travail plus fondamental est conduit pour connaître les mécanismes de pathogénicité de ces deux espèces de Vibrio mais aussi pour prévenir les occurences d'infections virales par des approches ARN Interférence. Des marqueurs de l'état physiologique des oeufs, larves, post-larves et animaux en élevage, tels que les enzymes du stress oxydant sont utilisés.Les gains de performance (résistance aux pathogènes et croissance) sont obtenus sur des hybrides issus du croisement de la souche locale avec une souche hawaienne. Finalement la base de données STYLOG est exploitée dans le but de distinguer les bonnes des mauvaises pratiques sur la base d'indicateurs fiables.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00143/25438/23591.pdf
http://archimer.ifremer.fr/doc/00143/25438/

Éditeur(s) : Elsevier Science Bv
Résumé : There has been growing interest in the development of mud crab aquaculture in New Caledonia. However, for this to become established at a commercial level, a cost-effective formulated feed based on internationally-available ingredients needs to be developed. We have evaluated the optimal dietary protein content for juvenile crabs, Scylla serrata (Forskål, 1775), using a series of diets with a protein content ranging from 27 to 49% and soy protein concentrate (SPC) as the main protein source. For this purpose, 54 individually housed crabs were allocated to five dietary treatments (n = 10 or 11). The crabs were fed ad libitum, for 81 days with the allocated diets. The apparent digestibilities of dry mater, crude protein and energy were high (96.2-97.3%), irrespective of the diet. The voluntary feed intake (VFI) of crabs widely varied from 46 to 220 g kg- 1of fresh initial body weight per week (iBW week- 1) whatever the diet. However, SPC intake and protein intake increased significantly with dietary protein content up to the diet with 40% crude protein, but did not increase further with diets containing 44% and 49% crude protein. The cumulative molts were strongly affected by the VFI levels or energy intake and also, to a lesser extent, by the levels of SPC or protein in diets. Two phases in tissue gain were observed after ecdysis: an initial deposition phase lasting around 30 days followed by a plateau which lasted until the next molt. The daily tissue growth was 16.5% of dry body weight (dry BW) one day after ecdysis and dramatically decreased to 3.6% of dry BW over the first 10 days, then decreased more slowly to the minimum value of 1.3% of dry BW over the next 70 days. During the course of experiment, the best growth (tissue growth and molt frequency) and the best feed efficiency (FCR, PER, retention of proteins and lipids) were obtained with crabs fed on the diet with 40% crude protein. This result was confirmed by a bioenergetic study which showed significantly higher allocation of the energy intake for growth (RE) of crabs fed on diet 40% crude protein. Finally, under our experimental conditions, 1 kg of juvenile crabs required 6.5 ± 1.1 g of protein per day. This level was obtained with the diet SPC-42 that contained 40% of protein of which almost three quarters were derived from SPC. Two hypotheses are proposed to explain the negative effect of high level of SPC or protein on growth and feed efficiency for crabs fed on in diets containing 52% and 60% SPC.
Aquaculture (0044-8486) (Elsevier Science Bv), 2014-10 , Vol. 434 , P. 499-509

Droits : 2014 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00211/32196/30630.pdf
http://archimer.ifremer.fr/doc/00211/32196/

Éditeur(s) : Blackwell science
Résumé : The prawn Penaeus stylirostris (Stimpson), when fed for 28 days with n-3 highly unsaturated fatty acid (HUFA)-enriched feed pellets, demonstrated an enhanced resistance to variations in environmental parameters (a decrease in temperature and salinity over a 4-day period from 28 degreesC to 17 degreesC and from 35 parts per thousand to 10 parts per thousand respectively) and an improvement in their immune defence potential, i.e. increased agglutination titre of plasma and increased respiratory burst of haemocytes.
Aquaculture Research (1355-557X) (Blackwell science), 2001-02 , Vol. 32 , N. 2 , P. 91-94

Droits : 2001 Blackwell
http://archimer.ifremer.fr/doc/2001/publication-606.pdf
DOI:10.1046/j.1365-2109.2001.00534.x
http://archimer.ifremer.fr/doc/00000/606/

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 : In recent years the biological control of diseases by environmental friendly methods such as probiotics has become an important subject of investigation in aquaculture research. Probiotics are live microorganisms which when administrated in adequate amounts confer a health benefit on the host . In the last 4 years, IFREMER in collaboration with Lallemand company, have carried out researchs in New Caledonia with the aim to assess the probiotic strain P. acidilactici MA 18/5M on farmed shrimp Litopenaeus stylirostris.This project started in 2005 demonstrated the beneficial effects of the probiotic Pediococcus acidilactici dietary supplementation on the nutrition and the health status of peneid shrimps and highlighted that its use as probiotic can be part of the natural solutions proposed to face the challenge of today’s shrimp farming industry.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00197/30873/29241.pdf
http://archimer.ifremer.fr/doc/00197/30873/

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 : Scientific and technical studies carried out under semi-intensive farming conditions, with large earthen ponds (Fig 1), to assess the effects of treatments on zootechnical results are highly complex due to the many logistical, economic and/or experimental constraints involved. In our study, we evaluated the use of floatingcages (Paquotte et al., 1998) immersed in earthen ponds as an experimental tool in order to design future powerful and economical expe-riments under semi-intensive farming conditions.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00197/30872/29240.pdf
http://archimer.ifremer.fr/doc/00197/30872/

Éditeur(s) : Elsevier
Résumé : in this study we evaluated the effects of the probiotic Pediococcus acidilactici MA18/5M on shrimp, Litopenaeus stylirostris (also called Penaeus stylirostris), first on antioxidant defences and secondly on the oxidative stress status in the shrimps' haemolymph and digestive gland. We conducted two experiments with the same protocol in which shrimps were fed two diets for three weeks: a control diet and a probiotic diet containing 1 g of live P. acidilactici MA18/5M kg(-1). In the first experiment, the shrimps were found to be healthy over the trial period; no mortalities and non-detectable signs of infection were recorded. These resulted in high final survival rates (above 90% in both treatments). On the other hand, during the second trial, carried out at a period of increased risk for an outbreak of the summer syndrome, higher mortalities were recorded, associated with high V. nigripulchritudo prevalence and loads in the shrimp haemolymph. In healthy shrimps (trial 1), no detectable response of the antioxidant defence system and of oxidative stress bio-indicators were observed. However, feeding the probiotic significantly increased the total antioxidant status (TAS) and glutathione peroxidase activity, while all other parameters remained significantly unchanged. In the shrimps exposed to V nigripulchritudo (trial 2), the antioxidant response was characterized by higher antioxidant enzyme activities (superoxide dismutase and catalase) and higher oxidative stress level in the digestive gland (higher oxidized/reduced glutathione ratio, higher malonclialdehyde and carbonyl protein contents) compared to levels found in trial 1. However, shrimps fed the probiotic diet exhibited (i) significantly higher final survival rates (67 +/- 3%) compared to the control (47 +/- 4%) and (ii) a lower prevalence of V nigripulchritudo throughout the trial. Moreover, the antioxidant response and the oxidative stress level recorded in the digestive gland with shrimps submitted to the probiotic diet were lower. In the light of these results, we confirm that P acidilactici enrichment in shrimps' diet seems an effective way of reducing the susceptibility of shrimps to bacterial pathogens. (c) 2009 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier), 2009-09 , Vol. 294 , N. 3-4 , P. 306-313

Droits : 2009 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6780.pdf
DOI:10.1016/j.aquaculture.2009.06.016
http://archimer.ifremer.fr/doc/00000/6780/

Éditeur(s) : Elsevier
Résumé : The consequences of handling stress (fishing, transfer, eyestalk ablation) on shrimp broodstock are poorly documented. The weakness of farmed shrimp, Litopenaeus stylirostris, during winter is a major problem in New Caledonia, because of seasonal climate (tropical-sub-temperate). The transfer of broodstock in winter from earthen outdoor ponds to indoor maturation tanks in the hatchery (T=20 degrees C, Salinity=35 parts per thousand, fed shrimp) usually leads, after 48 h, to high mortality (up to 70%). Eyestalk ablation to induce ovarian maturation in females leads to further mortality. Starting from a background analysis of physiological disturbances (initial osmoregulatory imbalance) associated with handling stress (Wabete, N., Chim, L., Lernaire, P., Massabuau, J.-C., 2004. Caracterisation de problemes de physiologie respiratoire et d'echanges ioniques associes A la manipulation chez la crevette peneide Litopenaeus stylirostris a 20 degrees C. Styli 2003. Trente ans de crevetticulture en Nouvelle-Caledonie. Ed. Ifremer. Actes Colloq. 38, 75-84.), we developed aprotocol using a soft technology, based on modifications of water salinity, temperature and feeding regime. The aim was to minimize problems of osmoregulatory imbalance and associated mortalities. The protocol we developed, called the LSD OT protocol (Low Salinity and Diet, Optimal Temperature), was first evaluated on sub-adult shrimp (20-25 g) and then applied to broodstock. Survival after transfer and following eyestalk ablation, as well as reproductive achievement (spawning rate, nauplii number) was considerably improved when shrimps were transferred under "physiological comfort" i.e. warmed isosmotic water (26 degrees C and 26 parts per thousand) and unfed for 3 d. This new handling protocol, based on a better control of salinity, temperature and feeding conditions, has been transferred successfully to private hatcheries and already contributes to an increased profitability of New-Caledonian shrimp industry. (c) 2006 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier), 2006-09 , Vol. 260 , N. 1-4 , P. 181-193

Droits : 2006 Elsevier
http://archimer.ifremer.fr/doc/2006/publication-1880.pdf
DOI:10.1016/j.aquaculture.2006.06.041
http://archimer.ifremer.fr/doc/00000/1880/