Inactivated Piscine orthoreovirus vaccine protects against heart and skeletal muscle inflammation in Atlantic salmon          下载免费PDF全文

Øystein Wessel  Øyvind Haugland  Marit Rode  Børge N. Fredriksen  Maria K. Dahle  Espen Rimstad 《Journal of fish diseases》2018,41(9):1411-1419

Heart‐ and skeletal muscle inflammation (HSMI) caused by infection with Piscine orthoreovirus (PRV) is one of the most common viral diseases in farmed Atlantic salmon (Salmo salar) in Norway, and disease outbreaks have been reported in most countries with large‐scale Atlantic salmon aquaculture. Currently there is no vaccine available for protection against HSMI, partly due to the lack of a cell line for efficient virus propagation. Erythrocytes are the primary target cells for PRV in vivo and a potential source for isolation of PRV particles. In this study, PRV was purified from infected erythrocytes, inactivated and used in a vaccination trial against HSMI. A single immunization with adjuvanted, inactivated PRV induced protection against HSMI in Atlantic salmon infected by virus injection 6 weeks later, while a moderate protection was obtained in fish infected through natural transmission, i.e. cohabitation. The PRV vaccine significantly reduced PRV loads and histopathological lesions typical for HSMI compared to the unvaccinated control group. This is the first demonstration of protective vaccination against PRV, and promising for future control of HSMI in Atlantic salmon aquaculture.  相似文献   

Atlantic salmon (Salmo salar L.) as a net producer of long-chain marine ω-3 fatty acids     

Sanden M  Stubhaug I  Berntssen MH  Lie Ø  Torstensen BE 《Journal of agricultural and food chemistry》2011,59(23):12697-12706

The objective of the present study was to investigate the effects of replacing high levels of marine ingredients with vegetable raw materials and with emphasis on lipid metabolism and net production of long-chain polyunsaturated ω-3 fatty acids (EPA + DHA). Atlantic salmon were fed three different replacement vegetable diets and one control marine diet before sensory attributes, β-oxidation capacity, and fatty acid productive value (FAPV) of ingested fatty acids (FAs) were evaluated. Fish fed the high replacement diet had a net production of 0.8 g of DHA and a FAPV of 142%. Fish fed the marine diet had a net loss of DHA. The present work shows that Atlantic salmon can be a net producer of marine DHA when dietary fish oil is replaced by vegetable oil with minor effects on sensory attributes and lipid metabolism.  相似文献   

Frost tolerance,regeneration capacity after frost exposure and high photosystem II efficiency during winter and early spring support high winter survival in Juncus spp.          下载免费PDF全文

L Østrem  J Folkestad  K A Solhaug  L O Brandsæter 《Weed Research》2018,58(1):25-34

During the past two decades, significant spread of the perennial weeds Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in coastal parts of Norway seems to have coincided with an observed rise in winter temperatures. This study investigated the frost tolerance (LT₅₀) and effects of moderate frost exposure on rush plant regrowth over time during the period late November to late winter/spring, and photosynthetic activity in late winter/spring. Juncus effusus and J. conglomeratus of physiologically young age (seedlings) displayed similar high frost tolerance (LT₅₀) and did not differ significantly in regenerative ability following prolonged frost exposure. Regrowth capacity generally increased during winter and when stress conditions increased, shoot formation was prioritised over total biomass production. Maximum quantum efficiency of photosystem II (F_v/F_m) and performance index of photosystem II (PI) were high in late winter/spring, with J. effusus showing higher values than J. conglomeratus. Green, photosynthetically active shoots, which facilitate accumulation of carbohydrates during autumn and even in winter, may provide Juncus spp. with substantial competitiveness in late winter and spring. The results revealed that the dominance of J. effusus over J. conglomeratus in pastures and leys is not due to major differences in winter survival parameters, but probably the higher photosynthetic efficiency observed in J. effusus. Generally higher temperatures during winter and lower frost kill may be contributing to the current increase in rush infestation.  相似文献   

Molecular cloning of MDA5, phylogenetic analysis of RIG‐I‐like receptors (RLRs) and differential gene expression of RLRs,interferons and proinflammatory cytokines after in vitro challenge with IPNV,ISAV and SAV in the salmonid cell line TO          下载免费PDF全文

I‐K G Nerbøvik  M A Solheim  H Ø Eggestøl  A Rønneseth  R A Jakobsen  H I Wergeland  G T Haugland 《Journal of fish diseases》2017,40(11):1529-1544

The RIG‐I receptors RIG‐I, MDA5 and LGP2 are involved in viral recognition, and they have different ligand specificity and recognize different viruses. Activation of RIG‐I‐like receptors (RLRs) leads to production of cytokines essential for antiviral immunity. In fish, most research has focused on interferons, and less is known about the production of proinflammatory cytokines during viral infections. In this study, we have cloned the full‐length MDA5 sequence in Atlantic salmon, and compared it with RIG‐I and LGP2. Further, the salmonid cell line TO was infected with three fish pathogenic viruses, infectious pancreatic necrosis virus (IPNV), infectious salmon anaemia virus (ISAV) and salmonid alphavirus (SAV), and differential gene expression (DEG) analyses of RLRs, interferons (IFNa‐d) and proinflammatory cytokines (TNF‐α1, TNF‐α2, IL‐1β, IL‐6, IL‐12 p40s) were performed. The DEG analyses showed that the responses of proinflammatory cytokines in TO cells infected with IPNV and ISAV were profoundly different from SAV‐infected cells. In the two aforementioned, TNF‐α1 and TNF‐α2 were highly upregulated, while in SAV‐infected cells these cytokines were downregulated. Knowledge of virus recognition by the host and the immune responses during infection may help elucidate why and how some viruses can escape the immune system. Such knowledge is useful for the development of immune prophylactic measures.  相似文献   

Are hybrids between Atlantic salmon and brown trout suitable long‐term hosts of Gyrodactylus salaris during winter?          下载免费PDF全文

R Knudsen  E H Henriksen  K Ø Gjelland  H Hansen  D K Hendrichsen  R Kristoffersen  K Olstad 《Journal of fish diseases》2017,40(10):1299-1307

The monogenean parasite Gyrodactylus salaris poses serious threats to many Atlantic salmon populations and presents many conservation and management questions/foci and challenges. It is therefore critical to identify potential vectors for infection. To test whether hybrids of native Atlantic salmon (Salmo salar) × brown trout (Salmo trutta) are suitable as reservoir hosts for G. salaris during winter, infected hybrid parr were released into a natural subarctic brook in the autumn. Six months later, 23.9% of the pit‐tagged fish were recaptured. During the experimental period, the hybrids had a sixfold increase in mean intensity of G. salaris, while the prevalence decreased from 81% to 35%. There was high interindividual hybrid variability in susceptibility to infections. The maximum infrapopulation growth rate (0.018 day^?1) of G. salaris throughout the winter was comparable to earlier laboratory experiments at similar temperatures. The results confirm that infrapopulations of G. salaris may reproduce on a hybrid population for several generations at low water temperatures (~1 °C). Wild salmon–trout hybrids are undoubtedly susceptible to G. salaris and represent an important reservoir host for the parasite independent of other co‐occurring susceptible hosts. Consequently, these hybrids may pose a serious risk for G. salaris transmission to nearby, uninfected rivers by migratory individuals.  相似文献   

Nutritional responses in rainbow trout (Oncorhynchus mykiss) fed diets with different physical qualities at stable or variable environmental conditions     

T.S. AAS  B.F. TERJESEN  T. SIGHOLT  M. HILLESTAD  J. HOLM  S. REFSTIE  G. BAEVERFJORD  K.‐A. RØRVIK  M. SØRENSEN  M. OEHME  T. ÅSGÅRD 《Aquaculture Nutrition》2011,17(6):657-670

Rainbow trout with initial body weight 1144 g were fed two diets with high (feed A) or low (feed B) water stability for 6 weeks. During the last 2 weeks either stable or fluctuating oxygen saturation, salinity and temperature was introduced. High water stability of the feed was associated with harder pellets, less dust formation and less broken pellets compared to feed with low water stability. During the first 4 weeks, feed intake was 23% higher in trout fed diet B than in those fed diet A. Fluctuating environment resulted in a severe drop in feed intake for both dietary groups. At termination of the trial, stomachs of trout fed feed B contained mashed pellets and free water and oil. Stomachs of trout fed feed A contained more intact pellets and little fluid. The apparent digestibility of protein, starch, dry matter and energy was highest in feed A. The apparent digestibility of P and Zn was highest at stable environment, and the absorption of P was highest from feed A. In conclusion, physical quality affected the nutritional value of the feeds, and differences in nutritional value at stable or fluctuating environment appeared to be related to feed intake.  相似文献   

Survival and behaviour of Atlantic salmon smolts passing a run‐of‐river hydropower facility with a movable bulb turbine          下载免费PDF全文

E. B. Thorstad  T. B. Havn  S. A. Sæther  L. Heermann  M. A. K. Teichert  O. H. Diserud  M. Tambets  J. Borcherding  F. Økland 《Fisheries Management and Ecology》2017,24(3):199-207

Downstream migration of radio‐tagged Atlantic salmon smolts, Salmo salar L., was studied in the Kinzig, Germany, to examine effects of passing a run‐of‐river hydropower station with a movable bulb turbine. Immediate mortality for smolts passing the power station was low (3%–6%), probably facilitated by a curved rack in front of the turbine and the possibility to pass over it. Mortality in the impounded stretch above the power station was also low (1.5% extra mortality compared to a control stretch). The combined mortality due to hydropower was 5%–8%, excluding delayed effects. Most smolts followed the main flow passing through the turbine area (94%). Only few used a fishway (4%) or a nearby millstream (2%). Migration speed was slowed down at the power station, but the passage only caused a short delay (average/median 8.6/1.3 hr). However, even low mortality and short delays at several power stations and reservoirs may have considerable cumulative effects.  相似文献   

The risk of individual fish being captured multiple times in a catch and release fishery     

Eva B. Thorstad  Ola H. Diserud   yvind Solem  Torgeir B. Havn  Lars Oftedal Bjrum  Torstein Kristensen  Henning Andre Urke  Martin R. Johansen  Robert J. Lennox  Peder Fiske  Ingebrigt Uglem 《Fisheries Management and Ecology》2020,27(3):248-257

The proportion of angled Atlantic salmon Salmo salar L. being caught and released has increased. If individuals are repeatedly captured, this may have fish welfare consequences. Of 995 Atlantic salmon tagged during catch and release in eight Norwegian rivers, 10% were captured twice, while 3% were captured three times within the same fishing season. The probability that released salmon were captured again decreased with decreasing time left of the fishing season, decreased for larger‐sized fish and varied among rivers/years. Increased exploitation rates within the river, indicating an increased fishing pressure, strongly increased the probability that fish would be recaptured. However, the proportion of salmon caught a second time was much lower than the total exploitation rates in the same rivers (which was on average 46%). For fish tagged in the sea, the likelihood of being angled decreased with time since entering the river, which may explain why the recapture rates of caught and released fish were lower than the total exploitation rates.  相似文献   

Cover Image     

Toni Erkinharju  Guro Strandskog   yvind Vgnes  Ivar Hordvik  Roy A. Dalmo  Tore Seternes 《Journal of fish diseases》2019,42(12):i-i

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Are There Arid Land Soilscapes in Southwestern Europe?     

Juan Jos Ibez  Rufino Prez‐Gmez  Cecilio Oyonarte  Eric C. Brevik 《Land Degradation \u0026amp; Development》2015,26(8):853-862

No studies have proven the existence of soil assemblages typical of arid lands in Europe. This study was carried out in a representative territory of the southeastern part of the Iberian Peninsula, Almería province, which is the driest part of Europe, to determine if soils characteristic of arid lands are present. In order to analyse the spatial distribution of soils, the authors made use of mathematical tools previously developed in biodiversity and pedodiversity analysis, such as richness, entropy indices, abundance distribution models, diversity‐area relationships and nested subset analysis. The study demonstrates that the soil types or pedotaxa are typical of mountainous arid lands. Shallow and weakly developed soils (e.g. Leptosols, Regosols and Arenosols), Calcisols, Gypsisols and Solonchaks, cover most of the study area, and pedodiversity analysis demonstrates that the pedotaxa spatial patterns follow the same regularities as in other areas, environments and scales. In view of the fact that the class of landscapes identified in this study is unique in Europe, the Tarbernas desert and other arid lands sites of the study area merit preservation as part of the European geological, geomorphological and pedological heritage. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献