Introduction and comparison of two methods of assessment of coronary lesions in Atlantic salmon, Salmo salar L     

Seierstad SL  Poppe T  Larsen S 《Journal of fish diseases》2005,28(4):189-197

This study investigated and compared quantitative and semi-quantitative coronary lesion evaluation in Atlantic salmon, Salmo salar. A total of 121 immature farmed and 47 sexually mature wild Atlantic salmon were included. Coronary arteries from all fish were morphometrically evaluated using a semi-quantitative method. A subsample of 76 salmon was additionally evaluated using a quantitative method. Another subsample of 71 salmon was used for reliability testing of the semi-quantitative method. Ten cross-sections of coronary arteries located on the ventral surface of the bulbus arteriosus were semi-quantitatively scored with regard to myointimal coronary lesions. Quantitative measurements comprised maximal intimal thickness and area lesion (%) while semi-quantitative measurements comprised maximal intimal thickness and lesion degree (%). Scores for individual fish were expressed as the average of lesion score, denoted as mean range lesion. One person performed all evaluations blindly. Two pathologists tested repeatability of the semi-quantitative lesion score measurements blindly. Both semi-quantitative and quantitative variables increased significantly with increasing lesion score. Semi-quantitative estimation gave significantly higher maximal intimal thickness values than quantitative measurement. Semi-quantitative measurements were found to explain 63.2% of variation in quantitatively measured maximal intimal thickness. Due to lack of agreement, the two methods are not directly comparable and one method cannot replace the other. Repeatability within and between observers with regard to semi-quantitative classification was very good with Kappa values larger than 61.5%. The semi-quantitative method was a valid and reliable method for coronary lesion evaluation in Atlantic salmon.  相似文献   

Short Paper     

Chutima Khomvilai  Shuichi Karita  Masaaki Kashiwagi  Motoi Yoshioka 《Fisheries Science》2005,71(5):1188-1190

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陆封型大西洋鲑生物学特性与移植驯化技术     

夏重志  陆九韶  李永发  牟振波  曹广斌 《水产学杂志》2003,16(2):19-26

本文报道了陆封型大西洋鲑移植驯化技术及养殖生物学跟踪观察结果。通过引进陆封型大西洋鲑发眼卵，在水温3～11℃的条件下进行孵化，积温达到140～22l度日孵出仔鱼，孵化率达到85％；历经3周年流水低温育种，培育出苗种10万尾。采用强化培育，人工调控环境生态因子诱导亲鱼性成熟的方法，育出后备亲鱼5万尾，成熟亲鱼0．4万尾，成功地实现了大西洋鲑在我国全人工繁殖的研究工作。  相似文献   

Field evaluation of live chilling with CO₂ on stunning Atlantic salmon (Salmo salar) and the subsequent effect on quality     

Bjorn Roth  Erik Slinde  & David H F Robb 《Aquaculture Research》2006,37(8):799-804

Atlantic salmon were slaughtered in three ways on a commercial slaughter line: (1) killed by a percussive stun after crowding; (2) killed by percussive stun after crowding, pumping and live chilling; (3) killed by exsanguination after crowding, pumping and live chilling. The live‐chilled fish were exposed to seawater (2°C) saturated with carbon dioxide (pH 5.5–5.7) for 40 min. The fish were calm after live chilling, but not unconscious, as eye rolling was observed in all individuals. Subsequent exsanguination of the unstunned fish resulted in death. Both rapid live chilling and the subsequent exsanguination appeared stressful to the fish, as a large and rapid pH drop coupled with earlier onset of rigor mortis, indicative of high muscle activity during the process were observed. The muscle core temperature during ice storage showed that live chilling only has an effect on carcass temperature during the first 6 h post mortem. After 6 h, no significant differences in temperature were detected between live‐chilled and traditionally ice‐chilled fish. We conclude that commercial use of live chilling in combination with high levels of CO₂ does not stun Atlantic salmon. Live chilling followed by exsanguination of the unstunned fish appears to be highly stressful and should be avoided.  相似文献   

Vaccine-associated granulomatous inflammation and melanin accumulation in Atlantic salmon, Salmo salar L., white muscle     

Koppang EO  Haugarvoll E  Hordvik I  Aune L  Poppe TT 《Journal of fish diseases》2005,28(1):13-22

The purpose of this study was to investigate the nature of variably sized pigmented foci encountered in fillets of farmed Atlantic salmon, Salmo salar L. The material was sampled on the fillet production line and on salmon farms from fish with an average size of 3 kg from various producers. The fish had been routinely vaccinated by injection. Gross pathology, histology, immunohistochemistry using antisera against major histocompatibility complex (MHC) class II beta chain and transmission electron microscopy (TEM) were used to characterize the changes. Macroscopically, melanized foci were seen penetrating from the peritoneum deep into the abdominal wall, sometimes right through to the skin, and also embedded in the caudal musculature. Histological investigation revealed muscle degeneration and necrosis, fibrosis and granulomatous inflammation containing varying numbers of melano-macrophages. Vacuoles, either empty or containing heterogeneous material, were frequently seen. The presence of abundant MHC class II+ cells indicated an active inflammatory condition. TEM showed large extracellular vacuoles and leucocytes containing homogeneous material of lipid-like appearance. The results showed that the melanized foci in Atlantic salmon fillet resulted from an inflammatory condition probably induced by vaccination. The described condition is not known in wild salmon and in farmed salmon where injection vaccination is not applied.  相似文献   

In vitro protein digestion, and growth of Atlantic salmon with different trypsin isozymes     

M. Bassompierre  T.H. Ostenfeld  E. McLean  K. Rungruangsak Torrissen 《Aquaculture International》1998,6(1):47-56

Growth and in vitro digestion was examined in three iso-trypsin phenotypes (patterns 1, 2 and 2) of Atlantic salmon, Salmo salar. Fish grew equally well during the 128 day experiment irrespective of phenotype. At day 64 and 91, weight-specific growth rate of 2 phenotype animals were significantly lower (p < 0.05). At the end of the experiment, significant differences (p < 0.05) were noted between groups with respect to size. An in vitro method was used to examine protein digestion by the different trypsin phenotypes. Three fish meals (FM I > FM II > FM III) of high, medium and low quality, as defined by chemical analyses, were used. Phenotype 1 was able to differentiate between three fish meals ranking FM I > FM II > FM III. In contrast, phenotypes 2 and 2 were not able to separate between meals. In vitro digestion efficiency was dependent upon the three salmon types, ranking phenotype 2 > 1 = 2.  相似文献   

Nutrient composition and metamorphosis success of Atlantic halibut (Hippoglossus hippoglossus, L.) larvae fed natural zooplankton or Artemia   总被引：1，自引：0，他引：1  

K. HAMRE  I. OPSTAD  M. ESPE  J. SOLBAKKEN  G.-I. HEMRE  & K. PITTMAN 《Aquaculture Nutrition》2002,8(2):139-148

Atlantic halibut larvae were fed docosohexanoic acid- (DHA) selco enriched Artemia (RH-cysts) or wild zooplankton in duplicate tanks from first-feeding and 60 days onward. The zooplankton were collected from a fertilized sea water pond and consisted mainly of different stages of Eurytemora affinis and Centropages hamatus . There were no differences in survival, or in growth during the first 45 days of feeding, between larvae fed the two prey items, but the larvae fed Artemia showed much higher incidence of malpigmentation and impaired eye migration than larvae fed zooplankton. The prey organisms contained similar amounts of dry matter and protein, but Artemia was higher in lipid and glycogen than the zooplankton. Larvae fed Artemia were higher in both glycogen and lipid than the zooplankton-fed larvae towards the end of the feeding period. There were large differences between the prey organisms in the concentrations of essential fatty acids (% of total fatty acids) which was reflected in the fatty acid composition of the larval body. It is concluded that the macronutrient composition of Artemia in the present study was probably within the optimal range for promotion of growth and survival in young Atlantic halibut. The concentration of n-3 HUFA, and especially DHA, is however, very much lower in enriched Artemia than in copepods, and may be one of the factors triggering developmental errors in Atlantic halibut.  相似文献   

Spatial and temporal trends in abundance of Atlantic salmon, Salmo salar, in Newfoundland with emphasis on impacts of the 1992 closure of the commercial fishery     

J. B. Dempson  M. F. O'Connell  & C. J. Schwarz 《Fisheries Management and Ecology》2004,11(6):387-402

Closure of the Newfoundland commercial Atlantic salmon, Salmo salar L., fishery in 1992 was the most restrictive measure introduced to help rebuild depressed local stocks of salmon. Here, the effects of the closure are evaluated by analysing trends in abundance since 1984, and estimates of survival in both freshwater and marine environments derived from enumeration of salmon at fish counting facilities. While freshwater production of smolts generally has been maintained, marine survival rates remain low (2–10%), and highly variable. Overall, total stock size differs little from that prior to the closure of the commercial salmon fishery. Spawning escapements have increased by a factor of 2 or 3 in some rivers, but in other areas total returns are lower on average than those prior to the fishery closure. Factors other than exploitation are contributing to lack of stock recovery, resulting in continued conservation concerns.  相似文献   

Blood chemistry and organ nutrient composition in Atlantic salmon, Salmo salar L., fed graded amounts of wheat starch     

G.I. HEMRE  K. SANDNES  ø. LIE  R. WAAGBø 《Aquaculture Nutrition》1995,1(1):37-42

After feeding Atlantic salmon, Salmo salar L., five graded amounts of wheat starch from 0 to 310 g kg^?1, low but increased levels of glycogen in kidney, heart and gills were determined. No variations were found in proximate or glycogen compositions of muscle, whereas the liver composition reflected the diet composition. Whole-body homogenates varied in dry matter and lipid levels; the variation was according to g lipid eaten per fish. Plasma glucose levels ranged above average levels only when the starch level in the feed was higher than 220 g kg^?1. Although feed intake and thereby lipid intake increased as dietary carbohydrate increased in the present experiment, no differences in plasma concentrations of cholesterol and only small changes in triglycerides were determined. The increase in dietary carbohydrate was balanced with protein, and total plasma protein concentrations followed the decrease in feed protein content. Haematocrit, haemoglobin, mean cell volume and mean cell haemoglobin all showed significantly reduced levels as dietary starch increased, indicating a fibre effect from ‘left-over’ starch in the intestine followed by reduced absorption of divalent ions, such as iron.  相似文献   

Influences of mean advection and simple behavior on the distribution of cod and haddock early life stages on Georges Bank   总被引：2，自引：0，他引：2  

FRANCISCO E. WERNER  FRED H. PAGE  DANIEL R. LYNCH  JOHN W. LODER  R. GREGORY LOUGH  R. IAN PERRY  DAVID A. GREENBERG  MICHAEL M. SINCLAIR 《Fisheries Oceanography》1993,2(2):43-64

Results of a modeling study designed to explore the influences of physical advection and certain biological mechanisms on the distribution of cod (Gadus morhua) and haddock (Melarwgrammus aeglefinus) early life stages on Georges Bank are described. Using a late-winter/early-spring 3-D circulation field driven by the M₂ tidal current, mean wind stress and Scotian Shelf inflow, we examine the distribution of cod and haddock larvae spawned on the Northeast Peak of the Bank. The sensitivity to a March-April baroclinic field is also explored. Results indicate that larvae remaining in the surface Ekman layer are generally advected off-bank. However, downwelling associated with Ekman layer convergence near the shelf break provides a mechanism for larvae to exit from the off-bank surface drift. Larvae below the surface layer are transported south-westward along the southern flank of Georges Bank and are retained on the Bank if their position immediately upstream of the Great South Channel is shoalward of (roughly) the 70 m isobath. Within the Great South Channel region and between the 50 and 70 m isobaths, retention can depend on the phase of the tide. Spawning shoalward of the 50 m isobath on the Northeast Peak greatly increases the chances of retention. These results apply to passive larvae and to those with specified vertical distributions and migration based on observations. Directional on-bank swimming at rates of 0.5 to 1 body length per second would substantially enhance shoalward displacement, resulting in larval distributions during the first 2 months that are consistent with field observations.  相似文献