Progress of migrating Atlantic salmon (Salmo salar) along an estuary, observed by ultrasonic tracking

1975 ◽  
Vol 7 (3) ◽  
pp. 329-338 ◽  
Author(s):  
Aivars B. Stasko
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
Ultrasonic Tracking

Role of Olfaction in the Behavioral and Neuronal Responses of Atlantic Salmon, Salmo salar, to Hydrographic Stratification

1985 ◽  
Vol 42 (10) ◽  
pp. 1658-1667 ◽  
Author(s):  
Kjell B. Døving ◽  
Håkan Westerberg ◽  
Peter B. Johnsen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Water Samples ◽  
Olfactory Nerve ◽  
Control Fish ◽  
Fine Scale ◽  
Vertical Movements ◽  
Atlantic Salmon Salmo Salar ◽  
Hydrographic Features ◽  
Ultrasonic Tracking

The behavior of sham-operated and anosmic Atlantic salmon, Salmo salar, was studied in a fjord system with close reference to the fine-scale hydrographic features. Control fish made small-amplitude vertical movements, with sudden large-amplitude excursions. The anosmic fish made large continuous searches up and down in the water column, descended below the sill depth of the fjord, and followed the bottom contours. None of these three behaviors was seen in the control fish. The trauma caused by the surgical incision did not prevent the fish from active swimming, and a fish with unilateral sectioning of the olfactory nerve returned to the river of release. Activity of single olfactory bulb neurons was recorded during stimulation of salmon olfactory epithelium with water samples taken from different depths of the fjord. These water samples had been taken from regions that showed layering and to which migrating salmon demonstrated behavioral preferences in ultrasonic tracking experiments. Ninety percent of responding neurons showed differencial responses to the water samples, indicating the capacity of the olfactory system to discriminate among stratified water layers found in the ocean. We conclude that olfactory discrimination of fine-scale hydrographic features may provide a necessary reference system for successful orientation in nearshore regions by salmon.

Behavior of Atlantic salmon (Salmo salar) During Suspended Migration in an Estuary, Sheet Harbour, Nova Scotia, Observed Visually and By Ultrasonic Tracking

1982 ◽  
Vol 39 (2) ◽  
pp. 248-256 ◽  
Author(s):  
Vivien M. Brawn
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Small Area ◽  
Migration Behavior ◽  
Ground Speed ◽  
Atlantic Salmon Salmo Salar ◽  
East River ◽  
Constant Distance ◽  
Ultrasonic Tracking

The movements of adult Atlantic salmon (Salmo salar) were followed in an estuary from August to November 1978 and in July and August 1979 by ultrasonic tracking. During these periods, the proportion of time spent by salmon in apparent random movement inside a small area steadily increased, reaching 97 or 98% in September and October, and then declined. This behavior was observed visually in schools of 17 to 75 salmon which showed no preference for sun or shade, were not easily disturbed, kept a constant distance from the surface associated with the halocline, and were in currents too low to measure. As the frequency of this behavior increased, average ground speed of moving fish decreased. Suspended migrations of up to [Formula: see text] mo were recorded. Salmon planted as smolts in East River and returning as adults remained almost exclusively in the East River arm of the Y-shaped estuary. Salmon favored areas having water deeper than 3 m, but showed no preference for areas deeper than 5 m inside the 3-m contour. Moving fish showed a tendency to move upstream on a rising tide and downstream on a falling tide, but these movements could be reversed by high turbine flows at the mouth of East River. A means of removing ultrasonic tags from live salmon without injury was developed.Key words: Atlantic salmon, estuary, migration, behavior, ultrasonic tracking

Microstructure and texture of fresh and smoked Atlantic salmon, Salmo salar L., fillets from fish reared and slaughtered under different conditions

2001 ◽  
Vol 32 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sjofn Sigurgisladottir ◽  
Margret S. Sigurdardottir ◽  
Helga Ingvarsdottir ◽  
Ole J. Torrissen ◽  
Hannes Hafsteinsson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar

Persistence of Orally Administered Salmonella enterica Serovars Agona and Montevideo in Atlantic Salmon (Salmo salar L.)

2005 ◽  
Vol 68 (7) ◽  
pp. 1336-1339 ◽  
Author(s):  
L. L. NESSE ◽  
T. LØVOLD ◽  
B. BERGSJØ ◽  
K. NORDBY ◽  
C. WALLACE ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Salmonella Enterica ◽  
Most Probable Number ◽  
Fish Feed ◽  
Internal Organs ◽  
Probable Number ◽  
Atlantic Salmon Salmo Salar ◽  
Gastric Intubation

The objective of our experiments was to study the persistence and dissemination of orally administered Salmonella in smoltified Atlantic salmon. In experiment 1, salmon kept at 15°C were fed for 1 week with feed contaminated with 96 most-probable-number units of Salmonella Agona per 100 g of feed and then starved for 2 weeks. Samples were taken from the gastrointestinal tract and examined for Salmonella 1, 2, 8, 9, 15, and 16 days after the feeding ended. In experiment 2, Salmonella Agona and Montevideo were separately mixed with feed and administered by gastric intubation. Each fish received 1.0 × 108, 1.0 × 106, or 1.0 × 104 CFU. The different groups were kept in parallel at 5 and 15°C and observed for 4 weeks. Every week, three fish in each group were sacrificed, and samples were taken from the skin, the pooled internal organs, the muscle, and the gastrointestinal tract and examined for the presence of Salmonella. The results from the two experiments showed that the persistence of Salmonella in the fish was highly dependent on the dose administered. Salmonella was not recovered from any of the fish that were fed for 1 week with the lowest concentration of Salmonella. In the fish given the highest dose of Salmonella, bacteria persisted for at least 4 weeks in the gastrointestinal tract as well as, to some extent, the internal organs. The present study shows that under practical conditions in Norway, the risk of Salmonella in fish feed being passed on to the consumer of the fish is negligible.

scholarly journals The Analysis of Live-Attenuated Piscirickettsia salmonis Vaccine Reveals the Short-Term Upregulation of Innate and Adaptive Immune Genes in Atlantic Salmon (Salmo salar): An In Situ Open-Sea Cages Study

2021 ◽  
Vol 9 (4) ◽  
pp. 703
Author(s):  
Deborah Vargas ◽  
Eva Vallejos-Vidal ◽  
Sebastián Reyes-Cerpa ◽  
Aarón Oyarzún-Arrau ◽  
Claudio Acuña-Castillo ◽  
...  
Keyword(s):  
Immune Response ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Cellular Response ◽  
Short Term ◽  
Live Attenuated Vaccine ◽  
Gene Markers ◽  
Post Vaccination ◽  
Atlantic Salmon Salmo Salar ◽  
Piscirickettsia Salmonis

Piscirickettsia salmonis, the etiological agent of the Salmon Rickettsial Septicemia (SRS), is one the most serious health problems for the Chilean salmon industry. Typical antimicrobial strategies used against P. salmonis include antibiotics and vaccines, but these applications have largely failed. A few years ago, the first attenuated-live vaccine against SRS (ALPHA JECT LiVac® SRS vaccine) was released to the market. However, there is no data about the agents involved in the activation of the immune response induced under field conditions. Therefore, in this study we evaluated the expression profile of a set of gene markers related to innate and adaptive immunity in the context of a cellular response in Atlantic salmon (Salmo salar) reared under productive farm conditions and immunized with a live-attenuated vaccine against P. salmonis. We analyzed the expression at zero, 5-, 15- and 45-days post-vaccination (dpv). Our results reveal that the administration of the attenuated live SRS LiVac vaccine induces a short-term upregulation of the cellular-mediated immune response at 5 dpv modulated by the upregulation of ifnα, ifnγ, and the cd4 and cd8α T cell surface markers. In addition, we also registered the upregulation of il-10 and tgfβ. Altogether, the results suggest that a balanced activation of the immune response took place only at early times post-vaccination (5 dpv). The scope of this short-term upregulation of the cellular-mediated immune response against a natural outbreak in fish subjected to productive farm conditions deserves further research.

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