Histological Comparisons of the Adrenal-Cortical Cells of Hatchery and Wild Landlocked Atlantic Salmon (Salmo salar)

1971 ◽  
Vol 28 (4) ◽  
pp. 505-508
Author(s):  
Robert M. Davis ◽  
Owen C. Fenderson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Cortical Cell ◽  
Cell Nuclei ◽  
Natural Conditions ◽  
Cortical Cells ◽  
Atlantic Salmon Salmo Salar ◽  
One Year ◽  
The One ◽  
Adrenal Cortical Cells

No differences were found in mean diameters of adrenal-cortical cell nuclei between hatchery parr of landlocked Atlantic salmon (Salmo salar) killed immediately after removal from hatchery rearing pools and wild parr electrofished in two streams, and between hatchery and wild parr held for various periods in an outdoor stream aquarium simulating natural conditions. The similarities suggested that the wild and hatchery parr were similar in physiological response to environmental stress. In both hatchery and wild parr, the diameters differed at different times, indicating a downward trend from May to August in the one year of the study. No consistent relation was found between nucleus diameter and social behavior.

Reversible Changes in Adrenal Cortical Cell Morphology and Plasma Hydroxycorticosteroids During Freshwater Portion of the Spawning Journey of Atlantic Salmon (Salmo salar)

1972 ◽  
Vol 29 (3) ◽  
pp. 311-314 ◽  
Author(s):  
Henry L. Heyl ◽  
Stanley J. Carpenter
Keyword(s):  
Atlantic Salmon ◽  
Pacific Salmon ◽  
Dense Body ◽  
Cortical Cell ◽  
Electron Microscopic ◽  
Cortical Cells ◽  
Multiple Spawning ◽  
Cyclic Changes ◽  
Adrenal Cortical Cells

Adrenal cortical tissue taken from Atlantic salmon netted in the estuary of the Miramichi River, New Brunswick, at three stages of gonadal activity showed increasing hyperplasia from July to October, with varying degrees of regression or degeneration by the following April. Adrenal cortical cells in April fish contained a characteristic paranuclear dense body, the light and electron microscopic appearances of which are described and discussed. Levels of 17-hydroxycorticosteroids in the plasma almost doubled from July to October and returned to July values by the following April. The presence of these cyclic changes in Atlantic salmon and their absence in Pacific salmon are discussed. Data indicate that genetic factors may be important in determination of the capacity for multiple spawning journeys by some Atlantic salmon.

Changes in plasma thyroxine levels during smoltification in hatchery-reared one-year and two-year Atlantic salmon (Salmo salar)

Aquaculture ◽  
1988 ◽  
Vol 74 (3-4) ◽  
pp. 369-378 ◽  
Author(s):  
Richard J. Lin ◽  
Thomas F. Cross ◽  
Christopher P.R. Mills ◽  
Richard S. Nishioka ◽  
E.Gordon Grau ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
One Year

Does climate during embryonic development influence parr growth and age of seaward migration in Atlantic salmon (Salmo salar)?

2005 ◽  
Vol 62 (11) ◽  
pp. 2502-2508 ◽  
Author(s):  
Nina Jonsson ◽  
Bror Jonsson ◽  
Lars Petter Hansen
Keyword(s):  
Atlantic Salmon ◽  
Water Temperature ◽  
Early Development ◽  
Salmo Salar ◽  
Climatic Conditions ◽  
First Year ◽  
Long Term Effects ◽  
Atlantic Salmon Salmo Salar ◽  
One Year ◽  
First Year Of Life

Climatic conditions experienced by Atlantic salmon (Salmo salar) in their early development appear to affect parr size at the end of the first growth season and age at emigration from the nursery river. North Atlantic Oscillation indices (NAOIs) correlated positively with water temperature (degree-days) and discharge in the River Imsa during winter (January–April) 1976–2002, indicating a significant oceanic influence on the winter conditions in the river. Specific growth rate of Atlantic salmon parr during the first year of life and the proportion of one-year-old smolts correlated positively with water temperature, flow, and NAOI during February–April during the winter of egg incubation, but only NAOI was significant when cross-correlating the two series using a time difference of 1 year. Water temperature correlated significantly with the proportion of salmon cohorts smolting and migrating to sea at age-1. Such long-term effects of climate during early development may be more important than generally recognized.

Differences in antipredator behaviour between wild and hatchery-reared juvenile Atlantic salmon (Salmo salar) under seminatural conditions

2011 ◽  
Vol 68 (12) ◽  
pp. 2157-2166 ◽  
Author(s):  
Christopher D. Jackson ◽  
Grant E. Brown
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Antipredator Behaviour ◽  
Source Population ◽  
Alarm Cues ◽  
Natural Conditions ◽  
Atlantic Salmon Salmo Salar ◽  
Chemical Alarm Cues ◽  
Two Generations ◽  
Differential Experience

Captive rearing may elicit experiential or genetically based changes to salmonid antipredator behaviour, which may reduce survival of hatchery-reared fishes when they are released into the wild. Nevertheless, few studies have compared the behaviour between local wild-caught and local hatchery-reared fish (two generations or less), and none have done so under natural conditions. We conducted a seminatural field study comparing the antipredator behaviour of wild-caught, F1 (offspring of wild-caught adults) with that of F2 (second generation) hatchery-reared young-of-the-year Atlantic salmon ( Salmo salar , from the same source population) in response to standardized chemical alarm cues. Wild-caught salmon exhibited the strongest antipredator response to a standardized threat (conspecific alarm cues), while F2 salmon exhibited the weakest response. F1 salmon were intermediate in their behavioural response. The observed differences between wild-caught and F1 salmon suggests that differential experience may play a significant role in predator avoidance behaviours. Furthermore, the observed differences between F1 and F2 salmon suggests that even one full generation of hatchery rearing may be sufficient to select for maladaptive responses to predators under natural conditions. Given the controversy regarding the effectiveness of hatchery programs for conservation use, the results of this study suggest that minimizing hatchery time may reduce the behavioural differences between wild and hatchery-reared fishes.

scholarly journals Sensory complement model helps to predict diel alarm response patterns in juvenile Atlantic salmon (Salmo salar) under natural conditions

2010 ◽  
Vol 88 (4) ◽  
pp. 398-403 ◽  
Author(s):  
Antoine O.H.C. Leduc ◽  
Jae-Woo Kim ◽  
Camille J. Macnaughton ◽  
Grant E. Brown
Keyword(s):  
Atlantic Salmon ◽  
Predation Risk ◽  
Salmo Salar ◽  
Visual Cues ◽  
Response Patterns ◽  
Natural Conditions ◽  
Perception Of Risk ◽  
Alarm Response ◽  
Atlantic Salmon Salmo Salar ◽  
In The Wild

Fish rely on both chemical and visual cues to evaluate predation risk. Decisions with respect to activity partitioning in time (i.e., night vs. day) rely on accurate assessment of predation risk relative to energy intake; predation risk is generally thought to be lower at night at the expense of feeding opportunities. At night, the sensory complement model predicts greater reliance on chemical perception of risk. Under this condition, a lower ability to use vision should result in a more conservative response to chemical cues than during the day. We tested this hypothesis under natural conditions by comparing the alarm response of young-of-the-year Atlantic salmon ( Salmo salar L., 1758) under summer day and night conditions in salmon nursery streams. We found that salmon responded to the alarm cues to a significantly greater extent at night. This suggests that the sensory complement model may be correct and that nocturnal perception of risk may be generally higher than previously believed for juvenile salmon in the wild. In the absence of a more precise indicator of risk (e.g., vision), a greater reliance on chemosensory risk assessment at night may cause fish to shift to more risk-adverse behaviour.

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
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