Seminatural Rearing of Atlantic Salmon (Salmo salar) in Newfoundland

1987 ◽  
Vol 44 (2) ◽  
pp. 337-347 ◽  
Author(s):  
V. A. Pepper ◽  
T. Nicholls ◽  
N. P. Oliver
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Natural Food ◽  
Average Weight ◽  
Artificial Rearing ◽  
Commercial Diet ◽  
First Feeding ◽  
Salmon Fry ◽  
Riverine Habitat ◽  
Daphnia Catawba

Atlantic salmon fry (Salmo salar) obtained from an artificial spawning channel and a deep-substrate incubator, were reared in mesh "troughs" in an artificial rearing channel and in floating lake cages. Fry placed in the lake cages were able to complete their first feeding phase on a diet of natural lake zooplankton but growth performance was improved when artifical diets were used to supplement natural food. Parr fed selectively on Daphnia catawba and mature Epischura lacustris. Parr reared in the mesh troughs were hand-fed a commercial diet. The 90-d average release weight ranged from 1.8 to 3.1 g for parr from the mesh troughs and from 0.9 to 3.1 g for parr from the lake cages. Growth of parr in these experiments resulted in an average weight advantage of approximately 2.3–4.5 times over parr captured from natural riverine habitat at the end of the experiment. Overall swim-up fry to fall-fingerling survival from these experiments was 52% in 1983 and 76% in 1984. Survival and growth varied inversely with density in the mesh trough experiments.

scholarly journals Endogenous production of n-3 long-chain PUFA from first feeding and the influence of dietary linoleic acid and the α-linolenic:linoleic ratio in Atlantic salmon (Salmo salar)

2019 ◽  
Vol 122 (10) ◽  
pp. 1091-1102 ◽  
Author(s):  
Matthew Sprague ◽  
Gong Xu ◽  
Monica B. Betancor ◽  
Rolf E. Olsen ◽  
Ole Torrissen ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Chain Pufa ◽  
First Feeding ◽  
Endogenous Production ◽  
Epa And Dha ◽  
Salmon Fry ◽  
Sunflower Oils ◽  
Long Chain

AbstractAtlantic salmon (Salmo salar) possess enzymes required for the endogenous biosynthesis of n-3 long-chain PUFA (LC-PUFA), EPA and DHA, from α-linolenic acid (ALA). Linoleic acid (LA) competes with ALA for LC-PUFA biosynthesis enzymes leading to the production of n-6 LC-PUFA, including arachidonic acid (ARA). We aimed to quantify the endogenous production of EPA and DHA from ALA in salmon fed from first feeding on diets that contain no EPA and DHA and to determine the influence of dietary LA and ALA:LA ratio on LC-PUFA production. Salmon were fed from first feeding for 22 weeks with three diets formulated with linseed and sunflower oils to provide ALA:LA ratios of approximately 3:1, 1:1 and 1:3. Endogenous production of n-3 LC-PUFA was 5·9, 4·4 and 2·8 mg per g fish and that of n-6 LC-PUFA was 0·2, 0·5 and 1·4 mg per g fish in salmon fed diets with ALA:LA ratios of 3:1, 1:1 and 1:3, respectively. The ratio of n-3:n-6 LC-PUFA production decreased from 27·4 to 2·0, and DHA:EPA ratio increased and EPA:ARA and DHA:ARA ratios decreased, as dietary ALA:LA ratio decreased. In conclusion, with a dietary ALA:LA ratio of 1, salmon fry/parr produced about 28 μg n-3 LC-PUFA per g fish per d, with a DHA:EPA ratio of 3·4. Production of n-3 LC-PUFA exceeded that of n-6 LC-PUFA by almost 9-fold. Reducing the dietary ALA:LA ratio reduced n-3 LC-PUFA production and EPA:ARA and DHA:ARA ratios but increased n-6 LC-PUFA production and DHA:EPA ratio.

Drifters versus residents: assessing size and age differences in Atlantic salmon (Salmo salar) fry

2004 ◽  
Vol 61 (2) ◽  
pp. 273-282 ◽  
Author(s):  
Valérie Bujold ◽  
Richard A Cunjak ◽  
Jason P Dietrich ◽  
David A Courtemanche
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Driving Forces ◽  
Active Movement ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Fry ◽  
Riverine Habitat ◽  
Life History Patterns ◽  
Young Of The Year ◽  
Set Up

Some young-of-the-year Atlantic salmon (Salmo salar) have a tendency to drift soon after emergence from the gravel, whereas others, called resident fry, set up and defend territories. Little is known about the mechanisms regulating this strong tendency to drift soon after emergence, a phenomenon that can greatly influence survival within a population. This study was carried out in the Western Brook system, Gros Morne National Park, Newfoundland, Canada. The objective was to assess differences, through biometric characteristics, between drifting and resident Atlantic salmon fry by examining both groups of fish caught simultaneously in the same riverine habitat. Resident salmon fry can be up to 4.8% longer and 20.4% heavier compared with drifting fry of similar age (measured in days since emergence). Therefore, it seems that competition, more than prior residence effect, could be part of the driving forces behind this active movement and that differences between subpopulations of Atlantic salmon fry can have major repercussions on life history patterns.

Hypervitaminosis A in first-feeding fry of the Atlantic salmon (Salmo salar L.)

2002 ◽  
Vol 8 (1) ◽  
pp. 7-13 ◽  
Author(s):  
R. ØRNSRUD ◽  
I. E. GRAFF ◽  
S. HØIE ◽  
G. K. TOTLAND ◽  
G.-I. HEMRE
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Hypervitaminosis A ◽  
Atlantic Salmon Salmo Salar ◽  
First Feeding

First feeding of Atlantic salmon, Salmo salar L., under different photoperiods and light intensities

1990 ◽  
Vol 21 (4) ◽  
pp. 435-441 ◽  
Author(s):  
S. O. STEFANSSON ◽  
R. NORTVEDT ◽  
T. J. HANSEN ◽  
G. L. TARANGER
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
First Feeding ◽  
Light Intensities

Annual variation in size-selective mortality of Atlantic salmon (Salmo salar) fry

2001 ◽  
Vol 58 (6) ◽  
pp. 1187-1195 ◽  
Author(s):  
S P Good ◽  
J J Dodson ◽  
M G Meekan ◽  
D AJ Ryan
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Total Mortality ◽  
Weather Conditions ◽  
Fish Length ◽  
Selective Mortality ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Fry ◽  
Mean Size ◽  
The Mean

We investigated the size-selective mortality of Atlantic salmon (Salmo salar) fry during two consecutive summers that differed markedly in weather conditions. We sampled fry shortly after emergence in June and at the end of August to compare the distributions of back-calculated body size at hatching by examining otolith microstructure. Size-selective mortality was observed in both summers; however, the direction and strength of mortality differed. During the drought conditions of 1995, selective mortality was relatively weak and directed towards the smaller fry in the population. During the flood conditions of 1996, selective mortality was relatively strong and directed towards the larger fry of the same population. Interannual variability in size-selective mortality contributed to significant differences in the mean size of fry at the end of their first summer of life. Size-selective mortality rates estimated from the shifts in fish length at hatching observed during the first summer of life were comparable with published estimates of total mortality of Atlantic salmon fry, indicating that early mortality may be largely size selective. Mortality associated with hydroclimatic events can select against either small or large fish and is a key determinant of mean size attained by the end of the first summer of life.

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