Experimental demonstration of differences in sheltering behaviour between Icelandic populations of Atlantic salmon (Salmo salar) and Arctic char (Salvelinus alpinus)

2000 ◽  
Vol 57 (4) ◽  
pp. 719-724 ◽  
Author(s):  
Sveinn K Valdimarsson ◽  
Neil B Metcalfe ◽  
Skúli Skúlason
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Population Differences ◽  
Experimental Demonstration ◽  
Local Adaptations ◽  
Atlantic Salmon Salmo Salar ◽  
Different Temperatures ◽  
Different Populations

Most salmonids, as well as many other freshwater fish species in the Northern Hemisphere, have been reported to show some form of daytime sheltering behaviour over the winter. Previous work has shown that temperatures around 6-8°C trigger the onset of this sheltering behaviour. However, fish from colder environments would be expected to respond differently to temperature than fish from warmer environments. The incidence of sheltering at different temperatures between two Icelandic populations of both juvenile Atlantic salmon (Salmo salar) and juvenile Arctic char (Salvelinus alpinus) was examined by quantifying the use of refuges in identical controlled laboratory conditions. The results showed clear differences in the sheltering response between the different populations. Salmon from a warm, productive stream and riverine char emerged more by day from their shelter at low temperatures (5-8°C) than did either salmon from a cold, unproductive stream or char from a landlocked lake population. These population differences indicate local adaptations that must be kept in mind when managing fish populations; moreover, the differences do not appear to be predictable on the basis of ambient thermal regimes.

Temperature Requirements in Atlantic Salmon (Salmo salar), Brown Trout (Salmo trutta), and Arctic Char (Salvelinus alpinus) from Hatching to Initial Feeding Compared with Geographic Distribution

1989 ◽  
Vol 46 (5) ◽  
pp. 786-789 ◽  
Author(s):  
Arne J. Jensen ◽  
Bjørn O. Johnsen ◽  
Laila Saksgård
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Geographic Distribution ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Development Time ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Atlantic Salmon Salmo Salar ◽  
Brown Trout Salmo Trutta

Development time at different temperatures from hatching to 50% feeding was studied in Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) alevins. Live animals were used as food. In both species the development time decreased with increasing temperature, and these relationships were described by power curves. The results were compared with similar data for Arctic char (Salvelinus alpinus). At temperatures above about 8 °C, the development time to 50% feeding was the same for all three species. However, at lower temperatures Atlantic salmon alevins needed more time to reach the stage of initial feeding than did Arctic char. Brown trout were intermediate. These results are in accordance with the known optimum temperature ranges for the three species and their geographic distribution.

Cardiorespiratory responses of seawater-acclimated adult Arctic char (Salvelinus alpinus) and Atlantic salmon (Salmo salar) to an acute temperature increase

2014 ◽  
Vol 71 (7) ◽  
pp. 1096-1105 ◽  
Author(s):  
Chantelle M. Penney ◽  
Gordon W. Nash ◽  
A. Kurt Gamperl
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Temperature Increase ◽  
Thermal Tolerance ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Acclimation Temperature ◽  
Atlantic Salmon Salmo Salar ◽  
Interspecific Differences ◽  
Significant Difference

In this first study examining the thermal tolerance of adult Arctic char (Salvelinus alpinus) acclimated to seawater, we measured their critical thermal maximum (CTMax) and several cardiorespiratory parameters (oxygen consumption (MO2), heart rate (fH), stroke volume (SV), cardiac output (Q), ventilatory frequency (VF), opercular pressure (PO), and ventilatory effort (VE)) when exposed to a temperature increase of 2 °C·h−1. Further, we directly compared these results with those obtained for the eurythermal Atlantic salmon (Salmo salar) under identical conditions. There was no significant difference in cardiorespiratory values between the two species at their acclimation temperature (9.5–10 °C). In contrast, the slope of the MO2–temperature relationship was lower (by 27%) in the char as compared with that in the salmon, and the char had significantly lower values for maximum fH (by 13%), maximum MO2 (by 35%), absolute metabolic scope (by 39%), and CTMax (approximately 23 versus 26.5 °C, respectively). Although not a focus of the study, preliminary data suggest that interspecific differences in mitochondrial respiration (oxidative phosphorylation), and its temperature sensitivity, may partially explain the difference in thermal tolerance between the two species. These results provide considerable insights into why Atlantic salmon are displacing Arctic char in the current era of accelerated climate change.

Timing of smolt migration in sympatric populations of Atlantic salmon (Salmo salar), brown trout (Salmo trutta), and Arctic char (Salvelinus alpinus)

2012 ◽  
Vol 69 (4) ◽  
pp. 711-723 ◽  
Author(s):  
Arne J. Jensen ◽  
Bengt Finstad ◽  
Peder Fiske ◽  
Nils Arne Hvidsten ◽  
Audun H. Rikardsen ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Water Flow ◽  
Salmo Salar ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Atlantic Salmon Salmo Salar ◽  
Local Selection ◽  
Brown Trout Salmo Trutta

A study over a 22-year period of first-time migrants (smolts) of three sympatric salmonids (Atlantic salmon ( Salmo salar ), brown trout ( Salmo trutta ), and Arctic char ( Salvelinus alpinus )) in a watercourse in northern Norway demonstrated that although there was considerable overlap in smolt migration timing among the species, Atlantic salmon migrated first, followed by Arctic char, and finally brown trout. The migration period of Arctic char had a smaller range and less annual variation than those of the two other species, possibly partly related to their more lake-dwelling habitat preference. For all species, water flow was important in explaining day-to-day variations in smolt runs. Water flow was most important for brown trout, change in flow for Atlantic salmon, whereas photoperiod was most important for Arctic char. These results suggest that both age and size of smolts and the timing of the smolt migration have been shaped by the different habitat preferences of these species both in fresh water and sea through local selection.

Transferrin Polymorphism in Atlantic Salmon (Salmo salar)

1970 ◽  
Vol 27 (9) ◽  
pp. 1617-1625 ◽  
Author(s):  
Dag Møller
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Genetic Basis ◽  
Gene Frequencies ◽  
Wild Salmon ◽  
Atlantic Salmon Salmo Salar ◽  
Different Populations ◽  
Transferrin Polymorphism ◽  
Starch Agar

Three main patterns of transferrins, made up of two molecular types, were found by starch–agar electrophoresis in plasma of hatchery and wild Atlantic salmon (Salmo salar).Distributions of the observed patterns from progenies of three hatchery matings agreed with expected Mendelian distributions in offspring of known parentage, implying that the bands have their origin in two codominant alleles. In nearly all samples of the wild salmon the genetic basis of transferrin variation was demonstrated by nonsignificant differences between observed and expected distributions when the Hardy–Weinberg formula was applied.Frequencies of the TfA allele differed in samples from different rivers and within the same river; the Atlantic salmon forms genetically different populations. Interchange of stocks probably influenced the values of the different gene frequencies found.

Effect of Sea-Age on the Reproductive Potential of Atlantic Salmon (Salmo salar) in Eastern Canada

1989 ◽  
Vol 46 (12) ◽  
pp. 2210-2218 ◽  
Author(s):  
R. G. Randall
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Reproductive Potential ◽  
Female Size ◽  
Eastern Canada ◽  
Age Composition ◽  
Atlantic Salmon Salmo Salar ◽  
Egg Deposition ◽  
Different Populations ◽  
Spawning Run

Reproductive potential of Atlantic salmon (Salmo salar), defined as average eggs per fish in the spawning run, varied three-fold both within stocks over time and among stocks from different geographic areas. Eggs per spawner is a function of fecundity, sea-age, proportion of females, and female size; the latter three traits varied significantly among years for salmon in both the Miramichi and Restigouche Rivers, New Brunswick. Because all of the above traits are related to sea-age at maturity, eggs per spawner was significantly correlated with mean sea-age in both rivers (R2 = 0.88 and 0.61, respectively). Among 10 different populations in eastern Canada, reproductive potential was also correlated with sea-age; for mean sea-ages (MSA) ranging from 1.0 to 1.8 yr, reproductive potential (RP) was defined by the power regression: RP = 1831.26 MSA1.30 (R2 = 0.64 P < 0.05). Thus reproductive potential can be estimated for any population for which the sea-age composition of spawners is known. Assuming a target egg deposition rate of 2.4 × 104 eggs per hectare, required spawners varied inversely with reproductive potential among the 10 populations, from five spawners (MSA = 1.75 yr) to 16 spawners (MSA = 1.15 yr) per hectare.

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