Difficulties in Aging Atlantic Salmon ( Salmo salar ) and Brown Trout ( Salmo trutta ) from Cold Rivers Due to Lack of Scales as Yearlings
Scales in Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) from two cold Norwegian rivers first appeared when the salmon were 33–34 mm long (total length) and the trout were 35–38 mm long. A considerable proportion of the yearlings did not form scales in years with a low water temperatur...
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Canadian Science Publishing
1982
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Online Access: | http://dx.doi.org/10.1139/f82-044 http://www.nrcresearchpress.com/doi/pdf/10.1139/f82-044 |
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crcansciencepubl:10.1139/f82-044 2024-05-12T08:01:06+00:00 Difficulties in Aging Atlantic Salmon ( Salmo salar ) and Brown Trout ( Salmo trutta ) from Cold Rivers Due to Lack of Scales as Yearlings Jensen, Arne Johan Johnsen, Bjørn Ove 1982 http://dx.doi.org/10.1139/f82-044 http://www.nrcresearchpress.com/doi/pdf/10.1139/f82-044 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 39, issue 2, page 321-325 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 1982 crcansciencepubl https://doi.org/10.1139/f82-044 2024-04-18T06:54:53Z Scales in Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) from two cold Norwegian rivers first appeared when the salmon were 33–34 mm long (total length) and the trout were 35–38 mm long. A considerable proportion of the yearlings did not form scales in years with a low water temperature (less than 1000–1100 degree-days from May to October); these individuals lacked the first annulus in the scales. Scales with five circuli or more seldom occurred. The number of days per year with a water temperature above 6.5 °C was better correlated to the formation of scales in Atlantic salmon than the degree-days. In years when the water temperature exceeded 6.5 °C for more than 70–80 days, only minor errors arose in age determination of the salmon; when the temperature exceeded 6.5 °C for less than 70–80 days, some individuals lacked the first annulus in their scales.Key words: Atlantic salmon, brown trout, age determination, temperature, scale formation Article in Journal/Newspaper Atlantic salmon Salmo salar Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 39 2 321 325 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
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Aquatic Science Ecology, Evolution, Behavior and Systematics Jensen, Arne Johan Johnsen, Bjørn Ove Difficulties in Aging Atlantic Salmon ( Salmo salar ) and Brown Trout ( Salmo trutta ) from Cold Rivers Due to Lack of Scales as Yearlings |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
Scales in Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) from two cold Norwegian rivers first appeared when the salmon were 33–34 mm long (total length) and the trout were 35–38 mm long. A considerable proportion of the yearlings did not form scales in years with a low water temperature (less than 1000–1100 degree-days from May to October); these individuals lacked the first annulus in the scales. Scales with five circuli or more seldom occurred. The number of days per year with a water temperature above 6.5 °C was better correlated to the formation of scales in Atlantic salmon than the degree-days. In years when the water temperature exceeded 6.5 °C for more than 70–80 days, only minor errors arose in age determination of the salmon; when the temperature exceeded 6.5 °C for less than 70–80 days, some individuals lacked the first annulus in their scales.Key words: Atlantic salmon, brown trout, age determination, temperature, scale formation |
format |
Article in Journal/Newspaper |
author |
Jensen, Arne Johan Johnsen, Bjørn Ove |
author_facet |
Jensen, Arne Johan Johnsen, Bjørn Ove |
author_sort |
Jensen, Arne Johan |
title |
Difficulties in Aging Atlantic Salmon ( Salmo salar ) and Brown Trout ( Salmo trutta ) from Cold Rivers Due to Lack of Scales as Yearlings |
title_short |
Difficulties in Aging Atlantic Salmon ( Salmo salar ) and Brown Trout ( Salmo trutta ) from Cold Rivers Due to Lack of Scales as Yearlings |
title_full |
Difficulties in Aging Atlantic Salmon ( Salmo salar ) and Brown Trout ( Salmo trutta ) from Cold Rivers Due to Lack of Scales as Yearlings |
title_fullStr |
Difficulties in Aging Atlantic Salmon ( Salmo salar ) and Brown Trout ( Salmo trutta ) from Cold Rivers Due to Lack of Scales as Yearlings |
title_full_unstemmed |
Difficulties in Aging Atlantic Salmon ( Salmo salar ) and Brown Trout ( Salmo trutta ) from Cold Rivers Due to Lack of Scales as Yearlings |
title_sort |
difficulties in aging atlantic salmon ( salmo salar ) and brown trout ( salmo trutta ) from cold rivers due to lack of scales as yearlings |
publisher |
Canadian Science Publishing |
publishDate |
1982 |
url |
http://dx.doi.org/10.1139/f82-044 http://www.nrcresearchpress.com/doi/pdf/10.1139/f82-044 |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 39, issue 2, page 321-325 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f82-044 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
39 |
container_issue |
2 |
container_start_page |
321 |
op_container_end_page |
325 |
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1798843187711705088 |