Sexual maturation versus immaturity: different tactics with adaptive values in Baltic salmon ( Salmo salar L.) male smolts
Precocious 2-year-old male parr of the Baltic salmon (Salmo salar L.) were retained in freshwater or exposed to brackish water (4.6–5‰) in net pens after smoltification. Comparisons of growth rates and the incidence of sexual maturation revealed great differences between the two groups. In the fresh...
Published in: | Canadian Journal of Zoology |
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Language: | English |
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Canadian Science Publishing
1982
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Online Access: | http://dx.doi.org/10.1139/z82-236 http://www.nrcresearchpress.com/doi/pdf/10.1139/z82-236 |
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crcansciencepubl:10.1139/z82-236 2024-10-13T14:10:32+00:00 Sexual maturation versus immaturity: different tactics with adaptive values in Baltic salmon ( Salmo salar L.) male smolts Lundqvist, Hans Fridberg, Gunnar 1982 http://dx.doi.org/10.1139/z82-236 http://www.nrcresearchpress.com/doi/pdf/10.1139/z82-236 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 60, issue 8, page 1822-1827 ISSN 0008-4301 1480-3283 journal-article 1982 crcansciencepubl https://doi.org/10.1139/z82-236 2024-09-19T04:09:47Z Precocious 2-year-old male parr of the Baltic salmon (Salmo salar L.) were retained in freshwater or exposed to brackish water (4.6–5‰) in net pens after smoltification. Comparisons of growth rates and the incidence of sexual maturation revealed great differences between the two groups. In the freshwater group, the growth rate was retarded from mid-July and the fish acquired parr markings. In autumn, they all matured. The group in brackish water became rapidly growing, immature postsmolts. Only 7% matured in the autumn. The increase in mean weight of the postsmolts was 500% from the start of the experiment compared with 90% for the fish retained in freshwater.It is hypothesized that these alternative tactics expressed by salmon male smolts, i.e., sexual maturation combined with a low growth rate while in freshwater compared with sexual immaturity and a high growth rate while in sea, are mutually exclusive. Furthermore, it is suggested that these processes are controlled by annual endogenous rhythms (circannual rhythms) in interaction with the environment–neuroendocrine axis. Article in Journal/Newspaper Salmo salar Canadian Science Publishing Canadian Journal of Zoology 60 8 1822 1827 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
Precocious 2-year-old male parr of the Baltic salmon (Salmo salar L.) were retained in freshwater or exposed to brackish water (4.6–5‰) in net pens after smoltification. Comparisons of growth rates and the incidence of sexual maturation revealed great differences between the two groups. In the freshwater group, the growth rate was retarded from mid-July and the fish acquired parr markings. In autumn, they all matured. The group in brackish water became rapidly growing, immature postsmolts. Only 7% matured in the autumn. The increase in mean weight of the postsmolts was 500% from the start of the experiment compared with 90% for the fish retained in freshwater.It is hypothesized that these alternative tactics expressed by salmon male smolts, i.e., sexual maturation combined with a low growth rate while in freshwater compared with sexual immaturity and a high growth rate while in sea, are mutually exclusive. Furthermore, it is suggested that these processes are controlled by annual endogenous rhythms (circannual rhythms) in interaction with the environment–neuroendocrine axis. |
format |
Article in Journal/Newspaper |
author |
Lundqvist, Hans Fridberg, Gunnar |
spellingShingle |
Lundqvist, Hans Fridberg, Gunnar Sexual maturation versus immaturity: different tactics with adaptive values in Baltic salmon ( Salmo salar L.) male smolts |
author_facet |
Lundqvist, Hans Fridberg, Gunnar |
author_sort |
Lundqvist, Hans |
title |
Sexual maturation versus immaturity: different tactics with adaptive values in Baltic salmon ( Salmo salar L.) male smolts |
title_short |
Sexual maturation versus immaturity: different tactics with adaptive values in Baltic salmon ( Salmo salar L.) male smolts |
title_full |
Sexual maturation versus immaturity: different tactics with adaptive values in Baltic salmon ( Salmo salar L.) male smolts |
title_fullStr |
Sexual maturation versus immaturity: different tactics with adaptive values in Baltic salmon ( Salmo salar L.) male smolts |
title_full_unstemmed |
Sexual maturation versus immaturity: different tactics with adaptive values in Baltic salmon ( Salmo salar L.) male smolts |
title_sort |
sexual maturation versus immaturity: different tactics with adaptive values in baltic salmon ( salmo salar l.) male smolts |
publisher |
Canadian Science Publishing |
publishDate |
1982 |
url |
http://dx.doi.org/10.1139/z82-236 http://www.nrcresearchpress.com/doi/pdf/10.1139/z82-236 |
genre |
Salmo salar |
genre_facet |
Salmo salar |
op_source |
Canadian Journal of Zoology volume 60, issue 8, page 1822-1827 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z82-236 |
container_title |
Canadian Journal of Zoology |
container_volume |
60 |
container_issue |
8 |
container_start_page |
1822 |
op_container_end_page |
1827 |
_version_ |
1812817842992578560 |