Seawater adaptability in Baltic salmon, Salmo salar , immature smolt and mature male parr: lack of effect of springtime castration
Seawater adaptability was tested in different categories of 2-year-old Baltic salmon from the Ume River stock over the smoltification period in late spring – early summer by means of seawater challenge tests. Previously mature male parr and immature fish adapted equally well in early to mid May, whe...
| Published in: | Canadian Journal of Zoology |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1990
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/z90-302 http://www.nrcresearchpress.com/doi/pdf/10.1139/z90-302 |
| Summary: | Seawater adaptability was tested in different categories of 2-year-old Baltic salmon from the Ume River stock over the smoltification period in late spring – early summer by means of seawater challenge tests. Previously mature male parr and immature fish adapted equally well in early to mid May, whereas in later May and June the previously mature males displayed much higher plasma sodium levels after challenge than the immature fish. Neither castration nor sham operation of previously mature males in March led to decreases in plasma sodium levels following seawater challenges in June. In addition, sham-operated immature females were not affected. The results indicate that sexual maturation exerts an effect on osmoregulation that prevails long after the androgen source has disappeared. |
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