Effect of stripping on the length, condition and gonadal state of mature male Atlantic salmon, Salmo salar L., parr during autumn and winter

Hatchery‐reared mature male Atlantic salmon parr were shorter than immature parr of the same age through the winter period and this difference increased prior to smolting in spring. Stripping had no effect on growth. In autumn mature male parr had a higher condition factor (CF) than immature parr, b...

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Bibliographic Details
Published in:Journal of Fish Biology
Main Authors: Greenstreet, S. P. R., Morgan, R. I. G., Thorpe, J. E.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1992
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Online Access:http://dx.doi.org/10.1111/j.1095-8649.1992.tb02649.x
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.1992.tb02649.x
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.1992.tb02649.x
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Summary:Hatchery‐reared mature male Atlantic salmon parr were shorter than immature parr of the same age through the winter period and this difference increased prior to smolting in spring. Stripping had no effect on growth. In autumn mature male parr had a higher condition factor (CF) than immature parr, but from early January no difference was observed between unstripped mature males and immature parr. Stripping reduced the CF of male parr but the difference had disappeared by the time of smolting when the CFs of both mature groups were lower than that of immature fish. The quantity of expressible milt in stripped males decreased from c . 3% body weight in November and December to <0.05% by 2 March, after which no further milt expression was recorded. Milt expression in previously unstripped males was about 1% of body weight on 2 March, similar to that of stripped males 1 month earlier.