کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8496037 | 1552914 | 2011 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Reduced daylength stimulates size-dependent precocious maturity in 0+ male Atlantic salmon parr
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موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم آبزیان
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چکیده انگلیسی
To study relationships between fish length, photoperiod and the onset of precocious maturity in 0+ parr during intensive rearing of Atlantic salmon (Salmo salar L.), 0+ juveniles of 55-89Â mm length were individually tagged with Passive Induced Transponders (PITs) in May and exposed to reduced daylength (LD12:12) in May, June or July, or kept as control fish under continuous light (LD24:0). Relationships between the length of the fish and maturity were studied by the use of probabilistic maturation reaction norms. The incidence of mature males and the proportion of fish of lower modal group size in autumn were highest in the groups exposed to short days in May, and lowest under continuous light. In contrast with the expectation that high growth rates promote maturation, the future mature male parr were smaller than the immature males at the start of the experiment, and they also grew more slowly during the subsequent maturation process. Variability in condition factor was low until autumn, when the condition factor of maturing males rose well above that of immature males during autumn as the fish grew from ~Â 80 to ~Â 95Â mm length. Reduced daylength increased the probability of the onset of precocious maturity in the fish smaller than, but not above a threshold length of ~Â 90-100Â mm (9 - 11Â g). Intensively reared parr of 60-90Â mm, and possibly also smaller fish, may be particularly sensitive to photoperiod manipulations that may influence the probabilities of fish adopting one of the three life-history alternatives, to enter lower or upper mode or to mature precociously.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Aquaculture - Volume 311, Issues 1â4, 3 February 2011, Pages 168-174
Journal: Aquaculture - Volume 311, Issues 1â4, 3 February 2011, Pages 168-174
نویسندگان
Ove T. Skilbrei, Mikko Heino,