Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8974580 | Aquaculture | 2005 | 10 Pages |
Abstract
Plasma growth hormone (GH), insulin-like growth factor-I (IGF-I), and insulin were measured in two groups of Salmo salar L. during a one-year study. The fish were reared under either a simulated natural photoperiod (SNP) from January to December or a regime of continuous light from January to June, followed by SNP until December (LL/SNP). Plasma GH levels during spring were low, and lower in the LL/SNP fish (< 0.9 ng mlâ 1) than in the SNP fish (> 1.9 ng mlâ 1), although the LL/SNP grew better (0.8% per day) than the SNP fish (0.5% per day). Plasma IGF-I levels increased transiently from January (64.7 ng mlâ 1) to maximum in late September in the LL/SNP (85.8 ng mlâ 1) and in November in the SNP group (87.3 ng mlâ 1). The ratio GH:IGF-I was lower in the LL/SNP group during spring when this group grew better than the SNP group.
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Authors
Ulla Nordgarden, Tom Hansen, Gro-Ingunn Hemre, Anne Sundby, Björn Thrandur Björnsson,