| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 2422214 | Aquaculture | 2013 | 6 Pages |
The objective of this study has been to investigate the effect of light intensity (10, 21, 43, 200 and 650 lx) during smolting and its potential influence on gill Na+,K+-ATPase (NKA) activity, endocrinology, ion regulation, growth, morphology, and spinal development in Atlantic salmon. Gill Na+,K+-ATPase activity, plasma glucose and blood PCO2 were all affected by time (study duration 176 days), while no differences were seen as a result of the different light intensity treatments. Growth rate was positively correlated to light intensity. Lower body silvering index, reduced fin area (5–7% lower in the 10 and 21 lux groups) and increased percentage of skeletal abnormalities (6.9% in the 10 lux group vs. 1% in the 650 lux group) at low light intensity were seen. In a second experiment juvenile Atlantic salmon parr were reared in August at LD12:12, at either 1 lx or 1000 lx and circulating plasma thyroxin (FT) levels measured. Plasma FT4 levels remained low in the low light intensity group (1 lx), whereas FT4 levels increased significantly from 2 to 5 h in the high intensity group (1000 lx). Total T4 levels were nearly 2-fold higher 5 h after lights-on in the high intensity group compared with the low. Overall, the present data suggests that a minimum light intensity of 43 lx is needed to secure optimal smolt quality, development, welfare and growth in Atlantic salmon.
► We investigate the effect of light intensity during smolting in Atlantic salmon. ► Growth rate was positively correlated to light intensity. ► Low light intensity leads to increased percentage of skeletal abnormalities. ► Thyroxin levels in plasma were higher at high light intensity. ► A minimum of 43 lx is needed to secure optimal smolt quality in Atlantic salmon.
