Plasma growth hormone levels increase during seawater exposure of sexually mature Atlantic salmon parr (Salmo salar L.)

1990 ◽  
Vol 80 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Magnus Rydevik ◽  
Bertil Borg ◽  
Carl Haux ◽  
Hiroshi Kawauchi ◽  
Björn Th. Björnsson
Keyword(s):  
Growth Hormone ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Plasma Growth Hormone ◽  
Hormone Levels ◽  
Salmon Parr ◽  
Sexually Mature ◽  
Atlantic Salmon Parr

Growth, Parr–Smolt Transformation, and Changes in Growth Hormone of Atlantic Salmon (Salmo salar) Reared under Different Photoperiods

1991 ◽  
Vol 48 (11) ◽  
pp. 2100-2108 ◽  
Author(s):  
Sigurd O. Stefansson ◽  
Björn Th. Bjömsson ◽  
Tom Hansen ◽  
Carl Haux ◽  
G. Lasse Taranger ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Rate ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Continuous Light ◽  
Plasma Growth Hormone ◽  
Hormone Levels ◽  
Light Regimes ◽  
Atlantic Salmon Salmo Salar ◽  
Natural Photoperiod

Potential 1+ smolts of Atlantic salmon (Salmo salar) were reared under three light regimes: simulated natural photoperiod (LDN), continuous light (LD24:0), or a combination of continuous, low-intensity background light and a superimposed simulated natural photoperiod (dual photoperiod, LDD). Growth rate in freshwater was enhanced by LD24:0 and LDD, and changes associated with smoking (increased salinity tolerance, reduced condition coefficient) were advanced under LD24:0. Plasma growth hormone levels were initially high on LD24:0 and LDD whereas on LDN, plasma growth hormone levels increased gradually from February through April. Overall GH levels were negatively correlated with condition coefficient during the final stages of smoking. After 16 mo in seawater, there were no significant size differences among the groups. The incidence of sexual maturation as postsmolts was higher in the LD24:0 and LDD groups whereas the incidence of grilsing was higher in LDN. Results demonstrate the significant influence of photoperiod on growth and smoking in Atlantic salmon. An abrupt increase to continuous light in winter may be sufficient to advance important aspects of the parr–smolt transformation. Dual photoperiod may be a way to combine the increased growth rate observed under continuous light and the normal parr–smolt transformation associated with natural photoperiod.

Degradation of DDT in Atlantic Salmon (Salmo salar)

1968 ◽  
Vol 25 (11) ◽  
pp. 2321-2326 ◽  
Author(s):  
G. L. Greer ◽  
U. Paim
Keyword(s):  
Atlantic Salmon ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Salmo Salar ◽  
Aqueous Suspensions ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Parr ◽  
Layer Chromatography ◽  
Atlantic Salmon Parr

As indicated by thin-layer chromatography, hatchery-reared Atlantic salmon parr degraded DDT, absorbed from aqueous suspensions, to DDE and TDE within 9 hr. DDT adsorbed on external surfaces of the salmon was not degraded.

Assessment of the transferability of biological habitat models for Atlantic salmon parr (Salmo salar)

2003 ◽  
Vol 60 (11) ◽  
pp. 1398-1408 ◽  
Author(s):  
J C Guay ◽  
D Boisclair ◽  
M Leclerc ◽  
M Lapointe
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Mathematical Structure ◽  
Habitat Patches ◽  
Suitability Index ◽  
Preference Curve ◽  
Substrate Size ◽  
Salmon Parr ◽  
Predicted Values ◽  
Atlantic Salmon Parr

We assessed the transferability of the habitat suitability index (HSI) and the habitat probabilistic index (HPI) between two rivers. Transferability was measured by the ability of HSI and HPI models developed in the Sainte-Marguerite River to predict the distribution of Atlantic salmon parr (Salmo salar) in the Escoumins River. HSI and HPI were based on the pattern of utilization by fish of water depth, current velocity, and substrate size. HSI was developed using the preference curve approach, and HPI was developed using a multiple logistic regression. Predicted values of HSI and HPI in Escoumins River ranged from 0 (poor habitat) to 1 (excellent habitat). Fish density in habitat patches assigned different HSI or HPI values ranged from 0 to 1 fish·100 m–2. Only HPI adequately predicted local variations in parr density (r2 = 0.84) in habitat patches of Escoumins River. Our results suggest that HSI is less transferable between rivers than HPI. Differences in substrate size between the two rivers is suspected to impede the transferability of the HSI model. We also argue that the mathematical structure of HPI provides a larger degree of flexibility that facilitates its transferability and its potential generalization.

Downstream Movements and Estuarine Residence by Atlantic Salmon Parr (Salmo salar)

1989 ◽  
Vol 46 (9) ◽  
pp. 1466-1471 ◽  
Author(s):  
R. A. Cunjak ◽  
E. M. P. Chadwick ◽  
M. Shears
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Significant Proportion ◽  
River Mouth ◽  
Northwest Coast ◽  
Total Production ◽  
Younger Age ◽  
Mean Size ◽  
Salmon Parr ◽  
Atlantic Salmon Parr

Downstream migrations and estuarine residence by Atlantic salmon (Salmo salar) parr and smolts were studied in a small river on the northwest coast of Newfoundland in 1983 and in 1987. There were large downstream migrations in the spring and small downstream migrations in the fall. The major differences between the two types of migrant were that parr migrated about 1 wk before smolts and at a younger age compared with smolts and while parr remained in the estuary throughout the summer, smoits did not. Modal age and mean size were less for parr sampled in the estuary compared with those sampled at the counting-fence which suggested that the smallest parr were not captured by the fence. The estuarine population of parr represented a significant proportion of the river's total production of salmon. Parr were found throughout the estuary in salinities up to 24 parts per thousand but were most abundant near the river mouth. There was evidence that larger parr became smolts and eventually migrated to sea, but smaller parr probably returned to the river for overwintering. It is clear that estuaries should be included as habitat used for rearing Atlantic salmon.

Osmoregulation, feed intake, growth and growth hormone levels in 0+ Atlantic salmon (Salmo salar L.) transferred to seawater at different stages of smolt development

Aquaculture ◽  
2003 ◽  
Vol 222 (1-4) ◽  
pp. 167-187 ◽  
Author(s):  
Arne M. Arnesen ◽  
Hilde Toften ◽  
Thorleifur Agustsson ◽  
Sigurd O. Stefansson ◽  
Sigurd O. Handeland ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Feed Intake ◽  
Hormone Levels ◽  
Atlantic Salmon Salmo Salar
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