Daily growth increments in the otoliths of Atlantic salmon parr, Salmo salar L., and the influence of environmental factors on their periodicity

1991 ◽  
Vol 39 (1) ◽  
pp. 103-113 ◽  
Author(s):  
P. J. Wright ◽  
D. Rowe ◽  
J. E. Thorpe
Keyword(s):  
Environmental Factors ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Daily Growth ◽  
Growth Increments ◽  
Salmon Parr ◽  
Atlantic Salmon Parr

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.

Increased Growth Rate in Atlantic Salmon Parr (Salmo salar) by Using a Two-Coloured Diet

1987 ◽  
Vol 44 (5) ◽  
pp. 1079-1082 ◽  
Author(s):  
Per Johan Jakobsen ◽  
Geir Helge Johnsen ◽  
Jens Christian Holm
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Diet Group ◽  
Mixed Diet ◽  
Feeding Rates ◽  
Highest Weight ◽  
Food Particles ◽  
Salmon Parr ◽  
Swarm Size ◽  
Atlantic Salmon Parr

Fishes hunting by sight are known to pay a cost of confusion when faced with high densities of uniform food particles. Factors such as swarm size, density, and visual uniformity increase confusion. Therefore, it may be profitable in pisciculture to introduce food particles in low densities or to reduce the uniformity and density of each type of feed pellet. This was tested by feeding Atlantic salmon parr (Salmo salar) brown pellets, yellow pellets, or a mixed diet. Mean growth rates were significantly higher for those fish fed a mixed diet. Of the smaller fish in all groups, those in the mixed diet group showed the highest weight/length ratio. We suggest that small individuals have to pay more attention to conspecifics than do large ones, and thus tolerate less confusion when feeding. Larger individuals, tolerating higher confusion costs, achieve higher feeding rates in high densities of uniform feed pellets.

Taste Responses in Atlantic Salmon (Salmo salar) Parr

1970 ◽  
Vol 27 (11) ◽  
pp. 1927-1942 ◽  
Author(s):  
A. M. Sutterlin ◽  
N. Sutterlin
Keyword(s):  
Amino Acids ◽  
Atlantic Salmon ◽  
Chain Length ◽  
Salmo Salar ◽  
Divalent Cations ◽  
Caproic Acid ◽  
Aliphatic Acid ◽  
Salmon Parr ◽  
Chloride Salts ◽  
Atlantic Salmon Parr

External receptors located in the snout region of Atlantic salmon parr are innervated by the facial nerve and are differentially sensitive to several chloride salts (NaCl = KCl > MgCl2 > CaCl2). They are also sensitive to mineral and organic acids but insensitive to uncharged molecules such as neutral amino acids and simple sugars.The palatine organ containing taste buds situated on the roof of the mouth is sensitive to strongly ionized as well as uncharged molecules.The two classes of receptors differ in temporal patterns of discharge and in their susceptibility to the blocking agents Hg++ and Pb++ and the potentiating agent Cu++.Salmon parr can detect Hg++ in concentrations lower than other divalent cations as judged electrophysiologically; food pellets treated with dilute solutions of Hg++ are rejected by the fish.As chain length increases in the aliphatic acid series the compounds become increasingly stimulatory as measured by nerve discharges in the palatine nerve.Inert carriers treated with aliphatic acids of increasing chain length become increasingly preferred by salmon, and carriers treated with valeric and caproic acid are ingested.Anosmic fish are capable of discriminating chemically treated carriers in a way similar to fish in which the olfactory organ is intact.The cellular nature of external receptors of the snout is uncertain; the possibility that they are neuromasts is discussed.

Sign in / Sign up

Export Citation Format

Share Document