Mating between anadromous and nonanadromous Atlantic salmon, Salmo salar

1985 ◽  
Vol 63 (9) ◽  
pp. 2219-2221 ◽  
Author(s):  
J. A. Hutchings ◽  
R. A. Myers
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Phenotypic Variation ◽  
The Other ◽  
Atlantic Salmon Salmo Salar ◽  
Isolating Mechanisms

Mating experiments were conducted to determine whether behavioural isolating mechanisms exist that would prevent interbreeding between anadromous and nonanadromous Atlantic salmon, Salmo salar. Males of both forms attempted to stimulate females of the other form to spawn and females responded by digging redds, spawning, and covering redds. Viable eggs were produced in both cases. These forms probably represent within-population phenotypic variation where they co-occur. Interbreeding can be expected if anadromous salmon are introduced into areas formerly occupied only by the nonanadromous form.

Genetically distinct sympatric populations of resident and anadromous Atlantic salmon, Salmo salar

1989 ◽  
Vol 67 (6) ◽  
pp. 1453-1461 ◽  
Author(s):  
E. Verspoor ◽  
L. J. Cole
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
River System ◽  
Population Variation ◽  
The Other ◽  
Gene Pools ◽  
Sympatric Populations ◽  
Polymorphic Loci ◽  
Atlantic Salmon Salmo Salar

Atlantic salmon (Salmo salar) from Little Gull Lake on the Gander River system of central Newfoundland were found to be electrophoretically polymorphic at 5 of 20 protein loci screened. Four of the polymorphic loci were structural and one was regulatory. Major heterozygote deficiencies relative to Castle–Hardy–Weinberg expectations were detected at the two most polymorphic loci, Aat-3 and Mdh-3,4, and significant nonrandom associations between genotypes at these loci and the other polymorphic loci, Sdh-1, Me-2, and Pgm1-t, were also found. The heterozygote deficiencies and the nonrandom genotype associations were attributable to the admixture of genetically distinct gene pools of resident and anadromous salmon in the lake. This is the first documented case of coexistence of reproductively separated populations of Atlantic salmon of the two life history types, and shows that the sympatric occurrence of the two forms can represent between-population variation.

Effects of Environmental pH on the Hepatic Mixed Function Oxidases in Atlantic Salmon (Salmo salar)

1991 ◽  
Vol 48 (3) ◽  
pp. 445-447 ◽  
Author(s):  
Douglas E. Willis ◽  
Allison J. Edwards ◽  
Richard F. Addison
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Cytochromes P450 ◽  
Microsomal Protein ◽  
The Other ◽  
Monooxygenase System ◽  
Atlantic Salmon Salmo Salar ◽  
Body Weights ◽  
Hepatic Monooxygenase ◽  
Pyrene Hydroxylase

Atlantic salmon (Salmo salar) were held for some months in the Medway River, N.S., at pH 5.2–5.5 and in the Westfield River, N.S., in either untreated ("acidic") water at pH 4.7–5.2 or limed water at pH 51.–5.9 and were examined for effects on hepatic monooxygenases. Fish from the Westfield'acidic regime had lower body weights than those from the other two regimes, but similar liver weights. Females generally had higher hepatic microsomal protein contents than males, but this variable was not affected by environmental pH. Westfield acidic fish usually had higher benzo[a]pyrene hydroxylase and lower ethoxyresorufin O-deethylase activity than those from the other two regimes. Cytochromes P450 and b5 showed no clear difference between groups. Although the different pH environments affected reproductive success and steroid hormone metabolism, such changes were not reflected in these components of the hepatic monooxygenase system.

Parasites as Potential Biological Tags of Atlantic Salmon (Salmo salar) smolts in the Miramichi River System, New Brunswick

1976 ◽  
Vol 33 (5) ◽  
pp. 1139-1143 ◽  
Author(s):  
G.M. Hare ◽  
M. D. B. Burt
Keyword(s):  
Atlantic Salmon ◽  
New Brunswick ◽  
Salmo Salar ◽  
Parasite Species ◽  
River System ◽  
The Other ◽  
Atlantic Salmon Salmo Salar ◽  
Diplostomum Spathaceum ◽  
Biological Tags

Ten parasite species (one protozoan, eight helminth, one mollusc) were collected from 1262 smolts of Atlantic salmon (Salmo salar) in the eight tributaries and estuary of the Miramichi River, New Brunswick, Canada during 1970 and 1971. Three of these parasites, Discocotyle sagittata, Diplostomum spathaceum, and Neoechinorhynchus rutili showed restricted distributions within the study area. Discocotyle sagittata infected 32.6% of 435 smolts collected from tributaries draining into the Main Northwest Miramichi River but only 0.3% of 604 smolts collected from tributaries draining into the Main Southwest Miramichi River. Diplostomum spathaceum infected 18.9% of 148 smolts collected from the Southwest Miramichi River but was absent in 819 smolts collected from the remaining tributaries. Neoechinorhynchus rutili infected 18.8% of 144 smolts collected from the Bartholomew River but only 0.2% of 895 smolts collected from the other tributaries. Presence of Discocotyle sagittata on smolts collected in the estuary of the Miramichi River would identify smolts that originated in the Main Northwest Miramichi River, thus allowing for a separation of smolts from this branch and the other main branch, the Main Southwest Miramichi River. Presence of Diplostomum spathaceum in smolts collected in the Main Southwest Miramichi River or in the estuary of the Miramichi River would identify smolts that originated in the Southwest Miramichi River. Presence of N. rutili in smolts collected in the Main Southwest Miramichi River would identify smolts of Bartholomew River origin.

Selection by Brook Trout (Salvelinus fontinalis) and Juvenile Atlantic Salmon (Salmo salar) of Shade Related to Water Depth

1975 ◽  
Vol 32 (9) ◽  
pp. 1652-1656 ◽  
Author(s):  
R. John Gibson ◽  
G. Power
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Water Depth ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
The Other ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Selection For ◽  
Salmon Parr

Salmon parr and small brook trout were observed in two stream tanks providing choices of cover. One tank was shallow (24–29 cm) and the other deep (43–50 cm). In the shallow tank brook trout occurred most frequently in shade. When salmon were the sole species, they were most frequently in shade, but were mostly away from shade in the presence of trout. This selection for shade was not evident by either species in the deep tank.

Effects of Constant Day Length on Sexual Maturation and Growth of Atlantic Salmon (Salmo salar) Parr

1988 ◽  
Vol 45 (1) ◽  
pp. 60-64 ◽  
Author(s):  
R. L. Saunders ◽  
E. B. Henderson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Seasonal Changes ◽  
The Other ◽  
Day Length ◽  
Length Frequency ◽  
Frequency Distributions ◽  
Atlantic Salmon Salmo Salar ◽  
First Feeding ◽  
Sexually Mature

Atlantic salmon (Salmo salar) were reared for 6 mo from first feeding under four photoperiod regimes: LD 12:12, LD 16:8, LD 24:0, and simulated natural (LDN). Water temperature followed seasonal changes but was adjusted so as not to exceed 16 °C in summer or to fall below 6 °C in winter. Growth rates were highest in the LD 24:0 group during the first 3 mo; subsequently, the LD 16:8 fish grew faster than all others. Length–frequency distributions were skewed towards smaller sized fish in January. Sexually mature males were mainly in the lower halves of the length–frequency distributions; females and immature males were distributed throughout. The incidence of mature males was highest in the LDN group (67% of males) but reached high levels (44–58%) in the other groups.

Microstructure and texture of fresh and smoked Atlantic salmon, Salmo salar L., fillets from fish reared and slaughtered under different conditions

2001 ◽  
Vol 32 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sjofn Sigurgisladottir ◽  
Margret S. Sigurdardottir ◽  
Helga Ingvarsdottir ◽  
Ole J. Torrissen ◽  
Hannes Hafsteinsson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar

Persistence of Orally Administered Salmonella enterica Serovars Agona and Montevideo in Atlantic Salmon (Salmo salar L.)

2005 ◽  
Vol 68 (7) ◽  
pp. 1336-1339 ◽  
Author(s):  
L. L. NESSE ◽  
T. LØVOLD ◽  
B. BERGSJØ ◽  
K. NORDBY ◽  
C. WALLACE ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Salmonella Enterica ◽  
Most Probable Number ◽  
Fish Feed ◽  
Internal Organs ◽  
Probable Number ◽  
Atlantic Salmon Salmo Salar ◽  
Gastric Intubation

The objective of our experiments was to study the persistence and dissemination of orally administered Salmonella in smoltified Atlantic salmon. In experiment 1, salmon kept at 15°C were fed for 1 week with feed contaminated with 96 most-probable-number units of Salmonella Agona per 100 g of feed and then starved for 2 weeks. Samples were taken from the gastrointestinal tract and examined for Salmonella 1, 2, 8, 9, 15, and 16 days after the feeding ended. In experiment 2, Salmonella Agona and Montevideo were separately mixed with feed and administered by gastric intubation. Each fish received 1.0 × 108, 1.0 × 106, or 1.0 × 104 CFU. The different groups were kept in parallel at 5 and 15°C and observed for 4 weeks. Every week, three fish in each group were sacrificed, and samples were taken from the skin, the pooled internal organs, the muscle, and the gastrointestinal tract and examined for the presence of Salmonella. The results from the two experiments showed that the persistence of Salmonella in the fish was highly dependent on the dose administered. Salmonella was not recovered from any of the fish that were fed for 1 week with the lowest concentration of Salmonella. In the fish given the highest dose of Salmonella, bacteria persisted for at least 4 weeks in the gastrointestinal tract as well as, to some extent, the internal organs. The present study shows that under practical conditions in Norway, the risk of Salmonella in fish feed being passed on to the consumer of the fish is negligible.

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