Diet, feeding patterns, and prey selection of subyearling Atlantic salmon (Salmo salar
) and subyearling chinook salmon (Oncorhynchus tshawytscha
) in a tributary of Lake Ontario

Heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar) was first diagnosed in Norway in 1999. The disease is caused by Piscine orthoreovirus-1 (PRV-1). The virus is prevalent in farmed Atlantic salmon, but not always associated with disease. Phylogeny and sequence analyses of 31 PRV-1 genomes collected over a 30-year period from fish with or without HSMI, grouped the viral sequences into two main monophylogenetic clusters, one associated with HSMI and the other with low virulent PRV-1 isolates. A PRV-1 strain from Norway sampled in 1988, a decade before the emergence of HSMI, grouped with the low virulent HSMI cluster. The two distinct monophylogenetic clusters were particularly evident for segments S1 and M2. Only a limited number of amino acids were unique to the association with HSMI, and they all located to S1 and M2 encoded proteins. The observed co-evolution of the S1-M2 pair coincided in time with the emergence of HSMI in Norway, and may have evolved through accumulation of mutations and/or segment reassortment. Sequences of S1-M2 suggest selection of the HSMI associated pair, and that this segment pair has remained almost unchanged in Norwegian salmon aquaculture since 1997. PRV-1 strains from the North American Pacific Coast and Faroe Islands have not undergone this evolution, and are more closely related to the PRV-1 precursor strains not associated with clinical HSMI.

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Temperature Selection of Juvenile Atlantic Salmon (Salmo salar) as Influenced by Various Toxic Substances

Journal of the Fisheries Research Board of Canada ◽

10.1139/f76-219 ◽

1976 ◽

Vol 33 (8) ◽

pp. 1722-1730 ◽

Cited By ~ 17

Author(s):

R. H. Peterson

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Toxic Substances ◽

Term Survival ◽

Preferred Temperature ◽

Atlantic Salmon Salmo Salar ◽

Juvenile Atlantic Salmon ◽

Sodium Pentachlorophenate ◽

Selection Of ◽

Short Term Survival

Previous exposure to sodium pentachlorophenate (NaPCP), Guthion®, malathion, Dursban®, and Dibrom® lowered the preferred temperature for juvenile Atlantic salmon (Salmo salar) tested in a horizontal temperature gradient. Lindane, CuSO4, ZnSO4, CdSO4, Sevin®, heptachlor, and fenitrothion did not change the preferred temperature significantly. Comparison with other published results indicates that those substances that increase the preferred temperature are more toxic (based on relevant changes in 24-h LC50) at low temperatures and vice versa. It is suggested that such shifts in selected temperature may be of potential immediate, short-term, survival value to the fish.

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Selection of Microhabitat in Summer by Juvenile Atlantic Salmon (Salmo salar)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f87-015 ◽

1987 ◽

Vol 44 (1) ◽

pp. 120-129 ◽

Cited By ~ 105

Author(s):

D. L. Morantz ◽

R. K. Sweeney ◽

C. S. Shirvell ◽

D. A. Longard

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

The Body ◽

Flow Conditions ◽

Atlantic Salmon Salmo Salar ◽

Juvenile Atlantic Salmon ◽

Salmon Fry ◽

Study Sites ◽

Selection Of ◽

Atlantic Salmon Parr

This study was designed to define the microhabitats selected in summer by juvenile Atlantic salmon (Salmo salar). Curves were developed describing the preference of 880 young salmon for water velocity at the fish's position (nose velocity), mean water column velocity, total water depth, and stream substrate size. Study sites were chosen in six morphologically diverse streams in Nova Scotia and New Brunswick during 1982–84. Of the four variables measured, only nose velocity chosen by both fry and parr was not significantly different among years or rivers. Atlantic salmon fry (< 65 mm) most frequently selected nose velocities between 5 and 15 cm∙s−1, small parr (65–100 mm) between 5 and 25 cm∙s−1 and large parr (> 100 mm) between 5 and 35 cm∙s−1. Apparently, juvenile salmon utilized water depths and stream substrates which varied within tolerable limits according to their availability in conjunction with preferred water velocities. Significant differences in the body shape and size of the pectoral fin of Atlantic salmon parr in different rivers did not influence the selection of nose velocities within the range of flow conditions sampled.

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