Heart rate and swimming activity as stress indicators for Atlantic salmon (Salmo salar)

Adult Atlantic salmon (Salmo salar) were exposed for 48 h to water from acidified (pH 5.2) Fossbekk River (Norway), with and without 94 µg aluminium (Al)/L added as AlCl3, and to water from circumneutral (pH 6.7) Ims River (Norway) (controls). Cardiac output, heart rate, and stroke volume were monitored throughout the exposure period with Doppler flow probes placed around the ventral aorta of the fish. Fish exposed to Fossbekk River water without added Al showed few physiological disturbances. When 94 µg Al/L was added to Fossbekk River water, most of the fish died before the end of the 48-h exposure period, and a large elevation in heart rate was observed together with a decrease in plasma chloride concentrations and an increase in haematocrit, plasma glucose and plasma cortisol levels. Cardiac output was maintained at basal levels during the first 24 h of exposure because the tachycardia was accompanied by a concomitant reduction of stroke volume. Signs of arrhythmia appeared after 32 h of exposure and were associated with a further decrease in stroke volume that caused cardiac output to decrease below basal levels. The incapacity of the tachycardia to elevate cardiac output and the subsequent death of the fish suggest that this response to low pH and Al is more of a maladaptation reaction than a compensatory or adaptative reaction.

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Effects of Thyroid Hormones on Behavior of Yearling Atlantic Salmon (Salmo salar)

Journal of the Fisheries Research Board of Canada ◽

10.1139/f74-227 ◽

1974 ◽

Vol 31 (11) ◽

pp. 1787-1790 ◽

Cited By ~ 34

Author(s):

J.-G. Godin ◽

P. A. Dill ◽

D. E. Drury

Keyword(s):

Atlantic Salmon ◽

Thyroid Hormones ◽

Aggressive Behavior ◽

Salmo Salar ◽

Swimming Activity ◽

Control Fish ◽

Atlantic Salmon Salmo Salar

Swimming activity, aggressive behavior, and upstream orientation of yearling Atlantic salmon (Salmo salar) treated with 6.43 × 10−11 M thyroxine were significantly lower than those of control fish injected with solvent alone. Two concentrations of triiodothyronine (7.43 × 10−11 M; 7.43 × 10−10 M) caused similar but less pronounced effects.Because similar behavioral modifications accompany smolt migration, we hypothesize that thyroid hormones may play a role in arousing migratory tendencies in Atlantic salmon.

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Effect of Nitrite on the Embryonic Development of Atlantic Salmon (Salmo salar)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f89-218 ◽

1989 ◽

Vol 46 (10) ◽

pp. 1726-1729 ◽

Cited By ~ 12

Author(s):

E. M. Williams ◽

F. B. Eddy

Keyword(s):

Heart Rate ◽

Atlantic Salmon ◽

Salmo Salar ◽

Growth And Development ◽

Developmental Stages ◽

Cardiovascular Effects ◽

Environmental Implications ◽

Atlantic Salmon Salmo Salar ◽

Delayed Hatching

Effects of nitrite on eggs, alevins, and fry of Atlantic salmon (Salmo salar) were studied and of these developmental stages eggs were the most resistant with a 24-h LC50 value of 3276 mg∙L−1 N∙NO2. Upon hatching tolerance sharply decreased, the 24-h LC50 value for early alevins (2940 mg∙L−1 N∙NO2) decreasing to 121.8 mg∙L−1 N∙NO2. Development in freshwater or dilute saline (10 mmol∙L−1 NaCl) proceeded normally without mortalities. Long-term exposure to nitrite concentrations as low as 14 mg∙L−1 N∙NO2 delayed hatching and retarded embryo growth and development as well as producing cardiovascular effects such as a reduced heart rate. The physiological and environmental implications of nitrite exposure are discussed.

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Cardiac Responses to a Natural Odorant as Evidence of a Sensitive Period for Olfactory Imprinting in Young Atlantic Salmon, Salmo salar

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f89-016 ◽

1989 ◽

Vol 46 (1) ◽

pp. 122-130 ◽

Cited By ~ 35

Author(s):

Pierre-Philippe Morin ◽

Julian J. Dodson ◽

François Y. Doré

Keyword(s):

Heart Rate ◽

Atlantic Salmon ◽

Salmo Salar ◽

Age Groups ◽

Sensitive Period ◽

Age Group ◽

Olfactory Recognition ◽

Atlantic Salmon Salmo Salar ◽

Cardiac Responses ◽

Olfactory Imprinting

Olfactory imprinting was assessed in young Atlantic salmon, Salmo salar, undergoing smoltification (parr–smolt transition) by measuring their cardiac responses to a natural odorant, L-cysteine. Condition factor and body coloration were used for characterizing the degree of smoltification. In Experiment 1, heart rate conditioning to L-cysteine was used to compare olfactory learning between fish from different age groups of smoltification. In Experiments 2 and 3, other fish from the same age groups of smoltification were exposed to L-cysteine and their long-term olfactory memory was assessed by measuring their unconditioned cardiac responses to L-cysteine after smoltification. In Experiment 2, the time from the end of odor exposure to testing for olfactory recognition was kept constant for ail age groups of smoltification whereas in Experiment 3, the age of fish tested for olfactory recognition was kept constant. Greater conditioning (heart rate reduction) to L-cysteine occurred in age-groups 3 (612–619 d since birth) and 6 (642–649 d) as compared with any other age group of smoltification. Fish tested for odor recognition exhibited a greater unconditioned response (cardiac deceleration) to L-cysteine if they belonged to age-group 3 than to any other age group of smoltification. Our results demonstrated the existence of a sensitive period for olfactory imprinting in Atlantic salmon that occurred between 21 and 28 d after the onset of smoltification induced in the laboratory.

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