Oxygen consumption of adult Atlantic salmon (Salmo salar L.) males and females in fish culture

Weighted mean hourly rates of oxygen consumption in embryonated ova of Atlantic salmon, Salmo salar L., during embryogenesis, were reduced significantly by levels of dissolved oxygen below air saturation and by a temperature of 5 °C, relative to those for ova incubated at 10 °C. Total oxygen consumption during embryogenesis also was reduced significantly by the lower levels of dissolved oxygen, but not by temperature. The decrease in the pace of embryogenesis in the lots of ova at 5 °C extended the developmental time so that the lower rate of oxygen uptake was offset. Thus, within each level of dissolved oxygen there was no appreciable difference in the products of time units and units of oxygen uptake. At 5 °C, 100% air saturation, mean hourly uptake was 0.0141 mg O2/ovum, and total uptake was 28.153 mg O2/ovum. At 10 °C, 100% air saturation, these values were 0.0270 mg O2/ovum, and 27.974 mg O2/ovum, respectively. Values for ova incubated at 50 and 30% air saturation were correspondingly lower.

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Changes in Plasma T4 and T3 Levels during Reconditioning and Rematuration in Male and Female Wild Atlantic Salmon (Salmo salar) Kelts Held in Freshwater under Two Photoperiod Regimes

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f91-286 ◽

1991 ◽

Vol 48 (12) ◽

pp. 2443-2448 ◽

Cited By ~ 9

Author(s):

J. G. Eales ◽

D. G. Cyr ◽

K. Finnson ◽

C. E. Johnston

Keyword(s):

Plasma Level ◽

Atlantic Salmon ◽

Salmo Salar ◽

Early Spring ◽

Reproductive State ◽

Male And Female ◽

Atlantic Salmon Salmo Salar ◽

17Β Estradiol ◽

Males And Females ◽

Low Levels

The plasma level of L-thyroxine (T4) of wild reconditioned Atlantic salmon (Salmo salar) kelts held in freshwater at seasonal temperatures on a natural simulated photoperiod showed a robust seasonal profile with a marked peak in early spring followed by low levels throughout the summer. Plasma T4 was low in kelts that did not recondition and was uninfluenced by gender, eventual reproductive state, or imposition of a 6-mo compressed photocycle. The plasma 3,5,3′-triiodo-L-thyronine (T3) level also rose in spring in both males and females. In males and nonreproducing females, plasma T3 remained high during the growth phase in summer and decreased in fall and winter. Plasma T3 was very low in nonfeeding fish and showed some influence by the 6-mo compressed photocycle. Plasma T3 was particularly low in females at the time of vitellogenesis when 17β-estradiol was high. It is concluded that in reconditioned Atlantic salmon kelts, levels of plasma T4 and T3 appear to be controlled independently and that plasma T3 is more susceptible than T4 to vitellogenic state and other factors relating to metabolic demands.

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Activity, Respiration, and Excretion of Ammonia by Atlantic Salmon (Salmo salar) Smolt and Postsmolt

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f89-098 ◽

1989 ◽

Vol 46 (5) ◽

pp. 790-795 ◽

Cited By ~ 22

Author(s):

A. J. Wiggs ◽

E. B. Henderson ◽

R. L. Saunders ◽

M. N. Kutty

Keyword(s):

Oxygen Consumption ◽

Atlantic Salmon ◽

Spontaneous Activity ◽

Salmo Salar ◽

Condition Factor ◽

Ammonia Excretion ◽

Initial Increase ◽

Atlantic Salmon Salmo Salar ◽

Substantial Change ◽

Increased Activity

Spontaneous activity, oxygen consumption, and excretion of ammonia by juvenile Atlantic salmon (Salmo salar) were measured over 17 wk as the appearance of the fish changed from early smolt to smolt and then postsmolt. A substantial change in routine oxygen consumption from 66 to 148 mL∙kg−1∙h−1 was primarily correlated with the increase in activity. An initial increase in ammonia excretion from about 5 to about 14 mL∙kg−1∙h−1 was largely correlated with the decline in condition factor from 0.99 to 0.79 suggesting that increased metabolic needs caused by the increased activity were not being met by the amount of food ingested. This is supported by the secondary increase in condition factor (C.F. = 0.93) and decrease in ammonia excretion (to about 7 mg∙kg−1∙h−1) that occurred after the meal size was increased.

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