Salinity Preference, Thyroid Activity and the Seaward Migration of Four Species of Pacific Salmon (Oncorhynchus)

1960 ◽  
Vol 17 (3) ◽  
pp. 295-322 ◽  
Author(s):  
Bertha Baggerman
Keyword(s):  
Fresh Water ◽  
Sockeye Salmon ◽  
Pacific Salmon ◽  
Salt Water ◽  
Iodine Content ◽  
Day Length ◽  
Thyroid Activity ◽  
Seaward Migration ◽  
Salinity Preference ◽  
External Stimuli

In juvenile Pacific salmon the changes in salinity preference associated with seaward migration and thyroid activity were studied and used as criteria for the induction of the physiological condition required for migration (migration-disposition).Four species of Oncorhynchus (chum, pink, coho and sockeye) changed preference from fresh to salt water at the onset of seaward migration and maintained this preference throughout the migration season. At the end of this migration period coho and sockeye salmon changed preference from salt to fresh water if retained in fresh water, indicating a re-adaptation to this medium in which they may survive for several years. Chum and pink fry did not show this change in preference and usually died when retained in fresh water. They were apparently unable to re-adapt to this environment.The increasing day length in spring controls the time at which the change in preference from fresh to salt water takes place, and is thus involved in timing the induction of migration-disposition.The photoperiod seems to affect particularly the pituitary-thyroid system. Thyroid activity increases shortly before the onset of migration, remains high during the migration season, and decreases towards its end. The level of thyroid hormone in the blood influences salinity tolerance and preference and, thus, the induction of migration-disposition. Metamorphosis, osmotic "stress" and iodine content of the water may have some additional effect on thyroid activity, but are not the only factors responsible for thyroid hyperactivity during migration.Animals in which migration-disposition has been induced are thought to have become susceptible to appropriate external stimuli "releasing" migration.

VARIATIONS IN THE SODIUM AND POTASSIUM CONTENT OF THE MUSCLE TISSUE OF PACIFIC SALMON WITH PARTICULAR REFERENCE TO MIGRATION

1958 ◽  
Vol 36 (1) ◽  
pp. 1257-1268 ◽  
Author(s):  
Robert A. MacLeod ◽  
R. E. E. Jonas ◽  
J. R. McBride
Keyword(s):  
Fresh Water ◽  
Muscle Tissue ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Salt Water ◽  
Small Fish ◽  
Spawning Ground ◽  
Marked Rise ◽  
Mature Fish

Further confirmation was obtained of the observation made previously that the Na+ and K+ levels of the muscle tissue of spring salmon (Oncorhynchus tschawytscha) on the Pacific coast appear to vary with the size of the fish and, in the case of small fish, with the season of the year. Small fish (3 to 5 lb) caught in regions of relatively constant salinity had higher Na+ and lower K+ concentrations in the spring and summer than in fall and winter. Under the same conditions the levels of Na+ and K+ in the flesh of larger fish (9 to 10 lb) did not vary.When spring salmon were sampled along the route of their spawning migration up the Fraser River it was found that at the mouth of the river the Na+ level was less than in fish at sea. Further up the river, Na+ had dropped to less than one-half of the value at sea. At the spawning grounds in three groups out of four examined, Na+ rose again to levels the same as or above those prevailing at sea. In general, a drop in Na+ was accompanied by a rise in K+ and vice versa, though at the spawning ground the drop in K+ considerably exceeded the rise in Na+.In the case of sockeye salmon (Oncorhynchus nerka) heading up river, a lowered Na+ and elevated K+ occurred in the muscle tissue of the fish while they were still in salt water. After the fish had entered fresh water the ion levels were restored and maintained at levels similar to those normally prevailing at sea. At or near the spawning ground a marked rise in Na+ as well as a drop in K+ occurred. Evidence was obtained that this change occurred first in the male of the species.The flesh of juvenile coho salmon (Oncorhynchus kisutch) migrating to the sea was found to contain less Na+ and more K+ than mature fish of the same species caught at sea. Young sockeye in fresh water, however, contained about the same levels of Na+ and K+ as the mature fish at sea.

THE THYROID GLAND IN RELATION TO THE SEAWARD MIGRATION OF PACIFIC SALMON

1950 ◽  
Vol 28d (3) ◽  
pp. 126-136 ◽  
Author(s):  
William S. Hoar ◽  
G. Mary Bell
Keyword(s):  
Fresh Water ◽  
Chum Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
River Estuary ◽  
Salt Balance ◽  
Thyroid Activity ◽  
Salmon Fry ◽  
Thyroid Glands ◽  
Seaward Migration

Histological examination of the thyroid glands from chum salmon fry taken in the river, estuary, or sea shows the organ to be in a quiescent condition at the time of migration. If, however, this species is retained in fresh water for two or three months the gland becomes extremely hyperplastic. The pink salmon thyroid behaves in essentially the same way as that of the chum, but migrating pink fry taken at great distances from the sea have active glands. The thyroids of yearling coho and sockeye moving into the sea display heightened activity. Thyroid activity is apparently greater in coho migrants taken later in the season from the headwaters of rivers. In part, the heightened thyroid activity seen in these migrating Pacific salmon is probably a spring-time seasonal change. It seems, however, to be more particularly related to the increased metabolic work of osmotic regulation and salt balance in a fish physiologically prepared for life in the sea. In general, this study suggests that the increased thyroid activity seen in young migrating salmonoids is largely due to increased demands for thyroid hormone in the metabolism of a fish no longer completely adjusted physiologically to fresh water.

VARIATIONS IN THE SODIUM AND POTASSIUM CONTENT OF THE MUSCLE TISSUE OF PACIFIC SALMON WITH PARTICULAR REFERENCE TO MIGRATION

1958 ◽  
Vol 36 (12) ◽  
pp. 1257-1268 ◽  
Author(s):  
Robert A. MacLeod ◽  
R. E. E. Jonas ◽  
J. R. McBride
Keyword(s):  
Fresh Water ◽  
Muscle Tissue ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Salt Water ◽  
Small Fish ◽  
Spawning Ground ◽  
Marked Rise ◽  
Mature Fish

Further confirmation was obtained of the observation made previously that the Na+ and K+ levels of the muscle tissue of spring salmon (Oncorhynchus tschawytscha) on the Pacific coast appear to vary with the size of the fish and, in the case of small fish, with the season of the year. Small fish (3 to 5 lb) caught in regions of relatively constant salinity had higher Na+ and lower K+ concentrations in the spring and summer than in fall and winter. Under the same conditions the levels of Na+ and K+ in the flesh of larger fish (9 to 10 lb) did not vary.When spring salmon were sampled along the route of their spawning migration up the Fraser River it was found that at the mouth of the river the Na+ level was less than in fish at sea. Further up the river, Na+ had dropped to less than one-half of the value at sea. At the spawning grounds in three groups out of four examined, Na+ rose again to levels the same as or above those prevailing at sea. In general, a drop in Na+ was accompanied by a rise in K+ and vice versa, though at the spawning ground the drop in K+ considerably exceeded the rise in Na+.In the case of sockeye salmon (Oncorhynchus nerka) heading up river, a lowered Na+ and elevated K+ occurred in the muscle tissue of the fish while they were still in salt water. After the fish had entered fresh water the ion levels were restored and maintained at levels similar to those normally prevailing at sea. At or near the spawning ground a marked rise in Na+ as well as a drop in K+ occurred. Evidence was obtained that this change occurred first in the male of the species.The flesh of juvenile coho salmon (Oncorhynchus kisutch) migrating to the sea was found to contain less Na+ and more K+ than mature fish of the same species caught at sea. Young sockeye in fresh water, however, contained about the same levels of Na+ and K+ as the mature fish at sea.

Salinity Preference: an Orientation Mechanism in Salmon Migration

1964 ◽  
Vol 21 (5) ◽  
pp. 995-1018 ◽  
Author(s):  
John E. McInerney
Keyword(s):  
Fresh Water ◽  
Pacific Salmon ◽  
Temporal Changes ◽  
Open Ocean ◽  
Salinity Gradients ◽  
Seaward Migration ◽  
Salinity Preference ◽  
Juvenile Pacific Salmon ◽  
Orientation Mechanism ◽  
Seawater Concentration

An examination of the modal salinity preferences of five Pacific salmon species showed the following pattern of temporal changes. The sequence began with a preference for fresh water, then changed gradually, in the direction of increasing seawater concentration. The terminal pattern indicated a preference for water of open ocean concentration. This temporal progression of salinity preference changes was shown to parallel closely the salinity gradients typical of river outflows through which young salmon pass on their way to the ocean. On the basis of this evidence the following orientation mechanism was proposed: that juvenile Pacific salmon are able to use estuarial salinity gradients as one of the directive cues in their seaward migration.

scholarly journals Evidence for Freshwater Residualism in Coho Salmon, Oncorhynchus kisutch, From a Watershed on the North Coast of British Columbia

2017 ◽  
Vol 130 (4) ◽  
pp. 336 ◽  
Author(s):  
Eric A Parkinson ◽  
Chris J Perrin ◽  
Daniel Ramos-Espinoza ◽  
Eric B Taylor
Keyword(s):  
British Columbia ◽  
Fresh Water ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Water Levels ◽  
North Coast ◽  
The North ◽  
Seaward Migration ◽  
Mature Fish

The Coho Salmon, Oncorhynchus kisutch, is one of seven species of Pacific salmon and trout native to northeastern Pacific Ocean watersheds. The species is typically anadromous; adults reproduce in fresh water where juveniles reside for 1–2 years before seaward migration after which the majority of growth occurs in the ocean before maturation at 2–4 years old when adults return to fresh water to spawn. Here, we report maturation of Coho Salmon in two freshwater lakes on the north coast of British Columbia apparently without their being to sea. A total of 15 mature fish (11 males and four females) were collected in two lakes across two years. The mature fish were all at least 29 cm in total length and ranged in age from three to five years old. The occurrence of Coho Salmon that have matured in fresh water without first going to sea is exceedingly rare in their natural range, especially for females. Such mature Coho Salmon may represent residual and distinct breeding populations from those in adjacent streams. Alternatively, they may result from the ephemeral restriction in the opportunity to migrate seaward owing to low water levels in the spring when Coho Salmon typically migrate to sea after 1–2 years in fresh water. Regardless of their origin, the ability to mature in fresh water without seaward migration may represent important adaptive life history plasticity in response to variable environments.

THE EFFECT OF TSH AND ANTITHYROID SUBSTANCES ON SALINITY PREFERENCE AND THYROID ACTIVITY IN JUVENILE PACIFIC SALMON

1963 ◽  
Vol 41 (2) ◽  
pp. 307-319 ◽  
Author(s):  
Bertha Baggerman
Keyword(s):  
Thyroid Gland ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Secretory Activity ◽  
Conversion Ratio ◽  
Sodium Thiocyanate ◽  
Thyroid Activity ◽  
Salinity Preference ◽  
Juvenile Pacific Salmon

Underyearling coho salmon treated with TSH showed a change from fresh- to saltwater preference, which was correlated with an increase in thyroid activity (as measured by the amount of radioiodine taken up by the gland and the conversion ratio).Under-yearling pink salmon treated with thiourea showed a change from salt-to freshwater preference, which was accompanied by a decrease in thyroid activity. In this species treatment with thiouracil and sodium thiocyanate also induced a change from salt- to freshwater preference.It is concluded that the secretory activity of the thyroid gland is intimately involved in the induction of changes in salinity preference, which, in their turn, are closely associated with the onset and end of the migration season.

Influence of Photoperiod on Smolt Development and Growth of Atlantic Salmon (Salmo solar)

1970 ◽  
Vol 27 (7) ◽  
pp. 1295-1311 ◽  
Author(s):  
Richard L. Saunders ◽  
Eugene B. Henderson
Keyword(s):  
Atlantic Salmon ◽  
Sea Water ◽  
Endocrine System ◽  
Growth Patterns ◽  
Day Length ◽  
Thyroid Activity ◽  
Thyroid Glands ◽  
Before And After ◽  
Natural Photoperiod ◽  
External Stimuli

Atlantic salmon (Salmo salar) subjected in the spring to a constant photoperiod of 13 hr light/day or to simulated natural photoperiod (increasing day length) smoltified and grew rapidly before and after entering sea water. Others subjected to the reciprocal (complement) of natural photoperiod (decreasing day length in the spring) had the silvery color of smolts and grew rapidly but, unlike smolts, developed high condition factors while in fresh water. After they were transferred to sea water these fish ate less, grew more slowly, and had lower efficiencies of food conversion than those subjected to natural and constant photoperiod.Salmon experiencing reciprocal photoperiod had decreased sensitivity to external stimuli, suggesting reduced thyroid activity. Histological studies in June showed no differences in the appearance of the thyroid glands, suggesting no difference in thyroid activity between groups in natural and reciprocal photoperiod. Nor was there any difference in plasma osmotic and chloride levels between natural and reciprocal photoperiod groups, either in routinely active or fatigued fish.It is suggested that photoperiod acts through the endocrine system to affect growth patterns during and after smoking and possibly certain aspects of the smolting process itself. Effects of photoperiod on smolting and growth of salmon are discussed in connection with other cyclical changes in salmonid physiology known to be influenced by photoperiod.

Review of the Rate of Growth and Mortality of Pacific Salmon in Salt Water, and Noncatch Mortality Caused by Fishing

1976 ◽  
Vol 33 (7) ◽  
pp. 1483-1524 ◽  
Author(s):  
W. E. Ricker
Keyword(s):  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Salt Water ◽  
Pink Salmon ◽  
Total Yield ◽  
Coastal Region ◽  
Natural Mortality ◽  
Time Of Year

Mortality (other than landed catch) caused by pelagic gillnetting is estimated to be equal to the catch, for salmon in their penultimate year of life, and equal to about a quarter of the catch for salmon in their final year of life. Mortality caused by trolling for coho (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) averages about one fish killed (mostly below legal size) for every two that are boated. The natural mortality rate for sockeye salmon (O. nerka) in their final year of life averages about 0.015 per mo and is somewhat more in earlier years of pelagic life; the greater part of natural mortality after the smolt stage occurs during the downstream migration and early months of "coastal" life. For coho and chinook the best natural mortality estimate for the last year of life is 0.013 per mo, and that for pink (O. gorbuscha) and chum (O. keta) is of the same order. Growth rates during the final growing season vary from 0.26 per mo for pink and coho salmon to 0.06 per mo for chinook in their 5th ocean yr. Gains from ceasing to take immature salmon on the high seas range up to 300% of the catch now being taken in that category, while for fish taken in their final year they range up to about 70%, depending on the time of year at which the fishing is done. Gains from transferring existing pelagic net fisheries to the coastal region would be 76% (North American sockeye) and 86% (Asian sockeye) of the weight of fish now caught pelagically. Gains in total yield of existing salmon fisheries (pelagic and coastal) are estimated as 78% for Asian pink salmon and 72% for Asian sockeye. The increase in weight of the total catch from discontinuing ocean trolling for Columbia River chinook salmon and increasing river fishing correspondingly is estimated tentatively as between 63 and 98%.

Survival of certain naturally acquired freshwater parasites of juvenile sockeye salmon, Oncorhynchus nerka (Walbaum), in hosts held in fresh and sea water, and implications for their use as population tags

1989 ◽  
Vol 67 (7) ◽  
pp. 1757-1766 ◽  
Author(s):  
R. E. Bailey ◽  
L. Margolis ◽  
G. D. Workman
Keyword(s):  
British Columbia ◽  
Fresh Water ◽  
Water Samples ◽  
Sockeye Salmon ◽  
Sea Water ◽  
Salt Water ◽  
Oncorhynchus Nerka ◽  
The Other ◽  
Maximum Life Span ◽  
Natural Tags

Sockeye salmon (Oncorhynchus nerka) smolts were captured from the outlet streams of Cultus Lake, British Columbia, in 1985 and 1986, and from Fraser Lake, British Columbia, in 1986. Samples collected in 1985 were reared in salt water. Samples collected from each lake in 1986 were divided equally into two groups: one group was reared in fresh water, the other was maintained in salt water. Initially biweekly, and later monthly, subsamples from each group were examined for seven parasite taxa: Myxidium salvelini, Diplostomulum sp. metacercaria, Phyllodistomum umblae, Eubothrium sp. (immature), Proteocephalus sp. (immature), Neoechinorhynchus salmonis, and Salmincola californiensis. The maximum life-span was greater than the duration of the experiments (32–40 weeks) for all species in hosts reared in fresh water (except for S. californiensis, which was removed from all freshwater hosts). Survival of M. salvelini, P. umblae, and S. californiensis was reduced in hosts reared in sea water. No differences in survival of each of Diplostomulum sp. metacercaria, Eubothrium sp., Proteocephalus sp., and N. salmonis were observed between hosts held in fresh water or salt water. Implications for the use of these parasites as natural tags are discussed.

scholarly journals XII. An easy method to distill fresh water from salt water at sea; by Capt. Newland

1772 ◽  
Vol 62 ◽  
pp. 90-92 ◽  
Keyword(s):  
Fresh Water ◽  
Salt Water ◽  
Easy Method

The materials necessary for this process are the following; a copper or iron pot of 15 or 20 gallons, an empty cask, some sheet lead, a small jar, a few wood-ashes or soap, and billet-wood for fewel.

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