Reverse migration of adult pink salmon (Oncorhynchus gorbuscha) to the sea after their return to fresh water

2021 ◽  
Author(s):  
Kentaro Morita
Keyword(s):  
Fresh Water ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Reverse Migration

THE EFFECT OF PRUDHOE BAY CRUDE OIL ON SURVIVAL AND GROWTH OF EGGS, ALEVINS, AND FRY OF PINK SALMON, ONCORHYNCHUS GORBUSCHA

1975 ◽  
Vol 1975 (1) ◽  
pp. 503-507 ◽  
Author(s):  
Stanley D. Rice ◽  
D. Adam Moles ◽  
Jeffrey W. Short
Keyword(s):  
Fresh Water ◽  
Oil Pollution ◽  
Life Stage ◽  
Pink Salmon ◽  
Water Soluble ◽  
Subsurface Water ◽  
Oncorhynchus Gorbuscha ◽  
Life Stages ◽  
Infrared Spectrophotometry ◽  
Pink Salmon Oncorhynchus Gorbuscha

ABSTRACT Standard 96-hour bioassays with “total” oil solutions in fresh water and seawater determined differences in sensitivity of the developing life stages of pink salmon (Oncorhynchus gorbuscha). Eggs were the most resistant and emergent fry (yolk sac absorbed) the most sensitive to acute 4-day exposures. In fresh water, the 96-hour median tolerance limit (TLm) of fry was 0.4 ml oil/liter mixed mechanically (12 ppm as measured in subsurface water by infrared spectrophotometry). In seawater, it was 0.04 ml oil/liter mixed mechanically (6 ppm as measured in subsurface water by infrared spectrophotometry). Three life stages of alevins were exposed to 10-day sublethal exposures of the water-soluble fraction to determine what doses might affect growth. Growth was affected most severely in alevins exposed during later developmental stages. Decreased growth was observed in fry after 10-day exposures at the lowest dose tested–0.015 ml oil/liter mixed by water agitation (0.73 ppm in subsurface water by infrared spectrophotometry–less than 10% of the 96-hour TLm limit for that life stage). In fresh water, susceptibility of early life history stages of pink salmon to oil pollution is great at the time of emergence (completion of yolk absorption). Susceptibility is even greater in seawater after fry migration.

A novel pattern of smoltification in the most anadromous salmonid: pink salmon (Oncorhynchus gorbuscha)

2013 ◽  
Vol 70 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Z.S. Gallagher ◽  
J.S. Bystriansky ◽  
A.P. Farrell ◽  
C.J. Brauner
Keyword(s):  
Fresh Water ◽  
Salinity Tolerance ◽  
Pink Salmon ◽  
Yolk Sac ◽  
Whole Body ◽  
Oncorhynchus Gorbuscha ◽  
Two Stage ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
First Time ◽  
Osmoregulatory Ability

Pink salmon (Oncorhynchus gorbuscha) enter seawater earlier and smaller (0.2 g) than any other salmonid following a two-stage salinity tolerance process initiated around yolk-sac absorption and completed with seawater entry. For the first time, this two-stage ontogeny of salinity tolerance was characterized by either holding posthatch pink salmon in fresh water or transferring them to seawater every 2 weeks. A window of salinity tolerance around yolk-sac absorption was evidenced by a period of zero morbidity in seawater compared with 100% morbidity for newly hatched alevins and 25% morbidity for fry (∼0.2–0.3 g). Increased hypo-osmoregulatory ability at the time of yolk-sac absorption was indicated in fish held in fresh water under constant photoperiod (12 h light : 12 h dark) and temperature (5 °C) by a switch from catabolic to anabolic growth, increased gill Na+K+-ATPase activity and α-1b/α-1a isoform expression, and a plateau in whole-body water content, implying that pink salmon go through a form of smoltification. A large increase in whole-body [Na+] observed in fresh water at yolk-sac absorption may represent a unique strategy for maintaining water balance once fish enter seawater.

Supplementary Checks on the Scales of Pink Salmon (Oncorhynchus gorbuscha) and Chum Salmon (O. keta)

1965 ◽  
Vol 22 (6) ◽  
pp. 1477-1489 ◽  
Author(s):  
H. T. Bilton ◽  
W. E. Ricker
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Commercial Fisheries ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Clear Cut ◽  
Second Year Of Life ◽  
Second Year ◽  
Similar Incidence

Among 159 central British Columbia pink salmon that had been marked by removal of two fins as fry and had been recovered in commercial fisheries after one winter in the sea, the scales of about one-third showed a supplementary or "false" check near the centre of the scale, in addition to the single clear-cut annulus. This evidence from fish of known age confirms the prevailing opinion that such extra checks do not represent annuli, hence that the fish bearing them are in their second year of life rather than their third. Unmarked pink salmon from the same area, and some from southern British Columbia, had a generally similar incidence of supplementary checks. In both marked and unmarked fish the supplementary checks varied in distinctness from faint to quite clear. In a sample of scales of 14 double-fin marked chum salmon which were known to be in their 4th year, all fish had the expected 3 annuli, and 12 fish had a supplementary check inside the first annulus.

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