Sex ratio control in pink salmon (Oncorhynchus gorbuscha and chum salmon (O. keta) populations: The possible causes and mechanisms of changes in the sex ratio

2008 ◽  
Vol 44 (7) ◽  
pp. 786-792 ◽  
Author(s):  
Vl. A. Brykov ◽  
A. D. Kukhlevsky ◽  
E. A. Shevlyakov ◽  
N. M. Kinas ◽  
L. O. Zavarina
Keyword(s):  
Sex Ratio ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha

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.

Results for Three Generations from Transfers of Pink Salmon (Oncorhynchus gorbuscha) Spawn to the Qualicum River in 1963 and 1964

1971 ◽  
Vol 28 (5) ◽  
pp. 647-654 ◽  
Author(s):  
C. E. Walker ◽  
D. B. Lister
Keyword(s):  
Chum Salmon ◽  
Pink Salmon ◽  
Stream Temperature ◽  
Rate Of Return ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Three Generations ◽  
Salmon Eggs ◽  
Bear River

Transfers of pink salmon (Oncorhynchus gorbuscha) eggs were made to the Qualicum River in two years, utilizing 5.79 million eggs from Cheakamus River stock in 1963 and 6.85 million eggs from Bear River stock in 1964. Adult returns to the Qualicum River were 100 spawners in 1965, 1967, and 1969; 11,940 in 1966; 3000 in 1968; and 300 in 1970. Differences between the odd- and even-year plants were noted in times of egg-take (equivalent to time of spawning of donor stock), incubation, and fry emigration, lengths of emigrating fry, possibility of losses through predation by herring on estuarine fry, and direction of orientation to the recipient (Qualicum River) stream. Pronounced differences between donor stock in rate of return are thought to be primarily related to differences in spawning times and stream temperature. The decrease in numbers of adults in the even-year generation may have been due to lower freshwater survival during incubation as a result of suspected superimposition of chum salmon on the earlier deposited pink salmon eggs; the loss was estimated to be in the order of 46%.

Species Selective Predation on Juvenile Pink (Oncorhynchus gorbuscha) and Chum Salmon (O. keta) by Coho Salmon (O. kisutch)

1985 ◽  
Vol 42 (4) ◽  
pp. 659-668 ◽  
Author(s):  
N. Brent Hargreaves ◽  
Robin J. Lebrasseur
Keyword(s):  
Chum Salmon ◽  
Prey Species ◽  
Coho Salmon ◽  
Prey Size ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Selective Predation ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Mixed Populations

Predation on juvenile pink salmon (Oncorhynchus gorbuscha) and chum salmon (O. keta) by yearling coho (O. kisutch) was studied in marine enclosures in Masset Inlet, B.C. These experiments demonstrate that coho prey selectively upon pink salmon even when chums are both significantly smaller and more abundant than pink salmon. Reexamination of the results of similar experiments conducted in Burke Channel, B.C., also confirms that mortality was biased towards pink salmon. Prey species may be more important than prey size for coho that prey upon mixed populations of pink and chum salmon during early sea-life.

Effects of salmon on the diet and condition of stream-resident sculpins

2014 ◽  
Vol 71 (4) ◽  
pp. 521-532 ◽  
Author(s):  
Noel R. Swain ◽  
Morgan D. Hocking ◽  
Jennifer N. Harding ◽  
John D. Reynolds
Keyword(s):  
Chum Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
Nitrogen Stable Isotope ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Carbon And Nitrogen ◽  
Stable Isotope Signatures ◽  
The Individual

Pacific salmon (Oncorhynchus spp.) can subsidize freshwater food webs with marine-derived nutrients from their eggs, juveniles, and carcasses. However, trophic interactions between spawning salmon and freshwater fish across natural gradients in salmon subsidies remain unclear. We tested how salmon affected the diets and condition of two dominant freshwater consumers — prickly and coastrange sculpins (Cottus asper and Cottus aleuticus, respectively) — across a wide gradient of pink salmon (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) biomass from 33 streams in the Great Bear Rainforest of British Columbia, Canada. Sculpin diets shifted from invertebrates and juvenile salmonids to salmon eggs when salmon arrived in autumn, with salmon-derived nutrient contributions to diets and sculpin condition increasing with increasing biomass of spawning salmon among streams. Season, habitat, and individual sculpin body size and species also mediated the effects of salmon on sculpin diet as inferred from their carbon and nitrogen stable isotope signatures. This study shows the timing and pathways by which spawning salmon influence the diets and condition of freshwater consumers, and some of the individual and environmental factors that can regulate uptake of salmon nutrients in streams, thus informing ecosystem-based management.

Developmental stability and heterozygosity in chum (Oncorhynchus keta) and pink (Oncorhynchus gorbuscha) salmon

1987 ◽  
Vol 65 (7) ◽  
pp. 1823-1826 ◽  
Author(s):  
T. D. Beacham ◽  
R. E. Withler
Keyword(s):  
Fluctuating Asymmetry ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Morphological Characters ◽  
Developmental Stability ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Gill Raker ◽  
Fin Length

We compared developmental stability as measured by fluctuating asymmetry within individual adults for gill raker and branchiostegal ray number and pectoral and pelvic fin length for three populations of chum salmon (Oncorhynchus keta) and one of pink salmon (Oncorhynchus gorbuscha). There was no association between individual heterozygosity calculated at 10 electrophoretic loci for chum salmon and 13 loci for pink salmon and magnitude of fluctuating asymmetry for the four morphological characters examined. More heterozygous individuals were not less asymmetrical, and thus our results provide no evidence to suggest that increased heterozygosity results in an increased canalization of morphology during development and growth.

Variation in Length and Body Depth of Pink Salmon (Oncorhynchus gorbuscha) and Chum Salmon (O. keta) in Southern British Columbia

1985 ◽  
Vol 42 (2) ◽  
pp. 312-319 ◽  
Author(s):  
Terry D. Beacham ◽  
Clyde B. Murray
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Body Depth ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Gain Access

The magnitude of within-stock variability of postorbital–hypural length and body depth was investigated for spawning pink salmon (Oncorhynchus gorbuscha) and chum salmon (O. keta) stocks. Variability of postorbital–hypural length and body depth of male pink salmon, all maturing at 2 yr of age, was greater than that for male chum salmon, maturing at ages of 3–5 yr. Female pink salmon were less variable for the two characters than all ages of female chum salmon, equally variable when only age 3 or age 4 female chum salmon were considered, and more variable in comparison with age 5 female chum salmon. Males were more variable for each character than females for both species. Small males of both species tend to resemble females when body depths are compared. It is suggested that small males mimic females to reduce aggression from larger males and gain access to spawning females.

scholarly journals Principles Affecting the Size of Pink and Chum Salmon Populations in British Columbia

1953 ◽  
Vol 9a (9) ◽  
pp. 450-491 ◽  
Author(s):  
Ferris Neave
Keyword(s):  
British Columbia ◽  
Egg Production ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Fish Populations ◽  
Oncorhynchus Gorbuscha ◽  
Combined Effects ◽  
Adult Fish ◽  
Free Swimming ◽  
Pink Salmon Oncorhynchus Gorbuscha

In pink salmon (Oncorhynchus gorbuscha) the survival during the freshwater phases of the life-cycle has been found to vary from about 1 to 24 per cent of available eggs. Natural survival during marine existence is considered to average about 5 per cent. In the central region of the British Columbia coast the annual catch averages about 60 per cent of the adult fish. Populations maturing in "even" and "odd" years vary in size independently. Fluctuations in level of stock originate mainly in fresh water.Population levels and changes are determined by the combined effects of three types of mortality: (a) mortality which becomes relatively heavier as populations increase in density (compensatory); (b) mortality which becomes relatively heavier as populations decrease in density (depensatory); (c) mortality which is independent of density (extrapensatory). Compensatory mortality is especially identified with the, period of spawning and incubation. Depensatory mortality is considered to occur mainly during the period of fry migration and to be due to predation. Extrapensatory mortality may occur at any stage; it is most variable during the period between entrance of the adults into fresh water and emergence of the free-swimming fry.Populations of chum salmon (O. keta) are controlled by similar influences. Effects are modified by higher egg-production and a less rigid life-span than in the pink salmon.

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