Photoperiod and its effect on incidence of sexual maturity in pink salmon (Oncorhynchus gorbuscha)

1990 ◽  
Vol 68 (6) ◽  
pp. 1209-1213 ◽  
Author(s):  
Terry D. Beacham ◽  
Clyde B. Murray
Keyword(s):  
Sexual Maturation ◽  
Sexual Maturity ◽  
Pink Salmon ◽  
Rate Of Change ◽  
Day Length ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha

Pink salmon (Oncorhynchus gorbuscha) were reared for 15 months after fry emergence under three photoperiod regimes. About 50% of males matured in a photoperiod that had two periods of declining day length within the 15-month study period. No males matured in photoperiods having only one period of declining day length, and no females matured in any photoperiod. The rate of change of day length is likely of greater importance than the amplitude of change in inducing sexual maturation in males.

Fertilization of Pink Salmon (Oncorhynchus gorbuscha) Ova by Spermatozoa from Gonadotropin-Injected Juveniles

1972 ◽  
Vol 29 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Edward M. Donaldson ◽  
James D. Funk ◽  
F. C. Withler ◽  
R. B. Morley
Keyword(s):  
British Columbia ◽  
Sexual Maturation ◽  
Chinook Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Testicular Development ◽  
Fraser River ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Early Maturation ◽  
Two Stages

Sexual maturation in male pink salmon (Oncorhynchus gorbuscha) from Jones Creek, a tributary of the Fraser River, British Columbia, was accelerated by intraperitoneal injections of partially purified chinook salmon (O. tshawytscha) gonadotropin. The treated pinks produced milt 1 year earlier than normal. Milt from these fish was compared with milt from wild Lower Babine River pinks with respect to its ability to fertilize the ova of Lower Babine River females. There were no marked differences in proportions of ova fertilized, in survival to hatching, or in numbers of deformed larvae. Densities of sperm in the milt from treated males ranged from 0.15 × 109 to 7.35 × 109 per ml; sperm densities in the milt from wild males ranged from 19.3 × 109 to 38.6 × 109 per ml. Two stages in testicular development were identified among the treated males and found to be directly related to the success of fertilization. The significance of induced early maturation in attempts to establish pink runs in the "off" year rivers is discussed.

Influence of photoperiod and temperature on timing of sexual maturity of pink salmon (Oncorhynchus gorbuscha)

1988 ◽  
Vol 66 (8) ◽  
pp. 1729-1732 ◽  
Author(s):  
Terry D. Beacham ◽  
Clyde B. Murray
Keyword(s):  
Temperature Regime ◽  
Growth Rates ◽  
Sexual Maturity ◽  
Pink Salmon ◽  
Survival Rates ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Males And Females

The effect of two photoperiods and rearing at 10, 13, and 16 °C on the development of pink salmon (Oncorhynchus gorbuscha) maturity 12 to 13 months after fry emergence was examined. Highest rates of maturity for both males and females were observed in the 10 °C temperature regime with a normal first summer, short winter, and short second summer photoperiod. In any environment examined, males were more likely to have matured than females. Highest survival rates and fastest overall growth rates were also observed at 10 °C. The feasibility of transplanting genes from one pink salmon brood line to another is examined.

Induction of precocious sexual maturity in male pink salmon (Oncorhynchus gorbuscha)

1972 ◽  
Vol 50 (11) ◽  
pp. 1413-1419 ◽  
Author(s):  
James D. Funk ◽  
Edward M. Donaldson
Keyword(s):  
Body Weight ◽  
Dehydrogenase Activity ◽  
Sexual Maturity ◽  
Oncorhynchus Tshawytscha ◽  
Pink Salmon ◽  
Mitotic Division ◽  
Oncorhynchus Gorbuscha ◽  
Time Interval ◽  
Juvenile Male ◽  
Pink Salmon Oncorhynchus Gorbuscha

In the juvenile male pink salmon (Oncorhynchus gorbuscha) complete sexual maturity was attained by September in the year of hatching with thrice-weekly treatments of 10.0 and 1.0 μg partially purified salmon (Oncorhynchus tshawytscha) gonadotropin (SG-G100) per gram body weight. The time of onset of mitotic division of spermatogonia and the rate of spermiogenesis were accelerated in the precociously mature testes. At sexual maturity, a scattering of localizations of Δ5-3 β hydroxysteroid dehydrogenase activity was observed in the testes which corresponded to the distribution of the interstitial cells. A stock of larger pink salmon (body weight at maturity 64.2 g) developed mature testes in the same time interval as the smaller sized individuals, but in these the gonads were four times larger. Immature Oncorhynchus tshawytscha matured more slowly and showed less 3 β-ol dehydrogenase activity in response to SG-G100 than the pink salmon.

Genetic analysis of growth and maturity in pink salmon (Oncorhynchus gorbuscha)

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 529-535 ◽  
Author(s):  
Terry D. Beacham ◽  
Clyde B. Murray
Keyword(s):  
British Columbia ◽  
Genetic Analysis ◽  
Growth Rates ◽  
Variance Components ◽  
Sexual Maturity ◽  
Pink Salmon ◽  
Genetic Component ◽  
Oncorhynchus Gorbuscha ◽  
Late Winter ◽  
Pink Salmon Oncorhynchus Gorbuscha

Variation in growth and sexual maturity was examined for five stocks of pink salmon (Oncorhynchus gorbuscha) spawning at different times in British Columbia. In each stock, four males were mated with eight females in a nested breeding design, and the juveniles were reared for 500 d after fry emergence. Adults in early-spawning northern stocks were smaller than those in late-spawning southern ones, but pink salmon from northern stocks had faster growth rates than those from southern ones. The relative ranking within stocks of family weight remained constant after late winter in the year of maturity. Heritability of weight based upon sire variance components was usually greater than 0.9 after 150 d of rearing. Pink salmon from the earlier-spawning stocks were in a more advanced state of sexual maturity when the experiment was terminated than were those from later-spawning stocks, indicative of a significant genetic component in timing of sexual maturity.Key words: Oncorhynchus, salmon, growth rates, sexual maturity.

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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