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.

Comparison of the effect of salmon gonadotropin administered by pellet implantation or injection on sexual development of juvenile male pink salmon (Oncorhynchus gorbuscha)

1978 ◽  
Vol 56 (1) ◽  
pp. 86-89 ◽  
Author(s):  
Colin N. MacKinnon ◽  
Edward M. Donaldson
Keyword(s):  
Body Weight ◽  
Chinook Salmon ◽  
Sexual Development ◽  
Oncorhynchus Tshawytscha ◽  
Pink Salmon ◽  
Mitotic Division ◽  
Oncorhynchus Gorbuscha ◽  
Juvenile Male ◽  
Time Intervals ◽  
Pink Salmon Oncorhynchus Gorbuscha

In juvenile male pink salmon complete maturity was induced by September in the year of hatching by both pellet implantation (once per 3 weeks) and injection (thrice weekly) of 1.0μg of chinook salmon (Oncorhynchus tshawytscha) gonadotropin per gram body weight. Time of onset of mitotic division of spermatogonia and rate of spermatogenesis were accelerated in the precociously mature testes. Similar doses of salmon gonadotropin injected at longer time intervals (once per week and once per 2 weeks) resulted in slower maturation.

Induction of precocious sexual development in female pink salmon (Oncorhynchus gorbuscha)

1973 ◽  
Vol 51 (5) ◽  
pp. 493-500 ◽  
Author(s):  
James D. Funk ◽  
Edward M. Donaldson ◽  
Helen M. Dye
Keyword(s):  
Body Weight ◽  
Chinook Salmon ◽  
Sexual Development ◽  
Oncorhynchus Tshawytscha ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Ovarian Maturation ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Large Numbers ◽  
Estradiol 17Β

Acceleration of ovarian maturation was achieved in immature pink salmon (Oncorhynchus gorbuscha) with injections of chinook (spring) salmon (Oncorhynchus tshawytscha) gonadotropin alone, and in combination with estradiol 17β. Oocytes containing yolk globules were evident in fish treated three times per week with 1.0 μg/g body weight salmon gonadotropin in combination with 1.5 μg/g body weight estradiol 17β for 126 days. After 168 days they were also seen in salmon treated with the same dosage of salmon gonadotropin alone. Estradiol 17β alone, at a dosage of 15 μg/g body weight, or in combination with salmon gonadotropin, inhibited vitellogenesis. Formation of oocytes 2 mm in diameter required [Formula: see text] months of treatment with 1.0 μg/g body weight salmon gonadotropin in combination with 1.5 μg/g body weight estradiol 17β, and 9 months of injections with 1.0 μg/g body weight gonadotropin alone. Few large yolky oocytes were developed by any of the treatments. Large numbers of preovulatory corpora atretica were observed in all treated fish.Only a small amount of histochemically demonstrable Δ5-3β hydroxysteroid dehydrogenase activity was present in ovaries from pink or chinook salmon juveniles treated for 3 months with various dosages of salmon gonadotropin.

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.

Genetic variation in body weight of pink salmon (Oncorhynchus gorbuscha)

Genome ◽  
1989 ◽  
Vol 32 (2) ◽  
pp. 227-231
Author(s):  
Terry D. Beacham
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Maternal Effects ◽  
Egg Quality ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
In Captivity ◽  
Factorial Mating ◽  
Factorial Mating Design

A factorial mating design was used in which three males were mated to either two or three females in each of the three sets of pink salmon (Oncorhynchus gorbuscha), and the juveniles were reared for 420 days after fry emergence. The parents used were derived from pink salmon that had been reared for one generation in captivity. Pink salmon families from this captive second generation were characterized by low growth rates, high within-family variance in juvenile weight, and low (< 0.11) heritability of juvenile weight. Maternal effects were estimated to account for about 20% of the observed variation in juvenile weight after the juveniles had been reared for 420 days. The observed results were postulated to be accounted for by variation in egg quality in the parental generation, presumably a consequence of an inadequate diet.Key words: development, genetics, growth, pink salmon, size.

Survival of Puget Sound chinook salmon (Oncorhynchus tshawytscha) in response to climate-induced competition with pink salmon (Oncorhynchus gorbuscha)

2004 ◽  
Vol 61 (9) ◽  
pp. 1756-1770 ◽  
Author(s):  
Gregory T Ruggerone ◽  
Frederick A Goetz
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Pink Salmon ◽  
Puget Sound ◽  
Oncorhynchus Gorbuscha ◽  
First Year ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Growth And Survival ◽  
Coastal Streams ◽  
Delayed Maturation

We tested for competition between pink salmon (Oncorhynchus gorbuscha) and chinook salmon (Oncorhynchus tshawytscha) originating from rivers in the Puget Sound area using coded-wire-tagged subyearling hatchery chinook salmon. Following a 2-year life cycle, many juvenile pink salmon enter Puget Sound in even-numbered years, whereas few migrate during odd-numbered years. During 1984–1997, juvenile chinook salmon released during even-numbered years experienced 59% lower survival than those released during odd-numbered years, a trend consistent among 13 chinook salmon stocks. Lower even-numbered-year survival of chinook salmon was associated with reduced first-year growth and survival and delayed maturation. In contrast, chinook salmon released into coastal streams, where few pink salmon occur, did not exhibit an alternating-year pattern of survival, suggesting that the interaction occurred within Puget Sound and the lower Strait of Georgia. Unexpectedly, the survival pattern of Puget Sound chinook salmon was reversed prior to the 1982–1983 El Niño: chinook salmon survival was higher when they migrated with juvenile pink salmon during 1972–1983. We hypothesize that chinook salmon survival changed as a result of a shift from predation- to competition-based mortality in response to recent declines in predator and prey abundances and increases in pink salmon abundance. Alternating-year mortality accounted for most of the 50% decline in marine survival of chinook salmon between 1972–1983 and 1984–1997.

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.

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.

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