Detection of Natural Hybridization between Pink Salmon (Oncorhynchus gorbuscha) and Chinook Salmon (Oncorhynchus tshawytscha) in the Laurentian Great Lakes Using Meristic, Morphological, and Color Evidence

Copeia ◽  
1998 ◽  
Vol 1998 (3) ◽  
pp. 706 ◽  
Author(s):  
Jonathan A. Rosenfield
Keyword(s):  
Great Lakes ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Pink Salmon ◽  
Natural Hybridization ◽  
Laurentian Great Lakes ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha

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.

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.

Genetic Changes in Pink Salmon (Oncorhynchus gorbuscha) Following Their Introduction Into the Great Lakes

1987 ◽  
Vol 44 (4) ◽  
pp. 787-792 ◽  
Author(s):  
A. J. Gharrett ◽  
M. A. Thomason
Keyword(s):  
British Columbia ◽  
Great Lakes ◽  
Salt Water ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Major Step ◽  
River Population ◽  
Genetic Changes ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Allelic Frequencies

Pink salmon (Oncorhynchus gorbuscha) previously thought to require salt water for completion of their life cycle, have been firmly established in the Great Lakes following an accidental introduction into Lake Superior. We compare allelic frequencies at 27 protein-coding loci from collections of pink salmon from the Great Lakes with those from the anadromous population (Lakelse River, British Columbia) from which they were derived. Although the allelic frequencies in the Great Lakes collections are consistent with a single introduction, the frequencies observed in these collections differ substantially from those of the Lakelse River population. Alleles of G3p-1 and Ck-1, rarely observed (frequency < 0.005) in British Columbia population, are present in Great Lakes pink salmon at frequencies between 0.06 and 0.27. Smaller changes were observed at 11 other loci; 14 loci were monomorphic in all collections. Loss of variability in the Great Lakes was reflected by a decrease in average number of alleles per locus. Selection for physiologically tolerant phenotypes may have been necessary to establish this unique, self-perpetuating, freshwater population. The biochemical genetic changes we observed, however, can be adequately explained by genetic drift resulting from bottlenecks occurring at the first and at subsequent generations. Any decreases in survival resulting from freshwater intolerance would have exacerbated the bottlenecks. This adaptively distinct lineage produced by the ecological change coupled with the bottlenecks may be a major step toward speciation.

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.

Epizootics of thyroid hyperplasia in Lake Superior and Lake Erie pink salmon (Oncorhynchus gorbuscha (Walbaum))

1988 ◽  
Vol 66 (12) ◽  
pp. 2676-2687 ◽  
Author(s):  
Douglas B. Noltie ◽  
John F. Leatherland ◽  
Miles H. A. Keenleyside
Keyword(s):  
British Columbia ◽  
Body Size ◽  
Great Lakes ◽  
Lake Erie ◽  
Lake Superior ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Negative Effects ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Thyroid Hyperplasia

All Lake Superior and Lake Erie pink salmon (Oncorhynchus gorbuscha (Walbaum)) collected exhibited thyroid hyperplasia. Samples from British Columbia, however, were unaffected. In fish from Lake Superior, lesion sizes increased through a graded series and were correlated with increased body size. In contrast, almost all Lake Erie fish exhibited extreme hyperplasia regardless of body size. Pink salmon lesion histopathology differed markedly from that shown by Great Lakes coho (Oncorhynchus kisutch (Walbaum)) and chinook (Oncorhynchus ishawytscha (Walbaum)) salmon. Among Great Lakes populations, males and females were equally afflicted. Greater proportions of females entered their spawning streams with immature gonads in Lake Erie, where fish exhibited larger lesions. Indications are that males showed poorer secondary sexual character development there as well. Gonad weights in Lake Erie males were proportionally smaller than in Lake Superior males, and liver weights in Lake Superior fish were smaller than in British Columbia specimens. Thyroid hormone levels and lesion sizes were negatively correlated, providing evidence of hypothyroidism. These findings warn of potential water quality problems in Lake Superior, and suggest a useful means of assessing the goitrogenic potential of Great Lakes systems. Despite its negative effects, however, thyroid hyperplasia has not prevented the increase of pink salmon numbers and distribution in the Great Lakes.

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