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

Genome ◽  
1989 ◽  
Vol 32 (2) ◽  
pp. 227-231
Author(s):  
Terry D. Beacham

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.

1978 ◽  
Vol 56 (1) ◽  
pp. 86-89 ◽  
Author(s):  
Colin N. MacKinnon ◽  
Edward M. Donaldson

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.


1973 ◽  
Vol 51 (5) ◽  
pp. 493-500 ◽  
Author(s):  
James D. Funk ◽  
Edward M. Donaldson ◽  
Helen M. Dye

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.


1991 ◽  
Vol 48 (9) ◽  
pp. 1744-1749 ◽  
Author(s):  
A. J. Gharrett ◽  
W. W. Smoker

Hybrids of genetically isolated odd- and even-year pink salmon (Oncorhynchus gorbuscha) from the same stream were made by fertilizing eggs with cryopreserved milt. Anadromous first-generation (F1) hybrids and controls returned to the hatchery at equal rates (153 of 5483 and 160 of 5492, respectively), on the same average date, and with the same size. However, variances of F1 size (female length and weight and male length) exceeded variances of control sizes, suggesting increased genetic variation in F1's. Only 11 of 5165 F2's returned. F2's were similar meristically and in size to fish of their parents' generation, but were bilaterally more asymmetric in number of gill rakers and in combined numbers of gill rakers and of branchiostegals. Increased F1 variation followed by low F2 returns and increased bilateral asymmetry is a pattern to be expected when coadapted allele complexes are disrupted by outbreeding depression.


1972 ◽  
Vol 50 (11) ◽  
pp. 1413-1419 ◽  
Author(s):  
James D. Funk ◽  
Edward M. Donaldson

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.


1998 ◽  
Vol 55 (9) ◽  
pp. 2048-2057 ◽  
Author(s):  
K P Hebert ◽  
P L Goddard ◽  
W W Smoker ◽  
A J Gharrett

Quantitative genetic variation of development rate was evident among 20 half-sib and 40 full-sib families within each of two seasonally separate components of a population of pink salmon (Oncorhynchus gorbuscha) (Ho: no sire effect on temperature units at hatch, P < 0.02). Differences between averages of families spawned 3 weeks apart may have had genetic or environmental sources (e.g., in constant 8°C, early embryos hatched at 606 temperature units, and late embryos, at 625). Statistical interactions between paternal effects and environment (embryos were cultured in four temperature regimes, two simulated natural regimes and two constant temperatures; Ho: no sire by regime interaction effect on temperature units at hatch, P < 0.09) were weak evidence that genotype by environment interactions contributed to variation. Paternal effects in analysis of variance (evidence of additive genetic variation) were detected only at later stages. Evidences of genetic variation and of interactions between genotypes and environments are pertinent to resource conservation because they suggest that harvest management or hatchery practice have the potential to reduce genetic variation in salmon populations.


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