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

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.

1938 ◽  
Vol 4a (2) ◽  
pp. 141-150 ◽  
Author(s):  
A. L. Pritchard

In 1931, 1933, 1935, odd-numbered years, when no natural runs of pink salmon (Oncorhynchus gorbuscha) occur in the Masset area, British Columbia, transfers of eggs were made from the Tlell river on the east coast of Graham island to McClinton creek, a tributary of Masset inlet. The following free-swimming fry were released: from the 1931 experiment—753,646 normal and 124,002 "marked" by the removal of the adipose and left ventral fins, and from that of 1935—397,657 normal and 108,200 "marked" by the removal of the adipose and right ventral fins. From the former, 40 "marked" adults were recovered in the Fraser river fishery in 1933, and from the latter four "marked" adults at McClinton creek in 1937. In the 1933 experiment 540,294 eyed eggs were planted but these were destroyed by freshets the following winter. Possible reasons for the failure of these experiments and the absolute blank in the "off" years are suggested.


1987 ◽  
Vol 44 (2) ◽  
pp. 348-356 ◽  
Author(s):  
I. V. Williams ◽  
J. R. Brett

Critical swimming speeds were determined for male and female pink salmon (Oncorhynchus gorbuscha) captured from the Fraser and Thompson rivers and Seton Creek, British Columbia. The fish were categorized into two basic groups. Lower river fish were captured from the Fraser River at Fort Langley and Yale, and up-river fish were captured from the Thompson River at the Canyon and at Ashcroft and from Seton Creek near Lillooet, British Columbia. The critical swimming speeds of males and females in various stages of maturation were compared. In general, the up-river fish were stronger swimmers than the lower river fish. Gravid fish were stronger swimmers than spawning fish, which in turn were stronger swimmers than fish which were spawned out. Standardized critical swimming speeds ranged from a mean of 1.73 ± 0.35 (SE) body lengths/s for spawned females up to 3.39 ± 0.48 lengths/s for up-river gravid males.


1985 ◽  
Vol 42 (9) ◽  
pp. 1474-1483 ◽  
Author(s):  
Terry D. Beacham ◽  
Ruth E. Withler ◽  
Allan P. Gould

We used electrophoresis to examine genetic variability at 12 loci for 4 even-year broodline stocks and at 14 loci for 21 odd-year broodline stocks of pink salmon (Oncorhynchus gorbuscha) in southern British Columbia and Puget Sound. Allelic frequencies were most heterogeneous between the two pink salmon broodlines, but within the odd-year broodline, Fraser River, Canadian non-Fraser, and Puget Sound pink salmon had significantly different allelic frequencies at some loci. Canadian non-Fraser River stocks had the greatest heterogeneity of allelic frequencies within a region, whereas the Fraser River stocks had the least amount of heterogeneity. There was no significant two-locus linkage disequilibrium for the pink salmon stocks surveyed. Cluster analyses by allelic frequencies indicated that Fraser River, Canadian non-Fraser, and Puget Sound stocks were reasonably distinctive. We used differences in genotypic frequencies at 11 loci (3 were duplicated loci) to estimate stock composition of these three groups of pink salmon in mixtures in which the true compositions were known, and we were able to compare the accuracy and precision of our estimates with respect to mixture size and stock composition. We estimated that 100% of pink salmon sampled in a test fishery in Thompson Sound were of Canadian non-Fraser origin.


1965 ◽  
Vol 22 (6) ◽  
pp. 1477-1489 ◽  
Author(s):  
H. T. Bilton ◽  
W. E. Ricker

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.


1967 ◽  
Vol 24 (11) ◽  
pp. 2321-2338 ◽  
Author(s):  
M. C. Healey

During May and June 1966, the migration of pink salmon fry from the Bella Coola River was studied in Burke Channel, British Columbia. The movement of pink fry down Burke Channel was saltatory. Short periods of active migration were interspersed with longer periods when the fry did not migrate and accumulated in bays. Fry were sampled from these accumulations and their ability to orient using celestial cues was examined. During the early morning, fry tended to prefer directions at right angles to their direction of migration, but at other times of the day preferred the direction of migration. The preference for the direction of migration was strongest at midday. Fry were better oriented on clear days than on cloudy days. These data indicate that fry may use celestial cues to find directions during their oceanic migrations.


1992 ◽  
Vol 49 (7) ◽  
pp. 1294-1304 ◽  
Author(s):  
Murdoch K. McAllister ◽  
Randall M. Peterman ◽  
Darren M. Gillis

Since 1950, stocks of British Columbia pink salmon (Oncorhynchus gorbuscha) have shown up to a 34% decrease in mean adult body weight, causing significant reduction in economic value of commercial harvests. Previous research suggests that this trend is due to size-selective harvesting of large fish, but changes in oceanographic conditions are a plausible alternative. Corrective action by management agencies requires that the true causal mechanism be identified. We therefore examined several possible designs for a large-scale fishing experiment devised to test the size-selective fishing hypothesis. These designs would generate accurate and precise field estimates of the heritability (h2) of growth rate, which is important because it, in combination with the selection differential (D) caused by fishing, determines how rapidly body size changes. Monte Carlo simulations showed that block designs with three to six spatial replicates and relatively short durations generated high statistical power. For example, for h2 = 0.22, D = 0.25 kg, and four spatial replicates, an 8-yr experiment resulted in power = 0.87, which gave a SE < 0.10 for h2 = 0.22. We conclude that some experimental designs have good potential to test the possible effects of size-selective fishing on mean adult size of British Columbia pink salmon.


1981 ◽  
Vol 38 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Jean-Guy J. Godin

Stomach analyses showed that pink salmon fry fed mainly during daylight hours in the littoral zone of Departure Bay and Hammond Bay, British Columbia, in May. Although the diurnal feeding patterns of the fish differed slightly between the two bays, maximum mean prey biomass in the fishes' stomachs occurred near or at dusk in both bays. Daily rations consumed by Departure Bay and Hammond Bay fish were estimated to be 13.1 and 6.6% of their dry body weight, respectively. The fry consumed similar prey items in both bays, but in differing proportions. Harpacticoid copepods, copepod nauplii, and barnacle larvae comprised numerically 93.1 and 86.2% of the diets of Departure Bay and Hammond Bay fish, respectively. About 38% of the diet of Departure Bay fish and 51% of the diet of Hammond Bay fish comprised epibenthic prey, mainly harpacticoid copepods. The data provide additional support for the importance of the detritus-microbe-consumer type food chain supporting the production of pink salmon during their early period of marine residency.Key words: pink salmon, feeding behavior, daily rhythm, diet, ration, British Columbia


1988 ◽  
Vol 23 (1) ◽  
pp. 88-99 ◽  
Author(s):  
James A. Servizi ◽  
Robert W. Gordon ◽  
John H. Carey

Abstract Chlorophenol content of emergent pink salmon fry from five natal spawning grounds and fingerling Chinook from the Fraser River was determined. Major Chlorophenols identified were pentachlorophenol, 2,3,4,6-tetrachlorophenol, 2,4,6-trichlorophenol and 2,4-dichlorophenol. Sources of these compounds appear to be lumber mills using chlorophenol based fungicides and pulp and paper mill effluents. Chlorophenol content was greatest in pink salmon fry from the Thompson River (58.4 ng/g total Chlorophenols). Fingerling Chinook from the Fraser River contained 3 7.7 ng/g total Chlorophenols. The 96-hr LC50 of Woodbrite 24, a chlorophenol based fungicide to pink salmon during the egg-to-fry stage was determined to be in the 100 to 150 ug/L range. This range is about 100 times higher than average levels reported for Fraser River water.


1978 ◽  
Vol 56 (10) ◽  
pp. 2235-2238 ◽  
Author(s):  
J. C. Pearson ◽  
L. Margolis ◽  
N. P. Boyce

The metacercaria of Galactosomum phalacrocoracis (Trematoda: Heterophyidae), collected from Oncorhynchus gorbuscha (Walbaum) from coastal waters of British Columbia, is described.


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.


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