Counts of Gill Rakers and Pyloric Caeca in Pink Salmon

1945 ◽  
Vol 6d (5) ◽  
pp. 392-398
Author(s):  
A. L. Pritchard
Keyword(s):  
British Columbia ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Gill Rakers ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Pyloric Caeca ◽  
Breeding Group

Counts of gill rakers and pyloric caeca on pink salmon (Oncorhynchus gorbuscha) from different rivers in British Columbia overlap in range to such an extent that it would be impossible with any degree of accuracy to assign isolated individuals from an ocean population to a distinct "breeding group" on the basis of these characters. While the comparison of the averages of each character demonstrates significant differences between separate rivers in the same year in some cases, in others no such difference is noticeable. The averages for the characters do not consistently show differences between populations of two succeeding years which are known to be distinct, e.g. those of 1940 and 1941.

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.

Orientation of Pink Salmon (Oncorhynchus gorbuscha) During Early Marine Migration from Bella Coola River System

1967 ◽  
Vol 24 (11) ◽  
pp. 2321-2338 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
British Columbia ◽  
Pink Salmon ◽  
River System ◽  
Early Morning ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Fry ◽  
Marine Migration ◽  
Bella Coola

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.

Statistical Evaluation of a Large-Scale Fishing Experiment Designed to Test for a Genetic Effect of Size-Selective Fishing on British Columbia Pink Salmon (Oncorhynchus gorbuscha)

1992 ◽  
Vol 49 (7) ◽  
pp. 1294-1304 ◽  
Author(s):  
Murdoch K. McAllister ◽  
Randall M. Peterman ◽  
Darren M. Gillis
Keyword(s):  
British Columbia ◽  
Statistical Power ◽  
Large Scale ◽  
Pink Salmon ◽  
Genetic Effect ◽  
Oncorhynchus Gorbuscha ◽  
Causal Mechanism ◽  
Block Designs ◽  
Adult Size ◽  
Pink Salmon Oncorhynchus Gorbuscha

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.

Daily Patterns of Feeding Behavior, Daily Rations, and Diets of Juvenile Pink Salmon (Oncorhynchus gorbuscha) in Two Marine Bays of British Columbia

1981 ◽  
Vol 38 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Jean-Guy J. Godin
Keyword(s):  
British Columbia ◽  
Feeding Behavior ◽  
Littoral Zone ◽  
Pink Salmon ◽  
Early Period ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Fry ◽  
Harpacticoid Copepods ◽  
Additional Support

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

The metacercaria of Galactosomum phalacrocoracis (Trematoda: Heterophyidae) from pink salmon, Oncorhynchus gorbuscha, from British Columbia waters

1978 ◽  
Vol 56 (10) ◽  
pp. 2235-2238 ◽  
Author(s):  
J. C. Pearson ◽  
L. Margolis ◽  
N. P. Boyce
Keyword(s):  
British Columbia ◽  
Coastal Waters ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha

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

Evaluation of the Transplant of Pacific Pink Salmon (Oncorhynchus gorbuscha) from British Columbia to Newfoundland

1975 ◽  
Vol 32 (12) ◽  
pp. 2343-2356 ◽  
Author(s):  
W. H. Lear
Keyword(s):  
British Columbia ◽  
Environmental Conditions ◽  
Brook Trout ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Homing Behavior ◽  
Migration Patterns ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Surface Temperatures

Five transplants of eyed eggs of Pacific pink salmon (Oncorhynchus gorbuscha) were made between streams in southern British Columbia and North Harbour River, Newfoundland. Quantities transplanted were 0.25 million in 1959, 2.5 million in 1962, 3.4 million in 1964, 3.3 million in 1965, and 5.9 million in 1966. Adult returns from these transplants were 1, 49, 638, 8500, and 2426 during 1961, 1964, 1966, 1967, and 1968, respectively. Since 1969, returns have been the progeny of naturally spawning fish and have steadily declined in numbers. The reasons for failure of the transplant are not certain, but possibilities include the following: predation on the fry by brook trout and possibly eels in North Harbour Pond and estuary; unfavorable surface temperatures in the river during the fry run; predation by herring on fry in St. Mary’s Bay; year-class failure of the even-year stocks that were introduced; unsuitability of the donor stocks with respect to migration patterns and homing behavior; inadequate numbers of eggs were transplanted to produce populations required to maintain runs in anything below optimum environmental conditions.

Transplantation of Pink Salmon (Oncorhynchus gorbuscha) into Masset inlet, British Columbia, in the Barren Years

1938 ◽  
Vol 4a (2) ◽  
pp. 141-150 ◽  
Author(s):  
A. L. Pritchard
Keyword(s):  
British Columbia ◽  
East Coast ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Fraser River ◽  
Free Swimming ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
The Absolute ◽  
River Fishery

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.

Meristic and morphometric variation in pink salmon (Oncorhynchus gorbuscha) in southern British Columbia and Puget Sound

1985 ◽  
Vol 63 (2) ◽  
pp. 366-372 ◽  
Author(s):  
Terry D. Beacham
Keyword(s):  
British Columbia ◽  
Pink Salmon ◽  
Puget Sound ◽  
Genetic Differences ◽  
Oncorhynchus Gorbuscha ◽  
Morphometric Variation ◽  
Morphometric Characters ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Local Water ◽  
Gill Raker

Variation in the number of gill rakers and four morphometric characters was examined for 4 stocks from the even-year brood line and 20 stocks from the odd-year brood line of pink salmon (Oncorhynchus gorbuscha) in southern British Columbia and Puget Sound. Significant differences in gill-raker frequencies were observed among stocks within each brood line, but differences were greater between the brood lines than within each brood line. Sizes of the morphometric characters standardized to a body length of 419 mm were also variable among stocks within a brood line, but stocks spawning in rivers in the same region in alternate years were more similar morphometrically than to those spawning in different regions. It is suggested that patterns of meristic and morphometric variability are reflective of genetic differences, with meristic variability illustrating the genetic differences between the brood lines, and morphometric variability reflecting adaptation to local water velocity conditions in the streams the stocks return to during spawning.

Homing Tendency and Age at Maturity of Pink Salmon (Oncorhynchus gorbuscha) in British Columbia

1939 ◽  
Vol 4b (4) ◽  
pp. 233-251 ◽  
Author(s):  
A. L. Pritchard
Keyword(s):  
British Columbia ◽  
East Coast ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Age At Maturity ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Fry ◽  
Second Year ◽  
Transplantation Experiments

Pink salmon fry were marked by the removal of certain fins to ensure later identification as adults. This procedure does not affect the growth or the feeding reactions of the fish. Three experiments were conducted on natural runs at McClinton creek, Masset inlet, B.C. On the basis of the most significant one of these it is concluded that the majority of the fish return to spawn in the stream in which they were hatched. Isolated individuals, in numbers not economically significant, may wander to a distance of 400 miles (645 kilometres). In the case of fry resulting from transplantation experiments from Tlell river, east coast of Graham island, to McClinton creek, there appears no consistent behaviour in regard to "homing". For fry, hatchery-raised and pond-reared, from Vedder river, Swelter creek eggs, no return to the parent stream was reported. All pink salmon mature in the autumn of their second year. Certain incidental checks in growth have been discovered on scales which should not be interpreted as representing a winter.

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