Ceratomyxa shasta Noble, 1950 (Myxozoa: Myxosporea) present in the Fraser River system of British Columbia

1983 ◽  
Vol 61 (9) ◽  
pp. 1991-1994 ◽  
Author(s):  
T. E. McDonald
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Drainage Basin ◽  
Coho Salmon ◽  
Cutthroat Trout ◽  
River System ◽  
Salmo Gairdneri ◽  
Fraser River ◽  
Steelhead Trout

An examination of 220 chinook salmon (Oncorhynchus tshawytscha), 84 coho salmon (O. kisutch), 145 steelhead trout (Salmo gairdneri), and 21 cutthroat trout (S. clarki) for Ceratomyxa shasta (Myxozoa: Myxosporea) from 16 localities in the Fraser River drainage, British Columbia, showed that at all sites examined these salmonid species were infected, with a prevalence ranging between 11 and 100%. The study concludes that C. shasta, the causative agent of the salmonid disease ceratomyxosis, is widely distributed in the Fraser drainage basin and discusses these results in relation to proposed fish culture in the region.

Role of Off-Channel Ponds in the Life Cycle of Coho Salmon (Oncorhynchus kisutch) and Other Juvenile Salmonids in the Coldwater River, British Columbia

1989 ◽  
Vol 46 (2) ◽  
pp. 232-242 ◽  
Author(s):  
S. Swales ◽  
C. D. Levings
Keyword(s):  
British Columbia ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
River Population ◽  
Main Species ◽  
Main River ◽  
Density And Biomass

Off-channel ponds in the upper reaches of the Coldwater River, British Columbia, were major rearing areas for juvenile coho salmon (Oncorhynchus kisutch). Chinook salmon (Oncorhynchus tshawytscha), steelhead trout (Salmo gairdneri), and Dolly Varden char (Salvelinus malma) were generally scarce in the ponds, although they were numerous in the main river. Coho salmon were predominant at "natural" river sites while steelhead trout was the main species at sites with "rip-rap" bank stabilization. Catches of juvenile coho were much lower in the main river than in the ponds where they were the main species, and were more variable in the river. Population density and biomass estimates of juvenile coho in the ponds ranged from 0.100 fish∙m−2 and 1.00 g∙m−2 to 1.00 fish∙m−2 and 5.15 g∙m−2, compared with density estimates of 0.08–0.23 fish∙m−2 in the river. The coho population in the ponds consisted of 0+ and 1+ age-groups in similar proportions, while in the main river the 0+ age-group was much more abundant. The growth rate of coho in the ponds was faster than in the main river, with pond fish reaching mean lengths of 62–79 mm at the end of the first growing season, compared with 53 mm in the main river. Smolt outmigration from the main study pond occurred in late spring with peak outmigration in May and June coinciding with peak river discharge and increasing water temperatures in the main river and pond.

Individual variation in dispersal behaviour of newly emerged chinook salmon (Oncorhynchus tshawytscha) from the Upper Fraser River, British Columbia

1997 ◽  
Vol 54 (7) ◽  
pp. 1585-1592 ◽  
Author(s):  
M J Bradford ◽  
G C Taylor
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Population Variation ◽  
Fraser River ◽  
Movement Behaviour ◽  
Spawning Areas ◽  
Dispersal Distances ◽  
Stream Type ◽  
Downstream Movement

Immediately after emergence from spawning gravels, fry of stream-type chinook salmon (Oncorhynchus tshawytscha) populations from tributaries of the upper Fraser River, British Columbia, distribute themselves downstream from the spawning areas, throughout the natal stream, and into the Fraser River. We tested the hypothesis that this range in dispersal distances is caused by innate differences in nocturnal migratory tendency among individuals. Using an experimental stream channel, we found repeatable differences in downstream movement behaviour among newly emerged chinook fry. Fish that moved downstream were larger than those that held position in the channel. However, the incidence of downstream movement behaviours decreased over the first 2 weeks after emergence. We propose that the variation among individuals in downstream movement behaviour we observed leads to the dispersal of newly emerged fry throughout all available rearing habitats. Thus, between- and within-population variation in the freshwater life history observed in these populations may be caused by small differences in the behaviour of individuals.

Production of germline transgenic Pacific salmonids with dramatically increased growth performance

1995 ◽  
Vol 52 (7) ◽  
pp. 1376-1384 ◽  
Author(s):  
Robert H. Devlin ◽  
Timothy Y. Yesaki ◽  
Edward M. Donaldson ◽  
Shao Jun Du ◽  
Choy-Leong Hew
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Cutthroat Trout ◽  
Transgenic Fish ◽  
Somatic Tissue ◽  
Growth Enhancement ◽  
Gene Construct ◽  
Average Size

Transgenic Pacific salmon have been produced by microinjection of a DNA construct consisting of chinook salmon (Oncorhynchus tshawytscha) growth hormone sequences driven by an ocean pout (Macrozoarces americanus) antifreeze protein promoter. This construct was retained in approximately 4% of fish derived from injected eggs, and resulted in dramatic enhancement of growth relative to controls. For coho salmon (O. kisutch) at 15 months of age, the average size of transgenic fish was more than 10-fold that of controls, with the largest fish more than 30-fold larger than nontransgenic siblings. Dramatic growth enhancement was also observed in transgenic rainbow trout (O. mykiss), cutthroat trout (O. clarki), and chinook salmon using this same gene construct. Transgenic coho salmon underwent precocious parr–smolt transformation during their first fall, approximately 6 months in advance of their nontransgenic siblings. At 2 years of age, five male transgenic coho salmon became sexually mature, and four of these transmitted the gene construct to sperm, the negative fish being transgenic in blood but not fin tissue. These results show that while some fish are mosaic for the gene construct in different tissues, most are transgenic in both germline and somatic tissue.

Stress of Formalin Treatment in Juvenile Spring Chinook Salmon (Oncorhynchus tshawytscha) and Steelhead Trout (Salmo gairdneri)

1974 ◽  
Vol 31 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Gary Wedemeyer ◽  
W. T. Yasutake
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Physiological Stress ◽  
Plasma Cholesterol ◽  
Respiratory Alkalosis ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
Significant Treatment ◽  
Treatment Side Effects ◽  
Blood Ph

The physiological stress of 200 ppm formalin treatments at 10 C is more severe in the juvenile steelhead trout (Salmo gairdneri) than in the spring chinook salmon (Oncorhynchus tshawytscha). In the steelhead, a marked hypochloremia follows a 1-hr treatment and recovery requires about 24 hr. During longer treatments, hypercholesterolemia together with reduced regulatory precision, hypercortisolemia, alkaline reserve depletion, and hypocapnia unaccompanied by a fall in blood pH occur — suggestive of compensated respiratory alkalosis. In the spring chinook, hypochloremia and reduced plasma cholesterol regulatory precision are the significant treatment side effects but recovery requires only a few hours.Formalin treatments also cause epithelial separation, hypertrophy, and necrosis in the gills of both fishes but again, consistent with the physiological dysfunctions, these are more severe in the steelhead.

Overwintering habitats of coho salmon (Oncorhynchus kisutch) and other juvenile salmonids in the Keogh River system, British Columbia

1988 ◽  
Vol 66 (1) ◽  
pp. 254-261 ◽  
Author(s):  
S. Swales ◽  
F. Caron ◽  
J. R. Irvine ◽  
C. D. Levings
Keyword(s):  
Gasterosteus Aculeatus ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Cutthroat Trout ◽  
River System ◽  
Salmo Gairdneri ◽  
Dolly Varden Char ◽  
Main River ◽  
The Mean ◽  
Density And Biomass

Catches of overwintering juvenile coho salmon (Oncorhynchus kisutch) in the Keogh River system, Vancouver Island, were higher in two small (8 and 25 ha), shallow (mean depth 2 – 3 m) lakes and their outlet and inlet streams than in the main river, where steelhead trout (Salmo gairdneri) were predominant. Dolly Varden char (Salvelinus malma), cutthroat trout (Salmo clarki), and threespine stickleback (Gasterosteus aculeatus) were also present in the lakes. The distribution of coho salmon in the lakes was restricted largely to areas close to the bank, with few fish being captured in offshore areas or in mid-water. Apparent differences in the abundance of coho salmon between the two lakes may have been related to differences in fish community composition, with sticklebacks being particularly numerous in Misty Lake, where catches of coho salmon were lower than in Long Lake. The population density and biomass of coho salmon overwintering in Long Lake were estimated to be 176 fish/ha and 1.14 kg ha−1, respectively. The mean length of coho salmon in the lakes was greater than that of coho salmon in the tributary streams and main river, and the mean length of the salmon in the lakes generally increased with distance away from shore.

Relation of Water Temperature to Flexibacter columnaris Infection in Steelhead Trout (Salmo gairdneri), Coho (Oncorhynchus kisutch) and Chinook (O. tshawytscha) Salmon

1975 ◽  
Vol 32 (9) ◽  
pp. 1553-1559 ◽  
Author(s):  
R. A. Holt ◽  
J. E. Sanders ◽  
J. L. Zinn ◽  
J. L. Fryer ◽  
K. S. Pilcher
Keyword(s):  
Water Temperature ◽  
Experimental Infection ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Disease Process ◽  
Salmo Gairdneri ◽  
Contact Method ◽  
Steelhead Trout ◽  
Time To Death

The effect of water temperature upon mortality from experimental infection by Flexibacter columnaris and on mean time to death was investigated in juvenile steelhead trout (Salmo gairdneri), coho salmon (Oncorhynchus kisutch), and spring chinook salmon (Oncorhynchus tshawytscha). Eight temperatures increasing from 3.9 to 23.3 C (39 to 74 F) by increments of 2.8 C (5 F) were studied. Fish were infected by the direct contact method whereby a suspension of the pathogen was added to the water. It was found that at temperatures of 9.4 C (49 F) and below, no deaths due to the experimental infection with F. columnaris occurred. At 12.2 C (54 F) mortality varied from 4 to 20% among the three species, and increased progressively with increasing temperature to 100% in steelhead trout and coho salmon at 20.5 C (69 F), and 70% in chinook salmon at that temperature. With all three salmonid species, an inverse linear relationship was found between water temperature and the log10 of the mean number of days from exposure to death. This means that as the temperature increased above 12.2 C (54 F), the disease process was progressively accelerated, resulting in a minimum time to death at 20.5 or 23.3 C (69 or 74 F) and a maximum at 12.2 C (54 F). The results indicate that under the conditions of these experiments, columnaris disease in salmonids was completely suppressed by water temperatures of 9.4 C (49 F) or below.

Current Response and Agonistic Behavior in Newly Emerged Fry of Chinook Salmon, Oncorhynchus tshawytscha, from Ocean- and Stream- Type Populations

1986 ◽  
Vol 43 (3) ◽  
pp. 565-573 ◽  
Author(s):  
Eric B. Taylor ◽  
P. A. Larkin
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
River Estuary ◽  
Early Summer ◽  
Mirror Image ◽  
Current Response ◽  
Fraser River ◽  
Life History Pattern ◽  
Stream Type

In Slim Creek, a tributary to the upper Fraser River east of Prince George, B.C., chinook salmon (Oncorhynchus tshawytscha) fry summer and overwinter in their natal stream before migrating seaward as yearlings; they are "stream-type" in juvenile life history pattern. From the Harrison River, a tributary to the lower Fraser River, chinook fry migrate to the Fraser River estuary sometime during their first spring or early summer; they are "ocean-type." Newly emerged chinook fry from Slim Creek showed a stronger positive current response, were more aggressive in mirror image stimulation tests and intra- and inter-specific (with coho salmon (O. kisutch) fry) stream tank tests, and had larger and more brightly colored median fins than chinook fry from the Harrison River. These differences between Slim Creek and Harrison River chinook fry are in a direction consistent with their different patterns of length of freshwater residence as juveniles, since aggressive behavior, positive rheotaxis, and bright fin coloration are important components of extended stream residence in salmonids.

Winter habitat preferences of juvenile salmonids in two interior rivers in British Columbia

1986 ◽  
Vol 64 (7) ◽  
pp. 1506-1514 ◽  
Author(s):  
S. Swales ◽  
R. B. Lauzier ◽  
C. D. Levings
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Habitat Preferences ◽  
Main Channel ◽  
Steelhead Trout ◽  
Winter Habitat ◽  
Main Species ◽  
Juvenile Salmonids ◽  
Side Channels

The winter distribution and abundance of juvenile salmonids was investigated in various main channel and off-channel habitats in the Coldwater and Nicola rivers in the southern interior region of British Columbia. Catches were generally low in all main channel habitats, with coho salmon and steelhead trout being most abundant and chinook salmon and Dolly Varden char being present in smaller numbers. Coho salmon and steelhead trout catches were generally highest in pools with abundant instream and riparian cover. Steelhead trout was the main species in riprap bank protected areas, although catches were generally low. Highest overall catches were recorded in side channels and off-channel ponds, where water temperatures were usually several degrees higher than in the main river. Coho salmon was the main species in the two Coldwater off-channel ponds with overwintering populations of approximately 4000 and 1000 in 1- and 0.1-ha ponds, respectively (0.4–1.5 fish/m2): overwinter survival of coho salmon in the ponds was estimated to be 87 and 54%, respectively. High densities of coho salmon were also recorded in side channels on the Nicola River (1.5–1.8 fish/m2), together with smaller numbers of chinook salmon and steelhead trout (0.2–0.3 fish/m2). Growth in ponds and side channels appeared to be faster than in main channel habitats. We conclude that juvenile salmonids in the rivers investigated showed considerable habitat segregation during the winter. As in coastal rivers, juvenile coho salmon made extensive use of off-channel ponds, while rainbow trout and chinook salmon were generally most abundant in riprap and deep pools containing log debris, respectively.

Endohelminths of salmonids from two localities in eastern Lake Michigan, with emphasis on Echinorhynchus salmonis

1989 ◽  
Vol 67 (6) ◽  
pp. 1604-1607 ◽  
Author(s):  
Patrick M. Muzzall
Keyword(s):  
Chinook Salmon ◽  
Salmo Trutta ◽  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salvelinus Namaycush ◽  
Salmo Gairdneri ◽  
Brown Trout Salmo Trutta

Adult salmonids (101 chinook salmon, Oncorhynchus tshawytscha; 7 coho salmon, Oncorhynchus kisutch; 56 lake trout, Salvelinus namaycush; 6 steelhead, Salmo gairdneri; and 2 brown trout, Salmo trutta) were collected from eastern Lake Michigan (Ludington and Manistee, Michigan) in July–September 1986, and examined for helminths. Eight species (three Cestoda, three Nematoda, two Acanthocephala) were found in the digestive tract and other viscera. Echinorhynchus salmonis and Eubothrium salvelini were the most common helminths found. The intensity of E. salmonis significantly increased as chinook salmon became older and longer.

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