Susceptibility of six Fraser chinook salmon stocks to Ceratomyxa shasta and the effects of salinity on ceratomyxosis

1984 ◽  
Vol 62 (6) ◽  
pp. 1081-1083 ◽  
Author(s):  
Hilda Lei Ching ◽  
D. R. Munday
Keyword(s):  
Chinook Salmon ◽  
Drainage System ◽  
Infected Fish ◽  
Estuarine Environment ◽  
Fish Stock ◽  
Fraser River ◽  
Time Of Death ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
High Level

Juvenile chinook salmon representing six stocks from the Fraser River drainage system were tested for susceptibility to the myxozoan pathogen, Ceratomyxa shasta. Of the six stocks tested, three were collected from the Nechako, Quesnel, and Clearwater rivers and three were hatchery stocks originating from Slim Creek and the Bowron and Birkenhead rivers. Of 302 fish exposed in August 1982, 95% became infected and died of ceratomyxosis. Susceptibility was high and time of death varied with the fish stock. High river temperatures during the 10 days of exposure and a high level of abundance of infectious C. shasta contributed to high mortalities of fish. Results of maintenance of infected fish in seawater indicated that ceratomyxosis is not attenuated and fish will continue to die after entering the estuarine environment.

Assessment of the Impact of the Myxosporean Parasite Ceratomyxa shasta on Survival of Seaward Migrating Juvenile Chinook Salmon, Oncorhynchus tshawytscha, from the Fraser River, British Columbia

1992 ◽  
Vol 49 (9) ◽  
pp. 1883-1889 ◽  
Author(s):  
L. Margolis ◽  
T. E. McDonald ◽  
D. J. Whitaker
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Infected Fish ◽  
Migration Route ◽  
Fraser River ◽  
Juvenile Chinook Salmon ◽  
Myxosporean Parasite ◽  
Juvenile Chinook ◽  
The Impact

Approximately 3.3% of more than 3500 seaward migrating juvenile chinook salmon (Oncorhynchus tshawytscha) collected from the lower reaches and off the mouth of the Fraser River, British Columbia, between March and August 1985–87 were infected with Ceratomyxa shasta (Protozoa: Myxosporea). The fish were held live for up to 151 d before examination to allow the infections to become patent. The first infected fish were detected in samples taken in late May to early June, approximately 4 wk after the river water temperature had reached 10 °C. By this time, 40–65% of the fish had been collected, indicating that the majority of the juvenile chinook salmon had left the Fraser River before the infective stage of the parasite was present. Significant differences in prevalence of C. shasta were associated with both the migration route chosen by the fish and their age. Fish that used the lower flow rate North Arm had a greater prevalence (6.8%) of infection than those that migrated down the Main Arm (2.1%). Age 0 fish had a significantly higher prevalence (5.2%) of C. shasta than the age 1 group (1.5%). It is concluded that C. shasta is not a major cause of mortality of downstream migrating juvenile Fraser River chinook salmon.

Bioconcentration of Chlorophenols by Juvenile Chinook Salmon (Oncorhynchus tshawytscha) Overwintering in the Upper Fraser River: Field and Laboratory Tests

1988 ◽  
Vol 23 (1) ◽  
pp. 100-113 ◽  
Author(s):  
I. H. Rogers ◽  
J. A. Servizi ◽  
C. D. Levings
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Cold Water ◽  
Pulp Mill ◽  
Wood Preservative ◽  
Fraser River ◽  
Reference Sites ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
River Fish

Abstract Juvenile chinook salmon were sampled from August 1986 to March 1987 at stations near Prince George and Quesnel, influenced by sewage and pulp mill discharges. Maximum densities of 0.2 fish·mࢤ2 were recorded. Salmon were collected at reference sites in November 1986 and at Agassiz in April 1987. Fingerling chinook were exposed at 0.7°C to a commercial wood preservative containing 2,3,4,6 - tetrachlorophenol (TeCP) and pentachlorophenol (PCP) in the laboratory to simulate winter conditions in the upper Fraser River. Fish exposed for 62 days to 2 ug·Lࢤ1 contained a mean of 224 ng·gࢤ1 TeCP and 431 ng·gࢤ1 PCP. Chlorophenol uptake in feral fish was low. However, 3,4,5-trichloro-guaiacol levels to 304 ng·gࢤ1 and tetrachloroguaiacol values to 136 ng·gࢤ1 were measured in March. Fish from Agassiz, 518 km downstream of Quesnel, also contained these two substances. Thus chinook salmon can bioconcentrate persistent chlorophenols and chloroguaiacols directly from cold water (< 1°C). The biological consequences are uncertain.

Cytochrome P450 1A and related measurements in juvenile chinook salmon (Oncorhynchus tshawytscha) from the Fraser River

2000 ◽  
Vol 57 (2) ◽  
pp. 405-413 ◽  
Author(s):  
J Y Wilson ◽  
R F Addison ◽  
D Martens ◽  
R Gordon ◽  
B Glickman
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Erod Activity ◽  
Dna Adduct ◽  
Clear Correlation ◽  
Fraser River ◽  
Juvenile Chinook Salmon ◽  
Liver Histopathology ◽  
Polycyclic Aromatic ◽  
Juvenile Chinook

Juvenile chinook salmon (Oncorhynchus tshawytscha) were captured at six sites on the upper Fraser, Nechako, and Thompson rivers, British Columbia, Canada. Biological responses were measured in the liver to assess the effects of contaminants on the fish before they began migration downstream. Both ethoxyresorufin-O-deethylase (EROD) activity and CYP 1A concentrations were significantly enhanced, being two- to three-fold higher in Fraser River samples compared with those fish from reference sites on the Nechako River. DNA adduct concentrations were two- to four-fold higher in Fraser River fish, although liver histopathology appeared unaffected. Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in the carcasses contributed to total contaminant burdens of less than 1 pg·g-1. Polycyclic aromatic hydrocarbon (PAH) metabolites were undetectable in nearly all samples of bile. There were strong correlations between EROD activity, CYP 1A induction, and DNA adduct concentrations but no clear correlation between these responses and PCDD, PCDF, or PCB concentrations.

Geographic and seasonal distribution of the infectious stage of Ceratomyxa shasta Noble, 1950, a myxozoan salmonid pathogen in the Fraser River system

1984 ◽  
Vol 62 (6) ◽  
pp. 1075-1080 ◽  
Author(s):  
Hilda Lei Ching ◽  
D. R. Munday
Keyword(s):  
Chinook Salmon ◽  
River System ◽  
Seasonal Distribution ◽  
Fraser River ◽  
Infective Stage ◽  
Time To Death ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
Infectious Stage ◽  
Mean Time

The infective stage of C. shasta was demonstrated to be present at two lower Fraser River sites. However, it was absent in the McGregor River, a tributary of the upper Fraser, and rarely present in the upper Fraser River near Prince George, B.C. Seasonally, the infective stage occurred in the lower Fraser River from late April to mid-November. In April 1983, 12% of 25 fish became infected with C. shasta, indicating a low onset of activity. In experiments in 1981, 10- and 20-day exposures of 216 juvenile chinook salmon resulted in increased infections of C. shasta, from 72 to 75% in May to 96 and 98% in July. Time to death decreased from a mean of 54 to 30 days from first exposure. In 1982, 5- and 10-day exposures resulted in deaths of 98% of 181 fish from August to November. Mean time to death increased from 27 to 48 days and was probably due to decreasing river temperatures. In November, 90% of the fish became infected at water temperatures of 4 – 6 °C.

Comparative resistance of Oregon (Big Creek) and British Columbia (Capilano) juvenile chinook salmon to the myxozoan pathogen, Ceratomyxa shasta, after laboratory exposure to Fraser River water

1984 ◽  
Vol 62 (7) ◽  
pp. 1423-1424 ◽  
Author(s):  
Hilda Lei Ching
Keyword(s):  
British Columbia ◽  
River Water ◽  
High Resistance ◽  
Chinook Salmon ◽  
Juvenile Fish ◽  
Fraser River ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
Infectious Stage ◽  
Laboratory Exposure

In a laboratory experiment conducted in the fall 1983, Oregon (Big Creek) and British Columbia (Capilano) hatchery Chinook salmon were exposed to Fraser River water containing the infectious stage of the myxozoan pathogen, Ceratomyxa shasta. The juvenile fish were exposed for 10 days in 370 L of water (74 L replaced every other day for 5 days). While only 1 of 21 Big Creek fish became infected, all 20 of the Capilano fish died of C. shasta within 40 days. The Big Creek fish demonstrated high resistance to the parasite while the Capilano fish had low resistance. These results were similar to those from field exposures in previous studies.

Ceratomyxa shasta (Myxozoa: Myxosporea) in juvenile chinook salmon (Oncorhynchus tshawytscha): experimental transmission and natural infections in the Fraser River, British Columbia

1985 ◽  
Vol 63 (7) ◽  
pp. 1737-1740 ◽  
Author(s):  
Susan M. Bower
Keyword(s):  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Developmental Stages ◽  
River Estuary ◽  
Fraser River ◽  
Experimental Transmission ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
Intraperitoneal Inoculation

Ceratomyxa shasta (mainly trophozoites) from the intestinal tract of a naturally infected juvenile chinook salmon (Oncorhynchus tshawytscha) developed in the coelom of laboratory-reared chinook salmon when inoculated intraperitoneally. All developmental stages were observed. Successful subpassages were accomplished by intraperitoneal inoculation of trophozoites and sporoblasts, but an infection did not develop when these stages were pipetted into the esophagus of susceptible fish. Heavy infections, including the presence of C. shasta sporoblasts or spores, were observed in 2 of 28 feral juvenile chinook salmon seined from the Fraser River estuary in late July and early August. Trophozoite-like cells were observed in six other chinook salmon from this group. No C. shasta were observed in 15 juvenile sockeye salmon (Oncorhynchus nerka) caught in the estuary along with the chinook salmon.

scholarly journals Characterizing Juvenile Chinook Salmon Residency and Early Growth in the Lower Fraser River Estuary

2019 ◽  
pp. 13-15
Author(s):  
Lia Chalifour ◽  
David Scott ◽  
Misty MacDuffee ◽  
John Dower ◽  
Terry Beacham ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
River Estuary ◽  
Early Growth ◽  
Fraser River ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook
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