Ceratomyxa shasta is a myxozoan parasite identified as a contributor to salmon mortality in the Klamath River, USA. The parasite has a complex life cycle involving a freshwater polychaete, Manayunkia speciosa and a salmonid. As part of ongoing research on how environmental parameters influence parasite establishment and replication, we designed...
Ceratomyxa shasta is a myxozoan parasite identified as a contributor to salmon mortality in the Klamath River, USA. The parasite has a complex life cycle involving a freshwater polychaete, Manayunkia speciosa and a salmonid. As part of ongoing research on how environmental parameters influence parasite establishment and replication, we designed...
Ceratomyxa shasta is a myxozoan parasite identified as a contributor to salmon mortality in the Klamath River, USA. The parasite has a complex life cycle involving a freshwater polychaete, Manayunkia speciosa and a salmonid. As part of ongoing research on how environmental parameters influence parasite establishment and replication, we designed...
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velocity on the Ceratomyxa shasta infectious cycle
Sarah J. Bjork and JerriL. Bartholomew
Ceratomyxa shasta is a myxozoan parasite identified as a contributor to salmon mortality in the Klamath River, USA. The parasite has a complex life cycle involving a freshwater polychaete, Manayunkia speciosa and a salmonid. As part of ongoing research on how environmental parameters influence parasite establishment and replication, we designed...
Aseries of dams on the Deschutes River, Oregon, act as migration barriers that segregate the river system into upper
and lower basins. Proposed fish passage between basins would reunite populations of native potamodromous fish and
allow anadromous fish of Deschutes River origin access to the upper basin. We assessed the...
The distribution of the freshwater myxozoan parasite Ceratonova shasta in the Pacific Northwest of North America is limited to overlap in the ranges of its 2 hosts: the polychaete Manyunkia sp., and Pacific salmonids. Studies in the Klamath River (Oregon/California) and Deschutes River (Oregon), showed that the parasite population is...
Water temperature influences almost every biological and physiological process of salmon, including disease resistance. In the Klamath River (California), current thermal conditions are considered sub-optimal for juvenile salmon. In addition to borderline temperatures, these fish must contend with the myxozoan parasite Ceratomyxa shasta, a significant cause of juvenile salmonid mortality...
The removal of dams on a river is one potential tool for the ecological restoration of native salmonid fishes. However, the removal of barriers also introduces risks, such as the introduction of fish pathogens into previously isolated populations. The proposed removal of four dams on the Klamath River, Oregon–California, provides...
Native to the Pacific Northwest, Ceratomyxashastais a myxosporeanparasite that infects wild and cultivated salmon and has a significance impact on its population in the Klamath River basin. The study suggests that the transmission of mixed genotypes of the parasite are common in Chinook salmon but the age of the fish...
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Acknowledgements
Charlene Hurst
Dr. JerriBartholomew
Everyone at the Salmon Disease Lab and Bartholomew’s Lab
Native to the Pacific Northwest, Ceratomyxashastais a myxosporeanparasite that infects wild and cultivated salmon and has a significance impact on its population in the Klamath River basin. The study suggests that the transmission of mixed genotypes of the parasite are common in Chinook salmon but the age of the fish...
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and Persistence of Ceratomyxa shasta
Peter Wong, Charlene N. Hurst, R. Adam Ray, and JerriL
The freshwater trematode Nanophyetus salmincola has been demonstrated to impair salmonid immune function and resistance to the marine pathogen Vibrio anguillarum, potentially resulting in ocean mortality. We examined whether infection by the parasite N. salmincola similarly increases mortality of juvenile Chinook Salmon Oncorhynchus tshawytscha when they are exposed to the...
Parasites and pathogens influence the size and stability of wildlife populations, yet many population models ignore
the population-level effects of pathogens. Standard survival analysis methods (e.g., accelerated failure time models)
are used to assess how survival rates are influenced by disease. However, they assume that each individual is equally
susceptible...
Abstract: Myxobolus squamalis is a myxozoan skin parasite first reported from rainbow trout (Oncorhynchus mykiss). Identification of the parasite based on myxospore morphology is unreliable because M. squamalis is similar to several other myxobolids that share host species and geographic ranges. The only ssrRNA gene sequence available for M. squamalis...
Native to the Pacific Northwest, Ceratomyxashastais a myxosporeanparasite that infects wild and cultivated salmon and has a significance impact on its population in the Klamath River basin. The study suggests that the transmission of mixed genotypes of the parasite are common in Chinook salmon but the age of the fish...
The myxozoan parasite Ceratomyxa shasta is a significant pathogen of juvenile salmonids in the Pacific Northwest of North America and is limiting recovery of Chinook (Oncorhynchus tshawytscha) and coho (O. kisutch) salmon populations in the Klamath River. We conducted a 5-year monitoring program that comprised concurrent sentinel fish exposures and...
We investigated intra-specific variation in the response of salmon to infection with the
myxozoan Ceratomyxa shasta by comparing the progress of parasite infection and measures of
host immune response in susceptible and resistant Chinook salmon Oncorhynchus tshawytscha at
days 12, 25 and 90 post exposure. There were no differences in...
Monoclonal antibodies (Mabs) were produced against the
myxosporean parasite, Ceratomyxa shasta, and were characterized
by indirect immunofluorescent techniques, western blot analysis,
and immunoelectron microscopy. The resulting Mabs reacted
specifically with the trophozoite and sporoblast stages of the
parasite, but not with the mature spore, indicating that certain
antigens are stage-specific....
In spite of the high family demands associated with having an infant, an increasing number of women are choosing to retain close ties to the labor force during this period. This study explored the employment adjustments and job satisfaction of a group of women who became mothers for the first...
The recent identification of multiple genotypes of the salmonid parasite Ceratonova shasta with different virulence levels in Chinook salmon (Oncorhynchus tshawytscha) suggests that it may be possible to immunize fish against subsequent infection and disease. We hypothesized that exposure of Chinook salmon to the less virulent parasite genotype (II) prior...
The recent identification of multiple genotypes of the salmonid parasite Ceratonova shasta with different virulence levels in Chinook salmon (Oncorhynchus tshawytscha) suggests that it may be possible to immunize fish against subsequent infection and disease. We hypothesized that exposure of Chinook salmon to the less virulent parasite genotype (II) prior...
The recent identification of multiple genotypes of the salmonid parasite Ceratonova shasta with different virulence levels in Chinook salmon (Oncorhynchus tshawytscha) suggests that it may be possible to immunize fish against subsequent infection and disease. We hypothesized that exposure of Chinook salmon to the less virulent parasite genotype (II) prior...
The recent identification of multiple genotypes of the salmonid parasite Ceratonova shasta with different virulence levels in Chinook salmon (Oncorhynchus tshawytscha) suggests that it may be possible to immunize fish against subsequent infection and disease. We hypothesized that exposure of Chinook salmon to the less virulent parasite genotype (II) prior...
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to
Ceratonova shasta (Myxozoa)
Hurst, C. N., & Bartholomew, J. L. (2015). Lack of Protection
The recent identification of multiple genotypes of the salmonid parasite Ceratonova shasta with different virulence levels in Chinook salmon (Oncorhynchus tshawytscha) suggests that it may be possible to immunize fish against subsequent infection and disease. We hypothesized that exposure of Chinook salmon to the less virulent parasite genotype (II) prior...
Transmission dynamics of the actinospore stage of Ceratomyxa shasta to the salmonid host were investigated under field and laboratory conditions. The number of parasites transmitted and the transmission rate were compared between 2 different exposure durations and also among different water velocities, by means of field exposures. Under laboratory conditions,...
In mammals, CCR7 is the chemokine receptor for the CCL19 and CCL21 chemokines, molecules with a major role in the recruitment of lymphocytes to lymph nodes and Peyer´s patches in the intestinal mucosa, especially naïve T lymphocytes. In the current work, we have identified a CCR7 homologue in rainbow trout...
Ceratonova gasterostea n. gen. n. sp. is described from the intestine of freshwater Gasterosteus aculeatus L. from the Klamath River, California. Myxospores are arcuate, 22.4 +/- 2.6 μm thick, 5.2 +/- 0.4 μm long, posterior angle 45 +/- 24°, with 2 sub-spherical polar capsules, diameter 2.3 +/- 0.2 μm, which...
Severe infection by the endemic myxozoan parasite, Ceratonova (synonym, Ceratomyxa) shasta, has been associated with declines in and impaired recovery efforts of populations of fall-run Chinook Salmon Oncorhynchus tshawytscha in the Klamath River, California. The parasite has a complex life cycle involving a polychaete worm host as well as a...