Ceratomyxa shasta (Myxosporida) Disease in Chum Salmon (Oncorhynchus keta) in British Columbia

1975 ◽  
Vol 32 (9) ◽  
pp. 1640-1643 ◽  
Author(s):  
L. Margolis ◽  
T. P. T. Evelyn
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Host Record ◽  
Oncorhynchus Keta ◽  
New Host ◽  
Chum Salmon Oncorhynchus Keta ◽  
New Host Record ◽  
Natural Range ◽  
Juvenile Chum Salmon

Infections with the myxosporidan Ceratomyxa shasta Noble, 1950 were confirmed in four juvenile chum salmon (Oncorhynchus keta) caught at sea near Nanaimo in 1965 and 1968. These cases represent a new host record for C. shasta and a northward extension of the parasite’s known natural range. Ceratomyxosis was also presumptively diagnosed in a coho salmon (Oncorhynchus kisutch) in British Columbia.

Influence of the Abundance, Size, and Yolk Reserves of Juvenile Chum Salmon (Oncorhynchus keta) on Predation by Freshwater Fishes in a Small Coastal Stream

1987 ◽  
Vol 44 (2) ◽  
pp. 236-243 ◽  
Author(s):  
Kurt L. Fresh ◽  
Steven L. Schroder
Keyword(s):  
Chum Salmon ◽  
Coho Salmon ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Predator Prey ◽  
Chum Salmon Oncorhynchus Keta ◽  
Salmon Fry ◽  
Juvenile Chum Salmon ◽  
Controlled Flow ◽  
The Relationship

Predator–prey interactions between juvenile chum salmon (Oncorhynchus keta) and piscivores were studied in a small coastal stream and in sections of a controlled-flow channel. The predators were primarily large [Formula: see text] rainbow trout (Salmo gairdneri) and large [Formula: see text] coho salmon (O. kisutch). The relationship between chum salmon fry abundance and the quantity consumed by predators suggested a type II functional response. Neither prey size nor prey abundance influenced predation, but predators did select fry with relatively high yolk reserves. Our results suggest that the numbers of juvenile chum salmon needed to satiate predators and to enhance fry survival are attainable by enhancement projects located on smaller rivers and streams.

scholarly journals Neural Stem Cells/Neuronal Precursor Cells and Postmitotic Neuroblasts in Constitutive Neurogenesis and After ,Traumatic Injury to the Mesencephalic Tegmentum of Juvenile Chum Salmon, Oncorhynchus keta

2020 ◽  
Vol 10 (2) ◽  
pp. 65
Author(s):  
Pushchina ◽  
Kapustyanov ◽  
Varaksin
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Progenitor Cells ◽  
Chum Salmon ◽  
Precursor Cells ◽  
Oncorhynchus Keta ◽  
Neuronal Precursor ◽  
Chum Salmon Oncorhynchus Keta ◽  
Neuronal Precursor Cells ◽  
Juvenile Chum Salmon

The proliferation of neural stem cells (NSCs)/neuronal precursor cells (NPCs) and the occurrence of postmitotic neuroblasts in the mesencephalic tegmentum of intact juvenile chum salmon, Oncorhynchus keta, and at 3 days after a tegmental injury, were studied by immunohistochemical labeling. BrdU+ constitutive progenitor cells located both in the periventricular matrix zone and in deeper subventricular and parenchymal layers of the brain are revealed in the tegmentum of juvenile chum salmon. As a result of traumatic damage to the tegmentum, the proliferation of resident progenitor cells of the neuroepithelial type increases. Nestin-positive and vimentin-positive NPCs and granules located in the periventricular and subventricular matrix zones, as well as in the parenchymal regions of the tegmentum, are revealed in the mesencephalic tegmentum of juvenile chum salmon, which indicates a high level of constructive metabolism and constitutive neurogenesis. The expression of vimentin and nestin in the extracellular space, as well as additionally in the NSCs and NPCs of the neuroepithelial phenotype, which do not express nestin in the control animals, is enhanced during the traumatic process. As a result of the proliferation of such cells in the post-traumatic period, local Nes+ and Vim+ NPCs clusters are formed and become involved in the reparative response. Along with the primary traumatic lesion, which coincides with the injury zone, additional Nes+ and Vim+ secondary lesions are observed to form in the adjacent subventricular and parenchymal zones of the tegmentum. In the lateral tegmentum, the number of doublecortin-positive cells is higher compared to that in the medial tegmentum, which determines the different intensities and rates of neuronal differentiation in the sensory and motor regions of the tegmentum, respectively. In periventricular regions remote from the injury, the expression of doublecortin in single cells and their groups significantly increases compared to that in the damage zone.

Growth rate characteristics of juvenile chum salmon Oncorhynchus keta originating from the Pacific coast of Japan and reaching Konbumori, eastern Hokkaido

2017 ◽  
Vol 83 (6) ◽  
pp. 987-996 ◽  
Author(s):  
Kentaro Honda ◽  
Tatsuya Kawakami ◽  
Kengo Suzuki ◽  
Kyuji Watanabe ◽  
Toshihiko Saito
Keyword(s):  
Growth Rate ◽  
Chum Salmon ◽  
Pacific Coast ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
The Pacific ◽  
Juvenile Chum Salmon ◽  
Pacific Coast Of Japan

Ogmogaster antarcticus Johnston, 1931 (Trematoda: Notocotylidae) from the bowhead whale, Balaena mysticetus L., at Barrow, Alaska

1979 ◽  
Vol 57 (6) ◽  
pp. 1347-1348 ◽  
Author(s):  
Larry M. Shults
Keyword(s):  
British Columbia ◽  
Geographic Distribution ◽  
Host Record ◽  
Bowhead Whale ◽  
Balaena Mysticetus ◽  
New Host ◽  
New Host Record

One specimen of the trematode Ogmogaster antarcticus Johnston, 1931 was recovered from a sample of bowhead whale ingesta collected at Barrow, Alaska. This represents a new host record and extends the known geographic distribution of this helminth some 5000 km by sea north of British Columbia, Canada.

Biochemical Genetic Survey and Stock Identification of Chum Salmon (Oncorhynchus keta) in British Columbia

1987 ◽  
Vol 44 (10) ◽  
pp. 1702-1713 ◽  
Author(s):  
T. D. Beacham ◽  
A. P. Gould ◽  
R. E. Withler ◽  
C. B. Murray ◽  
L. W. Barner
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Electrophoretic Analysis ◽  
South Coast ◽  
Oncorhynchus Keta ◽  
Stock Identification ◽  
Fraser River ◽  
Genetic Method ◽  
Chum Salmon Oncorhynchus Keta ◽  
Queen Charlotte Islands

We examined genetic variability using electrophoretic analysis of 83 chum salmon (Oncorhynchus keta) stocks in British Columbia and used regional differences in genotypic frequencies of seven polymorphic loci to estimate stock compositions in a number of commercial and experimental test fisheries. Chum salmon from five regions could be discriminated: Queen Charlotte islands, north and central coast, west coast of Vancouver Island, the Fraser River and its tributaries, and the south coast (rivers draining into Johnstone Strait and the Strait of Georgia). Allelic frequencies from 33 stocks were generally stable over a period of 2 yr or more. South coast chum salmon was the dominant run migrating through upper Johnstone Strait in October 1982–85. The genetic method of stock identification provided managers with the relative proportions of Fraser River and other groups of chum salmon in a number of fisheries and allowed managers to regulate more effectively the exploitation rate of Fraser River chum salmon.

Size Selective Predation by Juvenile Chum Salmon (Oncorhynchus keta) on Epibenthic Prey in Puget Sound

1975 ◽  
Vol 32 (8) ◽  
pp. 1419-1429 ◽  
Author(s):  
Robert J. Feller ◽  
Victor W. Kaczynski
Keyword(s):  
Chum Salmon ◽  
Prey Selection ◽  
Puget Sound ◽  
Harpacticoid Copepod ◽  
Gut Contents ◽  
Oncorhynchus Keta ◽  
Size Spectrum ◽  
Natural Diet ◽  
Chum Salmon Oncorhynchus Keta ◽  
Juvenile Chum Salmon

Analysis of gut contents shows that juvenile (30–50 mm) chum salmon (Oncorhynchus keta) in Puget Sound select epibenthic organisms as their primary prey. Harpacticoid copepods numerically comprised over 80% of their natural diet in two areas studied, while terrestrial insects and cladocerans were most important in a third area. Calculation of Ivlev (1961) electivity coefficients indicated high selectivity factors for harpacticoids at one site (+0.59 to +0.94). Comparison of fish gut contents with quantitative epibenthic pump samples of available prey shows that prey selection was size related, but opposite that currently reported in the literature (e.g. Brooks and Dodson 1965); that is, the smaller of the available prey was preferred. This was true for both the total available prey size spectrum and the harpacticoid copepod fraction of the prey spectrum. Large numbers of prey eaten per fish suggest that juvenile chum salmon may exert high predation pressure on nearshore epibenthic organisms in Puget Sound during spring.

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