Phoma herbarum, a Fungal Plant Saprophyte, as a Fish Pathogen

1975 ◽  
Vol 32 (9) ◽  
pp. 1648-1652 ◽  
Author(s):  
A. J. Ross ◽  
W. T. Yasutake ◽  
Steve Leek
Keyword(s):  
Rainbow Trout ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Histopathological Examination ◽  
Oncorhynchus Kisutch ◽  
Salmo Gairdneri ◽  
Fish Pathogen ◽  
Experimental Infections ◽  
Phoma Herbarum ◽  
Low Incidence

Phoma herbarum, a fungal plant saprophyte, was isolated from diseased hatchery-reared coho salmon (Oncorhynchus kisutch), chinook salmon (O. tshawytscha), and rainbow trout (Salmo gairdneri). The disease was observed at 10 national fish hatcheries in Washington and Oregon, but the low incidence of experimental infections indicate that it is only weakly contagious. Histopathological examination suggests that the air bladder is one of the primary organs infected. The visceral organs are also affected in both natural and experimental infections.

Physiological Response of Juvenile Coho Salmon (Oncorhynchus kisutch) and Rainbow Trout (Salmo gairdneri) to Handling and Crowding Stress in Intensive Fish Culture

1976 ◽  
Vol 33 (12) ◽  
pp. 2699-2702 ◽  
Author(s):  
Gary A. Wedemeyer
Keyword(s):  
Rainbow Trout ◽  
Feeding Behavior ◽  
Coho Salmon ◽  
Physiological Stress ◽  
Oncorhynchus Kisutch ◽  
Fish Distribution ◽  
Salmo Gairdneri ◽  
Crowding Stress ◽  
Normal Feeding ◽  
Intensive Fish Culture

Moving 4–5-in. coho salmon (Oncorhynchus kisutch) held in soft (20 ppm CaCO3) water from the relatively light loading density of 0.5 lb/ft3 to 1, 2, or 4 lb/ft3 (density index, DI = 0.1, 0.2, 0.4, 0.8) caused significant stress as indicated by loss of feeding behavior, but only minimal physiological disturbances, as indicated by lack of hyperglycemia or hypochloremia. However, moving them to 6 or 12 lb/ft3 (DI = 1.2, 2.4) caused significant physiological stress which required at least a week for recovery. Smolting coho salmon were physiologically stressed by population densities of 1 lb/ft3 or more and a subclinical corynebacterial kidney infection was activated. Rainbow trout (Salmo gairdneri) (4–5 in.) were physiologically stressed when moved and held at 1 lb/ft3 or more but retained normal feeding behavior. This indicates that handling and crowding stress will be minimized in softwater areas if densities in fish distribution trucks or in ponds or raceways during disease treatments are held to 0.1–0.5 lb/gal.

Viral Hemorrhagic Septicemia: Comparative Susceptibility of Rainbow Trout (Salmo gairdneri) and Hybrids (S. gairdneri × Oncorhynchus kisutch) to Experimental Infection

1976 ◽  
Vol 33 (5) ◽  
pp. 1205-1208 ◽  
Author(s):  
Wilma M. Ord ◽  
Monique Le Berre ◽  
Pierre de Kinkelin
Keyword(s):  
Rainbow Trout ◽  
Experimental Infection ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salmo Gairdneri ◽  
Viral Hemorrhagic Septicemia ◽  
Comparative Susceptibility

Rainbow trout (Salmo gairdneri) fry and yearlings were compared with hybrids of rainbow trout and coho salmon (Oncorhynchus kisutch) for susceptibility to viral hemorrhagic septicemia (VHS). In three trials, exposure to waterborne infectivity consistently resulted in a 77% mortality of rainbow trout fry while loss among the hybrid fry averaged only 11%. Tests showed survivors might be carriers of virus. Hybrid yearlings infected by gill brushing were fully refractory to VHS whereas mortality (3:8) and viremia were recorded among gill-infected rainbow trout yearlings.

Relation of Water Temperature to Ceratomyxosis in Rainbow Trout (Salmo gairdneri) and Coho Salmon (Oncorhynchus kisutch)

1975 ◽  
Vol 32 (9) ◽  
pp. 1545-1551 ◽  
Author(s):  
L. R. Udey ◽  
J. L. Fryer ◽  
K. S. Pilcher
Keyword(s):  
Rainbow Trout ◽  
Water Temperature ◽  
Coho Salmon ◽  
Geometric Mean ◽  
Oncorhynchus Kisutch ◽  
Experimental Period ◽  
Salmo Gairdneri ◽  
Percent Mortality ◽  
Temperature Levels ◽  
Mean Time

Juvenile rainbow trout (Salmo gairdneri) were exposed to infection with Ceratomyxa shasta transferred in groups of 25 to aquaria, and tempered to various temperature levels increasing from 3.9 to 23.3 C (39 to 74 F) by 2.8 degree C (5 degree F) increments. During a 237-day observation period mortality in the experimental groups averaged about 80%, and was independent of water temperature between 6.3 and 23.3 C (44 and 74 F). No deaths occurred at 3.9 C (39 F). The geometric-mean time from exposure to death, however, was definitely a function of temperature, increasing from 14 days at 23.3 C (74 F) to 155 days at 6.7 C (44 F).A similar experiment with juvenile coho salmon (Oncorhynchus kisutch) gave quite different results. In this species, percent mortality due to C. shasta increased progressively from 2% at 9.4 C (49 F) to 22% at 15.0 C (59 F) and 84% at 20.5 C (69 F). No deaths occurred at 3.9 or 6.7 C (39 or 44 F) during the 201-day experimental period. As with the rainbow trout, the geometric-mean time from exposure to death was temperature dependent, increasing from 12.5 days at 23.3 C (74 F) to 146 days at 9.4 C (49 F). The data indicate that ceratomyxosis in coho can be suppressed by water temperatures of 6.7 C (44 F) or below.

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.

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.

The Stress of Formalin Treatments in Rainbow Trout (Salmo gairdneri) and Coho Salmon (Oncorhynchus kisutch)

1971 ◽  
Vol 28 (12) ◽  
pp. 1899-1904 ◽  
Author(s):  
Gary Wedemeyer
Keyword(s):  
Rainbow Trout ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salmo Gairdneri ◽  
Acid Base Balance ◽  
Acid Base ◽  
Blood Ph ◽  
Base Balance ◽  
Ventilation Rates ◽  
Gill Function

Changes in gill function, acid–base balance and pituitary activation occurring during standard 200 ppm formalin treatments of juvenile rainbow trout (Salmo gairdneri) and coho salmon (Oncorhynchus kisutch) were compared. Plasma Cl−, Ca++, total CO2, and interrenal vitamin C in the trout declined continuously and in proportion to the exposure time, but the salmon were able to maintain these metabolic parameters at approximately initial levels. Blood pH and alkaline reserve regulation of the salmon was also less affected by formalin treatments, especially during prolonged exposures. The oxygen consumption of both species was depressed, but substantially more so in the trout than could be accounted for by decreased ventilation rates. Little frank hemolysis occurred in either species, but there was a significant bilirubinemia in the trout.

Changes in Gill Adenosinetriphosphatase Activity Associated with Parr–Smolt Transformation in Steelhead Trout, Coho, and Spring Chinook Salmon

1972 ◽  
Vol 29 (2) ◽  
pp. 167-171 ◽  
Author(s):  
W. S. Zaugg ◽  
L. R. McLain
Keyword(s):  
Atpase Activity ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
Similar Increase ◽  
Activity Increase ◽  
Fish Hatchery ◽  
Transport Atpase

The average Na+- and K+-stimulated adenosinetriphosphatase (ATPase) activity of microsomes from gills of hatchery-reared coho salmon (Oncorhynchus kisutch) increased from about 12 μmoles ATP hydrolyzed/mg protein per hr during February through mid-April to approximately 24 in mid-May. Larger fish developed higher activities than smaller fish. Hatchery-reared spring chinook salmon (O. tshawytscha) exhibited a similar increase 2–3 weeks earlier.In 2-year-old hatchery-reared steelhead trout (Salmo gairdneri), Na+-, K+-ATPase activities were elevated in some, but not all, smolt-appearing animals. Parr-appearing fish, including maturing males, showed no activity increase. When held in fresh water to July, steelhead smolts lost their silvery color and became more parr-like in appearance, and the previously elevated ATPase activity decreased to near pre-smolt levels. Yearling steelhead held at the laboratory showed a more consistent rise in ATPase activity.The increase in transport ATPase (Na+-, K+-stimulated) activity occurring during parr–smolt transformation is probably a preparatory step for saltwater adaption and may also be closely associated with migratory disposition.L'activité moyenne de l'adénosinetriphosphatase (ATPase) stimulée par Na+ et K+ dans les microsomes des branchies de saumons coho (Oncorhynchus kisutch) élevés en pisciculture augmente de 12 μmoles environ d'ATPase hydrolysée/mg de protéine par h de février à la mi-avril à 24 à la mi-mai. Les gros poissons développent une activité plus grande que les petits. Les saumons chinook de printemps (O. tshawytscha) élevés en pisciculture font preuve d'un accroissement semblable deux à trois semaines avant les saumons coho.

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