Ceratomyxa shasta: Longevity, Distribution, Timing, and Abundance of the Infective Stage In Central Oregon

1983 ◽  
Vol 40 (10) ◽  
pp. 1622-1632 ◽  
Author(s):  
Donald E. Ratliff
Keyword(s):  
Rainbow Trout ◽  
River Water ◽  
Salmo Gairdneri ◽  
Infective Stage ◽  
Host Fish ◽  
Susceptible Host ◽  
River Temperature ◽  
Test Fish ◽  
Peak Abundance ◽  
Deschutes River

Characteristics of the infective stage of Ceratomyxa shasta were studied in the Deschutes River of central Oregon from 1972 through 1981. The infective stage remained viable < 10 d in Deschutes River water maintained in aerated, river-temperature-controlled aquaria. Live-cage exposures of susceptible rainbow trout (Salmo gairdneri) indicated that infectious C. shasta emanate from the bottoms of two reservoirs. Epilimnions of both reservoirs did not contain the infective stage during thermally stratified periods. Infectious C. shasta originating in one reservoir passed down the Deschutes and Columbia rivers. During spring and summer, infectious C. shasta in the other reservoir did not reach the outlet, located 56 m above the bottom. In the Deschutes River, the infective period began before March 31 in 1978, between April 3 and 10 in 1979, and between April 16 and 23 in 1981 when river temperatures were between 6.9 and 8.6 °C. Consecutive exposures of trout to the same water in aquaria indicated that all infectious C. shasta were removed or inactivated during initial exposures. Progressively doubling numbers of test fish exposed in different aquaria showed that one C. shasta is capable of causing the death of one susceptible fingerling rainbow trout. Peak abundance of C. shasta in Deschutes River water during 1979 was estimated at 148 infectious units/m3 on June 4. Abundance decreased significantly between 1978 and 1981, presumably because of elimination of ceratomyxosis-caused deaths of hatchery rainbow trout and associated spore deposition in one reservoir. Both the formation of reservoirs and liberation of susceptible host fish can lead to an increased number of C. shasta, and result in serious C. shasta-induced losses in native salmonid populations.

Effect of Shock Exposures of Chlorine on the Plasma Electrolyte Concentrations of Adult Rainbow Trout (Salmo gairdneri)

1977 ◽  
Vol 34 (7) ◽  
pp. 1034-1039 ◽  
Author(s):  
Ibrahim H. Zeitoun ◽  
Leroy D. Hughes ◽  
Duane E. Ullrey
Keyword(s):  
Rainbow Trout ◽  
Plasma Concentrations ◽  
Water Environment ◽  
Retention Mechanism ◽  
Salmo Gairdneri ◽  
Plasma Electrolyte ◽  
Fish Blood ◽  
Plasma Electrolytes ◽  
Test Fish ◽  
Copper Zinc

Blood was pooled from randomly selected 3-yr-old rainbow trout (Salmo gairdneri) before addition of chlorine to their water environment and afterward when fish began to gulp for air and lose equilibrium. In five duplicate tests, plasma concentrations of phosphorus, magnesium, iron, copper, zinc, and potassium increased substantially in the stressed fish. Calcium concentration was also higher, but not significantly so in the plasma of the test fish as compared with those of the controls. Sodium was the only electrolyte that dropped substantially (P < 0.01) in the test fish as compared with the controls.Chlorine toxicity appeared to disturb the mineral homeostasis in the fish blood. Rapid recruitment of electrolytes from the environment and movement into the plasma, a strong mineral retention mechanism, or mobilization of body mineral stores worked together or individually to compensate for those minerals lost with water during hemoconcentration. Key words: rainbow trout, plasma electrolytes, chlorine, hemolysis, hematology, toxicology

Some Factors in Susceptibility of Juvenile Rainbow Trout and Chinook Salmon to Chondrococcus columnaris

1971 ◽  
Vol 28 (11) ◽  
pp. 1739-1743 ◽  
Author(s):  
M. P. Fujihara ◽  
P. A. Olson ◽  
R. E. Nakatani
Keyword(s):  
Immune Response ◽  
Rainbow Trout ◽  
Water Temperature ◽  
River Water ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Response Times ◽  
Salmo Gairdneri ◽  
Subsequent Infection ◽  
Columnaris Disease

Susceptibility of juveniles of chinook salmon (Oncorhynchus tshawytscha) and rainbow trout (Salmo gairdneri) to Chondrococcus columnaris disease appeared to be influenced by age offish, crowding, and water temperature. Rainbow trout of about 1 g and chinook salmon of about 3 g were less susceptible than smaller fish, and tests with chinook salmon suggested that age was more important than weight. When chinook salmon averaging 4.3 g were exposed from July to October to the pathogen in river water, mortality ranged from 1.0% in a trough with 50 fish to 12% in one with 900. Mortality of rainbow trout averaging 2.4 g that were exposed to the pathogen in trough river water averaged 4.7–22% after 4 weeks, at temperatures from 17.2 to 17.8 C; the survivors, however, were generally resistant to subsequent infection, suggesting development of an immune response. Times to 100% mortality of sibling chinook salmon averaging 3.9 g that were exposed for 25 min to about 2.5 × 105 organisms per liter of sterile river water were about 19 hr at 10 C and 8 hr at 22 C. Survival of rainbow trout was higher when they were held at 2.2 degrees C below than when held at 2.2 degrees C above seasonal river temperatures.

The development of Philonema oncorhynchi (Nematoda: Philometridae) in Cyclops bicuspidatus in relation to temperature

1969 ◽  
Vol 47 (3) ◽  
pp. 307-312 ◽  
Author(s):  
Ronald C. Ko ◽  
James R. Adams
Keyword(s):  
British Columbia ◽  
Rainbow Trout ◽  
Larval Development ◽  
Sockeye Salmon ◽  
Natural Infection ◽  
Salmo Gairdneri ◽  
Infective Stage ◽  
Final Size ◽  
Rate Of Development ◽  
Larval Stages

Development of Philonema oncorhynchi was followed in Cyclops bicuspidatus kept at 4°, 10°, and 15 °C. The nematode molted twice in the haemocoel of copepods. Three larval stages are described. The final size of the infective stage was unaffected by temperature. The rate of larval development was directly proportional to temperature between 4° and 15 °C. An increase of 5 °C halved the rate. The significance of these findings to the natural infection of sockeye salmon in Cultus Lake, British Columbia, is discussed.The development of P. agubernaculum from the rainbow trout, Salmo gairdneri, was studied at 10 °C by the same methods. Morphological features and rate of development were similar to those of P. oncorhynchi.

Antibody Production and Immune Responses of Rainbow Trout and Coho Salmon to Chondrococcus columnaris

1971 ◽  
Vol 28 (9) ◽  
pp. 1253-1258 ◽  
Author(s):  
M. P. Fujihara ◽  
R. E. Nakatani
Keyword(s):  
Rainbow Trout ◽  
Immune Responses ◽  
Coho Salmon ◽  
Salmo Gairdneri ◽  
Oral Vaccination ◽  
Active Immunity ◽  
Columnaris Disease ◽  
Antibody Titers ◽  
Test Fish ◽  
Disease Free

Active immunity to Chondrococcus columnaris disease was established in coho salmon (Oncorhynchus kisutch) approximately 3 months old by oral vaccination with heat-killed cells. Average agglutinating titers were 1:17 for control survivors and 1:168 for the orally vaccinated salmon. When rainbow trout (Salmo gairdneri) approximately 3 months old were exposed in a trough to C. columnaris present as a natural contaminant in Columbia River water, 52% of the fish died during the first 6 weeks of the test. Fish that survived the exposure were generally resistant to subsequent challenge. Many age 1 + rainbow trout that survived the C. columnaris infection as juveniles, when sampled after several months of reexposure to the disease, were immune carriers of the pathogen and developed agglutinating antibody titers ranging from 1:80 to 1:640. Titers up to 1:5120 were developed in disease-free yearling rainbow trout by parenteral vaccination.

Temperature Selection of Rainbow Trout (Salmo gairdneri) Fingerlings in Vertical and Horizontal Gradients

1971 ◽  
Vol 28 (11) ◽  
pp. 1801-1804 ◽  
Author(s):  
R. W. McCauley ◽  
W. L. Pond
Keyword(s):  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Temperature Preference ◽  
Temperature Selection ◽  
Horizontal Gradients ◽  
Significant Difference ◽  
Preferred Temperatures ◽  
Laboratory Investigations ◽  
Horizontal Temperature Gradients ◽  
Selection Of

Preferred temperatures of underyearling rainbow trout (Salmo gairdneri) were determined in both vertical and horizontal temperature gradients. No statistically significant difference was found between the preferred temperatures by the two different methods. This suggests that the nature of the gradient plays a lesser role than generally believed in laboratory investigations of temperature preference.

scholarly journals The Distribution of 35S-Sulfadiazine and 14G-Trimethoprim in Rainbow Trout, Salmo Gairdneri

1979 ◽  
Vol 20 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Torill Bergsjø ◽  
Inger Nafstad ◽  
Kristian Ingebrigtsen
Keyword(s):  
Rainbow Trout ◽  
Salmo Gairdneri
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