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• 1. [Article] Growth and food consumption of juvenile coho salmon exposed to natural and elevated fluctuating temperatures

  The growth and food consumption of juvenile coho salmon [Oncorhynchus kisutch (Walbaum)] exposed to natural and elevated fluctuating temperatures were studied in the laboratory with wild fish collected ...

  Citation × Citation Citation Abstract Copy Title: Growth and food consumption of juvenile coho salmon exposed to natural and elevated fluctuating temperatures Author: Everson, Larry B. The growth and food consumption of juvenile coho salmon [Oncorhynchus kisutch (Walbaum)] exposed to natural and elevated fluctuating temperatures were studied in the laboratory with wild fish collected from a salmonid rearing stream. Control temperatures were similar to the temperature regime of a natural stream and the elevated temperatures were increased incrementally 3-4 C and 7-8 C. Short-term, 30-day experiments were conducted during five different seasonal periods in 1969 and 1970. Concurrent long-term studies were carried out during the entire experimental period. Relationships between rates of food consumption, growth and food assimilation of the fish were determined for the different experimental temperature conditions during the short-term experiments. Relationships between maintenance ration and temperature were derived from curves relating rates of food consumption and growth. The efficiency of food assimilation was determined from measurements of the quantities of the food consumed and the amounts of fecal wastes produced. Caloric measurements were obtained from oxygen bomb calorimetry of the fish and food consumed, and from wet combustion of the fecal wastes collected during short intervals within each experiment. Bioenergetic measurements were used to estimate the major fates of the energy of food consumed under the different temperature conditions during a period of fluctuating high summer temperatures. Long-term studies were conducted over eight-month and four-month periods under temperature conditions similar to those of the short-term experiments. Growth rates of the juvenile coho salmon were obtained from measurement of changes in their wet weight during 15-day intervals. The growth rates of salmon at equivalent ration levels were compared between the short- and long-term experiments. Growth rates of juvenile coho salmon kept as controls were generally greater than those of fish exposed to elevated temperatures for each of the five short-term experiments. Increases of ration size generally ameliorated the effects of elevated temperatures on the salmon growth rates. Comparisons of the caloric values of coho salmon recorded for a natural rearing stream with those of experimentally fed fish suggest that wild fish subsist on a restricted ration. Results of the long-term studies showed that salmon exposed to naturally fluctuating temperatures in the laboratory and fed restricted rations reached sizes typical of downstream smolts in Oregon coastal streams, whereas the fish exposed to incremental temperature increases of 3-4 C and 7-8 C were respectively 25 and 47 percent smaller than the control fish. Comparison of results of studies based upon naturally fluctuating temperatures with those of other workers based upon constant temperatures indicates that at average temperatures above 20 C the fluctuation of temperature is favorable for coho salmon growth. The results of the study suggest that temperature criteria for juvenile coho salmon derived from measurements based upon constant temperatures may not be satisfactory for protecting the fish during the extended period of their freshwater existence. Measurements of the growth of the young salmon during long-term experiments indicated that any substantial increases of temperature would result in a reduction in the size of smolts. Significant reductions of juvenile salmon growth resulting from elevated stream temperatures could influence the production of salmon populations through decreased marine survival. Long-term studies of the fish as well as other components of stream communities influenced by elevated temperatures are necessary for establishing meaningful temperature criteria. Title: Growth and food consumption of juvenile coho salmon exposed to natural and elevated fluctuating temperatures Author: Everson, Larry B. The growth and food consumption of juvenile coho salmon [Oncorhynchus kisutch (Walbaum)] exposed to natural and elevated fluctuating temperatures were studied in the laboratory with wild fish collected from a salmonid rearing stream. Control temperatures were similar to the temperature regime of a natural stream and the elevated temperatures were increased incrementally 3-4 C and 7-8 C. Short-term, 30-day experiments were conducted during five different seasonal periods in 1969 and 1970. Concurrent long-term studies were carried out during the entire experimental period. Relationships between rates of food consumption, growth and food assimilation of the fish were determined for the different experimental temperature conditions during the short-term experiments. Relationships between maintenance ration and temperature were derived from curves relating rates of food consumption and growth. The efficiency of food assimilation was determined from measurements of the quantities of the food consumed and the amounts of fecal wastes produced. Caloric measurements were obtained from oxygen bomb calorimetry of the fish and food consumed, and from wet combustion of the fecal wastes collected during short intervals within each experiment. Bioenergetic measurements were used to estimate the major fates of the energy of food consumed under the different temperature conditions during a period of fluctuating high summer temperatures. Long-term studies were conducted over eight-month and four-month periods under temperature conditions similar to those of the short-term experiments. Growth rates of the juvenile coho salmon were obtained from measurement of changes in their wet weight during 15-day intervals. The growth rates of salmon at equivalent ration levels were compared between the short- and long-term experiments. Growth rates of juvenile coho salmon kept as controls were generally greater than those of fish exposed to elevated temperatures for each of the five short-term experiments. Increases of ration size generally ameliorated the effects of elevated temperatures on the salmon growth rates. Comparisons of the caloric values of coho salmon recorded for a natural rearing stream with those of experimentally fed fish suggest that wild fish subsist on a restricted ration. Results of the long-term studies showed that salmon exposed to naturally fluctuating temperatures in the laboratory and fed restricted rations reached sizes typical of downstream smolts in Oregon coastal streams, whereas the fish exposed to incremental temperature increases of 3-4 C and 7-8 C were respectively 25 and 47 percent smaller than the control fish. Comparison of results of studies based upon naturally fluctuating temperatures with those of other workers based upon constant temperatures indicates that at average temperatures above 20 C the fluctuation of temperature is favorable for coho salmon growth. The results of the study suggest that temperature criteria for juvenile coho salmon derived from measurements based upon constant temperatures may not be satisfactory for protecting the fish during the extended period of their freshwater existence. Measurements of the growth of the young salmon during long-term experiments indicated that any substantial increases of temperature would result in a reduction in the size of smolts. Significant reductions of juvenile salmon growth resulting from elevated stream temperatures could influence the production of salmon populations through decreased marine survival. Long-term studies of the fish as well as other components of stream communities influenced by elevated temperatures are necessary for establishing meaningful temperature criteria. Close

• 2. [Article] Relationship Between Temperature and Ceratomyxa shasta–Induced Mortality In Klamath River Salmonids

  This is the publisher’s final pdf. The published article is copyrighted by American Society of Parasitologists and can be found at: http://amsocparasit.org/.

  Citation × Citation Citation Abstract Copy Title: Relationship Between Temperature and Ceratomyxa shasta–Induced Mortality In Klamath River Salmonids Author: Bartholomew, Jerri L., Holt, Richard A., Ray, R. Adam This is the publisher’s final pdf. The published article is copyrighted by American Society of Parasitologists and can be found at: http://amsocparasit.org/. Title: Relationship Between Temperature and Ceratomyxa shasta–Induced Mortality In Klamath River Salmonids Author: Bartholomew, Jerri L., Holt, Richard A., Ray, R. Adam This is the publisher’s final pdf. The published article is copyrighted by American Society of Parasitologists and can be found at: http://amsocparasit.org/. Close

• 3. [Article] Effects of logging on the growth of juvenile coho salmon

  The objective of this research was to study the effects of increased water temperature characteristic of clearcut watersheds of Pacific coastal streams upon the growth rate of juvenile coho salmon. The ...

  Citation × Citation Citation Abstract Copy Title: Effects of logging on the growth of juvenile coho salmon Author: Iwanaga, Paul M. The objective of this research was to study the effects of increased water temperature characteristic of clearcut watersheds of Pacific coastal streams upon the growth rate of juvenile coho salmon. The natural temperature fluctuations of the stream were used in the study of growth of underyearling fish held in aquariums and fed at various consumption levels. Juvenile coho experiencing the cooler temperatures of the control stream demonstrated generally better growth rates than did those that experienced the warmer temperatures of the clearcut stream. The reduced maintenance requirements in the control experiment indicated a reduced basal metabolic demand, which allowed for a greater portion of the food consumed to be utilized for growth. This was particularly true at low levels of consumption. Growth rates of juvenile coho salmon in the wild state were found to be higher in the logged stream as compared to the unlogged stream. This difference from the experimental results is thought to be due to a change in availability and abundance of food. There was a marked decrease in the cutthroat trout population in the clearcut stream, which may have reduced competition for the coho salmon. Increased exposure of the stream to solar radiation also may have permitted en increase in primary production essential for small organisms upon which the juvenile coho feed. There was no apparent influence of infestation by salmon poisoning fluke on the condition of the juvenile coho. Title: Effects of logging on the growth of juvenile coho salmon Author: Iwanaga, Paul M. The objective of this research was to study the effects of increased water temperature characteristic of clearcut watersheds of Pacific coastal streams upon the growth rate of juvenile coho salmon. The natural temperature fluctuations of the stream were used in the study of growth of underyearling fish held in aquariums and fed at various consumption levels. Juvenile coho experiencing the cooler temperatures of the control stream demonstrated generally better growth rates than did those that experienced the warmer temperatures of the clearcut stream. The reduced maintenance requirements in the control experiment indicated a reduced basal metabolic demand, which allowed for a greater portion of the food consumed to be utilized for growth. This was particularly true at low levels of consumption. Growth rates of juvenile coho salmon in the wild state were found to be higher in the logged stream as compared to the unlogged stream. This difference from the experimental results is thought to be due to a change in availability and abundance of food. There was a marked decrease in the cutthroat trout population in the clearcut stream, which may have reduced competition for the coho salmon. Increased exposure of the stream to solar radiation also may have permitted en increase in primary production essential for small organisms upon which the juvenile coho feed. There was no apparent influence of infestation by salmon poisoning fluke on the condition of the juvenile coho. Close

• 4. [Article] Effects of elevated temperature on juvenile Coho salmon and benthic invertebrates in model stream communities

  Juvenile coho salmon (Oncorhynchus kisutch (Walbaum)) and aquatic invertebrates were subjected to experimentally increased, but naturally fluctuating, temperatures in a model stream channel. Coho of the ...

  Citation × Citation Citation Abstract Copy Title: Effects of elevated temperature on juvenile Coho salmon and benthic invertebrates in model stream communities Author: Iverson, Ronald Albert Juvenile coho salmon (Oncorhynchus kisutch (Walbaum)) and aquatic invertebrates were subjected to experimentally increased, but naturally fluctuating, temperatures in a model stream channel. Coho of the 1969, 1970, and 1971 year classes were reared in the heated model stream and in an unheated control stream, both located at the Oak Creek laboratory west of Corvallis, Oregon. The average increment of experimental over control temperature was 4.3 C over the entire experimental period of 22 months. Temperatures in the control stream were generally favorable for growth of coho if food organisms were scarce, while temperatures in the heated stream were favorable for growth if food organisms were abundant. Coho of the 1969 year class were reared for one winter as yearlings, and total production of this group was approximately the same in the two streams. Coho of the 1970 year class were reared from small fry to smolts over a one-year period. In this group, total production in the control stream was approximately twice as great as in the heated stream. While population size was nearly the same in the two streams, coho in the control stream grew much more rapidly than in the heated stream. Total production of coho of the 1971 year class, which were reared from the egg stage, was approximately five times as great in the control as in the heated stream when the experiment was terminated in August 1971. The difference in production resulted from larger population size and higher growth rate in the control stream. Production of aquatic stages of insects was approximately twice as great in the control as in the heated stream over the period May 1970-May 1971. This difference between streams was especially marked in mayfly and stonefly nymphs, which were the most abundant insects in both streams, and which appeared to be the major sources of food for coho. The reduced growth rates of coho in the heated as compared to the control stream probably resulted from effects of temperature on the invertebrate food supply as well as from direct effects of temperature on the coho in raising their standard metabolic rates so that energy available for growth was reduced. Winter growth rates of coho in the heated stream were generally higher than in the control, probably as a result of an increase in appetite with increased temperature. Winter growth rates of the 1969 year class were high, probably because young coho fry were available as food. Winter growth rates of coho of the 1970 year class, which had a more natural food supply, were low in both streams. The insect fauna of the Oak Creek area is probably adapted to cool water temperatures, and this adaptation presumably contributed to the reduced insect production in the heated model stream. If heat tolerant species of insects were present in or able to migrate into a stream receiving a heated effluent, the simplication of the invertebrate fauna caused by the thermal pollution might increase the amount of food available to the top carnivore. Such heat-tolerant forms apparently were not present in the model streams or, if present, were not able to contribute significantly to total production. Title: Effects of elevated temperature on juvenile Coho salmon and benthic invertebrates in model stream communities Author: Iverson, Ronald Albert Juvenile coho salmon (Oncorhynchus kisutch (Walbaum)) and aquatic invertebrates were subjected to experimentally increased, but naturally fluctuating, temperatures in a model stream channel. Coho of the 1969, 1970, and 1971 year classes were reared in the heated model stream and in an unheated control stream, both located at the Oak Creek laboratory west of Corvallis, Oregon. The average increment of experimental over control temperature was 4.3 C over the entire experimental period of 22 months. Temperatures in the control stream were generally favorable for growth of coho if food organisms were scarce, while temperatures in the heated stream were favorable for growth if food organisms were abundant. Coho of the 1969 year class were reared for one winter as yearlings, and total production of this group was approximately the same in the two streams. Coho of the 1970 year class were reared from small fry to smolts over a one-year period. In this group, total production in the control stream was approximately twice as great as in the heated stream. While population size was nearly the same in the two streams, coho in the control stream grew much more rapidly than in the heated stream. Total production of coho of the 1971 year class, which were reared from the egg stage, was approximately five times as great in the control as in the heated stream when the experiment was terminated in August 1971. The difference in production resulted from larger population size and higher growth rate in the control stream. Production of aquatic stages of insects was approximately twice as great in the control as in the heated stream over the period May 1970-May 1971. This difference between streams was especially marked in mayfly and stonefly nymphs, which were the most abundant insects in both streams, and which appeared to be the major sources of food for coho. The reduced growth rates of coho in the heated as compared to the control stream probably resulted from effects of temperature on the invertebrate food supply as well as from direct effects of temperature on the coho in raising their standard metabolic rates so that energy available for growth was reduced. Winter growth rates of coho in the heated stream were generally higher than in the control, probably as a result of an increase in appetite with increased temperature. Winter growth rates of the 1969 year class were high, probably because young coho fry were available as food. Winter growth rates of coho of the 1970 year class, which had a more natural food supply, were low in both streams. The insect fauna of the Oak Creek area is probably adapted to cool water temperatures, and this adaptation presumably contributed to the reduced insect production in the heated model stream. If heat tolerant species of insects were present in or able to migrate into a stream receiving a heated effluent, the simplication of the invertebrate fauna caused by the thermal pollution might increase the amount of food available to the top carnivore. Such heat-tolerant forms apparently were not present in the model streams or, if present, were not able to contribute significantly to total production. Close

• 5. [Article] Infection and immune response induced by Vibrio anguillarum in juvenile coho salmon (Oncorhynchus kisutch)

  Immunity in juvenile coho salmon (Oncorhynchus kisutch) was evaluated after immunization against vibriosis by parenteral, oral or immersion methods. Relative levels of immunity were determined by protection ...

  Citation × Citation Citation Abstract Copy Title: Infection and immune response induced by Vibrio anguillarum in juvenile coho salmon (Oncorhynchus kisutch) Author: Groberg, Warren J. Immunity in juvenile coho salmon (Oncorhynchus kisutch) was evaluated after immunization against vibriosis by parenteral, oral or immersion methods. Relative levels of immunity were determined by protection of fish from experimental water-borne challenges with Vibrio anguillarum and by serum agglutination titers. Coho salmon eggs were exposed to bacterin during artificial spawning or as embryos 4-5 days before hatching. Two of the six injected embryos had agglutination titers 218 days later, and as juveniles these two fish demonstrated an anamnestic response following intraperitoneal injection of bacteria. Fish that had selected portions of their body immersed in bacteria had high levels of protection and lower agglutination titers when compared to those completely submerged in the same preparation. Results showed that parenterally immunized fish had high titers and a high level of protection, those immersed in the bacterin had lower titers but a high level of protection and those orally immunized had no serum agglutinins and only moderate protection. Previously unimmunized fish were significantly protected when passively immunized with coho salmon anti-V. anguillarum immunoglobulin partially purified by gel filtration. The agglutination titer of the partially purified antibody was 1:4. Serum or spleen cells obtained from orally immunized fish conferred no protection to fish injected with these substances. Serum from parenterally immunized fish, however, conferred a high level of protection in passively immunized fish and spleen cells from these same donors also provided moderate protection to previously nonimmune recipients. Coho salmon radiolabeled tetrameric immunoglobulin purified by ion exchange and gel filtration was effectively absorbed in the blood after it was intraperitoneally injected. The kinetics of absorption were related to water temperature with less immunoglobulin absorbed at the lower temperatures. Effects of temperature on infection were examined at seven water temperatures in 3°C increments from 3 to 21°C. The mean day to death and total mortality were related to temperature and a shorter mean day to death and higher mortality was observed at increased temperatures. The effect of temperature on the time of onset of agglutinating antibody formation in parenterally immunized fish was studied in fish held at 6, 12 and 18°C. Titers were first observed on days 10, 15 and 25 in fish held at 18, 12 and 6°C, respectively. Growth curves of V. anguillarum cultured in Brain Heart Infusion broth were determined at the same three temperatures with growth rates directly related to temperature. Title: Infection and immune response induced by Vibrio anguillarum in juvenile coho salmon (Oncorhynchus kisutch) Author: Groberg, Warren J. Immunity in juvenile coho salmon (Oncorhynchus kisutch) was evaluated after immunization against vibriosis by parenteral, oral or immersion methods. Relative levels of immunity were determined by protection of fish from experimental water-borne challenges with Vibrio anguillarum and by serum agglutination titers. Coho salmon eggs were exposed to bacterin during artificial spawning or as embryos 4-5 days before hatching. Two of the six injected embryos had agglutination titers 218 days later, and as juveniles these two fish demonstrated an anamnestic response following intraperitoneal injection of bacteria. Fish that had selected portions of their body immersed in bacteria had high levels of protection and lower agglutination titers when compared to those completely submerged in the same preparation. Results showed that parenterally immunized fish had high titers and a high level of protection, those immersed in the bacterin had lower titers but a high level of protection and those orally immunized had no serum agglutinins and only moderate protection. Previously unimmunized fish were significantly protected when passively immunized with coho salmon anti-V. anguillarum immunoglobulin partially purified by gel filtration. The agglutination titer of the partially purified antibody was 1:4. Serum or spleen cells obtained from orally immunized fish conferred no protection to fish injected with these substances. Serum from parenterally immunized fish, however, conferred a high level of protection in passively immunized fish and spleen cells from these same donors also provided moderate protection to previously nonimmune recipients. Coho salmon radiolabeled tetrameric immunoglobulin purified by ion exchange and gel filtration was effectively absorbed in the blood after it was intraperitoneally injected. The kinetics of absorption were related to water temperature with less immunoglobulin absorbed at the lower temperatures. Effects of temperature on infection were examined at seven water temperatures in 3°C increments from 3 to 21°C. The mean day to death and total mortality were related to temperature and a shorter mean day to death and higher mortality was observed at increased temperatures. The effect of temperature on the time of onset of agglutinating antibody formation in parenterally immunized fish was studied in fish held at 6, 12 and 18°C. Titers were first observed on days 10, 15 and 25 in fish held at 18, 12 and 6°C, respectively. Growth curves of V. anguillarum cultured in Brain Heart Infusion broth were determined at the same three temperatures with growth rates directly related to temperature. Close

• 6. [Article] Characterization and control of Cytophaga psychrophila (Borg) the causative agent of low temperature disease in young coho salmon (Oncorhynchus kisutch)

  The purpose of this study was to characterize Cytophaga psychrophila isolates obtained from coho fingerlings with low temperature disease collected at selected hatcheries in Oregon. In addition, cultures ...

  Citation × Citation Citation Abstract Copy Title: Characterization and control of Cytophaga psychrophila (Borg) the causative agent of low temperature disease in young coho salmon (Oncorhynchus kisutch) Author: Holt, Richard Allen The purpose of this study was to characterize Cytophaga psychrophila isolates obtained from coho fingerlings with low temperature disease collected at selected hatcheries in Oregon. In addition, cultures thought to be related to this bacterium were isolated from Siletz Hatchery water, deformed juvenile and spawning adult coho salmon, rainbow and brook trout and chinook salmon. These isolates some of which were believed to be epidemiologically significant were included in the study and their characteristics compared to those of the low temperature disease cultures. A total of 24 myxobacterial isolates were studied by examination of morphological, cultural, biochemical and serological characteristics. Results of these tests revealed all to be very closely related cultures of C. psychrophila. The cells were gram negative, flexible rods exhibiting gliding motility with no microcysts and fruiting structures formed. These aerobic psychropiles had an optimum growth temperature between 15-18°C and did not grow above 25°C. All cultures were proteolytic, lipolytic and shared at least one common antigen. A low temperature disease, adult coho salmon, deformed juvenile coho salmon, peduncle disease, and rainbow trout isolate were shown to have the ability to produce death in fingerling coho salmon when injected intramuscularly. A serological typing study of six selected isolates revealed no antigenic differences among those collected from fish in Oregon. A peduncle disease isolate from brook trout collected in the Eastern United States shared at least one common antigen with the Oregon cultures and in addition antigens unique to each were demonstrated. To determine if spawning adult coho salmon carry C. psychrophila, bacteriological cultures were prepared from the kidneys of adult fish collected at Siletz and Alsea Hatcheries. Approximarely 50% of these fish were carrying the disease agent suggesting that the eggs may become contaminated from this source. Several attempts to isolate C. psychrophila from coho salmon eggs were unsuccessful. Myxobacterial cultures obtained from deformed juvenile coho salmon occurring at fish hatcheries in Oregon subsequent to low temperature disease epizootics were demonstrated to be C. psychrophila. Furanace, a new nitrofuran chemotherapeutic agent, was tested in vitro and in vivo against the low temperature disease bacterium. Using the tube dilution method, minimal inhibitory concentrations of 0.007 (three isolates) and 0.062 (one isolate) [mu]g/ml Furanace were determined. Higher concentrations of 4. 0 to 8. 0 [mu]g/ ml Furanace were needed to produce a bactericidal effect. In in vivo studies, 0. 5 [mu]g/ml Furanace added to the water containing young coho salmon at Siletz River Salmon Hatchery provided complete protection against a natural outbreak of low temperature disease. Title: Characterization and control of Cytophaga psychrophila (Borg) the causative agent of low temperature disease in young coho salmon (Oncorhynchus kisutch) Author: Holt, Richard Allen The purpose of this study was to characterize Cytophaga psychrophila isolates obtained from coho fingerlings with low temperature disease collected at selected hatcheries in Oregon. In addition, cultures thought to be related to this bacterium were isolated from Siletz Hatchery water, deformed juvenile and spawning adult coho salmon, rainbow and brook trout and chinook salmon. These isolates some of which were believed to be epidemiologically significant were included in the study and their characteristics compared to those of the low temperature disease cultures. A total of 24 myxobacterial isolates were studied by examination of morphological, cultural, biochemical and serological characteristics. Results of these tests revealed all to be very closely related cultures of C. psychrophila. The cells were gram negative, flexible rods exhibiting gliding motility with no microcysts and fruiting structures formed. These aerobic psychropiles had an optimum growth temperature between 15-18°C and did not grow above 25°C. All cultures were proteolytic, lipolytic and shared at least one common antigen. A low temperature disease, adult coho salmon, deformed juvenile coho salmon, peduncle disease, and rainbow trout isolate were shown to have the ability to produce death in fingerling coho salmon when injected intramuscularly. A serological typing study of six selected isolates revealed no antigenic differences among those collected from fish in Oregon. A peduncle disease isolate from brook trout collected in the Eastern United States shared at least one common antigen with the Oregon cultures and in addition antigens unique to each were demonstrated. To determine if spawning adult coho salmon carry C. psychrophila, bacteriological cultures were prepared from the kidneys of adult fish collected at Siletz and Alsea Hatcheries. Approximarely 50% of these fish were carrying the disease agent suggesting that the eggs may become contaminated from this source. Several attempts to isolate C. psychrophila from coho salmon eggs were unsuccessful. Myxobacterial cultures obtained from deformed juvenile coho salmon occurring at fish hatcheries in Oregon subsequent to low temperature disease epizootics were demonstrated to be C. psychrophila. Furanace, a new nitrofuran chemotherapeutic agent, was tested in vitro and in vivo against the low temperature disease bacterium. Using the tube dilution method, minimal inhibitory concentrations of 0.007 (three isolates) and 0.062 (one isolate) [mu]g/ml Furanace were determined. Higher concentrations of 4. 0 to 8. 0 [mu]g/ ml Furanace were needed to produce a bactericidal effect. In in vivo studies, 0. 5 [mu]g/ml Furanace added to the water containing young coho salmon at Siletz River Salmon Hatchery provided complete protection against a natural outbreak of low temperature disease. Close

• 7. [Article] Influence of temperature on energy and material utilization by juvenile coho salmon

  Citation × Citation Citation Abstract Copy Title: Influence of temperature on energy and material utilization by juvenile coho salmon Author: Averett, R. C. Title: Influence of temperature on energy and material utilization by juvenile coho salmon Author: Averett, R. C. Close

• 8. [Article] The influence of dissolved oxygen concentration on the swimming performance of juvenile coho salmon at different temperatures

  Citation × Citation Citation Abstract Copy Title: The influence of dissolved oxygen concentration on the swimming performance of juvenile coho salmon at different temperatures Author: Davis, Gerald E. Title: The influence of dissolved oxygen concentration on the swimming performance of juvenile coho salmon at different temperatures Author: Davis, Gerald E. Close

• 9. [Article] Cellular dynamics of the intestinal epithelium of coho salmon, Oncorhynchus kisutch, as influenced by temperature and x-rays

  The cellular dynamics of the intestinal epithelium in the coho salmon, Oncorhynchus kisutch, has been studied to determine the effects of temperature and whole-body X-irradiation. In vivo experiments utilizing ...

  Citation × Citation Citation Abstract Copy Title: Cellular dynamics of the intestinal epithelium of coho salmon, Oncorhynchus kisutch, as influenced by temperature and x-rays Author: Johnson, Tod Schaefer The cellular dynamics of the intestinal epithelium in the coho salmon, Oncorhynchus kisutch, has been studied to determine the effects of temperature and whole-body X-irradiation. In vivo experiments utilizing colchicine mitotic inhibiting technique and tritiated thymidine (³H-TdR) radioautography were employed in order to evaluate the kinetics of the cell population. In vitro radiotracer enzyme assays were used to measure the conversion of ¹⁴C-2-thymidine to the precursors of DNA synthesis, dTMP, dTDP and dTTP. Colchicine solution at 0.04 mg/100 gm body weight was injected and fish sacrificed from 1 to 18 hours. Arrested mitotic figures occurred only in the basal region of the intestinal folds for all time periods. A series of ³H-TdR experiments were carried out using salmon thermally acclimated at 5°, 10°, or 18° C. Fish were injected intraperitoneally with ³H-TdR solution (1.5 μ C[subscript i]/gm body weight), then sacrificed sequentially from 10 minutes to 37 days after injection. Samples of the intestine were processed either for radioautography or for liquid scintillation studies. Radioautographs indicated initial ³H-TdR cell labeling occurred in the basal region of the intestinal folds, with subsequent cell migration up the folds, and sloughing of cells into the lumen from the tips of the folds. Renewal times were temperature dependent, with estimates of 13-15, 23-25, and in excess of 35 days for 18°, 10° and 5°C respectively. Whole-body X-irradiation at 10° C produced considerable cell damage by 21-22 days after exposure at 1,000 R level. The gastro-intestinal syndrome was manifested by 24 to 26 days after exposures of 4,000 and 8,000 R. ³H-TdR incorporation into the intestinal nucleoprotein fraction was dose dependent through 160 minutes after injection. A series of invitro radiotracer enzyme assay experiments were carried out using ¹⁴C-2-thymidine and the intestinal post-microsomal fraction (> 104,000 x G for 1 hr) from thermally acclimated coho salmon. Thymidine kinase exhibited pH optimum at pH 7.9 ± 0.1 while thymidylate kinase showed maximum activity at pH 6.8 ± 0.1. Formation of dTMP, dTDP, and dTTP exhibited saturation type substrate dependency curves, while dTMP activities measured at 5°, 100, and 18° C resulted in non-competitive inhibition at the lower temperatures. Relative thymidine kinase activities estimated for the different temperature levels were 3.6, 2.5, and 2.0 for 5° -5° C vs 10° -10° C, 5° -5° C vs 18° -18° C, and 10° -10° C vs 18° -18° C, respectively. Lowry protein assays indicated there was an inverse relationship between total protein per unit volume intestinal microsomal supernatant fraction and fish acclimation temperature. Title: Cellular dynamics of the intestinal epithelium of coho salmon, Oncorhynchus kisutch, as influenced by temperature and x-rays Author: Johnson, Tod Schaefer The cellular dynamics of the intestinal epithelium in the coho salmon, Oncorhynchus kisutch, has been studied to determine the effects of temperature and whole-body X-irradiation. In vivo experiments utilizing colchicine mitotic inhibiting technique and tritiated thymidine (³H-TdR) radioautography were employed in order to evaluate the kinetics of the cell population. In vitro radiotracer enzyme assays were used to measure the conversion of ¹⁴C-2-thymidine to the precursors of DNA synthesis, dTMP, dTDP and dTTP. Colchicine solution at 0.04 mg/100 gm body weight was injected and fish sacrificed from 1 to 18 hours. Arrested mitotic figures occurred only in the basal region of the intestinal folds for all time periods. A series of ³H-TdR experiments were carried out using salmon thermally acclimated at 5°, 10°, or 18° C. Fish were injected intraperitoneally with ³H-TdR solution (1.5 μ C[subscript i]/gm body weight), then sacrificed sequentially from 10 minutes to 37 days after injection. Samples of the intestine were processed either for radioautography or for liquid scintillation studies. Radioautographs indicated initial ³H-TdR cell labeling occurred in the basal region of the intestinal folds, with subsequent cell migration up the folds, and sloughing of cells into the lumen from the tips of the folds. Renewal times were temperature dependent, with estimates of 13-15, 23-25, and in excess of 35 days for 18°, 10° and 5°C respectively. Whole-body X-irradiation at 10° C produced considerable cell damage by 21-22 days after exposure at 1,000 R level. The gastro-intestinal syndrome was manifested by 24 to 26 days after exposures of 4,000 and 8,000 R. ³H-TdR incorporation into the intestinal nucleoprotein fraction was dose dependent through 160 minutes after injection. A series of invitro radiotracer enzyme assay experiments were carried out using ¹⁴C-2-thymidine and the intestinal post-microsomal fraction (> 104,000 x G for 1 hr) from thermally acclimated coho salmon. Thymidine kinase exhibited pH optimum at pH 7.9 ± 0.1 while thymidylate kinase showed maximum activity at pH 6.8 ± 0.1. Formation of dTMP, dTDP, and dTTP exhibited saturation type substrate dependency curves, while dTMP activities measured at 5°, 100, and 18° C resulted in non-competitive inhibition at the lower temperatures. Relative thymidine kinase activities estimated for the different temperature levels were 3.6, 2.5, and 2.0 for 5° -5° C vs 10° -10° C, 5° -5° C vs 18° -18° C, and 10° -10° C vs 18° -18° C, respectively. Lowry protein assays indicated there was an inverse relationship between total protein per unit volume intestinal microsomal supernatant fraction and fish acclimation temperature. Close

• 10. [Article] Exposure of coho salmon (Oncorhynchus lisutch) to petroleum hydrocarbons : effect on lipid metabolism and aryl hydrocarbon hydroxylase activity

  Coho salmon (Oncorhynchus kisutch) were exposed to sublethal levels of a water-soluble fraction (WSF) of Cook Inlet crude oil for periods ranging from 18 to 31 days, at four acclimation temperatures. The ...

  Citation × Citation Citation Abstract Copy Title: Exposure of coho salmon (Oncorhynchus lisutch) to petroleum hydrocarbons : effect on lipid metabolism and aryl hydrocarbon hydroxylase activity Author: Caldarone, Elaine Marie Coho salmon (Oncorhynchus kisutch) were exposed to sublethal levels of a water-soluble fraction (WSF) of Cook Inlet crude oil for periods ranging from 18 to 31 days, at four acclimation temperatures. The fatty acid composition of phospholipids extracted from muscle, gill, liver, and brain tissues, and, at three of the temperatures, the activity of the hepatic microsomal aryl hydrocarbon hydroxylase (AHH) system in the salmon, were determined. Induction of the ARE system due to exposure of the fish to the toxicant was observed in the warm acclimated (20.0 C) fish only. With minor exceptions, the fatty acid composition of phospholipids in all of the tissues analyzed, including those from the warm acclimated fish, were unaltered by exposure of the fish to the crude oil WSF. In both control and exposed fish, AHH activity was greater in fish acclimated to 7.8 C than to 20.0 C. The phospholipids from both exposed and control cold acclimated fish contained a higher percentage of polyunsaturated fatty acids than the phospholipids from the corresponding warm acclimated fish. The studies reported here indicate that exposure of coho salmon (O. kisutch) to sublethal levels of petroleum hydrocarbons does not appreciably alter the fatty acid composition of tissue phospholipids or affect the normal change in fatty acid composition associated with a change in acclimation temperature. The data obtained are insufficient to permit any conclusion regarding the possibility of an interaction between the MFO system and the metabolsim of polyunsaturated fatty acids in oil exposed salmon. Title: Exposure of coho salmon (Oncorhynchus lisutch) to petroleum hydrocarbons : effect on lipid metabolism and aryl hydrocarbon hydroxylase activity Author: Caldarone, Elaine Marie Coho salmon (Oncorhynchus kisutch) were exposed to sublethal levels of a water-soluble fraction (WSF) of Cook Inlet crude oil for periods ranging from 18 to 31 days, at four acclimation temperatures. The fatty acid composition of phospholipids extracted from muscle, gill, liver, and brain tissues, and, at three of the temperatures, the activity of the hepatic microsomal aryl hydrocarbon hydroxylase (AHH) system in the salmon, were determined. Induction of the ARE system due to exposure of the fish to the toxicant was observed in the warm acclimated (20.0 C) fish only. With minor exceptions, the fatty acid composition of phospholipids in all of the tissues analyzed, including those from the warm acclimated fish, were unaltered by exposure of the fish to the crude oil WSF. In both control and exposed fish, AHH activity was greater in fish acclimated to 7.8 C than to 20.0 C. The phospholipids from both exposed and control cold acclimated fish contained a higher percentage of polyunsaturated fatty acids than the phospholipids from the corresponding warm acclimated fish. The studies reported here indicate that exposure of coho salmon (O. kisutch) to sublethal levels of petroleum hydrocarbons does not appreciably alter the fatty acid composition of tissue phospholipids or affect the normal change in fatty acid composition associated with a change in acclimation temperature. The data obtained are insufficient to permit any conclusion regarding the possibility of an interaction between the MFO system and the metabolsim of polyunsaturated fatty acids in oil exposed salmon. Close