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• 1. [Article] The Chromosome Constitutions of a Hybrid Salmonid and Its Parental Types: Salmo Gairdneri and Salmo Clarki

  A study was undertaken to investigate the application of tissue culture and histochemical banding techniques normally used in mammalian studies to fish cells and to examine the mechanisms of chromosome ...

  Citation × Citation Citation Abstract Copy Title: The Chromosome Constitutions of a Hybrid Salmonid and Its Parental Types: Salmo Gairdneri and Salmo Clarki Author: Jacky, Peter Bruce Year: 1976 A study was undertaken to investigate the application of tissue culture and histochemical banding techniques normally used in mammalian studies to fish cells and to examine the mechanisms of chromosome evolution and speciation in salmonids by comparing the chromosomes of the hybrid to those of the parental types. The application of banding techniques was generally unsuccessful in revealing bands, though quinacrine staining did reveal the presence of two fluorescent spots in the vicinity of the centromere. These were thought to be heterochromatic blocks, possibly related to the high incidence of centric fusion or fission in salmonids. Results of chromosome analysis showerd a higher incidence of acrocentric chromosomes in the hybrid than in either parental type which together with evidence for tetraploidization in salmonids is consistant with some of the requirements for species diversification. Conditions of divergence in chromosome evolution and changes which would have to occur in the hybrid for divergence from the parental types to take place are discussed. The results of a preliminary electrophoretic examination of LDH and esterase activity tended to confirm hybridization. Title: The Chromosome Constitutions of a Hybrid Salmonid and Its Parental Types: Salmo Gairdneri and Salmo Clarki Author: Jacky, Peter Bruce Year: 1976 A study was undertaken to investigate the application of tissue culture and histochemical banding techniques normally used in mammalian studies to fish cells and to examine the mechanisms of chromosome evolution and speciation in salmonids by comparing the chromosomes of the hybrid to those of the parental types. The application of banding techniques was generally unsuccessful in revealing bands, though quinacrine staining did reveal the presence of two fluorescent spots in the vicinity of the centromere. These were thought to be heterochromatic blocks, possibly related to the high incidence of centric fusion or fission in salmonids. Results of chromosome analysis showerd a higher incidence of acrocentric chromosomes in the hybrid than in either parental type which together with evidence for tetraploidization in salmonids is consistant with some of the requirements for species diversification. Conditions of divergence in chromosome evolution and changes which would have to occur in the hybrid for divergence from the parental types to take place are discussed. The results of a preliminary electrophoretic examination of LDH and esterase activity tended to confirm hybridization. Close

• 2. [Article] Variability in expression of anadromy by female Oncorhynchus mykiss within a river network

  We described and predicted spatial variation in marine migration (anadromy) of female Oncorhynchus mykiss in the John Day River watershed, Oregon. We collected 149 juvenile O. mykiss across 72 sites and ...

  Citation × Citation Citation Abstract Copy Title: Variability in expression of anadromy by female Oncorhynchus mykiss within a river network Author: Zimmerman, Christian E., Jordan, Chris E., McMillan, John R., Mills, Justin S., Dunham, Jason B., Reeves, Gordon H. We described and predicted spatial variation in marine migration (anadromy) of female Oncorhynchus mykiss in the John Day River watershed, Oregon. We collected 149 juvenile O. mykiss across 72 sites and identified locations used by anadromous females by assigning maternal origin (anadromous versus non-anadromous) to each juvenile. These assignments used comparisons of strontium to calcium ratios in otolith primordia and freshwater growth regions to indicate maternal origin. We used logistic regression to predict probability of anadromy in relation to mean annual stream runoff using data from a subset of individuals. This model correctly predicted anadromy in a second sample of individuals with a moderate level of accuracy (e.g., 68% correctly predicted with a 0.5 classification threshold). Residuals from the models were not spatially autocorrelated, suggesting that remaining variability in the expression of anadromy was due to localized influences, as opposed to broad-scale gradients unrelated to mean annual stream runoff. These results are important for the management of O. mykiss because anadromous individuals (steelhead) within the John Day River watershed are listed as a threatened species, and it is difficult to discern juvenile steelhead from non-anadromous individuals (rainbow trout) in the field. Our results provide a broad-scale description and prediction of locations supporting anadromy, and new insight for habitat restoration, monitoring, and research to better manage and understand the expression of anadromy in O. mykiss. Title: Variability in expression of anadromy by female Oncorhynchus mykiss within a river network Author: Zimmerman, Christian E., Jordan, Chris E., McMillan, John R., Mills, Justin S., Dunham, Jason B., Reeves, Gordon H. We described and predicted spatial variation in marine migration (anadromy) of female Oncorhynchus mykiss in the John Day River watershed, Oregon. We collected 149 juvenile O. mykiss across 72 sites and identified locations used by anadromous females by assigning maternal origin (anadromous versus non-anadromous) to each juvenile. These assignments used comparisons of strontium to calcium ratios in otolith primordia and freshwater growth regions to indicate maternal origin. We used logistic regression to predict probability of anadromy in relation to mean annual stream runoff using data from a subset of individuals. This model correctly predicted anadromy in a second sample of individuals with a moderate level of accuracy (e.g., 68% correctly predicted with a 0.5 classification threshold). Residuals from the models were not spatially autocorrelated, suggesting that remaining variability in the expression of anadromy was due to localized influences, as opposed to broad-scale gradients unrelated to mean annual stream runoff. These results are important for the management of O. mykiss because anadromous individuals (steelhead) within the John Day River watershed are listed as a threatened species, and it is difficult to discern juvenile steelhead from non-anadromous individuals (rainbow trout) in the field. Our results provide a broad-scale description and prediction of locations supporting anadromy, and new insight for habitat restoration, monitoring, and research to better manage and understand the expression of anadromy in O. mykiss. Close

• 3. [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

• 4. [Article] Effect of short-term decrease in water temperature on body temperature and involvement of testosterone in steelhead and rainbow trout, Oncorhynchus mykiss

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Effect of short-term decrease in water temperature on body temperature and involvement of testosterone in steelhead and rainbow trout, Oncorhynchus mykiss Author: Schreck, Carl B., Noakes, David L.G., Yada, Takashi, Matsuda, Hiroyuki, Miura, Go, Munakata, Arimune To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Title: Effect of short-term decrease in water temperature on body temperature and involvement of testosterone in steelhead and rainbow trout, Oncorhynchus mykiss Author: Schreck, Carl B., Noakes, David L.G., Yada, Takashi, Matsuda, Hiroyuki, Miura, Go, Munakata, Arimune To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Close

• 5. [Article] Hepatic heat shock protein 70 and plasma cortisol levels in rainbow trout after tagging with a passive integrated transponder

  This study examined the potentially stressful effects of tagging juvenile rainbow trout Oncorhynchus mykiss with passive integrated transponder (PIT) tags by measuring short-term (<120-h) changes in plasma ...

  Citation × Citation Citation Abstract Copy Title: Hepatic heat shock protein 70 and plasma cortisol levels in rainbow trout after tagging with a passive integrated transponder Author: Feldhaus, Joseph W., Li, Hiram W., Mesa, Matthew G., Heppell, Scott A. This study examined the potentially stressful effects of tagging juvenile rainbow trout Oncorhynchus mykiss with passive integrated transponder (PIT) tags by measuring short-term (<120-h) changes in plasma concentrations of cortisol and hepatic heat shock protein 70 (hsp70). In a laboratory experiment, plasma cortisol levels were measured in fish before they were tagged (0 h) and at 2, 6, 24, and 120 h after being tagged. Hepatic hsp70 levels were measured at 0, 24, and 120 h. All results were compared with those for fish that were handled but not tagged. Plasma cortisol levels were significantly higher in both treatment groups (tagged and handled but not tagged) at 2 h than in the pretreatment groups (0 h). Plasma cortisol levels in the treatment groups returned to near pretreatment levels by 6 h. However, there was a significant difference in plasma cortisol levels between treatment groups at 6 h. There were no significant differences in hepatic hsp70 levels among the two treatment groups, and hepatic hsp70 levels did not change through time. Our results suggest that PIT tagging is a low-impact tagging procedure for juvenile salmonids. Title: Hepatic heat shock protein 70 and plasma cortisol levels in rainbow trout after tagging with a passive integrated transponder Author: Feldhaus, Joseph W., Li, Hiram W., Mesa, Matthew G., Heppell, Scott A. This study examined the potentially stressful effects of tagging juvenile rainbow trout Oncorhynchus mykiss with passive integrated transponder (PIT) tags by measuring short-term (<120-h) changes in plasma concentrations of cortisol and hepatic heat shock protein 70 (hsp70). In a laboratory experiment, plasma cortisol levels were measured in fish before they were tagged (0 h) and at 2, 6, 24, and 120 h after being tagged. Hepatic hsp70 levels were measured at 0, 24, and 120 h. All results were compared with those for fish that were handled but not tagged. Plasma cortisol levels were significantly higher in both treatment groups (tagged and handled but not tagged) at 2 h than in the pretreatment groups (0 h). Plasma cortisol levels in the treatment groups returned to near pretreatment levels by 6 h. However, there was a significant difference in plasma cortisol levels between treatment groups at 6 h. There were no significant differences in hepatic hsp70 levels among the two treatment groups, and hepatic hsp70 levels did not change through time. Our results suggest that PIT tagging is a low-impact tagging procedure for juvenile salmonids. Close

• 6. [Article] Individual condition and stream temperature influence early maturation of rainbow and steelhead trout, Oncorhynchus mykiss

  This is the publisher’s final pdf. The published article is copyrighted by Springer Science+Business Media and can be found at: http://www.springer.com.

  Citation × Citation Citation Abstract Copy Title: Individual condition and stream temperature influence early maturation of rainbow and steelhead trout, Oncorhynchus mykiss Author: Reeves, Gordon H., Jordan, Chris E., McMillan, John R., Mills, Justin S., Dunham, Jason B. This is the publisher’s final pdf. The published article is copyrighted by Springer Science+Business Media and can be found at: http://www.springer.com. Title: Individual condition and stream temperature influence early maturation of rainbow and steelhead trout, Oncorhynchus mykiss Author: Reeves, Gordon H., Jordan, Chris E., McMillan, John R., Mills, Justin S., Dunham, Jason B. This is the publisher’s final pdf. The published article is copyrighted by Springer Science+Business Media and can be found at: http://www.springer.com. Close

• 7. [Article] Accumulation of dietary polychlorinated biphenyl by rainbow trout (Salmo gairdneri)

  Citation × Citation Citation Abstract Copy Title: Accumulation of dietary polychlorinated biphenyl by rainbow trout (Salmo gairdneri) Author: Lieb, Andrew James Title: Accumulation of dietary polychlorinated biphenyl by rainbow trout (Salmo gairdneri) Author: Lieb, Andrew James Close

• 8. [Article] Feed conversion, protein utilization and growth of rainbow trout (Salmo gairdneri) fed 25 to 45 percent herring oil

  Triplicate groups of rainbow trout (Salmo gairdneri) fed six diets; five based on fish protein concentrate (FPC) ranging in caloric density from 4.36 to 6.19 kcal/g, and one based on vitamin free casein ...

  Citation × Citation Citation Abstract Copy Title: Feed conversion, protein utilization and growth of rainbow trout (Salmo gairdneri) fed 25 to 45 percent herring oil Author: Kellems, Richard O. Triplicate groups of rainbow trout (Salmo gairdneri) fed six diets; five based on fish protein concentrate (FPC) ranging in caloric density from 4.36 to 6.19 kcal/g, and one based on vitamin free casein with a caloric density of 5.26 kcal/g were evaluated with respect to diet ingredient utilization. The parameters used to evaluate efficiency of diet utilization were: feed conversion, energy and protein conversion, and growth. The desirability of the edible portion of the fish produced on the different treatments from a flavor and texture standpoint was determined. The protein level was maintained at 38% of the dry diet, with 7.8% supplied by gelatin and the remainder by either FPC or casein. The herring oil levels of the diets ranged from 25% to 45% of the dry diet, and was the primary source of calories. Alpha-cellulose was included as a filler and ranged from 12.2% to 31.2% of the dry diet. The FPC based diets produced statistically superior weight gains when compared to the casein based diet. The efficiency of feed conversion was improved as the level of herring oil was increased. The energy and protein conversions were relatively constant for the FPC based diets, with the casein based diet being lower (P < 0.05). Title: Feed conversion, protein utilization and growth of rainbow trout (Salmo gairdneri) fed 25 to 45 percent herring oil Author: Kellems, Richard O. Triplicate groups of rainbow trout (Salmo gairdneri) fed six diets; five based on fish protein concentrate (FPC) ranging in caloric density from 4.36 to 6.19 kcal/g, and one based on vitamin free casein with a caloric density of 5.26 kcal/g were evaluated with respect to diet ingredient utilization. The parameters used to evaluate efficiency of diet utilization were: feed conversion, energy and protein conversion, and growth. The desirability of the edible portion of the fish produced on the different treatments from a flavor and texture standpoint was determined. The protein level was maintained at 38% of the dry diet, with 7.8% supplied by gelatin and the remainder by either FPC or casein. The herring oil levels of the diets ranged from 25% to 45% of the dry diet, and was the primary source of calories. Alpha-cellulose was included as a filler and ranged from 12.2% to 31.2% of the dry diet. The FPC based diets produced statistically superior weight gains when compared to the casein based diet. The efficiency of feed conversion was improved as the level of herring oil was increased. The energy and protein conversions were relatively constant for the FPC based diets, with the casein based diet being lower (P < 0.05). Close

• 9. [Article] The characterization of the MFO system in rainbow trout fed cruciferous vegetables

  Several compounds have been shown to induce the mixed function oxidase enzyme system of animals, and also to inhibit tumor formation. Included in this category are several vegetables and isolated vegetable ...

  Citation × Citation Citation Abstract Copy Title: The characterization of the MFO system in rainbow trout fed cruciferous vegetables Author: Haight, Lynn Ellen Several compounds have been shown to induce the mixed function oxidase enzyme system of animals, and also to inhibit tumor formation. Included in this category are several vegetables and isolated vegetable components from the Cruciferae family. In this study rainbow trout were fed blanched freeze-dried cauliflower, broccoli, or Brussel sprouts at the 20% supplemental level for two months, or 500 ppm benzyl or phenethyl isothiocyanate. At this time the livers were removed and hepatic microsomal enzymes were studied. This treatment did not cause any increases in the metabolism of p-nitroanisole or benzo(a)pyrene and cytochrome P-450 levels were not elevated. On the contrary, benzo(a)pyrene monooxygenase, 7-ethoxycoumarin 0-dealkylase, resorufin 0-dealkylase, p-nitroanisole 0-demethylase, and cytochrome P-450 levels were increased in trout treated orally and intraperitoneally with β-napthoflavone. For all parameters studied, a greater increase in activity was seen in the trout treated intraperitoneally. The vegetable and isothiocyanate supplemented diets also did not inhibit tumor formation in trout challenged with 20 ppb aflatoxin B₁ for one month. A study with rats showed that both blanched freeze-dried cauliflower and air-dried cauliflower cause significant increases in p-nitroanisole 0-demethylase activity and benzo(a)pyrene monooxygenase activity and increased cytochrome P-450 levels in rat hepatic microsomes when fed at the 20% supplemental level for 25 days. It was concluded that the null effects seen with the trout fed the vegetables and isothiocyanates were not due to the heat treatment of the vegetables since rats fed blanched freeze-dried cauliflower had significant increases in enzymatic activity and increased cytochrome P-450 levels over controls. The results of the β-napthoflavone experiment verified the validity and reliability of the experimental assays and conditions and showed that trout hepatic microsomal enzymes can be induced by orally administered compounds. Title: The characterization of the MFO system in rainbow trout fed cruciferous vegetables Author: Haight, Lynn Ellen Several compounds have been shown to induce the mixed function oxidase enzyme system of animals, and also to inhibit tumor formation. Included in this category are several vegetables and isolated vegetable components from the Cruciferae family. In this study rainbow trout were fed blanched freeze-dried cauliflower, broccoli, or Brussel sprouts at the 20% supplemental level for two months, or 500 ppm benzyl or phenethyl isothiocyanate. At this time the livers were removed and hepatic microsomal enzymes were studied. This treatment did not cause any increases in the metabolism of p-nitroanisole or benzo(a)pyrene and cytochrome P-450 levels were not elevated. On the contrary, benzo(a)pyrene monooxygenase, 7-ethoxycoumarin 0-dealkylase, resorufin 0-dealkylase, p-nitroanisole 0-demethylase, and cytochrome P-450 levels were increased in trout treated orally and intraperitoneally with β-napthoflavone. For all parameters studied, a greater increase in activity was seen in the trout treated intraperitoneally. The vegetable and isothiocyanate supplemented diets also did not inhibit tumor formation in trout challenged with 20 ppb aflatoxin B₁ for one month. A study with rats showed that both blanched freeze-dried cauliflower and air-dried cauliflower cause significant increases in p-nitroanisole 0-demethylase activity and benzo(a)pyrene monooxygenase activity and increased cytochrome P-450 levels in rat hepatic microsomes when fed at the 20% supplemental level for 25 days. It was concluded that the null effects seen with the trout fed the vegetables and isothiocyanates were not due to the heat treatment of the vegetables since rats fed blanched freeze-dried cauliflower had significant increases in enzymatic activity and increased cytochrome P-450 levels over controls. The results of the β-napthoflavone experiment verified the validity and reliability of the experimental assays and conditions and showed that trout hepatic microsomal enzymes can be induced by orally administered compounds. Close

• 10. [Article] Aflatoxin mutagenesis and metabolism and their dietary modification in rainbow trout (Salmo gairdneri)

  Aflatoxin B₁ (AFB₁) is a mold-produced toxin which has been shown to be a potent hepatocarcinogen in many animal species. Of the species studied thus far, rainbow trout have proven to be the most sensitive. ...

  Citation × Citation Citation Abstract Copy Title: Aflatoxin mutagenesis and metabolism and their dietary modification in rainbow trout (Salmo gairdneri) Author: Coulombe, Roger A. Aflatoxin B₁ (AFB₁) is a mold-produced toxin which has been shown to be a potent hepatocarcinogen in many animal species. Of the species studied thus far, rainbow trout have proven to be the most sensitive. Experiments were conducted to investigate various aspects of AFB₁ metabolism in this species, including in vitro mutagenesis, and effects of dietary modifiers of AFB, carcinogenesis on in vitro metabolism and mutagenesis. A comparative study of AFB₁ metabolism in two salmonid species was also conducted. In the first study, the relative mutagenic potencies of several alfatoxin metabolites were evaluated using a trout liver fraction system. Preliminary studies characterizing trout liver fractions for use as an activation system were described. The results from comparative mutagenicity experiments demonstrated that in vitro mutagenic potencies qualitatively correlated with the in vivo carcinogenic activities of various aflatoxins in rainbow trout. The importance of these findings is discussed. In the second study fish hepatocytes were characterized to examine possible differences in activation of AFB₁ to bacterial mutagens by hepatocytes from rainbow trout and coho salmon, two species which are known to differ markedly in sensitivity to the carcinogenic effects of AFB₁. Activation efficiency was approximately three times greater in hepatocytes from trout compared to salmon. A more marked difference was seen when S20 liver fractions from the two species were used. Analysis of unbound [³H]AFB₁ metabolites revealed that trout hepatocytes metabolized [³H]AFB₁ to a greater extent than salmon. The results accurately reflected in vivo carcinogenesis trends in salmonid fish. Additional experiments were conducted to evaluate the effects of dietary modifiers of AFB₁ carcinogenesis on in vitro mutagenesis and metabolism of AFB₁. Dietary β-naphthoflavone (β-NF) was shown to induce the production of a novel trout metabolite of AFB₁, aflatoxicol M₁ (AFL-M₁). AFL-M₁ exhibited a mutagenic potency less than AFB₁ or aflatoxicol (AFL), but greater than that of aflatoxin-M₁ (AFM₁). Dietary β-NF, however, appeared to have no effect on in vitro mutagenic activation of AFB₁ using hepatocytes or liver S20 fraction from trout. Dietary PCBs (Aroclor 1254) was shown to significantly decrease in vitro mutagenesis of AFB₁, which reflected a similar PCB-mediated inhibitory effect on AFB₁ carcinogenesis in trout in vivo. Cyclopropenoid fatty acids (CPFAs) present in the diet (0-600 ppm) were shown to have no effect on in vitro mutagenesis of AFB₁, indicating CPFAs may not significantly alter in vivo initiation of AFB₁ carcinogenesis. Title: Aflatoxin mutagenesis and metabolism and their dietary modification in rainbow trout (Salmo gairdneri) Author: Coulombe, Roger A. Aflatoxin B₁ (AFB₁) is a mold-produced toxin which has been shown to be a potent hepatocarcinogen in many animal species. Of the species studied thus far, rainbow trout have proven to be the most sensitive. Experiments were conducted to investigate various aspects of AFB₁ metabolism in this species, including in vitro mutagenesis, and effects of dietary modifiers of AFB, carcinogenesis on in vitro metabolism and mutagenesis. A comparative study of AFB₁ metabolism in two salmonid species was also conducted. In the first study, the relative mutagenic potencies of several alfatoxin metabolites were evaluated using a trout liver fraction system. Preliminary studies characterizing trout liver fractions for use as an activation system were described. The results from comparative mutagenicity experiments demonstrated that in vitro mutagenic potencies qualitatively correlated with the in vivo carcinogenic activities of various aflatoxins in rainbow trout. The importance of these findings is discussed. In the second study fish hepatocytes were characterized to examine possible differences in activation of AFB₁ to bacterial mutagens by hepatocytes from rainbow trout and coho salmon, two species which are known to differ markedly in sensitivity to the carcinogenic effects of AFB₁. Activation efficiency was approximately three times greater in hepatocytes from trout compared to salmon. A more marked difference was seen when S20 liver fractions from the two species were used. Analysis of unbound [³H]AFB₁ metabolites revealed that trout hepatocytes metabolized [³H]AFB₁ to a greater extent than salmon. The results accurately reflected in vivo carcinogenesis trends in salmonid fish. Additional experiments were conducted to evaluate the effects of dietary modifiers of AFB₁ carcinogenesis on in vitro mutagenesis and metabolism of AFB₁. Dietary β-naphthoflavone (β-NF) was shown to induce the production of a novel trout metabolite of AFB₁, aflatoxicol M₁ (AFL-M₁). AFL-M₁ exhibited a mutagenic potency less than AFB₁ or aflatoxicol (AFL), but greater than that of aflatoxin-M₁ (AFM₁). Dietary β-NF, however, appeared to have no effect on in vitro mutagenic activation of AFB₁ using hepatocytes or liver S20 fraction from trout. Dietary PCBs (Aroclor 1254) was shown to significantly decrease in vitro mutagenesis of AFB₁, which reflected a similar PCB-mediated inhibitory effect on AFB₁ carcinogenesis in trout in vivo. Cyclopropenoid fatty acids (CPFAs) present in the diet (0-600 ppm) were shown to have no effect on in vitro mutagenesis of AFB₁, indicating CPFAs may not significantly alter in vivo initiation of AFB₁ carcinogenesis. Close