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Sample records for oncorhynchus nerka 1993-1994

  1. Genetic Analysis of Oncorhynchus Nerka : Life History and Genetic Analysis of Redfish Lake Oncorhynchus Nerka, 1993-1994 Completion Report.

    SciTech Connect

    Brannon, E.L.; Thorgaard, G.H.; Cummings, S.A.

    1994-10-01

    The study has shown through life history examination and DNA analysis that three forms of O. nerka are present in Redfish Lake. The three forms are closely related, but may be sufficiently different to be considered three separate stocks. Fishhook Creek kokanee are temporally isolated from the beach spawners, and may represent the gene pool most similar to the historic sockeye population that once spawned there. Fishhook Creek offers the best spawning area available in the lake system, and should be considered for use in reestablishing an anadromous Fishhook Creek sockeye swain. The resident beach spawning strain of O. nerka is likewise the most similar genetic form of the companion anadromous beach spawning O. nerka, and needs to be considered the most appropriate genetic source to help minimize reduced fitness of the sockeye from inbreeding.

  2. Sexual maturation in kokanee Oncorhynchus nerka

    USGS Publications Warehouse

    Patterson, S.D.; Scarnecchia, D.L.; Congleton, J.L.

    2008-01-01

    We used observational and experimental approaches to obtain information on factors affecting the timing of maturation of kokanee Oncorhynchus nerka, a semelparous, landlocked salmon. Gonadal staging criteria were developed and applied to three kokanee populations in Idaho lakes and reservoirs. Testes were classified into three stages: immature (stage one, S1), maturing (S2), and mature (S3). Ovaries were classified into eight stages: immature (S1-S3), transitional (stage S4), maturing (S5-S7), and mature (S8). Males entered the maturing stage (S2) in February through April of the spawning year. Females entered maturing stage (S5) as early as July of the year before the spawning year, and as late as March of the spawning year. Three hatchery experiments demonstrated that attainment of a larger body size 10 to 16 months before spawning increased the likelihood of initiation of maturation in both sexes. No gonads in a state of regression were observed. A gonadosomatic index above 0.1 by early July was a good indicator of a maturing male, and a gonadosomatic index above 1.0 by early July was a good indicator of a maturing female. Instantaneous growth rates were not good predictors of maturation, but attaining a size threshold of 18 to 19 cm in the fall was a good predictor of maturation the following year. This improved knowledge of kokanee maturation will permit more effectively management of the species for age, growth and size at maturity as well as for contributions to fisheries. ?? 2008 by the Northwest Scientific Association. All rights reserved.

  3. Genetic Analysis of Oncorhynchus Nerka : 1991 Annual Progress Report.

    SciTech Connect

    Brannon, E.L.; Setter, A.L.; Welsh, T.L.; Rocklage, S.J.

    1992-01-01

    The 1990 project to develop DNA assessment techniques for the purpose of determining relationships among populations of Oncorhynchus nerka demonstrated differences that had potential for such application. The work was continued in 1991 with specific application of the techniques to develop DNA probes that could be used in separating populations of 0. nerka associated with the lakes in the upper Salmon River, principally those in Redfish Lake. Research included sockeye-kokanee life history studies that might add supporting evidence for assessing the degree of difference or similarity among populations in the lake systems. This report summarizes the annual activities under the work plan.

  4. Recent ecological divergence despite migration in sockeye salmon (Oncorhynchus nerka)

    USGS Publications Warehouse

    Pavey, Scott A.; Nielsen, Jennifer L.; Hamon, Troy R.

    2010-01-01

    Ecological divergence may result when populations experience different selection regimes, but there is considerable discussion about the role of migration at the beginning stages of divergence before reproductive isolating mechanisms have evolved. However, detection of past migration is difficult in current populations and tools to differentiate genetic similarities due to migration versus recent common ancestry are only recently available. Using past volcanic eruption times as a framework, we combine morphological analyses of traits important to reproduction with a coalescent-based genetic analysis of two proximate sockeye salmon (Oncorhynchus nerka) populations. We find that this is the most recent (~500 years, 100 generations) natural ecological divergence recorded in a fish species, and report that this divergence is occurring despite migration. Although studies of fish divergence following the retreat of glaciers (10,000–15,000 years ago) have contributed extensively to our understanding of speciation, the Aniakchak system of sockeye salmon provides a rare example of the initial stages of ecological divergence following natural colonization. Our results show that even in the face of continued migration, populations may diverge in the absence of a physical barrier.

  5. Recent ecological divergence despite migration in sockeye salmon (Oncorhynchus nerka).

    PubMed

    Pavey, Scott A; Nielsen, Jennifer L; Hamon, Troy R

    2010-06-01

    Ecological divergence may result when populations experience different selection regimes, but there is considerable discussion about the role of migration at the beginning stages of divergence before reproductive isolating mechanisms have evolved. However, detection of past migration is difficult in current populations and tools to differentiate genetic similarities due to migration versus recent common ancestry are only recently available. Using past volcanic eruption times as a framework, we combine morphological analyses of traits important to reproduction with a coalescent-based genetic analysis of two proximate sockeye salmon (Oncorhynchus nerka) populations. We find that this is the most recent (approximately 500 years, 100 generations) natural ecological divergence recorded in a fish species, and report that this divergence is occurring despite migration. Although studies of fish divergence following the retreat of glaciers (10,000-15,000 years ago) have contributed extensively to our understanding of speciation, the Aniakchak system of sockeye salmon provides a rare example of the initial stages of ecological divergence following natural colonization. Our results show that even in the face of continued migration, populations may diverge in the absence of a physical barrier.

  6. Recent ecological divergence despite migration in sockeye salmon (Oncorhynchus nerka).

    PubMed

    Pavey, Scott A; Nielsen, Jennifer L; Hamon, Troy R

    2010-06-01

    Ecological divergence may result when populations experience different selection regimes, but there is considerable discussion about the role of migration at the beginning stages of divergence before reproductive isolating mechanisms have evolved. However, detection of past migration is difficult in current populations and tools to differentiate genetic similarities due to migration versus recent common ancestry are only recently available. Using past volcanic eruption times as a framework, we combine morphological analyses of traits important to reproduction with a coalescent-based genetic analysis of two proximate sockeye salmon (Oncorhynchus nerka) populations. We find that this is the most recent (approximately 500 years, 100 generations) natural ecological divergence recorded in a fish species, and report that this divergence is occurring despite migration. Although studies of fish divergence following the retreat of glaciers (10,000-15,000 years ago) have contributed extensively to our understanding of speciation, the Aniakchak system of sockeye salmon provides a rare example of the initial stages of ecological divergence following natural colonization. Our results show that even in the face of continued migration, populations may diverge in the absence of a physical barrier. PMID:20030707

  7. Plasma levels on thyroid hormones in sockeye salmon (Oncorhynchus nerka) decrease before spawning.

    PubMed

    Biddiscombe, S; Idler, D R

    1983-12-01

    Blood samples were taken from mature sockeye salmon (Oncorhynchus nerka) at various stages in their upstream migration to spawn at Adam's River in British Columbia, Canada. Plasma T3 and T4 levels decreased significantly in both males and females between time of entry into fresh water and postspawning.

  8. Heritability of tolerance for infectious hematopoietic necrosis in sockeye salmon (Oncorhynchus nerka)

    USGS Publications Warehouse

    McIntyre, John D.; Amend, Donald F.

    1978-01-01

    A hierarchical breeding design was used to demonstrate the heritability of tolerance for infectious hematopoietic necrosis (IHN) in sockeye salmon. Oncorhynchus nerka. Heritability was about 30%, indicating that artificial selection may increase the number of fish that can tolerate the disease.

  9. Low cardiac and aerobic scope in a coastal population of sockeye salmon Oncorhynchus nerka with a short upriver migration.

    PubMed

    Eliason, E J; Wilson, S M; Farrell, A P; Cooke, S J; Hinch, S G

    2013-06-01

    This study showed that a coastal population (Harrison) of Fraser River sockeye salmon Oncorhynchus nerka had a lower aerobic and cardiac scope compared with interior populations with more challenging upriver spawning migrations, providing additional support to the idea that Fraser River O. nerka populations have adapted physiologically to their local migratory environment. PMID:23731155

  10. Elevation of plasma cortisol during the spawning migration of landlocked kokanee salmon (Oncorhynchus nerka kennerlyi).

    PubMed

    Carruth, L L; Dores, R M; Maldonado, T A; Norris, D O; Ruth, T; Jones, R E

    2000-09-01

    Kokanee salmon (Oncorhynchus nerka kennerlyi ), a landlocked subspecies of sockeye salmon, exhibited hypothalamic-pituitary interrenal (HPI, adrenal homologue) axis activation and an increase in plasma cortisol concentration up to 639 +/- 55.9 ng/ml in association with upstream migration in the upper Colorado River even though they were not exposed to a change in salinity and lengthy migration. Kokanee salmon were collected at various stages of migration and concomitant sexual maturation. The pattern of cortisol elevation in kokanee is similar to that in ocean-run sockeye salmon (O. nerka nerka). The presence of plasma cortisol elevation in an upstream migrating, landlocked Pacific salmon suggests that stressors previously considered to cause the cortisol increase, such as long-distance migration and changes in salinity, may not be primary causes of the HPI axis activation.

  11. Oncorhynchus nerka population monitoring in the Sawtooth Valley Lakes

    SciTech Connect

    Teuscher, D.M.; Taki, D.; Ariwite, K.

    1996-05-01

    Critical habitat for endangered Snake River sockeye salmon includes five rearing lakes located in the Sawtooth Valley of central Idaho. Most of the lakes contain either introduced or endemic kokanee populations. Snake River sockeye occur naturally in Redfish Lake, and are being stocked in Redfish and Pettit Lakes. Because kokanee compete with sockeye for limited food resources, understanding population characteristics of both species such as spawn timing, egg-to-fry survival, distribution and abundance are important components of sockeye recovery. This chapter describes some of those characteristics. In 1995, hydroacoustic estimates of O. nerka densities in the Sawtooth Valley Lakes ranged from 57 to 465 fish/ha. Densities were greatest in Pettit followed by Redfish (167), Alturas (95), and Stanley Lakes. O. nerka numbers increased from 1994 values in Pettit and Alturas Lakes, but declined in Redfish and Stanley. Despite a decline in total lake abundance, O. nerka biomass estimates in Redfish Lake increased. Approximately 144,000 kokanee fry recruited to Redfish Lake from Fishhook Creek. O. nerka fry recruitment to Stanley and Alturas lake was 5,000 and 30,000 fry, respectively. Egg-to-fry survival was 14% in Fishhook and 7% in Stanley Lake Creek. In Fishhook Creek, kokanee spawning escapement was estimated using stream surveys and a weir. Escapement estimates were 4,860 from weir counts, and 7,000 from stream surveys. As part of the kokanee reduction program, 385 of the spawning female kokanee were culled. Escapement for Stanley Lake Creek was only 60 fish, a ten fold decrease from 1994. In Alturas Lake, kokanee spawners dropped by 50% to 1,600.

  12. Thermal regime, predation danger and the early marine exit of sockeye salmon Oncorhynchus nerka.

    PubMed

    Katinic, P J; Patterson, D A; Ydenberg, R C

    2015-01-01

    Marine exit timing of sockeye salmon Oncorhynchus nerka populations on the Haida Gwaii Archipelago, British Columbia, Canada, is described, with specific focus on Copper Creek. Marine exit in Copper Creek occurs > 130 days prior to spawning, one of the longest adult freshwater residence periods recorded for any O. nerka population. Copper Creek presents an easy upstream migration, with mild water temperatures (7 to 14°  C), short distance (13·1 km) and low elevation gain (41 m) to the lake where fish hold prior to spawning. An energetic model estimates that <1% of the initial energy reserve is required for upstream migration, compared with 62% for lake holding and 38% for reproductive development. Historical records suggest that it is unlikely that water temperature in any of the O.nerka streams in Haida Gwaii has ever exceeded the presumed temperature threshold (19° C) for early marine exit. Although it is not impossible that the thermal tolerance of Copper Creek O.nerka is very low, the data presented here appear inconsistent with thermal avoidance as an explanation for the early marine exit timing in Copper Creek and in three other populations on the archipelago with early marine exit. PMID:25494933

  13. Genetic Analysis of Snake River Sockeye Salmon (Oncorhynchus Nerka), 2003 Technical Report.

    SciTech Connect

    Faler, Joyce; Powell, Madison

    2003-12-01

    A total of 1720 Oncorhynchus nerka tissue samples from 40 populations were characterized using mitochondrial DNA RFLPs (Restriction Fragment Length Polymorphisms). Analysis of anadromous sockeye populations indicated the historical presence of four major maternal lineages. Thirty-five composite mitochondrial haplotypes were observed from the 40 populations of O. nerka sampled throughout the Pacific Northwest. Six of these composite haplotypes ranged in frequency from 7-26% overall and were commonly observed in most populations. The six haplotypes together comprised 90% of the sampled O. nerka. An average of 4.6 composite haplotypes were observed per population. Genetic markers used were satisfactory in separating Redfish Lake anadromous sockeye, residual sockeye and outmigrants from the sympatric kokanee population that spawns in the Fishhook Creek tributary. Outmigrants appear to be primarily composed of progeny from resident residual sockeye, and captively-reared progeny of the captive broodstock program. Thus, residual sockeye may be considered a suitable source of genetic variation to maintain genetic diversity among captive broodstocks of anadromous sockeye. Fishhook Creek kokanee are genetically diverse and during spawning, are temporally and spatially isolated from the residual sockeye population. Eleven composite haplotypes were observed in the kokanee population. The unusually high number of haplotypes is most likely a consequence of periodic stocking of Redfish Lake with kokanee from other sources. Genetic data from Redfish Lake creel samples taken during 1996-1999 putatively indicate the incidental take of a listed resident sockeye.

  14. Does among-population variation in burst swimming performance of sockeye salmon Oncorhynchus nerka fry reflect early life migrations?

    PubMed

    Sopinka, N M; Hinch, S G; Lotto, A G; Whitney, C K; Patterson, D A

    2013-11-01

    Using a fixed-speed test, burst swimming performance was found to vary among nine populations of emergent sockeye salmon Oncorhynchus nerka fry reared in a common-garden environment. No consistent relationship was, however, detected between difficulty of fry migration (upstream v. downstream) to rearing areas and total burst swimming duration or bursting rate. PMID:24117961

  15. The influence of maternal condition on offspring performance in sockeye salmon Oncorhynchus nerka.

    PubMed

    Tierney, K B; Patterson, D A; Kennedy, C J

    2009-10-01

    Eggs were taken from adult sockeye salmon Oncorhynchus nerka that had reached their journey's end in spawn-ready and moribund condition, and fertilized by healthy males. Egg number, size, hatching success and offspring growth did not differ with maternal condition, which suggests the absence of any persisting physiological maternal effects. Differences were noted in the swimming behaviour and physiology of the offspring at parr stage. In a 30 min schooling test conducted using groups of five in a flume, parr from moribund females were more likely to fatigue, were not as tightly schooled, and had a diminished startle response, both in the per cent responding and the burst distance. In individual, confined swimming tests conducted within a tube, post-exercise plasma lactate concentration, which is an indicator of white muscle use, was greater for parr from moribund adult females. The moribund females also had elevated lactate following exercise (their migration), which suggests heritable differences may exist in muscle use. This study shows that juvenile O. nerka artificially propagated from females exhausted by their return migration can exhibit swimming performance differences, indicating that maternal condition may need to be considered in breeding programmes.

  16. Provenance matters: thermal reaction norms for embryo survival among sockeye salmon Oncorhynchus nerka populations.

    PubMed

    Whitney, C K; Hinch, S G; Patterson, D A

    2013-04-01

    Differences in thermal tolerance during embryonic development in Fraser River sockeye salmon Oncorhynchus nerka were examined among nine populations in a controlled common-garden incubation experiment. Forcing embryonic development at an extreme temperature (relative to current values) of 16° C, representing a future climate change scenario, significantly reduced survival compared to the more ecologically moderate temperature of 10° C (55% v. 93%). Survival at 14° C was intermediate between the other two temperatures (85%). More importantly, this survival response varied by provenance within and between temperature treatments. Thermal reaction norms showed an interacting response of genotype and environment (temperature), suggesting that populations of O. nerka may have adapted differentially to elevated temperatures during incubation and early development. Moreover, populations that historically experience warmer incubation temperatures at early development displayed a higher tolerance for warm temperatures. In contrast, thermal tolerance does not appear to transcend life stages as adult migration temperatures were not related to embryo thermal tolerance. The intra-population variation implies potential for thermal tolerance at the species level. The differential inter-population variation in thermal tolerance that was observed suggests, however, limited adaptive potential to thermal shifts for some populations. This infers that the intergenerational effects of increasing water temperatures may affect populations differentially, and that such thermally mediated adaptive selection may drive population, and therefore species, persistence. PMID:23557297

  17. Comparison of polyunsaturated fatty acids content in filets of anadromous and landlocked sockeye salmon Oncorhynchus nerka.

    PubMed

    Gladyshev, Michail I; Lepskaya, Ekaterina V; Sushchik, Nadezhda N; Makhutova, Olesia N; Kalachova, Galina S; Malyshevskaya, Kseniya K; Markevich, Grigory N

    2012-12-01

    Fatty acid composition and content of 2 forms of sockeye salmon Oncorhynchus nerka from lakes in Kamchatka Peninsula (Russia) were compared. One form of sockeye salmon was anadromous ("marine"), that is, adult fish migrated in ocean to feed and grow and than return in the lake to breed. Fish of another form, kokanee, never migrate in the ocean. Per cent levels of the main indicators of nutritive value, eicosapentaenoic acid (EPA, 20:5n-3), and docosahexaenoic acid (DHA, 22:6n-3), were significantly higher in the landlocked O. nerka. However, concentrations of EPA and DHA per wet weight of filets were higher in the marine form, because of the relatively higher content of sum of fatty acids in their muscle tissue. As concluded, fish fed in marine environment had higher contents of long-chain n-3 fatty acids per wet weight than fish of the same species, fed in fresh waters. In general, both the anadromous sockeye salmon and the landlocked kokanee salmon can be recommended for human diet as a valuable product concerning contents of EPA and DHA. PMID:23240970

  18. Immunization of sockeye salmon (Oncorhynchus nerka) against vibriosis using the hyperosmotic infiltration technique

    USGS Publications Warehouse

    Croy, Thomas R.; Amend, Donald F.

    1977-01-01

    Various procedures of hyperosmotic infiltration (HI) and intraperitoneal injection were used to vaccinate sockeye salmon (Oncorhynchus nerka) with killed Vibrio anguillarum. Excellent protection was evident against experimentally induced vibriosis in the groups immunized by HI with 10 × Hanks' balanced salt solution (HBSS), 1 × HBSS with 8.0% NaCl and 5.3% NaCl, as well as in the injected groups. Comparisons were made among the various immunization methods by vaccinating fish with ten-fold serial dilutions of bacterin, then challenging them by the water contact method after 6 or 9 weeks. Protection was somewhat better with 10 × HBSS than with 5.3% NaCl, and 1 × HBSS containing 8.0% NaCl was markedly superior to the vaccination of fish without hyperosmotic treatment. Agglutinin titers did not exceed 1 : 8 in any group.

  19. Are there intergenerational and population-specific effects of oxidative stress in sockeye salmon (Oncorhynchus nerka)?

    PubMed

    Taylor, Jessica J; Wilson, Samantha M; Sopinka, Natalie M; Hinch, Scott G; Patterson, David A; Cooke, Steven J; Willmore, William G

    2015-06-01

    Intergenerational effects of stress have been reported in a wide range of taxa; however, few researchers have examined the intergenerational consequences of oxidative stress. Oxidative stress occurs in living organisms when reactive oxygen species remain unquenched by antioxidant defense systems and become detrimental to cells. In fish, it is unknown how maternal oxidative stress and antioxidant capacity influence offspring quality. The semelparous, migratory life history of Pacific salmon (Oncorhynchus spp.) provides a unique opportunity to explore intergenerational effects of oxidative stress. This study examined the effects of population origin on maternal and developing offspring oxidative stress and antioxidant capacity, and elucidated intergenerational relationships among populations of sockeye salmon (Oncorhynchus nerka) with varying migration effort. For three geographically distinct populations of Fraser River sockeye salmon (British Columbia, Canada), antioxidant capacity and oxidative stress were measured in adult female plasma, heart, brain, and liver, as well as in developing offspring until time of emergence. Maternal and offspring oxidative stress and antioxidant capacity varied among populations but patterns were not consistent across tissue/developmental stage. Furthermore, maternal oxidative stress and antioxidant capacity did not affect offspring oxidative stress and antioxidant capacity across any of the developmental stages or populations sampled. Our results revealed that offspring develop their endogenous antioxidant systems at varying rates across populations; however, this variability is overcome by the time of emergence. While offspring may be relying on maternally derived antioxidants in the initial stages of development, they rapidly develop their own antioxidant systems (mainly glutathione) during later stages of development. PMID:25660296

  20. Juvenile habitat partitioning and relative productivity in allochronically isolated sockeye salmon (Oncorhynchus nerka)

    PubMed Central

    Miller, EK Fillatre; Bradbury, IR; Heath, DD

    2011-01-01

    Allochronic divergence, like spatial isolation, may contribute to population diversity and adaptation, however the challenges for tracking habitat utilization in shared environments are far greater. Adult Klukshu River (Yukon, Canada) sockeye salmon, Oncorhynchus nerka, return as genetically distinct “early” and “late” runs. Early and late adult spawning populations (1999 and 2000) and their subsequent fry (sampled at 7 sites in 2000 and at 8 sites in 2001 throughout Klukshu Lake and River) were genotyped at eight microsatellite loci. Bayesian assignment was used to determine the spatial distribution of early versus late fry; although intermixed, the distribution of fry significantly differed in Klukshu Lake and in the Klukshu River in 2001, based on crosstab analyses. Late-run fry predominated in Klukshu Lake at all sites, while early-run fry were most common in the north and south of Klukshu Lake and in Klukshu River. Early-run spawners had significantly higher relative productivity (early life survival) than late-run fish (2.9 times more fry produced per early-run adult in 2000, and 9.2 times more in 2001). This study demonstrates spatial habitat partitioning and differences in the contribution of allochronically isolated populations to fry abundance, and highlights annual variability that likely contributes to recruitment variation. PMID:22393527

  1. Immersion vaccination of sockeye salmon (Oncorhynchus nerka) with two pathogenic strains of Vibrio anguillarum

    USGS Publications Warehouse

    Gould, R.W.; Antipa, R.; Amend, D.F.

    1979-01-01

    Sockeye salmon (Oncorhynchus nerka) were immersion-vaccinated in suspensions containing 5 × 107, 5 × 106, 5 × 105, or 5 × 104 bacteria/mL of bivalent or monovalent, formalin-killedVibrio anguillarum, Types I and II. The fish were split into two lots and held for 54 d. At that time one lot was challenged with living, virulent V. anguillarum, Type I, and one with living, virulent V.anguillarum, Type II. Immunization with bivalent bacterin effectively protected the fish from vibriosis, but monovalent vaccine was effective only against the homologous challenge. Immunization with the highest concentration of Type I monovalent bacterin resulted in 0% Type I and 58% Type II challenge mortality. Immunization with the highest concentration of Type II monovalent bacterin resulted in 41% Type I and 0% Type II challenge mortality. Immunization with the highest concentration of bivalent Type I/Type II bacterin resulted in 2% mortality in both challenges. Protective bacterins were effective at concentrations down to 5 × 105 bacteria/mL.Key words: immersion vaccination, bivalent vaccines, Vibrio anguillarum, vibriosis.

  2. Composition and location of simulated lake-shore redds influence incubation success in kokanee, Oncorhynchus nerka

    USGS Publications Warehouse

    Fincel, M.J.; Chipps, S.R.; Bennett, D.H.

    2009-01-01

    Methods for improving spawning habitat for lakeshore spawning kokanee, Oncorhynchus nerka (Walbaum), were explored by quantifying incubation success of embryos exposed to three substrate treatments in Lake Pend Oreille, Idaho, USA. Substrate treatments included no modification that used existing gravels in the lake (EXISTING), a cleaned substrate treatment where existing gravels were sifted in the water column to remove silt (CLEANED) and the addition of new, silt-free gravel (ADDED). Incubation success was evaluated using Whitlock-Vibert incubation boxes buried within each substrate treatment that contained recently fertilised embryos. Upon retrieval, live and dead sac fry and eyed eggs were enumerated to determine incubation success (sac fry and eyed eggs ?? 100/number of fertilised embryos). Incubation success varied significantly among locations and redd treatments. In general, incubation success among ADDED redds (0.0-13.0%) was significantly lower than that for EXISTING (1.4-61.0%) and CLEANED (0.4-62.5%) redds. Adding new gravel to spawning areas changed the morphometry of the gravel-water interface and probably exposed embryos to disturbance from wave action and reduced embryo survival. Moreover, efforts to improve spawning habitat for lakeshore spawning kokanee should consider water depth and location (e.g. protected shorelines) as important variables. Adding clean gravel to existing spawning areas may provide little benefit if water depth or lake-bottom morphometry are altered. ?? 2009 Blackwell Publishing Ltd.

  3. Adrenocorticotropin- and opiate-like hormones from pituitaries of the sockeye salmon Oncorhynchus nerka.

    PubMed

    Ng, T B; Hon, W K; Idler, D R

    1987-04-01

    The pituitaries of vitellogenic sockeye salmon (Oncorhynchus nerka) were extracted with a mixture of acetone, water, and hydrochloric acid. The precipitate which formed upon the addition of a copious volume of acetone to the extract, designated acid acetone powder, was subjected to salt fractionation and desalting, followed by ion-exchange chromatography on CM-cellulose. An unadsorbed fraction (S-1) and four adsorbed fractions (S-2, S-3, S-4 and S-5) were obtained. Adrenocorticotropic activity was detected in the fractions by their ability to stimulate isolated rat adrenal decapsular cells to produce corticosterone and by their immunoreactivities in an adrenocorticotropin-specific radioimmunoassay. The steroidogenic activities of all fractions, except S-4, were blocked by corticotropin inhibiting peptide. Opiate activity was detected in the fractions by their ability to inhibit the binding of either [3H]naloxone or (D-ala2, D-leu5)-[3H]enkephalin to rat brain membranes. There was a discrepancy in the potencies of the five fractions in the two opiate radioreceptor assays, indicating the presence of opiate peptides with different affinities of binding to the micron- and delta-opiate receptors of the rat brain. There was a separation between adrenocorticotropic and opiate receptor binding activities, suggesting that the activities were due to separate molecular entities. PMID:3038149

  4. Incubation temperature, developmental biology, and the divergence of sockeye salmon (Oncorhynchus nerka) within Lake Washington

    USGS Publications Warehouse

    Hendry, A.P.; Hensleigh, J.E.; Reisenbichler, R.R.

    1998-01-01

    Sockeye salmon (Oncorhynchus nerka) introduced into Lake Washington in the 1930s and 1940s now spawn at several different sites and over a period of more than 3 months. To test for evolutionary divergence within this derived lineage, embryos that would have incubated in different habitats (Cedar River or Pleasure Point Beach) or at different times (October, November, or December in the Cedar River) were reared in the laboratory at 5, 9, and 12.5??C. Some developmental variation mirrored predictions of adaptive divergence: (i) survival at 12.5??C was highest for embryos most likely to experience such temperatures in the wild (Early Cedar), (ii) development rate was fastest for progeny of late spawners (Late Cedar), and (iii) yolk conversion efficiency was matched to natural incubation temperatures. These patterns likely had a genetic basis because they were observed in a common environment and could not be attributed to differences in egg size. The absolute magnitude of divergence in development rates was moderate (Late Cedar embryos emerged only 6 days earlier at 9??C) and some predictions regarding development rates were not supported. Nonetheless our results provide evidence of adaptive divergence in only 9-14 generations.

  5. Revisiting evolutionary dead ends in sockeye salmon ( Oncorhynchus nerka) life history

    USGS Publications Warehouse

    Pavey, S.A.; Hamon, T.R.; Nielsen, J.L.

    2007-01-01

    This study challenges recent hypotheses about sockeye salmon (Oncorhynchus nerka) colonization based on life history and broadens the pathways that investigators should consider when studying sockeye colonization of novel habitats. Most sockeye populations exhibit lake-type life histories. Riverine populations are thought to be more likely to stray from their natal stream to spawn and therefore colonize new habitat. We examined genetic relationships among five geographically proximate sockeye populations from the Aniakchak region of the Alaska Peninsula, Alaska. Specifically, we sought to determine if the genetic population structure was consistent with the hypothesis that a riverine population colonized a recently available upriver volcanic caldera lake, and whether recent volcanism led to genetic bottlenecks in these sockeye populations. Heterozygosity and allelic richness were not higher in the riverine population. Patterns of genetic divergence suggested that the geographically proximate riverine sockeye population did not colonize the lake; the caldera populations were more genetically divergent from the downstream riverine population (FST  =  0.047) than a lake-type population in a different drainage (FST  =  0.018). Our results did not suggest the presence of genetic bottlenecks in the caldera populations.

  6. Pathogenesis of infectious hematopoietic necrosis virus in adult sockeye salmon (Oncorhynchus nerka)

    USGS Publications Warehouse

    Mulcahy, D.M.; Burke, J.; Pascho, R.J.; Jenes, C.K.

    1982-01-01

    The concentration of infectious hematopoietic necrosis (IHN) virus was determined in eight organs and two body fluids from each of 60 adult sockeye salmon (Oncorhynchus nerka). Included in the sample were 4 males and 56 prespawning, spawning, or spent female fish. All fish were infected, and virus was present in nearly all organs. There was an overall tendency for the mean concentration to increase in many of the organs over time as the fish progressed in ripeness. In prespawning females, IHN virus could be detected in all organs and in ovarian fluid but not in serum; the incidences were highest in the gills, spleen, and pyloric ceca, and the titers were highest in the pyloric ceca and liver. Incidences of infection in the organs were higher in spawning than in prespawning females and higher still in spent females in which the incidence of virus was 100% in all organs except brains (78%) and sera (67%). Virus concentrations in organs or fluids ranged from 5 to 4.0 × 109 plaque-forming units per millilitre. In males, the highest incidences of virus were found in gills, pyloric ceca, and liver. The gills were the only organ in which the virus concentration in males exceeded that of females.Key words: infectious hematopoietic necrosis, IHN, fish virus, viral pathogenesis, sockeye salmon

  7. Examining the relationships between egg cortisol and oxidative stress in developing wild sockeye salmon (Oncorhynchus nerka).

    PubMed

    Taylor, Jessica J; Sopinka, Natalie M; Wilson, Samantha M; Hinch, Scott G; Patterson, David A; Cooke, Steven J; Willmore, William G

    2016-10-01

    Maternally-derived hormones in oocytes, such as glucocorticoids (GCs), play a crucial role in embryo development in oviparous taxa. In fishes, maternal stressor exposure increases circulating and egg cortisol levels, the primary GC in fishes, as well as induces oxidative stress. Elevated egg cortisol levels modify offspring traits but whether maternal oxidative stress correlates with circulating and egg cortisol levels, and whether maternal/egg cortisol levels correlate with offspring oxidative stress have yet to be determined. The objective of this study was to examine the relationships among maternal and egg cortisol, and maternal and offspring oxidative stress to provide insight into the potential intergenerational effects of stressor exposure in sockeye salmon (Oncorhynchus nerka). Antioxidant concentration and oxidative stress were measured in maternal tissues (plasma, brain, heart and liver) as well as offspring developmental stages (pre-fertilization, 24h post-fertilization, eyed, and hatch), and were compared to both naturally-occurring and experimentally-elevated (via cortisol egg bath) levels of cortisol in eggs. Oxygen radical absorptive capacity of tissues from maternal sockeye salmon was measured spectrophotometrically and was not correlated with maternal or egg cortisol concentrations. Also, naturally-occurring and experimentally-elevated cortisol levels in eggs (to mimic maternal stress) did not affect oxidative stress or antioxidant capacity of the offspring. We conclude that the metrics of maternal stress examined in sockeye salmon (i.e., maternal/egg cortisol, maternal oxidative stress) are independent of each other, and that egg cortisol content does not influence offspring oxidative stress.

  8. Ecological transcriptomics of lake-type and riverine sockeye salmon (Oncorhynchus nerka)

    PubMed Central

    2011-01-01

    Background There are a growing number of genomes sequenced with tentative functions assigned to a large proportion of the individual genes. Model organisms in laboratory settings form the basis for the assignment of gene function, and the ecological context of gene function is lacking. This work addresses this shortcoming by investigating expressed genes of sockeye salmon (Oncorhynchus nerka) muscle tissue. We compared morphology and gene expression in natural juvenile sockeye populations related to river and lake habitats. Based on previously documented divergent morphology, feeding strategy, and predation in association with these distinct environments, we expect that burst swimming is favored in riverine population and continuous swimming is favored in lake-type population. In turn we predict that morphology and expressed genes promote burst swimming in riverine sockeye and continuous swimming in lake-type sockeye. Results We found the riverine sockeye population had deep, robust bodies and lake-type had shallow, streamlined bodies. Gene expression patterns were measured using a 16K microarray, discovering 141 genes with significant differential expression. Overall, the identity and function of these genes was consistent with our hypothesis. In addition, Gene Ontology (GO) enrichment analyses with a larger set of differentially expressed genes found the "biosynthesis" category enriched for the riverine population and the "metabolism" category enriched for the lake-type population. Conclusions This study provides a framework for understanding sockeye life history from a transcriptomic perspective and a starting point for more extensive, targeted studies determining the ecological context of genes. PMID:22136247

  9. Postglacial genetic differentiation of reproductive ecotypes of kokanee Oncorhynchus nerka in Okanagan Lake, British Columbia.

    PubMed

    Taylor, E B; Harvey, S; Pollard, S; Volpe, J

    1997-06-01

    Okanagan Lake, south-central interior of BC, contains two reproductive ecotypes of kokanee Oncorhynchus nerka; individuals spawn in tributary streams ('stream-spawners') as well as on shoreline gravel areas ('beach-spawners'). We tested the hypothesis that these sympatric ecotypes comprise a single panmictic population by assaying variation in morphological traits and at allozyme, mitochondrial and minisatellite DNA loci in fish collected from three stream-spawning and two beach-spawning sites. No morphological traits consistently distinguished the reproductive ecotypes with the exception of the number of anal fin rays which was greater in stream-spawning kokanee. Four of 18 allozyme loci screened were polymorphic, but no significant allele frequency differences were detected among populations within ecotypes or between ecotypes. Similarly, allele frequencies at two minisatellite DNA loci were not significantly different among populations or between ecotypes. By contrast, significant differences in the frequencies of mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) haplo-types were detected between stream- and beach-spawners, but not among populations within ecotypes. Further, two RFLPs that distinguished stream- and beach-spawning adults were found in juvenile kokanee sampled from the limnetic zone of Okanagan Lake. The two mtDNA RFLPs and a d-loop sequence variant appear to be unique to Okanagan Lake Kokanee because we did not observe these haplotypes in sockeye salmon and kokanee sampled outside of Okanagan Lake. Our data suggest that: (i) there is restricted female-mediated gene flow between stream- and beach-spawning kokanee in Okanagan Lake, (ii) the forms have diverged within the lake basin since the retreat of the Wisconsinian glaciers (< approximately equal to 11 000 years ago), and (iii) distinct reproductive niches may promote divergence in north temperate freshwater fish faunas.

  10. Genomic and metabolic preparation of muscle in sockeye salmon Oncorhynchus nerka for spawning migration.

    PubMed

    Morash, Andrea J; Yu, Wilson; Le Moine, Christophe M R; Hills, Jayme A; Farrell, Anthony P; Patterson, David A; McClelland, Grant B

    2013-01-01

    Prolonged endurance exercise and fasting are two major metabolic challenges facing Pacific salmon during spawning migrations that often occur over 1,000 km. Because both prolonged exercise and fasting stimulate the oxidation of lipids, particularly in heavily recruited tissues such as muscle, we sought to investigate the regulatory mechanisms that establish and maintain the capacity for substrate oxidation at four separate locations during the final 750 km of nonfeeding migration in sockeye salmon Oncorhynchus nerka. Transcript levels of multiple genes encoding for important regulators of lipid, carbohydrate, and protein oxidation as well as the activity of several important enzymes involved in lipid and carbohydrate oxidation were examined in red and white muscle. We found in both muscle types that the messenger RNA (mRNA) expression of carnitine palmitoyltransferase I isoforms, peroxisome proliferator-activated receptors α and β, and adenosine monophosphate-activated protein kinase β1 were all significantly higher at the onset compared to later stages of nonfeeding migration. However, the activities of β-hydroxyacyl-CoA dehydrogenase and citrate synthase were higher only early in migration and only in red muscle. Later in the migration and as muscle lipid stores were greatly depleted, the mRNA levels of hexokinase I and aspartate aminotransferase increased in white muscle. Overall, at the onset of migration, high transcript and metabolic enzyme activity levels in skeletal muscle of sockeye salmon may help support the high rates of lipid oxidation needed for endurance swimming. Furthermore, we suggest that the muscle capacity to use carbohydrates and proteins may be adjusted throughout migration on an as-needed basis to fuel burst exercise through very difficult hydraulic passages in the river and perhaps during mating activities. PMID:24241071

  11. Examining the relationships between egg cortisol and oxidative stress in developing wild sockeye salmon (Oncorhynchus nerka).

    PubMed

    Taylor, Jessica J; Sopinka, Natalie M; Wilson, Samantha M; Hinch, Scott G; Patterson, David A; Cooke, Steven J; Willmore, William G

    2016-10-01

    Maternally-derived hormones in oocytes, such as glucocorticoids (GCs), play a crucial role in embryo development in oviparous taxa. In fishes, maternal stressor exposure increases circulating and egg cortisol levels, the primary GC in fishes, as well as induces oxidative stress. Elevated egg cortisol levels modify offspring traits but whether maternal oxidative stress correlates with circulating and egg cortisol levels, and whether maternal/egg cortisol levels correlate with offspring oxidative stress have yet to be determined. The objective of this study was to examine the relationships among maternal and egg cortisol, and maternal and offspring oxidative stress to provide insight into the potential intergenerational effects of stressor exposure in sockeye salmon (Oncorhynchus nerka). Antioxidant concentration and oxidative stress were measured in maternal tissues (plasma, brain, heart and liver) as well as offspring developmental stages (pre-fertilization, 24h post-fertilization, eyed, and hatch), and were compared to both naturally-occurring and experimentally-elevated (via cortisol egg bath) levels of cortisol in eggs. Oxygen radical absorptive capacity of tissues from maternal sockeye salmon was measured spectrophotometrically and was not correlated with maternal or egg cortisol concentrations. Also, naturally-occurring and experimentally-elevated cortisol levels in eggs (to mimic maternal stress) did not affect oxidative stress or antioxidant capacity of the offspring. We conclude that the metrics of maternal stress examined in sockeye salmon (i.e., maternal/egg cortisol, maternal oxidative stress) are independent of each other, and that egg cortisol content does not influence offspring oxidative stress. PMID:27316822

  12. Development of the salmon louse Lepeophtheirus salmonis and its effects on juvenile sockeye salmon Oncorhynchus nerka.

    PubMed

    Jakob, E; Sweeten, T; Bennett, W; Jones, S R M

    2013-11-01

    Responses of sockeye salmon Oncorhynchus nerka during infection with Lepeophtheirus salmonis were assessed in controlled laboratory trials. Juvenile salmon were exposed to 100 copepodids fish-1 (Trials 1 and 2) or 300 copepodids fish-1 (Trial 3) at mean weights of approximately 40, 80 and 135 g, respectively. Infections occurred on all salmon in all trials, and mean abundances (infection densities) ranged between 3.3 and 19.4 lice fish-1 (0.08 and 0.44 lice g-1 fish) in Trial 1, between 7.2 and 18.3 (0.09 and 0.22) in Trial 2 and between 19.5 and 60.7 (0.15 and 0.46) in Trial 3. A cumulative mortality of 24.4% occurred in Trial 3. At attachment sites on gills, we observed hyperplasia of basal epithelial cells and fusion of secondary lamellae occasionally associated with a cellular infiltrate. At attachment sites on fins, partial to complete skin erosion occurred, with limited evidence of hyperplasia or inflammation. Scale loss and abrasions coincided with pre-adult lice around 20 d post infection (dpi). Plasma osmolality was significantly elevated in exposed fish in Trials 1 (21 dpi), 2 (15 and 36 dpi) and 3 (20 dpi), whereas haematocrit was significantly depressed in exposed fish in Trials 1 (21 and 28 dpi) and 3 (20 dpi). Plasma cortisol was significantly elevated in exposed fish at 20 dpi (Trial 3). Physiological changes and mortality were related to the intensity of infection and became most prominent with pre-adult stages, suggesting patterns of infection and response in sockeye salmon similar to those reported for Atlantic and Chinook salmon. PMID:24191999

  13. Global Assessment of Extinction Risk to Populations of Sockeye Salmon Oncorhynchus nerka

    PubMed Central

    Rand, Peter S.; Goslin, Matthew; Gross, Mart R.; Irvine, James R.; Augerot, Xanthippe; McHugh, Peter A.; Bugaev, Victor F.

    2012-01-01

    Background Concern about the decline of wild salmon has attracted the attention of the International Union for the Conservation of Nature (IUCN). The IUCN applies quantitative criteria to assess risk of extinction and publishes its results on the Red List of Threatened Species. However, the focus is on the species level and thus may fail to show the risk to populations. The IUCN has adapted their criteria to apply to populations but there exist few examples of this type of assessment. We assessed the status of sockeye salmon Oncorhynchus nerka as a model for application of the IUCN population-level assessments and to provide the first global assessment of the status of an anadromous Pacific salmon. Methods/Principal Findings We found from demographic data that the sockeye salmon species is not presently at risk of extinction. We identified 98 independent populations with varying levels of risk within the species' range. Of these, 5 (5%) are already extinct. We analyzed the risk for 62 out of 93 extant populations (67%) and found that 17 of these (27%) are at risk of extinction. The greatest number and concentration of extinct and threatened populations is in the southern part of the North American range, primarily due to overfishing, freshwater habitat loss, dams, hatcheries, and changing ocean conditions. Conclusions/Significance Although sockeye salmon are not at risk at the species-level, about one-third of the populations that we analyzed are at risk or already extinct. Without an understanding of risk to biodiversity at the level of populations, the biodiversity loss in salmon would be greatly underrepresented on the Red List. We urge government, conservation organizations, scientists and the public to recognize this limitation of the Red List. We also urge recognition that about one-third of sockeye salmon global population diversity is at risk of extinction or already extinct. PMID:22511930

  14. Genomic and metabolic preparation of muscle in sockeye salmon Oncorhynchus nerka for spawning migration.

    PubMed

    Morash, Andrea J; Yu, Wilson; Le Moine, Christophe M R; Hills, Jayme A; Farrell, Anthony P; Patterson, David A; McClelland, Grant B

    2013-01-01

    Prolonged endurance exercise and fasting are two major metabolic challenges facing Pacific salmon during spawning migrations that often occur over 1,000 km. Because both prolonged exercise and fasting stimulate the oxidation of lipids, particularly in heavily recruited tissues such as muscle, we sought to investigate the regulatory mechanisms that establish and maintain the capacity for substrate oxidation at four separate locations during the final 750 km of nonfeeding migration in sockeye salmon Oncorhynchus nerka. Transcript levels of multiple genes encoding for important regulators of lipid, carbohydrate, and protein oxidation as well as the activity of several important enzymes involved in lipid and carbohydrate oxidation were examined in red and white muscle. We found in both muscle types that the messenger RNA (mRNA) expression of carnitine palmitoyltransferase I isoforms, peroxisome proliferator-activated receptors α and β, and adenosine monophosphate-activated protein kinase β1 were all significantly higher at the onset compared to later stages of nonfeeding migration. However, the activities of β-hydroxyacyl-CoA dehydrogenase and citrate synthase were higher only early in migration and only in red muscle. Later in the migration and as muscle lipid stores were greatly depleted, the mRNA levels of hexokinase I and aspartate aminotransferase increased in white muscle. Overall, at the onset of migration, high transcript and metabolic enzyme activity levels in skeletal muscle of sockeye salmon may help support the high rates of lipid oxidation needed for endurance swimming. Furthermore, we suggest that the muscle capacity to use carbohydrates and proteins may be adjusted throughout migration on an as-needed basis to fuel burst exercise through very difficult hydraulic passages in the river and perhaps during mating activities.

  15. Effects of rearing temperature on immune functions in sockeye salmon (Oncorhynchus nerka)

    USGS Publications Warehouse

    Alcorn, S.W.; Murray, A.L.; Pascho, R.J.

    2002-01-01

    To determine if the defences of sockeye salmon (Oncorhynchus nerka) raised in captivity are affected by the rearing temperature or their life-cycle stage, various indices of the humoral and cellular immune functions were measured in fish reared at either 8 or 12??C for their entire life-cycle. Measures of humoral immunity included the commonly used haematological parameters, as well as measurements of complement, and lysozyme activity. Cellular assays quantified the ability of macrophages from the anterior kidney to phagocytise Staphylococcus aureus cells, or the activities of certain bactericidal systems of those cells. The T-dependent antibody response to a recombinant 57 kDa protein of Renibacterium salmoninarum was used to quantify the specific immune response. Fish were sampled during the spring and fall of their second, third and fourth years, corresponding to a period that began just before smolting and ended at sexual maturation. Fish reared at 8??C tended to have a greater percentage of phagocytic kidney macrophages during the first 2 years of sampling than the fish reared at 12??C. During the last half of the study the complement activity of the fish reared at 8??C was greater than that of the 12??C fish. Conversely, a greater proportion of the blood leucocytes were lymphocytes in fish reared at 12??C compared to the fish reared at 8??C. Fish reared at 12??C also produced a greater antibody response than those reared at 8??C. Results suggested that the immune apparatus of sockeye salmon reared at 8??C relied more heavily on the non-specific immune response, while the specific immune response was used to a greater extent when the fish were reared at 12??C. Although a seasonal effect was not detected in any of the indices measured, varying effects were observed in some measurements during sexual maturation of fish in both temperature groups. At that time there were dramatic decreases in complement activity and lymphocyte numbers. This study was unique in

  16. Antigen-binding cells in the peripheral blood of sockeye salmon, Oncorhynchus nerka Walbaum, induced by immersion or intraperitoneal injection of Vibrio languilarum bacterin

    USGS Publications Warehouse

    1981-01-01

    We used an immunocytoadherence assay to monitor the response of antigen-binding cells (ABC) in the peripheral blood of sockeye salmon, Oncorhynchus nerka, after immersion in, or intraperitoneal injection of, Vibrio anguillarum LS 1–74 bacterin. Both methods initiated an elevated ABC response in less than one day; this response persisted one week longer in the injected than in the immersed fish.

  17. Ecological relationship between freshwater sculpins (Genus cottus) and beach-spawning sockeye salmon (Oncorhynchus nerka) in Iliamna Lake, Alaska

    USGS Publications Warehouse

    Foote, C.J.; Brown, G.S.

    1998-01-01

    The interaction between two sculpin species, Cottus cognatus and Cottus aleuticus, and island beach spawning sockeye salmon (Oncorhynchus nerka) was examined in Iliamna Lake, Alaska. We conclude that sculpins actively move to specific spawning beaches and that the initiation of their movements precedes the start of spawning. Sculpin predation on sockeye eggs is positively dependent on sculpin size and on the state of the eggs (fresh versus water hardened), with the largest sculpins able to consume nearly 50 fresh eggs at a single feeding and 130 over a 7-day period. The number of sculpins in sockeye nests is greatest at the beginning of the spawning run, lowest in the middle, and high again at the end, with peak numbers of over 100 sculpins per nest (1 m2). We discuss the results in terms of energy flow of marine-derived nutrients into an oligotrophic system and in terms of the coevolution of sockeye spawning behavior and the predatory behavior of sculpins.

  18. [Intra- and interpopulation variability of southwestern Kamchatka sockeye salmon Oncorhynchus nerka inferred from the data on single nucleotide polymorphism].

    PubMed

    Khrustaleva, A M; Klovach, N V; Gritsenko, O F; Seeb, J E

    2014-07-01

    The variability of 45 single nucleotide polymorphism (SNP) loci was studied in nine samples of the sockeye salmon Oncorhynchus nerka from the rivers of southwestern Kamchatka. The Wahlund effect, gametic disequilibrium at some loci, and a decrease in interpopulation genetic diversity estimates observed in samples from the Bolshaya River outlet are explained in terms of the samples' heterogeneity. Partitioning of mixed samples using some biological characteristics of the individuals led to a noticeable decrease in the frequency of these phenomena. It was demonstrated that the allelic diversity between the populations within the river Plotnikovs accounted for the larger part of genetic variation, as compared to the differentiation between the basins. The SNP loci responsible for intra- and interpopulation differentiation of sockeye salmon from the rivers of southwestern Kamchatka were identified. Some recommendations for field population genetic studies of Asian sockeye salmon were formulated. PMID:25720142

  19. Mortality due to infectious hematopoietic necrosis of sockeye salmon (Oncorhynchus nerka) fry in streamside egg incubation boxes

    USGS Publications Warehouse

    Mulcahy, D.; Pascho, R.J.; Jenes, C.K.

    1983-01-01

    Infectious hematopoietic necrosis virus caused mortality of sockeye salmon (Oncorhynchus nerka) in streamside egg incubation boxes. Virus was not detectable in eggs or alevins; its first isolation coincided with the appearance of dead fish in a trap on the outflow from the box. Mortality due to the virus did not occur in every egg box studied. However, when fry from the boxes were held in the laboratory, epizootics began as much as 3 wk later, with total mortality exceeding 90%. More than 96% of the dead fry had titers exceeding 105 plaque-forming units per gram. The peak incidence of virus in fry migrating in the river coincided with the arrival of hatchery-produced fry, although some fry believed to have been produced by natural spawning were also infected.Englis

  20. Appearance and quantification of infectious hematopoietic necrosis virus in female sockeye salmon (Oncorhynchus nerka) during their spawning migration

    USGS Publications Warehouse

    Mulcahy, D.; Jenes, C.K.; Pascho, R.J.

    1984-01-01

    The incidence and amount of infectious hematopoietic necrosis (IHN) virus was determined in 10 organs and body fluids from each of 100 female sockeye salmon(Oncorhynchus nerka) before, during, and after their spawning migration into freshwater. Virus was found in high concentrations only in fish sampled during and after spawning. Infection rates increased from nil to 100 percent within 2 weeks. In spawning fish, incidences of IHN virus were high in all organs and fluids except brain and serum, and the highest concentrations were in the pyloric caeca and lower gut. Immediately before spawning, IHN virus was found most frequently in the gills, less frequently in the pyloric caeca and spleen, and rarely in other organs.

  1. Validation of daily increments and a marine-entry check in the otoliths of sockeye salmon Oncorhynchus nerka post-smolts.

    PubMed

    Freshwater, C; Trudel, M; Beacham, T D; Neville, C-E; Tucker, S; Juanes, F

    2015-07-01

    Juvenile sockeye salmon Oncorhynchus nerka that were reared and smolted in laboratory conditions were found to produce otolith daily increments, as well as a consistently visible marine-entry check formed during their transition to salt water. Field-collected O. nerka post-smolts of an equivalent age also displayed visible checks; however, microchemistry estimates of marine-entry date using Sr:Ca ratios differed from visual estimates by c. 9 days suggesting that microstructural and microchemical processes occur on different time scales. PMID:25959504

  2. Extensive feeding on sockeye salmon Oncorhynchus nerka smolts by bull trout Salvelinus confluentus during initial outmigration into a small, unregulated and inland British Columbia river.

    PubMed

    Furey, N B; Hinch, S G; Lotto, A G; Beauchamp, D A

    2015-01-01

    Stomach contents were collected and analysed from 22 bull trout Salvelinus confluentus at the edge of the Chilko Lake and Chilko River in British Columbia, Canada, during spring outmigration of sockeye salmon Oncorhynchus nerka smolts. Twenty of the 22 (>90%) stomachs contained prey items, virtually all identifiable prey items were outmigrant O. nerka smolts and stomach contents represented a large portion (0·0-12·6%) of estimated S. confluentus mass. The results demonstrate nearly exclusive and intense feeding by S. confluentus on outmigrant smolts, and support recent telemetry observations of high disappearance rates of O. nerka smolts leaving large natural lake systems prior to entering high-order unregulated river systems. PMID:25494841

  3. Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research : Annual Report 1992.

    SciTech Connect

    Spaulding, Scott

    1993-05-01

    This report outlines long-term planning and monitoring activities that occurred in 1991 and 1992 in the Stanley Basin Lakes of the upper Salmon River, Idaho for the purpose of sockeye salmon nerka) recovery. Limnological monitoring and experimental sampling protocol, designed to establish a limnological baseline and to evaluate sockeye salmon production capability of the lakes, are presented. Also presented are recommended passage improvements for current fish passage barriers/impediments on migratory routes to the lakes. We initiated O. nerka population evaluations for Redfish and Alturas lakes; this included population estimates of emerging kokanee fry entering each lake in the spring and adult kokanee spawning surveys in tributary streams during the fall. Gill net evaluations of Alturas, Pettit, and Stanley lakes were done in September, 1992 to assess the relative abundance of fish species among the Stanley Basin lakes. Fish population data will be used to predict sockeye salmon production potential within a lake, as well as a baseline to monitor long-term fish community changes as a result of sockeye salmon recovery activities. Also included is a paper that reviews sockeye salmon enhancement activities in British Columbia and Alaska and recommends strategies for the release of age-0 sockeye salmon that will be produced from the current captive broodstock.

  4. Efficacy of an infectious hematopoietic necrosis (IHN) virus DNA vaccine in Chinook Oncorhynchus tshawytscha and sockeye O. nerka salmon

    USGS Publications Warehouse

    Garver, K.A.; LaPatra, S.E.; Kurath, G.

    2005-01-01

    The level of protective immunity was determined for Chinook Oncorhynchus tshawytscha and sockeye/kokanee salmon (anadromous and landlocked) O. nerka following intramuscular vaccination with a DNA vaccine against the aquatic rhabdovirus, infectious hematopoietic necrosis virus (IHNV). A DNA vaccine containing the glycoprotein gene of IHNV protected Chinook and sockeye/kokanee salmon against waterborne or injection challenge with IHNV, and relative percent survival (RPS) values of 23 to 86% were obtained under a variety of lethal challenge conditions. Although this is significant protection, it is less than RPS values obtained in previous studies with rainbow trout (O. mykiss). In addition to the variability in the severity of the challenge and inherent host susceptibility differences, it appears that use of a cross-genogroup challenge virus strain may lead to reduced efficacy of the DNA vaccine. Neutralizing antibody titers were detected in both Chinook and sockeye that had been vaccinated with 1.0 and 0.1 ??g doses of the DNA vaccine, and vaccinated fish responded to viral challenges with higher antibody titers than mock-vaccinated control fish. ?? Inter-Research 2005.

  5. Transcriptomics of environmental acclimatization and survival in wild adult Pacific sockeye salmon (Oncorhynchus nerka) during spawning migration.

    PubMed

    Evans, Tyler G; Hammill, Edd; Kaukinen, Karia; Schulze, Angela D; Patterson, David A; English, Karl K; Curtis, Janelle M R; Miller, Kristina M

    2011-11-01

    Environmental shifts accompanying salmon spawning migrations from ocean feeding grounds to natal freshwater streams can be severe, with the underlying stress often cited as a cause of increased mortality. Here, a salmonid microarray was used to characterize changes in gene expression occurring between ocean and river habitats in gill and liver tissues of wild migrating sockeye salmon (Oncorhynchus nerka Walbaum) returning to spawn in the Fraser River, British Columbia, Canada. Expression profiles indicate that the transcriptome of migrating salmon is strongly affected by shifting abiotic and biotic conditions encountered along migration routes. Conspicuous shifts in gene expression associated with changing salinity, temperature, pathogen exposure and dissolved oxygen indicate that these environmental variables most strongly impact physiology during spawning migrations. Notably, transcriptional changes related to osmoregulation were largely preparatory and occurred well before salmon encountered freshwater. In the river environment, differential expression of genes linked with elevated temperatures indicated that thermal regimes within the Fraser River are approaching tolerance limits for adult salmon. To empirically correlate gene expression with survival, biopsy sampling of gill tissue and transcriptomic profiling were combined with telemetry. Many genes correlated with environmental variables were differentially expressed between premature mortalities and successful migrants. Parametric survival analyses demonstrated a broad-scale transcriptional regulator, cofactor required for Sp1 transcriptional activation (CRSP), to be significantly predictive of survival. As the environmental characteristics of salmon habitats continue to change, establishing how current environmental conditions influence salmon physiology under natural conditions is critical to conserving this ecologically and economically important fish species.

  6. Identification of Multiple QTL Hotspots in Sockeye Salmon (Oncorhynchus nerka) Using Genotyping-by-Sequencing and a Dense Linkage Map.

    PubMed

    Larson, Wesley A; McKinney, Garrett J; Limborg, Morten T; Everett, Meredith V; Seeb, Lisa W; Seeb, James E

    2016-03-01

    Understanding the genetic architecture of phenotypic traits can provide important information about the mechanisms and genomic regions involved in local adaptation and speciation. Here, we used genotyping-by-sequencing and a combination of previously published and newly generated data to construct sex-specific linkage maps for sockeye salmon (Oncorhynchus nerka). We then used the denser female linkage map to conduct quantitative trait locus (QTL) analysis for 4 phenotypic traits in 3 families. The female linkage map consisted of 6322 loci distributed across 29 linkage groups and was 4082 cM long, and the male map contained 2179 loci found on 28 linkage groups and was 2291 cM long. We found 26 QTL: 6 for thermotolerance, 5 for length, 9 for weight, and 6 for condition factor. QTL were distributed nonrandomly across the genome and were often found in hotspots containing multiple QTL for a variety of phenotypic traits. These hotspots may represent adaptively important regions and are excellent candidates for future research. Comparing our results with studies in other salmonids revealed several regions with overlapping QTL for the same phenotypic trait, indicating these regions may be adaptively important across multiple species. Altogether, our study demonstrates the utility of genomic data for investigating the genetic basis of important phenotypic traits. Additionally, the linkage map created here will enable future research on the genetic basis of phenotypic traits in salmon. PMID:26712859

  7. Testing of male sockeye salmon (Oncorhynchus nerka) and steelhead trout (Salmo gairdneri) for infectious hematopoietic necrosis virus

    USGS Publications Warehouse

    Mulcahy, D.; Pascho, R.J.; Batts, W.N.

    1987-01-01

    Infectious hematopoietic necrosis (IHN) virus has been isolated only rarely from whole milt samples of male sockeye salmon (Oncorhynchus nerka). In 3 yr of testing, virus incidences in males ranged from 0 to 13% when milt was sampled but were 60–100% with spleen or kidney. When IHN virus was isolated from sockeye salmon milt at titers less than 3.00 log10 plaque-forming units (pfu)/mL, the level of virus in the kidney or spleen exceeded 7.00 log10 pfu/g. Higher rates of IHN virus isolation from kidney or spleen than from milt were also generally found in steelhead trout (Salmo gairdneri), although the differences were less pronounced than in sockeye salmon. Furthermore, virus was sometimes isolated from steelhead trout milt when the level of virus in kidney or spleen samples was very low, and was recovered from some milt samples when none was isolated from the corresponding spleen sample. When male salmonids are tested for IHN virus, kidney or spleen samples are superior to whole milt, but milt should be included for critical examinations.

  8. Specific PCR for Myxobolus arcticus SSU rDNA in juvenile sockeye salmon Oncorhynchus nerka from British Columbia, Canada.

    PubMed

    Mahony, Amelia; Fraser, Sarah; Groman, David B; Jones, Simon R M

    2015-06-29

    A PCR for the specific detection of the salmon brain parasite Myxobolus arcticus (Pugachev and Khokhlov, 1979) was developed using primers designed to amplify a 1363 base pair fragment of the small subunit rDNA. The assay did not amplify DNA from 5 other Myxobolus species or from 7 other myxozoan species belonging to 5 other genera. For juvenile sockeye salmon Oncorhynchus nerka (Walbaum) collected from Chilko Lake, British Columbia (BC), Canada, in 2011, the prevalence by PCR was 96%, in contrast to 71% by histological examination of brain tissue. In 2010, the histological prevalence was 52.5%. Sequence identity between M. arcticus from Chilko Lake and other sites in BC ranged from 99.7 to 99.8% and was 99.6% for a Japanese sequence. In contrast, an M. arcticus sequence from Norway shared 95.3% identity with the Chilko Lake sequence, suggesting misidentification of the parasite. Chilko Lake sockeye salmon were previously reported free of infection with M. arcticus, and more research is required to understand the processes involved in the local and global dispersion of this parasite. PMID:26119303

  9. Sockeye salmon (Oncorhynchus nerka) return after an absence of nearly 90 years: A case of reversion to anadromy

    USGS Publications Warehouse

    Godbout, L.; Wood, C.C.; Withler, R.E.; Latham, S.; Nelson, R.J.; Wetzel, L.; Barnett-Johnson, R.; Grove, M.J.; Schmitt, A.K.; McKeegan, K.D.

    2011-01-01

    We document the recent reappearance of anadromous sockeye salmon (Oncorhynchus nerka) that were thought to have been extirpated by the construction of hydroelectric dams on the Coquitlam and Alouette rivers in British Columbia, Canada, in 1914 and 1927, respectively. Unexpected downstream migrations of juveniles during experimental water releases into both rivers in 2005 and 2006 preceded upstream return migrations of adults in 2007 and 2008. Genetic (microsatellite and mitochondrial DNA) markers and stable isotope (??34S and 87Sr/86Sr) patterns in otoliths confirm that both the juvenile downstream migrants and adult upstream migrants were progeny of nonanadromous sockeye salmon (kokanee) that inhabit Coquitlam and Alouette reservoirs. Low genetic diversity and evidence of genetic bottlenecks suggest that the kokanee populations in both reservoirs originated from relatively few anadromous individuals that residualized after downstream migration was largely prevented by the construction of dams. Once given an opportunity for upstream and downstream migration, both populations appear capable of reverting to a successful anadromous form, even after 25 generations.

  10. Early marine growth in relation to marine-stage survival rates for Alaska sockeye salmon (Oncorhynchus nerka)

    USGS Publications Warehouse

    Farley, Edward V.; Murphy, J.M.; Adkison, M.D.; Eisner, L.B.; Helle, J.H.; Moss, J.H.; Nielsen, J.

    2007-01-01

    We tested the hypothesis that larger juvenile sockeye salmon (Oncorhynchus nerka) in Bristol Bay, Alaska, have higher marine-stage survival rates than smaller juvenile salmon. We used scales from returning adults (33 years of data) and trawl samples of juveniles (n = 3572) collected along the eastern Bering Sea shelf during August through September 2000-02. The size of juvenile sockeye salmon mirrored indices of their marine-stage survival rate (e.g., smaller fish had lower indices of marine-stage survival rate). However, there was no relationship between the size of sockeye salmon after their first year at sea, as estimated from archived scales, and brood-year survival size was relatively uniform over the time series, possibly indicating size-selective mortality on smaller individuals during their marine residence. Variation in size, relative abundance, and marine-stage survival rate of juvenile sockeye salmon is likely related to ocean conditions affecting their early marine migratory pathways along the eastern Bering Sea shelf.

  11. Sphaerospora elwhaiensis sp.n. (Myxosporea: Sphaerosporidae) from landlocked sockeye salmon Oncorhynchus nerka (Salmoniformes: Salmonidae) in Washington State, USA.

    PubMed

    Jones, Simon; Fiala, Ivan; Prosperi-Porta, Gina; House, Marcia; Mumford, Sonia

    2011-06-01

    A new species of sphaerosporid myxosporean, Sphaerospora elwhaiensis sp. n., is described from kidney of non-anadromous sockeye salmon (kokanee) Oncorhynchus nerka (Walbaum) from Lake Sutherland in the northern Olympic Peninsula, Washington, USA. Infection with the parasite was detected in 45% of 177 kokanee examined over 5 years. While conforming to the morphological criteria by which members of the genus are defined, the parasite is distinguished from congeners in salmonids of western North America by a unique combination of valvular sculpting of the myxospore, the relatively large size of the myxospore and monosporous development within the pseudoplasmodium. In addition, nucleotide sequences of the parasite's small and large subunit ribosomal RNA gene are unique. Phylogenetic analyses of these sequences suggested that the parasite is most closely related to freshwater Myxidium spp. and Zschokkella spp. The molecular data have provided further evidence for a polyphyletic association previously recognized among members of the genus and emphasize the need for a taxonomic revision of Sphaerospora Thélohan, 1892 and related genera. PMID:21776889

  12. Excess post-exercise oxygen consumption in adult sockeye (Oncorhynchus nerka) and coho (O. kisutch) salmon following critical speed swimming.

    PubMed

    Lee, C G; Farrell, A P; Lotto, A; Hinch, S G; Healey, M C

    2003-09-01

    The present study measured the excess post-exercise oxygen cost (EPOC) following tests at critical swimming speed (Ucrit) in three stocks of adult, wild, Pacific salmon (Oncorhynchus sp.) and used EPOC to estimate the time required to return to their routine level of oxygen consumption (recovery time) and the total oxygen cost of swimming to Ucrit. Following exhaustion at Ucrit, recovery time was 42-78 min, depending upon the fish stock. The recovery times are several-fold shorter than previously reported for juvenile, hatchery-raised salmonids. EPOC varied fivefold among the fish stocks, being greatest for Gates Creek sockeye salmon (O. nerka), which was the salmon stock that had the longest in-river migration, experienced the warmest temperature and achieved the highest maximum oxygen consumption compared with the other salmon stocks that were studied. EPOC was related to Ucrit, which in turn was directly influenced by ambient test temperature. The non-aerobic cost of swimming to Ucrit was estimated to add an additional 21.4-50.5% to the oxygen consumption measured at Ucrit. While these non-aerobic contributions to swimming did not affect the minimum cost of transport, they were up to three times higher than the value used previously for an energetic model of salmon migration in the Fraser River, BC, Canada. As such, the underestimate of non-aerobic swimming costs may require a reevaluation of the importance of how in-river barriers like rapids and bypass facilities at dams, and year-to-year changes in river flows and temperatures, affect energy use and hence migration success.

  13. Consequences of high temperatures and premature mortality on the transcriptome and blood physiology of wild adult sockeye salmon (Oncorhynchus nerka)

    PubMed Central

    Jeffries, Ken M; Hinch, Scott G; Sierocinski, Thomas; Clark, Timothy D; Eliason, Erika J; Donaldson, Michael R; Li, Shaorong; Pavlidis, Paul; Miller, Kristi M

    2012-01-01

    Elevated river water temperature in the Fraser River, British Columbia, Canada, has been associated with enhanced mortality of adult sockeye salmon (Oncorhynchus nerka) during their upriver migration to spawning grounds. We undertook a study to assess the effects of elevated water temperatures on the gill transcriptome and blood plasma variables in wild-caught sockeye salmon. Naturally migrating sockeye salmon returning to the Fraser River were collected and held at ecologically relevant temperatures of 14°C and 19°C for seven days, a period representing a significant portion of their upstream migration. After seven days, sockeye salmon held at 19°C stimulated heat shock response genes as well as many genes associated with an immune response when compared with fish held at 14°C. Additionally, fish at 19°C had elevated plasma chloride and lactate, suggestive of a disturbance in osmoregulatory homeostasis and a stress response detectable in the blood plasma. Fish that died prematurely over the course of the holding study were compared with time-matched surviving fish; the former fish were characterized by an upregulation of several transcription factors associated with apoptosis and downregulation of genes involved in immune function and antioxidant activity. Ornithine decarboxylase (ODC1) was the most significantly upregulated gene in dying salmon, which suggests an association with cellular apoptosis. We hypothesize that the observed decrease in plasma ions and increases in plasma cortisol that occur in dying fish may be linked to the increase in ODC1. By highlighting these underlying physiological mechanisms, this study enhances our understanding of the processes involved in premature mortality and temperature stress in Pacific salmon during migration to spawning grounds. PMID:22957178

  14. Excess post-exercise oxygen consumption in adult sockeye (Oncorhynchus nerka) and coho (O. kisutch) salmon following critical speed swimming.

    PubMed

    Lee, C G; Farrell, A P; Lotto, A; Hinch, S G; Healey, M C

    2003-09-01

    The present study measured the excess post-exercise oxygen cost (EPOC) following tests at critical swimming speed (Ucrit) in three stocks of adult, wild, Pacific salmon (Oncorhynchus sp.) and used EPOC to estimate the time required to return to their routine level of oxygen consumption (recovery time) and the total oxygen cost of swimming to Ucrit. Following exhaustion at Ucrit, recovery time was 42-78 min, depending upon the fish stock. The recovery times are several-fold shorter than previously reported for juvenile, hatchery-raised salmonids. EPOC varied fivefold among the fish stocks, being greatest for Gates Creek sockeye salmon (O. nerka), which was the salmon stock that had the longest in-river migration, experienced the warmest temperature and achieved the highest maximum oxygen consumption compared with the other salmon stocks that were studied. EPOC was related to Ucrit, which in turn was directly influenced by ambient test temperature. The non-aerobic cost of swimming to Ucrit was estimated to add an additional 21.4-50.5% to the oxygen consumption measured at Ucrit. While these non-aerobic contributions to swimming did not affect the minimum cost of transport, they were up to three times higher than the value used previously for an energetic model of salmon migration in the Fraser River, BC, Canada. As such, the underestimate of non-aerobic swimming costs may require a reevaluation of the importance of how in-river barriers like rapids and bypass facilities at dams, and year-to-year changes in river flows and temperatures, affect energy use and hence migration success. PMID:12909706

  15. Zooplanktivory and nutrient regeneration by invertebrate (Mysis relicta) and vertebrate (Oncorhynchus nerka) planktivores: Implications for trophic interactions in oligotrophic lakes

    USGS Publications Warehouse

    Chipps, S.R.; Bennett, D.H.

    2000-01-01

    We investigated zooplanktivory and nutrient regeneration by the opossum shrimp Mysis relicta and kokanee Oncorhynchus nerka to assess the relative roles of these planktivores in oligotrophic food webs. Using bioenergetic models and clearance rate estimates, we quantified phosphorus (P) excretion rates and consumption of cladoceran prey by Mysis and kokanees in Lake Pend Oreille, Idaho, from 1995 to 1996. Consumption of cladoceran prey by Mysis was 186 kg ?? ha-1 ?? year-1, whereas consumption by kokanees was less than one quarter as much, at 45 kg ?? ha-1 ?? year-1. Similarly, Mysis excreted approximately 0.250 kg P ?? ha-1 ?? year-1 during nighttime migrations into the upper water column, whereas P excretion by kokanees was less than one third as much, at approximately 0.070 kg P ?? ha-1 ?? year-1. On a volumetric basis, nocturnal excretion by Mysis ranged from 0.002 to 0.007 ??g P ?? L-1 ?? d-1 and accounted for less than 1% of the soluble reactive P typically measured in the upper water column of the lake. Hence, nutrient recycling by Mysis may be limited in the upper water column because of the nocturnal feeding habitats that constrain Mysis to deeper strata for much of the day. In spring and autumn months, low abundance of cladoceran prey coincided with high seasonal energy requirements of the Mysis population that were linked to timing of annual Mysis brood release and abundance of age-0 Mysis. Predation by Mysis accounted for 5-70% of daily cladoceran standing stock, supporting the notion that seasonal availability of cladocerans may be regulated by Mysis predation. In lakes where Mysis experience little predation mortality, they likely play a dominant role in food web interactions (e.g., trophic cascades) relative to planktivorous fishes. Biotic mechanisms, such as successful predator-avoidance behavior, omnivorous feeding habits, and seasonal variation in Mysisbiomass, enhance the ability of Mysis to influence food web interactions from an intermediate

  16. Population Genetic Structure and Life History Variability in Oncorhynchus Nerka from the Snake River Basin, 1991-1993 Final Report.

    SciTech Connect

    Waples, Robin S.; Aebersold, Paul B.; Winans, Gary A.

    1997-05-01

    A detailed examination of O. nerka from lakes in the Sawtooth Valley of Idaho was undertaken to help guide recovery planning for the endangered Redfish Lake population and to help resolve relationships between resident and anadromous forms.

  17. Infectious haematopoietic necrosis virus genogroup-specific virulence mechanisms in sockeye salmon, Oncorhynchus nerka (Walbaum), from Redfish Lake, Idaho

    USGS Publications Warehouse

    Purcell, M.K.; Garver, K.A.; Conway, C.; Elliott, D.G.; Kurath, G.

    2009-01-01

    Characterization of infectious haematopoietic necrosis virus (IHNV) field isolates from North America has established three main genogroups (U, M and L) that differ in host-specific virulence. In sockeye salmon, Oncorhynchus nerka, the U genogroup is highly virulent, whereas the M genogroup is nearly non-pathogenic. In this study, we sought to characterize the virus-host dynamics that contribute to genogroup-specific virulence in a captive stock of sockeye salmon from Redfish Lake in Idaho. Juvenile sockeye salmon were challenged by immersion and injection with either a representative U or M viral strain and sampled periodically until 14 days post-infection (p.i.). Fish challenged with each strain had positive viral titre by day 3, regardless of challenge route, but the fish exposed to the M genogroup virus had significantly lower virus titres than fish exposed to the U genogroup virus. Gene expression analysis by quantitative reverse transcriptase PCR was used to simultaneously assess viral load and host interferon (IFN) response in the anterior kidney. Viral load was significantly higher in the U-challenged fish relative to M-challenged fish. Both viruses induced expression of the IFN-stimulated genes (ISGs), but expression was usually significantly lower in the M-challenged group, particularly at later time points (7 and 14 days p.i.). However, ISG expression was comparable with 3 days post-immersion challenge despite a significant difference in viral load. Our data indicated that the M genogroup virus entered the host, replicated and spread in the sockeye salmon tissues, but to a lesser extent than the U genogroup. Both virus types induced a host IFN response, but the high virulence strain (U) continued to replicate in the presence of this response, whereas the low virulence strain (M) was cleared below detectable levels. We hypothesize that high virulence is associated with early in vivo replication allowing the virus to achieve a threshold level, which the

  18. Geophysical Institute. Biennial report, 1993-1994

    SciTech Connect

    1996-01-01

    The 1993-1994 Geophysical Institute Biennial Report was published in November 1995 by the Geophysical Institute of the University of Alaska Fairbanks. It contains an overview of the Geophysical Institute, the Director`s Note, and research presentations concerning the following subjects: Scientific Predictions, Space Physics, Atmospheric Sciences, Snow, Ice and Permafrost, Tectonics and Sedimentation, Seismology, Volcanology, Remote Sensing, and other projects.

  19. Geophysical Institute. Biennial report, 1993-1994

    SciTech Connect

    1996-01-01

    The 1993-1994 Geophysical Institute Biennial Report was published in November 1995 by the Geophysical Institute of the University of Alaska Fairbanks. It contains an overview of the Geophysical Institute, the Director`s Note, and research presentations concerning the following subjects: scientific predictions, space physics, atmospheric sciences, snow, ice and permafrost, tectonics and sedimentation, seismology, volcanology, remote sensing, and other projects.

  20. Effect of loading density of sockeye salmon, Oncorhynchus nerka (Walbaum), eggs in incubation boxes on mortality caused by infectious haematopoietic necrosis

    USGS Publications Warehouse

    Mulcahy, D.; Bauersfeld, K.

    1983-01-01

    Infectious haematopoietic necrosis (IHN) can cause massive mortalities of sockeye salmon, Oncorhynchus nerka (Walbaum), cultured in hatcheries. One method of enhancing sockeye salmon populations is to use a streamside egg incubation box from which the fry are automatically released into the stream as they emerge from the gravel. In this system, however, IHN epizootics occur as the fry emerge and continue for up to two months after the fry leave the box (Mulcahy, unpublished data). In as much as the high density of eggs and alevins in incubation boxes might be conducive to the fulmination of an IHN epizootic, we varied the egg density in incubation boxes and studied the cffect on mortality caused by IHN.

  1. Alternative models of climatic effects on sockeye salmon (Oncorhynchus nerka) productivity in Bristol Bay, Alaska, and the Fraser River, British Columbia

    USGS Publications Warehouse

    Adkison, M.; Peterman, R.; Lapointe, M.; Gillis, D.; Korman, J.

    1996-01-01

    We compare alternative models of sockeye salmon (Oncorhynchus nerka) productivity (returns per spawner) using more than 30 years of catch and escapement data for Bristol Bay, Alaska, and the Fraser River, British Columbia. The models examined include several alternative forms of models that incorporate climatic influences as well as models not based on climate. For most stocks, a stationary stock-recruitment relationship explains very little of the interannual variation in productivity. In Bristol Bay, productivity co-varies among stocks and appears to be strongly related to fluctuations in climate. The best model for Bristol Bay sockeye involved a change in the 1970s in the parameters of the Ricker stock-recruitment curve; the stocks generally became more productive. In contrast, none of the models of Fraser River stocks that we examined explained much of the variability in their productivity.

  2. Quantification of ventricular β2 -adrenoceptor density and ligand binding affinity in wild sockeye salmon Oncorhynchus nerka smolts using a novel modification to the tritiated ligand technique.

    PubMed

    Goulding, A T; Farrell, A P

    2016-05-01

    A new, image-based, tritiated ligand technique for measuring cardiac β2 -adrenoceptor (β2 -AR) binding characteristics was developed and validated with adult rainbow trout Oncorhynchus mykiss hearts so that the tissue limitation of traditional receptor binding techniques could be overcome and measurements could be made in hearts nearly 14-times smaller than previously used. The myocardial cell-surface (functional) β2 -AR density of O. nerka smolts sampled at the headwaters of the Chilko River was 54·2 fmol mg protein(-1) and about half of that previously found in return migrating adults of the same population, but still more than twice that of adult hatchery O. mykiss (21·1 fmol mg protein(-1) ). This technique now opens the possibility of investigating cardiac receptor density in a much wider range of fish species and life stages. PMID:27095288

  3. Infection of gill and kidney of Fraser River sockeye salmon, Oncorhynchus nerka (Walbaum), by Parvicapsula minibicornis and its effect on host physiology.

    PubMed

    Bradford, M J; Lovy, J; Patterson, D A

    2010-09-01

    Adult sockeye salmon, Oncorhynchus nerka (Walbaum), migrating upstream in the Fraser River, British Columbia, are exposed to the myxozoan parasite Parvicapsula minibicornis when they enter the river from the ocean. Infections are initially localized in the kidney but have recently been associated with branchitis in one population. Adult fish from five locations in the watershed were sampled to determine whether branchitis was widespread. P. minibicornis infections in kidney glomeruli were prevalent in all samples except for a sample of fish that had just entered the Fraser River from the ocean. For fish captured in spawning streams, parasites were observed in the renal tubules and gill, and branchitis was observed in 70% of fish. Plasma osmolality was negatively correlated with the number of parasites in the kidney tubules, which we hypothesize to be caused by the breach of glomerular membranes as the parasite leaves the fish. Plasma lactate values increased with increasing levels of pathology in gills. These findings support the hypothesis that P. minibicornis impacts the physiology of migrating fish, which may in turn affect the likelihood that adults will be able to migrate and spawn successfully.

  4. Patterns of selection and allele diversity of class I and class II major histocompatibility loci across the species range of sockeye salmon (Oncorhynchus nerka).

    PubMed

    McClelland, Erin K; Ming, Tobi J; Tabata, Amy; Kaukinen, Karia H; Beacham, Terry D; Withler, Ruth E; Miller, Kristina M

    2013-09-01

    The major histocompatibility complex (MHC), an important component of the vertebrate immune system, provides an important suite of genes to examine the role of genetic diversity at non-neutral loci for population persistence. We contrasted patterns of diversity at the two classical MHC loci in sockeye salmon (Oncorhynchus nerka), MHC class I (UBA) and MHC class II (DAB), and neutral microsatellite loci across 70 populations spanning the species range from Washington State to Japan. There was no correlation in allelic richness or heterozygosity between MHC loci or between MHC loci and microsatellites. The two unlinked MHC loci may be responding to different selective pressures; the distribution of FST values for the two loci was uncorrelated, and evidence for both balancing and directional selection on alleles and lineages of DAB and UBA was observed in populations throughout the species range but rarely on both loci within a population. These results suggest that fluctuating selection has resulted in the divergence of MHC loci in contemporary populations. PMID:24033436

  5. Deposition Form and Bioaccessibility of Keto-carotenoids from Mamey Sapote (Pouteria sapota), Red Bell Pepper (Capsicum annuum), and Sockeye Salmon (Oncorhynchus nerka) Filet.

    PubMed

    Chacón-Ordóñez, Tania; Esquivel, Patricia; Jiménez, Víctor M; Carle, Reinhold; Schweiggert, Ralf M

    2016-03-01

    The ultrastructure and carotenoid-bearing structures of mamey sapote (Pouteria sapota) chromoplasts were elucidated using light and transmission electron microscopy and compared to carotenoid deposition forms in red bell pepper (Capsicum annuum) and sockeye salmon (Oncorhynchus nerka). Globular-tubular chromoplasts of sapote contained numerous lipid globules and tubules embodying unique provitamin A keto-carotenoids in a lipid-dissolved and presumably liquid-crystalline form, respectively. Bioaccessibility of sapotexanthin and cryptocapsin was compared to that of structurally related keto-carotenoids from red bell pepper and salmon. Capsanthin from bell pepper was the most bioaccessible pigment, followed by sapotexanthin and cryptocapsin esters from mamey sapote. In contrast, astaxanthin from salmon was the least bioaccessible keto-carotenoid. Thermal treatment and fat addition consistently enhanced bioaccessibility, except for astaxanthin from naturally lipid-rich salmon, which remained unaffected. Although the provitamin A keto-carotenoids from sapote were highly bioaccessible, their qualitative and quantitative in vivo bioavailability and their conversion to vitamin A remains to be confirmed.

  6. Deposition Form and Bioaccessibility of Keto-carotenoids from Mamey Sapote (Pouteria sapota), Red Bell Pepper (Capsicum annuum), and Sockeye Salmon (Oncorhynchus nerka) Filet.

    PubMed

    Chacón-Ordóñez, Tania; Esquivel, Patricia; Jiménez, Víctor M; Carle, Reinhold; Schweiggert, Ralf M

    2016-03-01

    The ultrastructure and carotenoid-bearing structures of mamey sapote (Pouteria sapota) chromoplasts were elucidated using light and transmission electron microscopy and compared to carotenoid deposition forms in red bell pepper (Capsicum annuum) and sockeye salmon (Oncorhynchus nerka). Globular-tubular chromoplasts of sapote contained numerous lipid globules and tubules embodying unique provitamin A keto-carotenoids in a lipid-dissolved and presumably liquid-crystalline form, respectively. Bioaccessibility of sapotexanthin and cryptocapsin was compared to that of structurally related keto-carotenoids from red bell pepper and salmon. Capsanthin from bell pepper was the most bioaccessible pigment, followed by sapotexanthin and cryptocapsin esters from mamey sapote. In contrast, astaxanthin from salmon was the least bioaccessible keto-carotenoid. Thermal treatment and fat addition consistently enhanced bioaccessibility, except for astaxanthin from naturally lipid-rich salmon, which remained unaffected. Although the provitamin A keto-carotenoids from sapote were highly bioaccessible, their qualitative and quantitative in vivo bioavailability and their conversion to vitamin A remains to be confirmed. PMID:26888016

  7. Simultaneous biologging of heart rate and acceleration, and their relationships with energy expenditure in free-swimming sockeye salmon (Oncorhynchus nerka).

    PubMed

    Clark, Timothy Darren; Sandblom, E; Hinch, S G; Patterson, D A; Frappell, P B; Farrell, A P

    2010-06-01

    Monitoring the physiological status and behaviour of free-swimming fishes remains a challenging task, although great promise stems from techniques such as biologging and biotelemetry. Here, implanted data loggers were used to simultaneously measure heart rate (f (H)), visceral temperature, and a derivation of acceleration in two groups of wild adult sockeye salmon (Oncorhynchus nerka) held at two different water speeds (slow and fast). Calibration experiments performed with individual fish in a swim tunnel respirometer generated strong relationships between acceleration, f (H), tail beat frequency and energy expenditure over a wide range of swimming velocities. The regression equations were then used to estimate the overall energy expenditure of the groups of fish held at different water speeds. As expected, fish held at faster water speeds exhibited greater f (H) and acceleration, and correspondingly a higher estimated energy expenditure than fish held at slower water speeds. These estimates were consistent with gross somatic energy density of fish at death, as determined using proximate analyses of a dorsal tissue sample. Heart rate alone and in combination with acceleration, rather than acceleration alone, provided the most accurate proxies for energy expenditure in these studies. Even so, acceleration provided useful information on the behaviour of fish and may itself prove to be a valuable proxy for energy expenditure under different environmental conditions, using a different derivation of the acceleration data, and/or with further calibration experiments. These results strengthen the possibility that biologging or biotelemetry of f (H) and acceleration may be usefully applied to migrating sockeye salmon to monitor physiology and behaviour, and to estimate energy use in the natural environment. PMID:20063165

  8. Expression of aquaporin-3 and -8 mRNAs in the parr and smolt stages of sockeye salmon, Oncorhynchus nerka: effects of cortisol treatment and seawater acclimation.

    PubMed

    Choi, Young Jae; Shin, Hyun Suk; Kim, Na Na; Cho, Sung Hwoan; Yamamoto, Yuzo; Ueda, Hiroshi; Lee, Jehee; Choi, Cheol Young

    2013-06-01

    This study aimed to examine the role of 2 aquaporin (AQP) isoforms (AQP3, and -8) in sockeye salmon (Oncorhynchus nerka) in response to a hyperosmotic challenge from freshwater to seawater (SW) during the parr and smoltification (smolt) stages. AQP3 mRNA was primarily detected in the osmoregulatory organs, such as gills, while AQP8 mRNA was primarily found in the intestine. These results suggested that AQP isoforms play a role in osmoregulation in specific osmoregulatory organs. Similarly, AQP3 mRNA expression in the gills (mean values:1.06 ± 0.05 [parr] and 1.29 ± 0.07 [smolt]) was significantly higher than AQP8 mRNA levels (parr: 0.04 ± 0.003; smolt: 0.14 ± 0.004), and in the intestine, AQP8 mRNA expression (parr: 0.89 ± 0.007; smolt: 1.91 ± 0.03) was significantly higher than AQP3 mRNA levels (parr: 0.24 ± 0.006; smolt: 0.83 ± 0.005); these expression patterns were similar in vivo and in vitro. Additionally, AQP mRNA levels were lower in cortisol treated than in control groups. Therefore, these results suggest that AQPs play important roles in the water absorption mechanisms associated with multiple AQP isoforms, and that cortisol enhances the hypo-osmoregulatory capacity of fish in SW, and also controls the expression of AQPs in a hyperosmotic environment. PMID:23507572

  9. Seasonal marine growth of Bristol Bay sockeye salmon (Oncorhynchus nerka) in relation to competition with Asian pink salmon (O. gorbuscho) and the 1977 ocean regime shift

    USGS Publications Warehouse

    Ruggerone, Gregory T.; Farley, E.; Nielsen, Jennifer L.; Hagen, P.

    2005-01-01

    Recent research demonstrated significantly lower growth and survival of Bristol Bay sockeye salmon (Oncorhynchus nerka) during odd-numbered years of their second or third years at sea (1975, 1977, etc.), a trend that was opposite that of Asian pink salmon (O. gorbuscha) abundance. Here we evaluated seasonal growth trends of Kvichak and Egegik river sockeye salmon (Bristol Bay stocks) during even- and odd-numbered years at sea by measuring scale circuli increments within each growth zone of each major salmon age group between 1955 and 2000. First year scale growth was not significantly different between odd- and even-numbered years, but peak growth of age-2. smolts was significantly higher than age-1. smolts. Total second and third year scale growth of salmon was significantly lower during odd- than during even-numbered years. However, reduced scale growth in odd-numbered years began after peak growth in spring and continued through summer and fall even though most pink salmon had left the high seas by late July (10-18% growth reduction in odd vs. even years). The alternating odd and even year growth pattern was consistent before and after the 1977 ocean regime shift. During 1977-2000, when salmon abundance was relatively great, sockeye salmon growth was high during specific seasons compared with that during 1955-1976, that is to say, immediately after entry to Bristol Bay, after peak growth in the first year, during the middle of the second growing season, and during spring of the third season. Growth after the spring peak in the third year at sea was relatively low during 1977-2000. We hypothesize that high consumption rates of prey by pink salmon during spring through mid-July of odd-numbered years, coupled with declining zooplankton biomass during summer and potentially cyclic abundances of squid and other prey, contributed to reduced prey availability and therefore reduced growth of Bristol Bay sockeye salmon during late spring through fall of odd

  10. Facing warm temperatures during migration: cardiac mRNA responses of two adult Oncorhynchus nerka populations to warming and swimming challenges.

    PubMed

    Anttila, K; Eliason, E J; Kaukinen, K H; Miller, K M; Farrell, A P

    2014-05-01

    The main findings of the current study were that exposing adult sockeye salmon Onchorhynchus nerka to a warm temperature that they regularly encounter during their river migration induced a heat shock response at an mRNA level, and this response was exacerbated with forced swimming. Similar to the heat shock response, increased immune defence-related responses were also observed after warm temperature treatment and with a swimming challenge in two different populations (Chilko and Nechako), but with some important differences. Microarray analyses revealed that 347 genes were differentially expressed between the cold (12-13° C) and warm (18-19° C) treated fish, with stress response (GO:0006950) and response to fungus (GO:0009620) elevated with warm treatment, while expression for genes involved in oxidative phosphorylation (GO:0006119) and electron transport chain (GO:0022900) elevated for cold-treated fish. Analysis of single genes with real-time quantitative PCR revealed that temperature had the most significant effect on mRNA expression levels, with swimming and population having secondary influences. Warm temperature treatment for the Chilko population induced expression of heat shock protein (hsp) 90α, hsp90β and hsp30 as well as interferon-inducible protein. The Nechako population, which is known to have a narrower thermal tolerance window than the Chilko population, showed even more pronounced stress responses to the warm treatment and there was significant interaction between population and temperature treatment for hsp90β expression. Moreover, significant interactions were noted between temperature treatment and swimming challenge for hsp90α and hsp30, and while swimming challenge alone increased expression of these hsps, the expression levels were significantly elevated in warm-treated fish swum to exhaustion. In conclusion, it seems that adult O. nerka currently encounter conditions that induce several cellular defence mechanisms during their once

  11. Disentangling the roles of air exposure, gill net injury, and facilitated recovery on the postcapture and release mortality and behavior of adult migratory sockeye salmon (Oncorhynchus nerka) in freshwater.

    PubMed

    Nguyen, Vivian M; Martins, Eduardo G; Robichaud, Dave; Raby, Graham D; Donaldson, Michael R; Lotto, Andrew G; Willmore, William G; Patterson, David A; Farrell, Anthony P; Hinch, Scott G; Cooke, Steven J

    2014-01-01

    We sought to improve the understanding of delayed mortality in migrating sockeye salmon (Oncorhynchus nerka) captured and released in freshwater fisheries. Using biotelemetry, blood physiology, and reflex assessments, we evaluated the relative roles of gill net injury and air exposure and investigated whether using a recovery box improved survival. Fish (n=238), captured by beach seine, were allocated to four treatment groups: captured only, air exposed, injured, and injured and air exposed. Only half of the fish in each group were provided with a 15-min facilitated recovery. After treatment, fish were radio-tagged and released to resume their migration. Blood status was assessed in 36 additional untagged fish sampled after the four treatments. Compared with fish sampled immediately on capture, all treatments resulted in elevated plasma lactate and cortisol concentrations. After air exposure, plasma osmolality was elevated and reflexes were significantly impaired relative to the control and injured treatments. Injured fish exhibited reduced short-term migration speed by 3.2 km/d and had a 14.5% reduced survival to subnatal watersheds compared to controls. The 15-min facilitated recovery improved reflex assessment relative to fish released immediately but did not affect survival. We suggest that in sockeye salmon migrating in cool water temperatures (∼13°-16°C), delayed mortality can result from injury and air exposure, perhaps through sublethal stress, and that injury created additive delayed mortality likely via secondary infections.

  12. Disentangling the roles of air exposure, gill net injury, and facilitated recovery on the postcapture and release mortality and behavior of adult migratory sockeye salmon (Oncorhynchus nerka) in freshwater.

    PubMed

    Nguyen, Vivian M; Martins, Eduardo G; Robichaud, Dave; Raby, Graham D; Donaldson, Michael R; Lotto, Andrew G; Willmore, William G; Patterson, David A; Farrell, Anthony P; Hinch, Scott G; Cooke, Steven J

    2014-01-01

    We sought to improve the understanding of delayed mortality in migrating sockeye salmon (Oncorhynchus nerka) captured and released in freshwater fisheries. Using biotelemetry, blood physiology, and reflex assessments, we evaluated the relative roles of gill net injury and air exposure and investigated whether using a recovery box improved survival. Fish (n=238), captured by beach seine, were allocated to four treatment groups: captured only, air exposed, injured, and injured and air exposed. Only half of the fish in each group were provided with a 15-min facilitated recovery. After treatment, fish were radio-tagged and released to resume their migration. Blood status was assessed in 36 additional untagged fish sampled after the four treatments. Compared with fish sampled immediately on capture, all treatments resulted in elevated plasma lactate and cortisol concentrations. After air exposure, plasma osmolality was elevated and reflexes were significantly impaired relative to the control and injured treatments. Injured fish exhibited reduced short-term migration speed by 3.2 km/d and had a 14.5% reduced survival to subnatal watersheds compared to controls. The 15-min facilitated recovery improved reflex assessment relative to fish released immediately but did not affect survival. We suggest that in sockeye salmon migrating in cool water temperatures (∼13°-16°C), delayed mortality can result from injury and air exposure, perhaps through sublethal stress, and that injury created additive delayed mortality likely via secondary infections. PMID:24457927

  13. Genetic diversity of sockeye salmon (`oncorhynchus nerka`) of Cook Inlet, Alaska, and its application to restoration of injured populations of the Kenai River. Exxon Valdez Oil Spill Restoration Project 93012 and 94255-2. Final report

    SciTech Connect

    Seeb, L.W.; Habicht, C.; Templin, W.D.; Fetzner, J.W.; Gates, R.B.

    1995-11-01

    Genetic data from sockeye salmon (Oncorhynchus nerka) were collected from all significant spawning populations contributing to mixed-stock harvests in Cook Inlet. A total of 68 allozyme loci were resolved from 37 populations. Mitochondrial DNA data from the NADH subunits 5 and 6 were collected from 19 of the populations. Mixed-stock analyses using maximum likelihood methods with 27 loci were evaluated to estimate the proportion of Kenai River populations in Central District drift fisheries. Simulations indicate that Kenai River populations can be identified in mixtures at a level of precision and accuracy useful for restoration and fishery management. Mixed-stock samples from Cook Inlet drift net fisheries were analyzed both inseason (48 hr) and post-season. Samples from fish wheels from the Kenai, Kasilof, Yentna, and Susitna River systems were also analyzed. Inclusion of mtDNA data in the analysis is being investigated to determine if it improves precision and accuracy. Results from this study are currently being used in the management and restoration of Kenai River sockeye salmon injured in the 1989 Exxon Valdex oil spill.

  14. Water Science and Technology Board. Annual report 1993-1994

    SciTech Connect

    Not Available

    1995-01-01

    This report summarizes the activities of the Water Science and Technology Board during 1993-1994. The WSTB is intended to be a dynamic forum, a mechanism by which the broad community of water science, technology, and policy professionals can help assure high-quality national water programs. The principal products of WSTB studies are written reports which cover a wide range of water resources issues of current national concern. A few recent examples are: Alternatives for ground water cleanup; Managing wastewater in coastal urban areas; and, Water transfers in the West - efficiency, equity and the environment. Projects completed, ongoing studies and published reports are described in detail in their respective sections of this report.

  15. The Chomsky-Place correspondence 1993-1994.

    PubMed

    Chomsky, N; Place, U T

    2000-01-01

    Edited correspondence between Ullin T. Place and Noam Chomsky, which occurred in 1993-1994, is presented. The principal topics are (a) deep versus surface structure; (b) computer modeling of the brain; (c) the evolutionary origins of language; (d) behaviorism; and (e) a dispositional account of language. This correspondence includes Chomsky's denial that he ever characterized deep structure as innate; Chomsky's critique of computer modeling (both traditional and connectionist) of the brain; Place's critique of Chomsky's alleged failure to provide an adequate account of the evolutionary origins of language, and Chomsky's response that such accounts are "pop-Darwinian fairy tales"; and Place's arguments for, and Chomsky's against, the relevance of behaviorism to linguistic theory, especially the relevance of a behavioral approach to language that is buttressed by a dispositional account of sentence construction. PMID:22477211

  16. The Chomsky-Place correspondence 1993-1994.

    PubMed

    Chomsky, N; Place, U T

    2000-01-01

    Edited correspondence between Ullin T. Place and Noam Chomsky, which occurred in 1993-1994, is presented. The principal topics are (a) deep versus surface structure; (b) computer modeling of the brain; (c) the evolutionary origins of language; (d) behaviorism; and (e) a dispositional account of language. This correspondence includes Chomsky's denial that he ever characterized deep structure as innate; Chomsky's critique of computer modeling (both traditional and connectionist) of the brain; Place's critique of Chomsky's alleged failure to provide an adequate account of the evolutionary origins of language, and Chomsky's response that such accounts are "pop-Darwinian fairy tales"; and Place's arguments for, and Chomsky's against, the relevance of behaviorism to linguistic theory, especially the relevance of a behavioral approach to language that is buttressed by a dispositional account of sentence construction.

  17. Educational programs in US medical schools, 1993-1994.

    PubMed

    Jonas, H S; Etzel, S I; Barzansky, B

    1994-09-01

    From the data on faculty, students, and curriculum, is it possible to identify any responses to actual or anticipated health system changes? While one could foresee medical school downsizing in response to a potentially more competitive environment in which income from faculty practice would be reduced, what has occurred, on average, is steady growth in the number of faculty members across departments, with a large increase in the past year. However, expansion is not consistent across states. Between 1992-1993 and 1993-1994, the number of full-time faculty members decreased 1.5% in California medical schools, increased 3% in Minnesota medical schools, increased 6% in North Carolina medical schools, and increased 10% in New York and Pennsylvania medical schools. These differences may reflect the fiscal situation at the state level as well as differences in the practice environment in different areas. For example, managed care has not had a major effect in many markets. It will be important to monitor trends in faculty at both the national and regional levels to understand the full impact of health system changes. There is considerable diversity among US medical schools: in goals, in student profiles, and in curriculum structure. A number of schools have goals or objectives that contain a reference to the training of primary care physicians. The majority of these are public institutions, but a number of private schools have chosen to address the issue as well. Many schools, both public and private, are under external scrutiny related to the performance and specialty and practice location choices of their graduates.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8064985

  18. Smolt Migration Characteristics and Mainstem Snake and Columbia River Detection Rates of PIT-Tagged Grande Ronde and Imnaha River Naturally Produced Spring Chinook Salmon, Annual Reports 1993, 1994, 1995 : Fish Research Project, Oregon.

    SciTech Connect

    Walters, Timothy R.; Carmichael, Richard W.; Keefe, MaryLouise

    1996-04-01

    This reports on the second, third, and fourth years of a multi-year study to assess smolt migration characteristics and cumulative detection rates of naturally produced spring chinook salmon (Oncorhynchus tshawytscha) from Northeast Oregon streams. The goal of this project is to develop an understanding of interpopulational and interannual variation in several early life history parameters of naturally produced spring and summer chinook salmon in the Grande Ronde and Imnaha River subbasins. This project will provide information to assist chinook salmon population recovery efforts. Specific populations included in the study are: (1) Catherine Creek; (2) Upper Grande Ronde River; (3) Lostine River; (4) Imnaha River; (5) Wenaha River; and (6) Minam River. In this document, the authors present findings and activities from research completed in 1993, 1994, and 1995.

  19. FAA/NASA Joint University Program for Air Transportation Research: 1993-1994

    NASA Technical Reports Server (NTRS)

    Hueschen, Richard M. (Compiler)

    1995-01-01

    This report summarizes the research conducted during the academic year 1993-1994 under the NASA/FAA sponsored Joint University Program for Air Transportation Research. The year end review was held at Ohio University, Athens, Ohio, July 14-15, 1994. The Joint University Program is a coordinated set of three grants sponsored by NASA Langley Research Center and the Federal Aviation Administration, one each with the Massachusetts Institute of Technology (NGL-22-009-640), Ohio University (NGR-36-009-017), and Princeton University (NGL-31-001-252). Completed works, status reports, and annotated bibliographies are presented for research topics which include navigation, guidance and control theory and practice, aircraft performance, human factors, and expert systems concepts applied to aircraft and airport operations. An overview of the year's activities for each university is also presented.

  20. Financing the Future: Postsecondary Students, Costs, and Financial Aid, 1993-1994. Household Economic Studies. Current Population Reports.

    ERIC Educational Resources Information Center

    Day, Jennifer Cheeseman; Witkowski, Kristine

    This report uses data collected in the Survey of Income and Program Participation (SIPP) to examine the characteristics of postsecondary education students, their schooling costs, and avenues of financing education for the academic year 1993-1994. The SIPP provides information on all students who were enrolled at any time, for any duration, during…

  1. Internal wave variability in the Beaufort Sea during the winter of 1993/1994

    NASA Astrophysics Data System (ADS)

    Halle, Chris; Pinkel, Robert

    2003-07-01

    Acoustic Doppler current profiler observations were obtained at the Sea Ice Mechanics Initiative Ice Camp as it drifted through the Beaufort Sea over the winter of 1993-1994. In this paper, the variability of the internal wave field is examined. Initially (December 1993-January 1994), the camp drifted westward through the central Canada Basin (75°N, 139°-153°W). Numerous anticyclonic baroclinic eddies were encountered. Internal wave energy levels averaged 1/25 of the Garrett-Munk (GM) standard. Shear variance averaged 1/17 GM. During February-March 1994, the camp drifted meridionally along 156°W (near the Northwind Ridge), reversing direction several times. Large baroclinic vortices were not detected. Internal wave energy levels were significantly greater during this period, peaking at 1/6 GM. Shear variance peaked at 1/3 GM. The waves were predominantly near inertial, resulting from three distinct surface generation events. Downward vertical energy fluxes ranged from typical values of 0.02 mW/m2 to a peak value of 0.15 mW/m2. Two thirds of the downward flux was associated with waves of vertical scale greater than 55 m; the remainder with smaller-scale waves. Upward energy fluxes ranged from 0.02 mW/m2 (typical) to 0.10 mW/m2 (peak), supported almost entirely by the larger-scale waves. High ice-water relative velocities (atmospheric storms), accompanied by ice deformation, appear to be necessary, but not sufficient, to assure a downward propagating wave generation event. The highly variable mesoscale has a significant effect on the near-inertial wave field propagation. The data suggest that the vertical propagation of near-inertial waves is strongly affected by the depth variation of the vertical component of mesoscale vorticity. The large Beaufort Sea vortices appear to have a dual effect on the wave field. Enhanced vertical propagation speed (and decreased energy density) is found in the negative vorticity cores. Propagation into the positive vorticity

  2. Physiological mechanisms of imprinting and homing migration in Pacific salmon Oncorhynchus spp.

    PubMed

    Ueda, H

    2012-07-01

    After several years of feeding at sea, salmonids have an amazing ability to migrate long distances from the open ocean to their natal stream to spawn. Three different research approaches from behavioural to molecular biological studies have been used to elucidate the physiological mechanisms underpinning salmonid imprinting and homing migration. The study was based on four anadromous Pacific salmon Oncorhynchus spp., pink salmon Oncorhynchus gorbuscha, chum salmon Oncorhynchus keta, sockeye salmon Oncorhynchus nerka and masu salmon Oncorhynchus masou, migrating from the North Pacific Ocean to the coast of Hokkaido, Japan, as well as lacustrine O. nerka and O. masou in Lake Toya, Hokkaido, where the lake serves as the model oceanic system. Behavioural studies using biotelemetry techniques showed swimming profiles from the Bering Sea to the coast of Hokkaido in O. keta as well as homing behaviours of lacustrine O. nerka and O. masou in Lake Toya. Endocrinological studies on hormone profiles in the brain-pituitary-gonad axis of O. keta, and lacustrine O. nerka identified the hormonal changes during homing migration. Neurophysiological studies revealed crucial roles of olfactory functions on imprinting and homing during downstream and upstream migration, respectively. These findings are discussed in relation to the physiological mechanisms of imprinting and homing migration in anadromous and lacustrine salmonids.

  3. Cross-matching TB and AIDS registries: TB patients with HIV co-infection, United States, 1993-1994.

    PubMed Central

    Moore, M; McCray, E; Onorato, I M

    1999-01-01

    OBJECTIVES: Because of limited reporting of HIV status in case reports to the national tuberculosis (TB) surveillance system, the authors conducted this study to estimate the proportion of US TB cases with HIV co-infection and to describe demographic and clinical characteristics of co-infected patients. METHODS: The 50 states, New York City, and Puerto Rico submitted the results of cross-matches of TB registries and HIV-AIDS registries. The authors determined the number of TB cases reported for 1993-1994 that were listed in HIV-AIDS registries and analyzed data on demographic and clinical characteristics by match status. RESULTS: Of 49,938 TB cases reported for 1993-1994, 6863 (14%) were listed in AIDS or HIV registries. The proportions of TB-AIDS cases among TB cases varied by reporting area, from 0% to 31%. Anti-TB drug resistance was higher among TB-AIDS cases, particularly resistance to isoniazid and rifampin (multidrug resistance) and rifampin alone, In some areas with low proportions of multidrug-resistant TB cases, however, the difference in multidrug resistance between TB-AIDS patients and non-AIDS TB patients was not found. CONCLUSIONS: The proportion of TB cases with HIV co-infection, particularly in some areas, underscores the importance of the HIV-AIDS epidemic for the epidemiology of TB. Efforts to improve HIV testing as well as reporting of HIV status for TB patients should continue to ensure optimum management of coinfected patients, enhance surveillance activities, and promote judicious resource allocation and targeted prevention and control activities. PMID:10476997

  4. Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993-1994

    USGS Publications Warehouse

    Squillace, P.J.; Zogorski, J.S.; Wilber, W.G.; Price, C.V.

    1996-01-01

    The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE) is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient groundwater from urban areas that were collected during 1993-1994 aspart of the U.S. Geological Survey's National Water-Quality Assessment program. Samples were collected from five drinking water wells, 12 springs, and 193 monitoring wells in urban areas. No MTBE was detected in drinking water wells. At a reporting level of 0.2 ??g/L, MTBE was detected most frequently in shallow groundwater from urban areas (27% of 210 wells and springs sampled in eight areas) as compared to shallow groundwater from agricultural areas (1.3% of 549 wells sampled in 21 areas) or deeper groundwater from major aquifers (1.0% of 412 wells sampled in nine areas). Only 3% of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 ??g/L, which is the estimated lower limit of the United States Environmental Protection Agency draft drinking water health advisory. Because MTBE is persistent and mobile in groundwater, it can move from shallow to deeper aquifers with time. In shallow urban groundwater, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylene (BTEX) compounds, which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in groundwater include point sources, such as leaking storage tanks, and non-point sources, such as recharge of precipitation and stormwater runoff.

  5. Over-winter ecology of Oncorhynchus nerka in the Sawtooth Valley Lakes

    SciTech Connect

    Steinhart, G.B.; Wurtsbaugh, W.A.

    1996-05-01

    Included in this section of the report on limnology of Lakes in the Snake River Plain are descriptions of winter limnological conditions and kokanee growth characteristics from 1993 to 1995. The winter is usually a very harsh period for animals, and little is know about the over-winter ecology os sockeye salmon. They are active a temperatures below 4 F. The chapter discusses methods and results. 14 figs, 4 tabs.

  6. Refined liquid smoke: a potential antilisterial additive to cold-smoked sockeye salmon (Oncorhynchus nerka).

    PubMed

    Montazeri, Naim; Himelbloom, Brian H; Oliveira, Alexandra C M; Leigh, Mary Beth; Crapo, Charles A

    2013-05-01

    Cold-smoked salmon (CSS) is a potentially hazardous ready-to-eat food product due to the high risk of contamination with Listeria monocytogenes and lack of a listericidal step. We investigated the antilisterial property of liquid smokes (LS) against Listeria innocua ATCC 33090 (surrogate to L. monocytogenes) as a potential supplement to vacuum-packaged CSS. A full-strength LS (Code 10-Poly), and three commercially refined fractions (AM-3, AM-10, and 1291) having less color and flavor (lower content of phenols and carbonyl-containing compounds) were tested. In vitro assays showed strong inhibition for all LS except for 1291. The CSS strips were surface coated with AM-3 and AM-10 at 1% LS (vol/wt) with an L-shaped glass rod and then inoculated with L. innocua at 3.5 log CFU/g, vacuum packaged, and stored at 4°C. The LS did not completely eliminate L. innocua but provided a 2-log reduction by day 14, with no growth up to 35 days of refrigerated storage. A simple difference sensory test by 180 untrained panelists showed the application of AM-3 did not significantly influence the overall sensorial quality of CSS. In essence, the application of the refined LS as an antilisterial additive to CSS is recommended.

  7. [Single-nucleotide polymorphism in populations of sockeye salmon Oncorhynchus nerka from Kamchatka Peninsula].

    PubMed

    Khrustaleva, A M; Gritsenko, O F; Klovach, N V

    2013-11-01

    The genetic polymorphism of 45 single-nucleotide polymorphism loci was examined in the four largest wild populations of sockeye salmon Oncorhynchusnerka from drainages of the Asian coast of the Pacific Ocean (Eastern and Western Kamchatka). It was demonstrated that sockeye salmon from the Palana River were considerably different from all other populations examined. The most probable explanation of the observed differences is the suggestion on possible demographic events in the history of this population associated with the decrease in its effective number. To study the origin, colonization patterns, and evolution of Asian sockeye salmon, as well as to resolve some of the applied tasks, like population assignment and genetic identification, a differentiation approach to SNP-marker selection was suggested. Adaptively important loci that evolve under the pressure of balancing (stabilizing) selection were identified, thanks to which the number of loci that provide the baseline classification error rates in the population assignment tests was reduced to 30. It was demonstrated that SNPs located in the MHC2 and GPH genes were affected by diversifying selection. Procedures for selecting single-nucleotide polymorphisms for phylogenetic studies of Asian sockeye salmon were suggested. Using principal-component analysis, 17 loci that adequately reproduce genetic differentiation within arid among the regions of the origin of Kamchatka sockeye salmon, were selected. PMID:25470934

  8. Refined liquid smoke: a potential antilisterial additive to cold-smoked sockeye salmon (Oncorhynchus nerka).

    PubMed

    Montazeri, Naim; Himelbloom, Brian H; Oliveira, Alexandra C M; Leigh, Mary Beth; Crapo, Charles A

    2013-05-01

    Cold-smoked salmon (CSS) is a potentially hazardous ready-to-eat food product due to the high risk of contamination with Listeria monocytogenes and lack of a listericidal step. We investigated the antilisterial property of liquid smokes (LS) against Listeria innocua ATCC 33090 (surrogate to L. monocytogenes) as a potential supplement to vacuum-packaged CSS. A full-strength LS (Code 10-Poly), and three commercially refined fractions (AM-3, AM-10, and 1291) having less color and flavor (lower content of phenols and carbonyl-containing compounds) were tested. In vitro assays showed strong inhibition for all LS except for 1291. The CSS strips were surface coated with AM-3 and AM-10 at 1% LS (vol/wt) with an L-shaped glass rod and then inoculated with L. innocua at 3.5 log CFU/g, vacuum packaged, and stored at 4°C. The LS did not completely eliminate L. innocua but provided a 2-log reduction by day 14, with no growth up to 35 days of refrigerated storage. A simple difference sensory test by 180 untrained panelists showed the application of AM-3 did not significantly influence the overall sensorial quality of CSS. In essence, the application of the refined LS as an antilisterial additive to CSS is recommended. PMID:23643122

  9. [Single-nucleotide polymorphism in populations of sockeye salmon Oncorhynchus nerka from Kamchatka Peninsula].

    PubMed

    2013-11-01

    The genetic polymorphism of 45 single-nucleotide polymorphism loci was examined in the four largest wild populations of sockeye salmon Oncorhynchusnerka from drainages of the Asian coast of the Pacific Ocean (Eastern and Western Kamchatka). It was demonstrated that sockeye salmon from the Palana River were considerably different from all other populations examined. The most probable explanation of the observed differences is the suggestion on possible demographic events in the history of this population associated with the decrease in its effective number. To study the origin, colonization patterns, and evolution of Asian sockeye salmon, as well as to resolve some of the applied tasks, like population assignment and genetic identification, a differentiation approach to SNP-marker selection was suggested. Adaptively important loci that evolve under the pressure of balancing (stabilizing) selection were identified, thanks to which the number of loci that provide the baseline classification error rates in the population assignment tests was reduced to 30. It was demonstrated that SNPs located in the MHC2 and GPH genes were affected by diversifying selection. Procedures for selecting single-nucleotide polymorphisms for phylogenetic studies of Asian sockeye salmon were suggested. Using principal-component analysis, 17 loci that adequately reproduce genetic differentiation within arid among the regions of the origin of Kamchatka sockeye salmon, were selected. PMID:25508561

  10. Founding events influence genetic population structure of sockeye salmon (Oncorhynchus nerka) in Lake Clark, Alaska

    USGS Publications Warehouse

    Ramstad, K.M.; Woody, C.A.; Sage, G.K.; Allendorf, F.W.

    2004-01-01

    Bottlenecks can have lasting effects on genetic population structure that obscure patterns of contemporary gene flow and drift. Sockeye salmon are vulnerable to bottleneck effects because they are a highly structured species with excellent colonizing abilities and often occupy geologically young habitats. We describe genetic divergence among and genetic variation within spawning populations of sockeye salmon throughout the Lake Clark area of Alaska. Fin tissue was collected from sockeye salmon representing 15 spawning populations of Lake Clark, Six-mile Lake, and Lake Iliamna. Allele frequencies differed significantly at 11 microsatellite loci in 96 of 105 pairwise population comparisons. Pairwise estimates of FST ranged from zero to 0.089. Six-mile Lake and Lake Clark populations have historically been grouped together for management purposes and are geographically proximate. However, Six-mile Lake populations are genetically similar to Lake Iliamna populations and are divergent from Lake Clark populations. The reduced allelic diversity and strong divergence of Lake Clark populations relative to Six-mile Lake and Lake Iliamna populations suggest a bottleneck associated with the colonization of Lake Clark by sockeye salmon. Geographic distance and spawning habitat differences apparently do not contribute to isolation and divergence among populations. However, temporal isolation based on spawning time and founder effects associated with ongoing glacial retreat and colonization of new spawning habitats contribute to the genetic population structure of Lake Clark sock-eye salmon. Nonequilibrium conditions and the strong influence of genetic drift caution against using estimates of divergence to estimate gene flow among populations of Lake Clark sockeye salmon.

  11. Biogeographic implications of cytochrome b sequences and allozymes in sockeye (Oncorhynchus nerka).

    PubMed

    Bickham, J W; Wood, C C; Patton, J C

    1995-01-01

    Nucleotide sequence and restriction site analyses of the cytochrome b gene of mitochondrial DNA revealed three relatively common haplotypes among sockeye salmon (N = 80) from eight populations representing four major drainages from Kamchatka (Russia), Alaska, and British Columbia. Macrogeographic variation in mtDNA was compared to that of three variable allozyme loci assayed for a much larger number of fish (N = 779). Sockeye from the Fraser River drainage of British Columbia were distinct from those from the other three drainages in both analyses. The GT haplotype was found in all four populations, but the GC haplotype was absent from the Fraser River (southern) drainage and present in the three northern drainages. The AC haplotype was common in the Fraser River drainage (frequency = 0.4), rare in the Skeena River drainage of British Columbia (0.1), and absent from the Alaskan and Russian samples. Cluster analysis (UPGMA) of allozyme allele frequencies showed a similar pattern of divergence with the populations from the Fraser River drainage being most divergent and clustering at an identity value of 0.93 with the rest of the populations. Five of the remaining six populations clustered at or above an identity value of 0.99. These data, combined with allozyme data for sockeye and mitochondrial DNA data for chinook salmon and the Steller sea lion, indicate the presence of a phylogeographic break between northern and southern populations ostensibly derived from glacial refugia in Beringia and the Columbia River, respectively. PMID:7751598

  12. AGS experiments: 1993 - 1994 - 1995

    SciTech Connect

    Depken, J.C.

    1996-04-01

    This report contains: FY 1995 AGS Schedule as Run; FY 1996-97 AGE Schedule (working copy); AGS Beams 1995; AGS Experimental Area FY 1993 Physics Program; AGS Experimental Area FY 1994 Physics Program; AGS Experimental Area FY 1995 Physics Program; AGS Experimental Area FY 1996 Physics Program (In progress); A listing of experiments by number; Two-page summaries of each experiment begin here, also ordered by number; Listing of publications of AGS experiments begins here; and Listing of AGS experimenters begins here. This is the twelfth edition.

  13. Virginia Resolves, 1993-1994.

    ERIC Educational Resources Information Center

    Morrow, S. Rex, Ed.

    1994-01-01

    These two issues of "Virginia Resolves" provide articles of interest to the social studies reader and provides ideas for social studies instruction and curriculum. The fall issue features seven articles: (1) "Death and the Young Child" (Rosanne J. Marek); (2) "Simulations: Bibliography for the Middle and Elementary Teachers" (William Coleman Redd…

  14. Field research, 1993-1994

    SciTech Connect

    Not Available

    1993-09-01

    This article summarizes field research during the 1993-94 field season in the Antarctic. Among other studies were descriptions of the following: Effects of ultraviolet radiation on the photosynthesis of phytoplankton in the antarctic marginal ice zone; Long-term ecological research (LTER) on the Antarctic marine ecosystem: microbiology and carbon flux; Geologic record of late Wisconsinan/Holocene ice sheet advance and retreat from the Ross Sea; Late Quarernary paleoclimatic history of southern Chile: evidence from the marine record; Integrated biostratigraphy and high resolution seismic stratigraphy of the Ross Sea: Implications for Cenozoic eustatic and climate change; Oxygen-isotope record from McMurdo dome and its relation to the geological climate record of the McMurdo Dry Valleys; Evaluation of processes at polar glacier grounding lines to constrain glaciological and oceanographic models; Reconstruction of paleotemperatures from precision borehole temperature logging; Cenozoic glacial and climatic history of the antarctic region; Observation and modeling studies of episodic events in the south polar atmospheric boundary layer; biogeochemistry of carbon and silica on the antarctic shelf; Chlorine and bromine containing trace gases in Antarctica; South Pole monitoring for climatic change; Aerosol Sampling at Palmer Station; several Ozone depletion studies.

  15. Incubation success and habitat selection of shore-spawning kokanee Onchorhynchus nerka: effects of water level regulation and habitat characteristics.

    USGS Publications Warehouse

    Whitlock, Steven L.; Quist, Michael; Dux, Andrew M.

    2014-01-01

    Changes to water-level regimes have been known to restructure fish assemblages and interfere with the population dynamics of both littoral and pelagic species. The effect of altered water-level regimes on shore-spawning kokanee Oncorhynchus nerka incubation success was evaluated using a comprehensive in situ study in Lake Pend Oreille, ID, USA. Survival was not related to substrate size composition or depth, indicating that shore-spawning kokanee do not currently receive a substrate-mediated survival benefit from higher winter water levels. Substrate composition also did not differ among isobaths in the nearshore area. On average, the odds of an egg surviving to the preemergent stage were more than three times greater for sites in downwelling areas than those lacking downwelling. This study revealed that shoreline spawning habitat is not as limited as previously thought. Downwelling areas appear to contribute substantially to shore-spawning kokanee recruitment. This research illustrates the value of rigorous in situ studies both for testing potential mechanisms underlying population trends and providing insight into spawning habitat selection.

  16. Application of AN Empirically Scaled Digital Echo Integrator for Assessment of Juvenile Sockeye Salmon (oncorhynchus Nerka Walbaum) Populations.

    NASA Astrophysics Data System (ADS)

    Nunnallee, Edmund Pierce, Jr.

    1980-03-01

    This dissertation consists of an investigation into the empirical scaling of a digital echo integrator for assessment of a population of juvenile sockeye salmon in Cultus Lake, British Columbia, Canada. The scaling technique was developed over the last ten years for use with totally uncalibrated but stabilized data collection and analysis equipment, and has been applied to populations of fish over a wide geographical range. This is the first investigation into the sources of bias and the accuracy of the technique, however, and constitutes a verification of the method. The initial section of the investigation describes hydroacoustic data analysis methods for estimation of effective sampling volume which is necessary for estimation of fish density. The second section consists of a computer simulation of effective sample volume estimation by this empirical method and is used to investigate the degree of bias introduced by electronic and physical parameters such as boat speed -fish depth interaction effects, electronic thresholding and saturation, transducer beam angle, fish depth stratification by size and spread of the target strength distribution of the fish. Comparisons of simulation predictions of sample volume estimation bias to actual survey results are given at the end of this section. A verification of the scaling method is then presented by comparison of a hydroacoustically derived estimation of the Cultus Lake smolt population to an independent and concurrent estimate made by counting the migrant fish as they passed through a weir in the outlet stream of the lake. Finally, the effect on conduct and accuracy of hydroacoustic assessment of juvenile sockeye salmon due to several behavioral traits are discussed. These traits include movements of presmolt fish in a lake just prior to their outmigration, daily vertical migrations and the emergence and dispersal of sockeye fry in Cultus Lake. In addition, a comparison of the summer depth preferences of the fish over their entire geographical distribution on the west coast of the U.S. and Canada are discussed in terms of hydroacoustic accessibility.

  17. Competition between Asian pink salmon (Oncorhynchus gorbuscha) and Alaskan sockeye salmon (O. nerka) in the North Pacific Ocean

    USGS Publications Warehouse

    Ruggerone, G.T.; Zimmermann, M.; Myers, K.W.; Nielsen, J.L.; Rogers, D.E.

    2003-01-01

    The importance of interspecific competition as a mechanism regulating population abundance in offshore marine communities is largely unknown. We evaluated offshore competition between Asian pink salmon and Bristol Bay (Alaska) sockeye salmon, which intermingle in the North Pacific Ocean and Bering Sea, using the unique biennial abundance cycle of Asian pink salmon from 1955 to 2000. Sockeye salmon growth during the second and third growing seasons at sea, as determined by scale measurements, declined significantly in odd-numbered years, corresponding to years when Asian pink salmon are most abundant. Bristol Bay sockeye salmon do not interact with Asian pink salmon during their first summer and fall seasons and no difference in first year scale growth was detected. The interaction with odd-year pink salmon led to significantly smaller size at age of adult sockeye salmon, especially among younger female salmon. Examination of sockeye salmon smolt to adult survival rates during 1977-97 indicated that smolts entering the ocean during even-numbered years and interacting with abundant odd-year pink salmon during the following year experienced 26% (age-2 smolt) to 45% (age-1 smolt) lower survival compared with smolts migrating during odd-numbered years. Adult sockeye salmon returning to Bristol Bay from even-year smolt migrations were 22% less abundant (reduced by 5.9 million fish per year) compared with returns from odd-year migrations. The greatest reduction in adult returns occurred among adults spending 2 compared with 3 years at sea. Our new evidence for interspecific competition highlights the need for multispecies, international management of salmon production, including salmon released from hatcheries into the ocean.

  18. Physical and nutritional properties of baby food containing added red salmon oil (Oncorhynchus nerka) and microencapsulated red salmon oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unpurified red salmon oil (UPSO) was purified (PSO) using chitosan. Both unpurified and purified oils were evaluated for peroxide value (PV), free fatty acids (FFA), fatty acid methyl esters (FAME), moisture, and color. An emulsion system containing PSO (EPSO) was prepared: system was analyzed for c...

  19. CIRCADIAN RHYTHM OF PLASMA PROLACTIN, GROWTH HORMONE, GLUCOSE AND FREE FATTY ACIDS IN JUVENIOE KOKANEE SALMON, ONCORHYNCHUS NERKA. (R823881)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. Piscine reovirus, but not Jaundice Syndrome, was transmissible to Chinook Salmon, Oncorhynchus tshawytscha (Walbaum), Sockeye Salmon, Oncorhynchus nerka (Walbaum), and Atlantic Salmon, Salmo salar L.

    USGS Publications Warehouse

    Garver, Kyle A.; Marty, Gary D.; Cockburn, Sarah N.; Richard, Jon; Hawley, Laura M.; Müller, Anita; Thompson, Rachel L.; Purcell, Maureen K.; Saksida, Sonja M.

    2016-01-01

    A Jaundice Syndrome occurs sporadically among sea-pen-farmed Chinook Salmon in British Columbia, the westernmost province of Canada. Affected salmon are easily identified by a distinctive yellow discolouration of the abdominal and periorbital regions. Through traditional diagnostics, no bacterial or viral agents were cultured from tissues of jaundiced Chinook Salmon; however, piscine reovirus (PRV) was identified via RT-rPCR in all 10 affected fish sampled. By histopathology, Jaundice Syndrome is an acute to peracute systemic disease, and the time from first clinical signs to death is likely <48 h; renal tubular epithelial cell necrosis is the most consistent lesion. In an infectivity trial, Chinook Salmon, Sockeye Salmon and Atlantic Salmon, intraperitoneally inoculated with a PRV-positive organ homogenate from jaundiced Chinook Salmon, developed no gross or microscopic evidence of jaundice despite persistence of PRV for the 5-month holding period. The results from this study demonstrate that the Jaundice Syndrome was not transmissible by injection of material from infected fish and that PRV was not the sole aetiological factor for the condition. Additionally, these findings showed the Pacific coast strain of PRV, while transmissible, was of low pathogenicity for Atlantic Salmon, Chinook Salmon and Sockeye Salmon.

  1. Piscine reovirus, but not Jaundice Syndrome, was transmissible to Chinook Salmon, Oncorhynchus tshawytscha (Walbaum), Sockeye Salmon, Oncorhynchus nerka (Walbaum), and Atlantic Salmon, Salmo salar L.

    PubMed

    Garver, K A; Marty, G D; Cockburn, S N; Richard, J; Hawley, L M; Müller, A; Thompson, R L; Purcell, M K; Saksida, S

    2016-02-01

    A Jaundice Syndrome occurs sporadically among sea-pen-farmed Chinook Salmon in British Columbia, the westernmost province of Canada. Affected salmon are easily identified by a distinctive yellow discolouration of the abdominal and periorbital regions. Through traditional diagnostics, no bacterial or viral agents were cultured from tissues of jaundiced Chinook Salmon; however, piscine reovirus (PRV) was identified via RT-rPCR in all 10 affected fish sampled. By histopathology, Jaundice Syndrome is an acute to peracute systemic disease, and the time from first clinical signs to death is likely <48 h; renal tubular epithelial cell necrosis is the most consistent lesion. In an infectivity trial, Chinook Salmon, Sockeye Salmon and Atlantic Salmon, intraperitoneally inoculated with a PRV-positive organ homogenate from jaundiced Chinook Salmon, developed no gross or microscopic evidence of jaundice despite persistence of PRV for the 5-month holding period. The results from this study demonstrate that the Jaundice Syndrome was not transmissible by injection of material from infected fish and that PRV was not the sole aetiological factor for the condition. Additionally, these findings showed the Pacific coast strain of PRV, while transmissible, was of low pathogenicity for Atlantic Salmon, Chinook Salmon and Sockeye Salmon. PMID:25630226

  2. Bioaccumulation of HCHs and DDTs in organs of Pacific salmon (genus Oncorhynchus) from the Sea of Okhotsk and the Bering Sea.

    PubMed

    Lukyanova, Olga N; Tsygankov, Vasiliy Yu; Boyarova, Margarita D; Khristoforova, Nadezhda K

    2016-08-01

    Concentrations of isomers of hexachlorocyclohexane (α-, β-, γ-HCH) and dichlorodiphenyltrichloroethane (DDT) and its metabolites (dichlorodiphenyldichloroethane (DDD) and dichlorodiphenyldichloroethylene (DDE) were assessed in organs of the pink (Oncorhynchus gorbuscha), chum (Oncorhynchus keta), chinook (Oncorhynchus tshawytscha), and sockeye salmon (Oncorhynchus nerka), caught near the Kuril Islands (the northern-western part of the Pacific Ocean), in the Sea of Okhotsk and the Bering Sea. Pesticides have been found to accumulate in fish organs in the following: muscles < liver < eggs < male gonads. The highest concentrations in muscles and liver have been recorded from sockeye. Of the DDT group, only DDE has been detected. The average concentration of HCHs + DDE in the muscles of pink, chum, chinook, and sockeye was 141, 125, 1241, 1641 ng/g lipids, respectively; and in the liver, 279, 183, 1305, 3805 ng/g lipids, respectively. The total concentration of HCHs isomers was higher than that of DDE. Average HCHs + DDE concentration in organs of salmon from study area is lower than that in salmon from Pacific coast of North America. PMID:27219293

  3. Selected Reference Books of 1993-1994.

    ERIC Educational Resources Information Center

    McIlvaine, Eileen

    1994-01-01

    Offers brief, critical reviews of recent scholarly and general works of interest to reference workers in university libraries. Titles covered include dictionaries, databases, religion, literature, music, dance, art and architecture, business, political science, social issues, and history. Brief descriptions of new editions and supplements for…

  4. ASPOD modifications of 1993-1994

    NASA Technical Reports Server (NTRS)

    Jackson, Jennifer J. (Editor); Fogarty, Paul W.; Muller, Matthew; Martucci, Thomas A., III; Williams, Daniel; Rowney, David A.

    1994-01-01

    ASPOD, Autonomous Space Processors for Orbital Debris, provides a unique way of collecting the space debris that has built up over the past 37 years. For the past several years, ASPOD has gone through several different modifications. This year's concentrations were on the solar cutting array, the solar tracker, the earth based main frame/tilt table, the controls for the two robotic arms, and accurate autocad drawings of ASPOD. This final report contains the reports written by the students who worked on the ASPOD project this year.

  5. Self-sustaining populations, population sinks or aggregates of strays: chum (Oncorhynchus keta) and Chinook salmon (Oncorhynchus tshawytscha) in the Wood River system, Alaska.

    PubMed

    Lin, Jocelyn E; Hilborn, Ray; Quinn, Thomas P; Hauser, Lorenz

    2011-12-01

    Small populations can provide insights into ecological and evolutionary aspects of species distributions over space and time. In the Wood River system in Alaska, USA, small aggregates of Chinook (Oncorhynchus tshawytscha) and chum salmon (O. keta) spawn in an area dominated by sockeye salmon (O. nerka). Our objective was to determine whether these Chinook and chum salmon are reproductively isolated, self-sustaining populations, population sinks that produce returning adults but receive immigration, or strays from other systems that do not produce returning adults. DNA samples collected from adult chum salmon from 16 streams and Chinook salmon from four streams in the Wood River system over 3 years were compared to samples from large populations in the nearby Nushagak River system, a likely source of strays. For both species, microsatellite markers indicated no significant genetic differentiation between the two systems. Simulations of microsatellite data in a large source and a smaller sink population suggested that considerable immigration would be required to counteract the diverging effects of genetic drift and produce genetic distances as small as those observed, considering the small census sizes of the two species in the Wood River system. Thus, the Wood River system likely receives substantial immigration from neighbouring watersheds, such as the Nushagak River system, which supports highly productive runs. Although no data on population productivity in the Wood River system exist, our results suggest source-sink dynamics for the two species, a finding relevant to other systems where salmonid population sizes are limited by habitat factors.

  6. Timing games in the reproductive phenology of female pacific salmon (Oncorhynchus spp.).

    PubMed

    Morbey, Yolanda E; Ydenberg, Ronald C

    2003-02-01

    We use a game-theoretic framework to investigate the reproductive phenology of female kokanee (Oncorhynchus nerka). As in the other semelparous species of Pacific salmon, females construct nests in gravel, spawn with males, bury their fertilized eggs, and defend their nest sites until they die several days later. Later-breeding females may reuse previous nest sites, and their digging behavior is thought to subject previously buried eggs to mortality. Using game-theoretic models, we show that females can reduce this risk by allocating resources to longevity (the period between arrival and death) as opposed to eggs. Waiting before territory settlement is also expected if it allows females to conserve energy and delay senescence. The models demonstrate how these costs and benefits interact to select for a seasonal decline in longevity, a well-known phenomenon in the salmonid literature, and a seasonal decline in wait duration. Both of these predictions were supported in a field study of kokanee. Female state of reproductive maturity was the most important proximate factor causing variation in longevity and wait duration. With more than 30% of territories being reused, dig-up is likely an important selective force in this population.

  7. Vertical transmission of infectious haematopoietic necrosis virus in sockeye salmon, Oncorhynchus nerka (Walbaum): isolation of virus from dead eggs and fry

    USGS Publications Warehouse

    Mulcahy, D.; Pascho, R.J.

    1985-01-01

    The control of epizootics of infectious haematopoietic necrosis (IIHN) virus in salmonid fishes is presently based on examination and certification of adult brood fish to prevent the introduction of virus-infected eggs into hatcheries (Canadian Fisherics and Marine Service 1976; McDaniel 1979). This strategy is based on the assumption that the virus is vertically transmitted in association with the gametes. However, evidence for vertical transmission of lHN virus is circumstantial, based mostly on the appearance of the disease outside the enzootic area (the west coast of North America) in fish hatched from eggs obtained from within that area (Plumb 1972; Holway & Smith 1973; Wolf, Quimby, Pettijohn & Landolt 1973, Sano, Nishimura, Okamoto, Yamazaki, Hanada & Watanabe 1977. Carlisle, Schat & Elston 1979). An indirect demonstration of vertical transmission was made by placing known virus-free fish in the water above and below raceways containing fish that suffered an IEEN epizootic in an cffort to climinate waterborne virus as a source of infection (Wingficid & Chan 1970). The fish placed below the raceway developed IHN, due to waterborne virus released from the affected fish in the raceway, but the fish placed above the raceway failed to develop IHN. These results suggested that the source of infection of the fish in the raceway was not the water supply, although it is possible that the virus was no longer present in the water supply at the time the sentinel fish were exposed to the water.

  8. Life history reconstruction of modern and fossil sockeye salmon ( Oncorhynchus nerka) by oxygen isotopic analysis of otoliths, vertebrae, and teeth: Implication for paleoenvironmental reconstructions

    NASA Astrophysics Data System (ADS)

    Zazzo, A.; Smith, G. R.; Patterson, W. P.; Dufour, E.

    2006-09-01

    We evaluate the use of oxygen isotope values of biogenic apatite for tracking freshwater to marine migration in modern and fossil Pacific sockeye salmon. Oxygen isotope analyses of otoliths, vertebrae, and teeth of three anadromous modern sockeye salmon from Alaska establish a basis for the interpretation of fossil vertebrae and tooth apatite from Pleistocene sockeye salmon of the Skokomish River Valley, Washington. High resolution δ18O profiles in salmon otoliths provide, at a monthly resolution, a detailed record of individual history including continental rearing, migration to sea, seasonal variation in sea surface temperatures during marine life, and spawning migration before capture. Pacific salmon teeth are constantly renewed with the last set of teeth forming under the influence of freshwater. Therefore, they do not allow inference concerning sea-run versus landlocked life history in fossil salmon. Salmon vertebrae are also ambiguous indicators of life history regarding fresh versus marine water because centra are minimally ossified in the freshwater stages of life and the outermost layer of vertebral bone might be resorbed to provide nutrients during the non-feeding phase of the spawning migration. Therefore, δ18O values of accretionary growth rings in sea-run salmon vertebrae are dominated by the marine signal only if they are not diagenetically altered in freshwater deposits. In Pleistocene sockeye reported here, neither the teeth nor vertebral apatite present clear marine δ18O values due to the combined effects of tooth replacement and diagenetic alteration of bone and dentine. δ18O(PO 4) values of fossil vertebrae are intermediate between δ18O(PO 4) values of enamel and basal tooth dentin. Assuming a similar rate of isotope exchange of vertebrae and dentine with freshwater during diagenesis, these results are interpreted to reflect formation of the teeth under the influence of freshwater, and formation of the vertebrae under the influence of oceanic water. Our approach demonstrates that when appropriate knowledge of tissue formation is available, isotopic differences between altered and unaltered tissue holds promise of distinguishing between marine and freshwater origin of the tissues.

  9. Beyond Correlation in the Detection of Climate Change Impacts: Testing a Mechanistic Hypothesis for Climatic Influence on Sockeye Salmon (Oncorhynchus nerka) Productivity.

    PubMed

    Tillotson, Michael D; Quinn, Thomas P

    2016-01-01

    Detecting the biological impacts of climate change is a current focus of ecological research and has important applications in conservation and resource management. Owing to a lack of suitable control systems, measuring correlations between time series of biological attributes and hypothesized environmental covariates is a common method for detecting such impacts. These correlative approaches are particularly common in studies of exploited fish species because rich biological time-series data are often available. However, the utility of species-environment relationships for identifying or predicting biological responses to climate change has been questioned because strong correlations often deteriorate as new data are collected. Specifically stating and critically evaluating the mechanistic relationship(s) linking an environmental driver to a biological response may help to address this problem. Using nearly 60 years of data on sockeye salmon from the Kvichak River, Alaska we tested a mechanistic hypothesis linking water temperatures experienced during freshwater rearing to population productivity by modeling a series of intermediate, deterministic relationships and evaluating temporal trends in biological and environmental time-series. We found that warming waters during freshwater rearing have profoundly altered patterns of growth and life history in this population complex yet there has been no significant correlation between water temperature and metrics of productivity commonly used in fisheries management. These findings demonstrate that pairing correlative approaches with careful consideration of the mechanistic links between populations and their environments can help to both avoid spurious correlations and identify biologically important, but not statistically significant relationships, and ultimately producing more robust conclusions about the biological impacts of climate change. PMID:27123845

  10. Beyond Correlation in the Detection of Climate Change Impacts: Testing a Mechanistic Hypothesis for Climatic Influence on Sockeye Salmon (Oncorhynchus nerka) Productivity

    PubMed Central

    Tillotson, Michael D.; Quinn, Thomas P.

    2016-01-01

    Detecting the biological impacts of climate change is a current focus of ecological research and has important applications in conservation and resource management. Owing to a lack of suitable control systems, measuring correlations between time series of biological attributes and hypothesized environmental covariates is a common method for detecting such impacts. These correlative approaches are particularly common in studies of exploited fish species because rich biological time-series data are often available. However, the utility of species-environment relationships for identifying or predicting biological responses to climate change has been questioned because strong correlations often deteriorate as new data are collected. Specifically stating and critically evaluating the mechanistic relationship(s) linking an environmental driver to a biological response may help to address this problem. Using nearly 60 years of data on sockeye salmon from the Kvichak River, Alaska we tested a mechanistic hypothesis linking water temperatures experienced during freshwater rearing to population productivity by modeling a series of intermediate, deterministic relationships and evaluating temporal trends in biological and environmental time-series. We found that warming waters during freshwater rearing have profoundly altered patterns of growth and life history in this population complex yet there has been no significant correlation between water temperature and metrics of productivity commonly used in fisheries management. These findings demonstrate that pairing correlative approaches with careful consideration of the mechanistic links between populations and their environments can help to both avoid spurious correlations and identify biologically important, but not statistically significant relationships, and ultimately producing more robust conclusions about the biological impacts of climate change. PMID:27123845

  11. Beyond Correlation in the Detection of Climate Change Impacts: Testing a Mechanistic Hypothesis for Climatic Influence on Sockeye Salmon (Oncorhynchus nerka) Productivity.

    PubMed

    Tillotson, Michael D; Quinn, Thomas P

    2016-01-01

    Detecting the biological impacts of climate change is a current focus of ecological research and has important applications in conservation and resource management. Owing to a lack of suitable control systems, measuring correlations between time series of biological attributes and hypothesized environmental covariates is a common method for detecting such impacts. These correlative approaches are particularly common in studies of exploited fish species because rich biological time-series data are often available. However, the utility of species-environment relationships for identifying or predicting biological responses to climate change has been questioned because strong correlations often deteriorate as new data are collected. Specifically stating and critically evaluating the mechanistic relationship(s) linking an environmental driver to a biological response may help to address this problem. Using nearly 60 years of data on sockeye salmon from the Kvichak River, Alaska we tested a mechanistic hypothesis linking water temperatures experienced during freshwater rearing to population productivity by modeling a series of intermediate, deterministic relationships and evaluating temporal trends in biological and environmental time-series. We found that warming waters during freshwater rearing have profoundly altered patterns of growth and life history in this population complex yet there has been no significant correlation between water temperature and metrics of productivity commonly used in fisheries management. These findings demonstrate that pairing correlative approaches with careful consideration of the mechanistic links between populations and their environments can help to both avoid spurious correlations and identify biologically important, but not statistically significant relationships, and ultimately producing more robust conclusions about the biological impacts of climate change.

  12. Lake Roosevelt Fisheries Evaluation Program : Lake Whatcom Kokanee Salmon (Oncorhynchus nerka kennerlyi) : Investigations in Lake Roosevelt Annual Report 1999-2000.

    SciTech Connect

    McLellan, Holly J.; Scholz, Allan T.; McLellan, Jason G.; Tilson, Mary Beth

    2001-07-01

    Lake Whatcom stock kokanee have been planted in Lake Roosevelt since 1988 with the primary goal of establishing a self-sustaining fishery. Returns of hatchery kokanee to egg collection facilities and recruitment to the creel have been minimal. Therefore, four experiments were conducted to determine the most appropriate release strategy that would increase kokanee returns. The first experiment compared morpholine and non-morpholine imprinted kokanee return rates, the second experiment compared early and middle run Whatcom kokanee, the third experiment compared early and late release dates, and the fourth experiment compared three net pen release strategies: Sherman Creek hatchery vs. Sherman Creek net pens, Colville River net pens vs. Sherman Creek net pens, and upper vs. lower reservoir net pen releases. Each experiment was tested in three ways: (1) returns to Sherman Creek, (2) returns to other tributaries throughout the reservoir, and (3) returns to the creel. Chi-square analysis of hatchery and tributary returns indicated no significant difference between morpholine imprinted and non-imprinted fish, early run fish outperformed middle run fish, early release date outperformed late release fish, and the hatchery outperformed all net pen releases. Hatchery kokanee harvest was estimated at 3,323 fish, which was 33% of the total harvest. Return rates (1998 = 0.52%) of Whatcom kokanee were low indicating an overall low performance that could be caused by high entrainment, predation, and precocity. A kokanee stock native to the upper Columbia, as opposed to the coastal Whatcom stock, may perform better in Lake Roosevelt.

  13. Evaluation of the protective immunogencity of the N, P, M, NV and G proteins of infectious hematopoietic necrosis virus in rainbow trout Oncorhynchus mykiss using DNA vaccines

    USGS Publications Warehouse

    Corbeil, S.; LaPatra, S.E.; Anderson, E.D.; Jones, J.; Vincent, B.; Hsu, Y.-L; Kurath, G.

    1999-01-01

    The protective immunogenicity of the nucleoprotein (N), phosphoprotein (P), matrix protein (M), non-virion protein (NV) and glycoprotein (G) of the rhabdovirus infectious hematopoietic necrosis virus (IHNV) was assessed in rainbow trout using DNA vaccine technology. DNA vaccines were produced by amplifying and cloning the viral genes in the plasmid pCDNA 3.1. The protective immunity elicited by each vaccine was evaluated through survival of immunized fry after challenge with live virus. Neutralizing antibody titers were also determined in vaccinated rainbow troutOncorhynchus mykiss fry (mean weight 2 g) and 150 g sockeye salmon Oncorhynchus nerka. The serum from the 150 g fish was also used in passive immunization studies with naïve fry. Our results showed that neither the internal structural proteins (N, P and M) nor the NV protein of IHNV induced protective immunity in fry or neutralizing antibodies in fry and 150 g fish when expressed by a DNA vaccine construct. The G protein, however, did confer significant protection in fry up to 80 d post-immunization and induced protective neutralizing antibodies. We are currently investigating the role of different arms of the fish immune system that contribute to the high level of protection against IHNV seen in vaccinated fish.

  14. AGS experiments: 1992, 1993, 1994. Revision December 1994

    SciTech Connect

    Depken, J.C.

    1995-03-01

    This document contains listings and two page summaries for experiments run at the GAS for 1992--1994. Listings are also given for publications and experimenters. A working copy of the 1995--1996 experiment schedule is also included.

  15. Geothermal Program Overview: Fiscal Years 1993-1994

    SciTech Connect

    Not Available

    1995-11-01

    Geothermal energy represents the largest U.S. energy resource base and already provides an important contribution to our nation's energy needs. This overview looks at the basic science behind the various geothermal technologies and provides information on DOE Geothermal Energy Program activities and accomplishments.

  16. [Djibouti, history of 2 epidemics of cholera: 1993-1994].

    PubMed

    Morillon, M; De Pina, J J; Husser, J A; Baudet, J M; Bertherat, E; Martet, G

    1998-01-01

    When two cholera epidemics broke out in Djibouti, respectively in 1993 and 1994, Bioforce was obliged to intervene. The first time, three goals were pursued: setting up a rehydration centre in a tent, organizing epidemiological surveillance and training local personnel in treatment and diagnosis techniques. The next year, the epidemic followed serious flooding. The epidemiological analysis showed that cholera had become endemic in the poor neighbourhoods of the town and that epidemic break-outs were favoured by contaminated surface water and disturbances in the distribution of drinking water. The epidemic of 1997, likewise following flooding, only confirmed this point of view. PMID:10078376

  17. Biomass Power: Program overview fiscal years 1993--1994

    SciTech Connect

    1995-03-01

    The Biomass Power Program and industry are developing technologies to expand the use of biomass that include methods of feedstock production and the equipment to convert feedstocks into electric power or process heat. With the help of advanced biomass power technologies and new feedstock supply systems, as much as 50,000 megawatts (MW) of biomass power capacity will be in place by the year 2010. The Biomass Power Program supports the development of three technologies--gasification, pyrolysis, and direct combustion--from the laboratory bench scale to the prototype commercial scale. Gasification equipment produces biogas that is burned in high-efficiency turbine-generators developed for the electric power industry. Pyrolysis processes produce oils from renewable biomass that burn like petroleum to generate electricity. In direct combustion technology, power plants today burn bulk biomass directly to generate electricity. Improving the direct combustion technology of these plants increases efficiency and reduces emissions. In addition to developing these three technologies, the Biomass Power Program supports joint ventures to plan and construct facilities that demonstrate the benefits of biomass power. The Program is supporting joint ventures to conduct 10 case studies of dedicated feedstock supply systems.

  18. Biomass Power: Program overview fiscal years 1993--1994

    NASA Astrophysics Data System (ADS)

    1995-03-01

    The Biomass Power Program and industry are developing technologies to expand the use of biomass that include methods of feedstock production and the equipment to convert feedstocks into electric power or process heat. With the help of advanced biomass power technologies and new feedstock supply systems, as much as 50,000 megawatts (MW) of biomass power capacity will be in place by the year 2010. The Biomass Power Program supports the development of three technologies -- gasification, pyrolysis, and direct combustion -- from the laboratory bench scale to the prototype commercial scale. Gasification equipment produces biogas that is burned in high-efficiency turbine-generators developed for the electric power industry. Pyrolysis processes produce oils from renewable biomass that burn like petroleum to generate electricity. In direct combustion technology, power plants today burn bulk biomass directly to generate electricity. Improving the direct combustion technology of these plants increases efficiency and reduces emissions. In addition to developing these three technologies, the Biomass Power Program supports joint ventures to plan and construct facilities that demonstrate the benefits of biomass power. The program is supporting joint ventures to conduct 10 case studies of dedicated feedstock supply systems.

  19. Geothermal program overview: Fiscal years 1993--1994

    SciTech Connect

    1995-11-01

    The DOE Geothermal Energy Program is involved in three main areas of research: finding and tapping the resource; power generation; and direct use of geothermal energy. This publication summarizes research accomplishments for FY 1993 and 1994 for the following: geophysical and geochemical technologies; slimhole drilling for exploration; resource assessment; lost circulation control; rock penetration mechanics; instrumentation; Geothermal Drilling Organization; reservoir analysis; brine injection; hot dry rock; The Geysers; Geothermal Technology Organization; heat cycle research; advanced heat rejection; materials development; and advanced brine chemistry.

  20. What's Happening in the Mathematical Sciences, 1993-1994.

    ERIC Educational Resources Information Center

    Cipra, Barry

    1993-01-01

    This document consists of the first two volumes of a new annual serial devoted to surveying some of the important developments in the mathematical sciences in the previous year or so. Mathematics is constantly growing and changing, reaching out to other areas of science and helping to solve some of the major problems facing society. Volumes 1 and…

  1. The 1993/1994 NASA Graduate Student Researchers Program

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The NASA Graduate Student Researchers Program (GSRP) attempts to reach a culturally diverse group of promising U.S. graduate students whose research interests are compatible with NASA's programs in space science and aerospace technology. Each year we select approximately 100 new awardees based on competitive evaluation of their academic qualifications, their proposed research plan and/or plan of study, and their planned utilization of NASA research facilities. Fellowships of up to $22,000 are awarded for one year and are renewable, based on satisfactory progress, for a total of three years. Approximately 300 graduate students are, thus, supported by this program at any one time. Students may apply any time during their graduate career or prior to receiving their baccalaureate degree. An applicant must be sponsored by his/her graduate department chair or faculty advisor; this book discusses the GSRP in great detail.

  2. Ionization in liquids [annual] progress report, 1993--1994

    SciTech Connect

    Bakale, G.

    1994-12-31

    Progress in 1993--94 was focused on delineating how ions of the model nonpolar spherical solute Buckminsterfullerene interact differently with various nonpolar solvents than does the ellipsoidal fullerene analog C-70, and exposing a variety of new audiences to the electrophilicity-carcinogenicity relationship in order to obtain fresh insight into this relationship that may lead to elucidation of the role of electrons in carcinogenesis and thereby a better understanding of the biological effects of ionizing radiation. To achieve these goals a new collaboration was established with scientists at Oak Ridge National Lab who have unique facilities to characterize fullerene and its radiolytic products.

  3. Service Development Plan. Fiscal Year 1993-1994.

    ERIC Educational Resources Information Center

    Joyner, Isaac; And Others

    This monograph presents long-range plans of South Carolina's "Continuum of Care for Emotionally Disturbed Children" program, which provides community based services to children and adolescents with severe disturbances, through coordination and utilization of public, private, and individual services. An executive summary notes that 323 such clients…

  4. Survey on Student Financial Assistance, 1993-1994.

    ERIC Educational Resources Information Center

    Journal of Dental Education, 1997

    1997-01-01

    Summarizes data from a survey of 54 dental schools concerning dental students' financial aid. Data and analyses include percent of students receiving aid; average annual aid per student; average first-year costs of dental school; aid distribution within private, public, and state-related schools; details on federal loan programs; grant and…

  5. Imported dengue--United States, 1993-1994.

    PubMed

    1995-05-12

    Dengue is a mosquito-transmitted acute disease caused by any of four virus serotypes (DEN-1, DEN-2, DEN-3, and DEN-4) and characterized by the sudden onset of fever, headache, myalgia, rash, nausea, and vomiting. The disease is endemic in most tropical areas of the world and has occurred in U.S. residents returning from travel to such areas. This report summarizes information about cases of imported dengue among U.S. residents during 1993 and 1994.

  6. School-to-Work Apprenticeship. Project Manual 1993-1994.

    ERIC Educational Resources Information Center

    Lee Coll., Baytown, TX.

    With Perkins tech prep funds, Lee College (Baytown, Texas), working with the Gulf Coast Tech Prep Consortium and the Goose Creek Consolidated Independent School District, developed a school-to-work apprenticeship model for tech prep programs. An advisory committe provided guidance in identifying targeted apprenticeable jobs, program content, and…

  7. OECD Economic Surveys 1993-1994: United States.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France).

    This book examines surveys based on government information dealing with economic factors and education factors in the United States and how those factors affect policy initiatives. Chapters include: (1) "Recent Trends and Prospects" where particular emphasis is placed on assessing the risks of higher inflation; (2) "Macroeconomic and Structural…

  8. Status Report on Institutional Effectiveness, 1993-1994.

    ERIC Educational Resources Information Center

    Losak, John

    This annual report provides evaluation of specific academic centers at Nova Southeastern University in Fort Lauderdale, Florida, reflecting specific goals, associated outcome measures, and attainment status relative to the goals. Twelve sections focus on the: (1) Abraham S. Fischler Center for the Advancement of Education; (2) Center for Computer…

  9. Kidney disease postorbital lesions in spring chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Hendricks, Jerry D.; Leek, Steve L.

    1975-01-01

    Gross exophthalmos in one or both eyes of yearling spring chinook salmon (Oncorhynchus tshawytscha) was caused by postorbital, granulomatous inflammatory tissue that developed in response to invasion of the site by Corynebacterium sp., the causative agent of bacterial kidney disease.

  10. Specificity of DNA vaccines against the U and M genogroups of infectious hematopoietic necrosis virus (IHNV) in rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Penaranda, M.M.D.; LaPatra, S.E.; Kurath, G.

    2011-01-01

    Infectious hematopoietic necrosis virus (IHNV) is a fish rhabdovirus that causes significant mortality in salmonid species. In North America IHNV has three major genogroups designated U, M, and L. Host-specificity of the M and U genogroups of IHNV has been established both in the field and in experimental challenges, with M isolates being more prevalent and more virulent in rainbow trout (Oncorhynchus mykiss), and U isolates being more prevalent and highly virulent in sockeye salmon (Oncorhynchus nerka). In this study, efficacy of DNA vaccines containing either M (pM) or U (pU) virus glycoprotein genes was investigated during intra- and cross-genogroup challenges in rainbow trout. In virus challenges at 7 days post-vaccination (early antiviral response), both pM and pU were highly protective against either M or U IHNV. In challenges at 28 days post-vaccination (specific antiviral response), both pM and pU were protective against M IHNV but the homologous pM vaccine was significantly more protective than pU in one of two experiments. At this stage both pM and pU induced comparably high protection against U IHNV challenge. Correlates of protection were also investigated by assessing the expression of the interferon-stimulated gene Mx-1 and the production of neutralizing antibodies (NAbs) following pM or pU DNA vaccination. Mx-1 gene expression, measured at 4 and 7 days post-vaccination as an indicator of the host innate immune response, was found to be significantly higher after pM than pU vaccination in some cases. Neutralizing antibody was produced in response to the two vaccines, but antibody titers did not show consistent correlation with protection. The results show that the rainbow trout innate and adaptive immune responses have some ability to distinguish between the U and M genogroup IHNV, but overall the pM and pU vaccines were protective against both homologous and cross-genogroup challenges.

  11. Cryopreservation of sperm of the endangered gila trout, Oncorhynchus gilae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gila trout, Oncorhynchus gilae, are native to the headwaters of the Gila River drainage in New Mexico and Arizona and the headwaters of the Verde River drainage in Arizona. The species is currently protected as endangered under the Endangered Species Act. Cryopreservation of sperm is now a widely us...

  12. Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss)

    EPA Science Inventory

    Rainbow trout (Oncorhynchus mykiss) confined to respirometer-metabolism chambers were dosed with perfluorooctane sulfonate (PFOS) by intra-arterial injection and sampled to obtain concentration time-course data for plasma, and either urine or expired water. The data were then an...

  13. Stabilizing Oils from Smoked Pink Salmon (Oncorhynchus gorbuscha)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Smoking of meats and fish is one of the earliest preservation technologies developed by humans. In this study, the smoking process was evaluated as a method for reducing oxidation of Pink Salmon (Oncorhynchus gorbuscha) oils and also maintaining the quality of oil in aged fish prior to oil extractio...

  14. Nomenclature of mitochondrial DNA haplotypes for Oncorhynchus mykiss

    USGS Publications Warehouse

    Graziano, Sara L.; Brown, K.H.; Nielsen, Jennifer L.

    2005-01-01

    Congruence of genetic data is critical for comparative and collaborative studies on natural fish populations. A comprehensive list of reported mitochrondrial DNA haplotypes for Oncorhynchus mykiss generated using the S-Phe/P2 primer set is presented as a resource for future investigations of this species.

  15. Evidence for competitive dominance of Pink salmon (Oncorhynchus gorbuscha) over other Salmonids in the North Pacific Ocean

    USGS Publications Warehouse

    Ruggerone, G.T.; Nielsen, J.L.

    2004-01-01

    Relatively little is known about fish species interactions in offshore areas of the world's oceans because adequate experimental controls are typically unavailable in such vast areas. However, pink salmon (Oncorhynchus gorbuscha) are numerous and have an alternating-year pattern of abundance that provides a natural experimental control to test for interspecific competition in the North Pacific Ocean and Bering Sea. Since a number of studies have recently examined pink salmon interactions with other salmon, we reviewed them in an effort to describe patterns of interaction over broad regions of the ocean. Research consistently indicated that pink salmon significantly altered prey abundance of other salmon species (e.g., zooplankton, squid), leading to altered diet, reduced total prey consumption and growth, delayed maturation, and reduced survival, depending on species and locale. Reduced survival was observed in chum salmon (O. keta) and Chinook salmon (O. tshawytscha) originating from Puget Sound and in Bristol Bay sockeye salmon (O. nerka). Growth of pink salmon was not measurably affected by other salmon species, but their growth was sometimes inversely related to their own abundance. In all marine studies, pink salmon affected other species through exploitation of prey resources rather than interference. Interspecific competition was observed in nearshore and offshore waters of the North Pacific Ocean and Bering Sea, and one study documented competition between species originating from different continents. Climate change had variable effects on competition. In the North Pacific Ocean, competition was observed before and after the ocean regime shift in 1977 that significantly altered abundances of many marine species, whereas a study in the Pacific Northwest reported a shift from predation- to competition-based mortality in response to the 1982/1983 El Nino. Key traits of pink salmon that influenced competition with other salmonids included great abundance, high

  16. [Genetic Differentiation of Sockeye Salmon Oncorhynchus nerka from Kamchatka River Basin and the Lake-River Systems of the West Coast of the Bering Sea as Inferred from Data on Single Nucleotide Polymorphism].

    PubMed

    Khrustaleva, A M; Klovach, N V; Vedischeva, E V; Seeb, J E

    2015-10-01

    The variability of 45 single nucleotide polymorphism loci (SNP) was studied in sockeye salmon from the Kamchatka River basin and four lake-river systems of the west coast of the Bering Sea. Based on the genetic differentiation estimates for the largest sockeye salmon populations of Eastern Kamchatka and Chukotka, the examined samples were combined into two regional groups represented by the population of the Kamchatka River drainage, which included numerous local subpopulations and seasonal races, and the northern population grouping from the rivers of Olutorsko-Navarinsky raion, wherein the sockeye salmon from Maynypilginskaya Lake-River system was relatively isolated. Considerable divergence was observed between the island (Sarannoe Lake, Bering Island) and continental populations. Genetic heterogeneity was revealed and groups of early- and late-maturing individuals were isolated in the sample of late-run sockeye salmon from Kamchatka River. In Apuka River, subdivision of the spawning run into two genetically distinct spatial and temporal groupings was also observed. The results suggest that the differentiation of sockeye salmon samples by single nucleotide substitution frequencies was largely due to differences in the direction and strength of local selection at some loci in the population complexes and intrapopulation groupings from the examined river basins of Eastern Kamchatka, Chukotka, and Commander Islands. PMID:27169229

  17. Lake Roosevelt Fisheries Monitoring Program; Artificial Imprinting of Lake Roosevelt Kokanee Salmon (Oncorhynchus Nerka) with Synthetic Chemicals: Measurement of Thyroxine Content as an Indicator of the Sensitive Period for Imprinting to Olfactory Cues; 1992 Supplement Report.

    SciTech Connect

    Scholz, Allan T.; White, Ronald J.; Tilson, Mary Beth

    1993-09-01

    In 1991, we initiated studies to determine the critical period for thyroxine-induced olfactory imprinting in kokanee salmon. In our preliminary investigation we found that thyroxine [T{sub 4}] levels of Lake Whatcom stock, 1990 year class, kokanee were relatively high in eggs and alevins as compared to post-swimup fry, and peaked at hatch and swimup. Here we report on follow-up studies conducted in 1992 designed to determine if our initial results could be replicated. Additionally, in 1992, we initiated experiments to determine if kokanee could be imprinted to synthetic chemicals--morpholine and phenethyl alcohol--at different life stages. In 1991, whole body thyroxine content [T{sub 4}] was measured in 460 Lake Whatcom stock kokanee and 480 Lake Pend Orielle (Cabinet Gorge) stock kokanee to indicate the critical period for imprinting. Lots of 20 kokanee eggs, alevins and fry from both stocks, reared at the Spokane Tribal hatchery, were collected at weekly intervals from November 1991 to August 1992 and assayed for T{sub 4} content by radioimmunoassay. T{sub 4} levels were monitored in Lake Whatcom stock, 1991 year class fish, from eyed egg (33 days post-fertilization) to fry (248 days post-fertilization) stages. T{sub 4} concentration ({+-} SEM) in eggs was 6.7 {+-} 1.3 rig/g body weight. T{sub 4} peaked on the day of hatch at 13.1 {+-} 2.5 ng/g body weight, then declined to 10.3 {+-} 1.1 ng/g body weight in recently post-hatch alevins. T{sub 4} peaked again at 22.1 {+-} 5.2 ng/g body weight during swimup, then steadily decreased to about 1.0 ng/g body weight in 176-248 day old fry. T{sub 4} levels were monitored in Lake Pend Orielle stock, 1991 year class, fish from the day of fertilization (day 0) to 225 days post-fertilization. T{sub 4} content of eggs was 9.5 {+-} 1.7 ng/g body weight and peaked on the day of hatch (day 53 post-fertilization) at 24.2 {+-} 4.5 ng/g body weight. After declining to 13.0 {+-} 2.9 ng/g body weight on day 81 post-fertilization, T{sub 4} peaked a second time during swimup (88-95 days post-fertilization) at 24.3 {+-} 3.8 ng/g body weight. After swimup, T{sub 4} concentration steadily declined to about 0.6 ng/g body weight in 225 day old post-fertilization fry. Thus, results of our 1992 investigations were consistent with our preliminary 1991 study. In all cases: (1) T{sub 4} concentration was relatively high in eggs and alevins as compared to older fry; and (2) T{sub 4} peaks occurred at hatch and swimup. Blood serum T{sub 4} concentration was measured in 9 month to 21 month-old Lake Whatcom stock, 1990 year class, kokanee from July 1991 to August 1992. T{sub 4} concentrations were low in summer, peaked slightly in October, were low in early winter, then peaked several times between January and May 1992. Thus, the 1990 year class Lake Whatcom kokanee evidenced high T{sub 4} activity from egg to swimup stages in their first year and in the winter and spring of their second year of life. The fish appeared to undergo smolt transformation between 16-18 months old. In 1992, Lake Whatcom (1991 cohort) kokanee were exposed to synthetic chemicals--1,072,000 to morpholine and 1,117,000 to phenethyl alcohol--at different life history stages: (1) eye to hatch; (2) hatch; (3) hatch to swimup; (4) swimup; and (5) post-swimup fry (in February, March, April and May-June). Additionally, Lake Whatcom (1990 cohort) kokanee were exposed to synthetic chemicals--36,000 to morpholine and 51,600 to phenethyl alcohol--at age 16-18 months. Most of these fish were marked and released in Lake Roosevelt in July and August 1992 as part of a field test. A portion of the fish from each group was retained at the Spokane Tribal hatchery until August-October 1993, when behavioral tests will be conducted to determine if the fish imprinted to their exposure odor.

  18. Chum salmon Oncorhynchus keta respond to moonlight during homeward migrations.

    PubMed

    Hasegawa, E I

    2012-07-01

    The swimming depth of chum salmon Oncorhynchus keta equipped with archival tags was investigated off the Pacific Ocean coast of Hokkaido and North Honshu, Japan. As shown from movements of the fish with disc tags, O. keta swam at shallower depths during the full-moon phase than in the other phases and their swimming speed during this phase was faster compared to other phases. In addition, the circadian rhythm suggests a biological clock. These observations are all consistent with the view that O. keta make use of moonlight in order to navigate at night-time during homeward migration.

  19. Teratological hermaphroditism in the chum salmon Oncorhynchus keta (Walbaum)

    USGS Publications Warehouse

    Uzmann, J.R.; Hesselholt, M.N.

    1957-01-01

    The anomalous condition of hermaphroditism appears to be no less rare in fish than in other normally dioecious animals. Previous records of bisexuality' in the Pacific salmons, Oncorhynchus spp., are few in number despite the intensive study accorded this group. Rutter (1902) reported the condition in two king salmon (O. tshawytscha); Crawford (1927) reported the condition in a silver salmon (O. kisutch); and Gibbs (1956) described a bisexual steelhead trout (Salmo gairdneri) and briefly noted another instance of hermaphroditism in the king salmon. We wish to record an example of this anomaly in the chum salmon (O. keta).

  20. Rainbow trout (Oncorhynchus mykiss) invasion and the spread of hybridization with native westslope cutthroat trout (Oncorhynchus clarkii lewisi)

    USGS Publications Warehouse

    Boyer, M.C.; Muhlfeld, C.C.; Allendorf, F.W.

    2008-01-01

    We analyzed 13 microsatellite loci to estimate gene flow among westslope cutthroat trout, Oncorhynchus clarkii lewisi, populations and determine the invasion pattern of hybrids between native O. c. lewisi and introduced rainbow trout, Oncorhynchus mykiss, in streams of the upper Flathead River system, Montana (USA) and British Columbia (Canada). Fourteen of 31 sites lacked evidence of O. mykiss introgression, and gene flow among these nonhybridized O. c. lewisi populations was low, as indicated by significant allele frequency divergence among populations (?ST = 0.076, ?ST = 0.094, P < 0.001). Among hybridized sites, O. mykiss admixture declined with upstream distance from a site containing a hybrid swarm with a predominant (92%) O. mykiss genetic contribution. The spatial distribution of hybrid genotypes at seven diagnostic microsatellite loci revealed that O. mykiss invasion is facilitated by both long distance dispersal from this hybrid swarm and stepping-stone dispersal between hybridized populations. This study provides an example of how increased straying rates in the invasive taxon can contribute to the spread of extinction by hybridization and suggests that eradicating sources of introgression may be a useful conservation strategy for protecting species threatened with genomic extinction. ?? 2008 NRC.

  1. Spread of hybridization between native westslope cutthroat trout, Oncorhynchus clarki lewisi, and nonnative rainbow trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    Hitt, Nathaniel P.; Frissell, Christopher A.; Muhlfeld, Clint C.; Fred W. Allendorf,

    2003-01-01

    We examined spatial and temporal patterns of hybridization between native westslope cutthroat trout, Oncorhynchus clarki lewisi, and nonnative rainbow trout, O. mykiss, in streams of the Flathead River system in Montana, U.S.A. We detected hybridization in 24 of 42 sites sampled from 1998 to 2001. We found new Oncorhynchus mykiss introgression in seven of 11 sample populations that were determined to be nonhybridized in 1984. Patterns of spatial autocorrelation and linkage disequilibrium indicated that hybridization is spreading among sites and is advancing primarily via post-F1 hybrids. Although hybridized populations were distributed widely throughout the study area, the genetic contribution from O. mykiss decreased with increasing upstream distance from the Flathead River mainstem, suggesting that O. mykiss introgression is spreading in an upstream direction. The spread of hybridization may be constrained more by demographic than by environmental factors, given that (i) hybridized populations generally encompassed the range of environmental variability in nonhybridized populations, and (ii) hybridization status was more strongly associated with neighborhood statistics than measured environmental gradients.

  2. Estrogenic Activity of Perfluoroalkyl Acids in Juvenile Rainbow Trout (Oncorhynchus Mykiss)

    EPA Science Inventory

    The potential estrogenic activity of perfluoroalkyl acids (PFAAs) was determined using separate screening and dose response studies with juvenile rainbow trout (Oncorhynchus mykiss). Results of this study indicate that some PFAAs may act as estrogens in fish.

  3. The epithelial neoplasm observed in the cultured coho salmon, Oncorhynchus kisutch.

    PubMed

    Atsuta, S; Sakai, M; Kobayashi, M; Sasaki, T

    1990-09-01

    The epithelial neoplasms were observed on the mouth of the cultured coho salmon, Oncorhynchus kisutch. Histopathologically, the tumors were formed to be proliferative epithelial cells, but no change was observed in other organs. The virus from this tumor was isolated in RTG-2 and CHSE-214 cells and developed the cytopathic effect which characterized to be the formation of syncytia and the migration of chromatin. This virus was neutralized with anti-Oncorhynchus masou virus (OMV) rabbit serum. PMID:2096259

  4. Gyrodactylid Ectoparasites in a Population of Rainbow Trout (Oncorhynchus mykiss)

    PubMed Central

    Garcia, Rachel L; Hansen, Adam G; Chan, Maia M; Sanders, George E

    2014-01-01

    A colony of rainbow trout (Oncorhynchus mykiss) in a decentralized aquatic animal facility was noted to have an increase in morbidity and mortality (from 4 or 5 fish each month to 3 or 4 fish daily) approximately 2 wk after experimental procedures began. The primary clinical signs were erratic swimming behavior and ‘flashing’ of fish against surfaces within housing enclosures. Moribund and normal rainbow trout were presented alive for diagnostic evaluation; samples of water from housing enclosures were provided for water quality assessment. The trout were determined to be infected with gyrodactylids, a common monogenean ectoparasite of the skin and gills in both marine and freshwater fish. This case report describes the diagnosis, pathology, and treatment of gyrodactylids and husbandry modifications associated with the resolution of this clinical aquatic-animal case. PMID:24411786

  5. Virulence of Flavobacterium columnare genomovars in rainbow trout Oncorhynchus mykiss.

    PubMed

    Evenhuis, Jason P; LaFrentz, Benjamin R

    2016-08-01

    Flavobacterium columnare is the causative agent of columnaris disease and is responsible for significant economic losses in aquaculture. F. columnare is a Gram-negative bacterium, and 5 genetic types or genomovars have been described based on restriction fragment length polymorphism of the 16S rRNA gene. Previous research has suggested that genomovar II isolates are more virulent than genomovar I isolates to multiple species of fish, including rainbow trout Oncorhynchus mykiss. In addition, improved genotyping methods have shown that some isolates previously classified as genomovar I, and used in challenge experiments, were in fact genomovar III. Our objective was to confirm previous results with respect to genomovar II virulence, and to determine the susceptibility of rainbow trout to other genomovars. The virulence of 8 genomovar I, 4 genomovar II, 3 genomovar II-B, and 5 genomovar III isolates originating from various sources was determined through 3 independent challenges in rainbow trout using an immersion challenge model. Mean cumulative percent mortality (CPM) of ~49% for genomovar I isolates, ~1% for genomovar II, ~5% for the II-B isolates, and ~7% for the III isolates was observed. The inability of genomovar II isolates to produce mortalities in rainbow trout was unanticipated based on previous studies, but may be due to a number of factors including rainbow trout source and water chemistry. The source of fish and/or the presence of sub-optimal environment may influence the susceptibility of rainbow trout to different F. columnare genomovars. PMID:27503917

  6. Sexual difference in PCB concentrations of coho salmon (Oncorhynchus kisutch).

    PubMed

    Madenjian, Charles P; Schrank, Candy S; Begnoche, Linda J; Elliott, Robert F; Quintal, Richard T

    2010-03-01

    We determined polychlorinated biphenyl (PCB) concentrations in 35 female coho salmon (Oncorhynchus kisutch) and 60 male coho salmon caught in Lake Michigan (Michigan and Wisconsin, United States) during the fall of 1994 and 1995. In addition, we determined PCB concentrations in the skin-on fillets of 26 female and 19 male Lake Michigan coho salmon caught during the fall of 2004 and 2006. All coho salmon were age-2 fish. These fish were caught prior to spawning, and therefore release of eggs could not account for sexual differences in PCB concentrations because female coho salmon spawn only once during their lifetime. To investigate whether gross growth efficiency (GGE) differed between the sexes, we applied bioenergetics modeling. Results showed that, on average, males were 19% higher in PCB concentration than females, based on the 1994-1995 dataset. Similarly, males averaged a 20% higher PCB concentration in their skin-on fillets compared with females. According to the bioenergetics modeling results, GGE of adult females was less than 1% higher than adult male GGE. Thus, bioenergetics modeling could not explain the 20% higher PCB concentration exhibited by the males. Nonetheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations.

  7. Multigenerational outbreeding effects in Chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    Lehnert, Sarah J; Love, Oliver P; Pitcher, Trevor E; Higgs, Dennis M; Heath, Daniel D

    2014-08-01

    Outbreeding, mating between genetically divergent individuals, may result in negative fitness consequences for offspring via outbreeding depression. Outbreeding effects are of notable concern in salmonid research as outbreeding can have major implications for salmon aquaculture and conservation management. We therefore quantified outbreeding effects in two generations (F1 hybrids and F2 backcrossed hybrids) of Chinook salmon (Oncorhynchus tshawytscha) derived from captively-reared purebred lines that had been selectively bred for differential performance based on disease resistance and growth rate. Parental lines were crossed in 2009 to create purebred and reciprocal hybrid crosses (n = 53 families), and in 2010 parental and hybrid crosses were crossed to create purebred and backcrossed hybrid crosses (n = 66 families). Although we found significant genetic divergence between the parental lines (FST = 0.130), reciprocal F1 hybrids showed no evidence of outbreeding depression (hybrid breakdown) or favorable heterosis for weight, length, condition or survival. The F2 backcrossed hybrids showed no outbreeding depression for a suite of fitness related traits measured from egg to sexually mature adult life stages. Our study contributes to the current knowledge of outbreeding effects in salmonids and supports the need for more research to better comprehend the mechanisms driving outbreeding depression. PMID:24952720

  8. Proteomic analysis of chinook salmon (Oncorhynchus tshawytscha) ovarian fluid.

    PubMed

    Johnson, Sheri L; Villarroel, Marsha; Rosengrave, Patrice; Carne, Alan; Kleffmann, Torsten; Lokman, P Mark; Gemmell, Neil J

    2014-01-01

    The ovarian, or coelomic, fluid that is released with the egg mass of many fishes is increasingly found to play an important role in several biological processes crucial for reproductive success. These include maintenance of oocyte fertility and developmental competence, prolonging of sperm motility, and enhancing sperm swimming speed. Here we examined if and how the proteome of chinook salmon (Oncorhynchus tshawytscha) ovarian fluid varied among females and then sought to examine the composition of this fluid. Ovarian fluid in chinook salmon was analyzed using 1D SDS PAGE and LC-MS/MS tryptic digest screened against Mascot and Sequest databases. We found marked differences in the number and concentrations of proteins in salmon ovarian fluid across different females. A total of 174 proteins were identified in ovarian fluid, 47 of which were represented by six or more peptides, belonging to one of six Gene Ontology pathways. The response to chemical stimulus and response to hypoxia pathways were best represented, accounting for 26 of the 174 proteins. The current data set provides a resource that furthers our understanding of those factors that influence successful egg production and fertilisation in salmonids and other species. PMID:25089903

  9. Virulence of Flavobacterium columnare genomovars in rainbow trout Oncorhynchus mykiss.

    PubMed

    Evenhuis, Jason P; LaFrentz, Benjamin R

    2016-08-01

    Flavobacterium columnare is the causative agent of columnaris disease and is responsible for significant economic losses in aquaculture. F. columnare is a Gram-negative bacterium, and 5 genetic types or genomovars have been described based on restriction fragment length polymorphism of the 16S rRNA gene. Previous research has suggested that genomovar II isolates are more virulent than genomovar I isolates to multiple species of fish, including rainbow trout Oncorhynchus mykiss. In addition, improved genotyping methods have shown that some isolates previously classified as genomovar I, and used in challenge experiments, were in fact genomovar III. Our objective was to confirm previous results with respect to genomovar II virulence, and to determine the susceptibility of rainbow trout to other genomovars. The virulence of 8 genomovar I, 4 genomovar II, 3 genomovar II-B, and 5 genomovar III isolates originating from various sources was determined through 3 independent challenges in rainbow trout using an immersion challenge model. Mean cumulative percent mortality (CPM) of ~49% for genomovar I isolates, ~1% for genomovar II, ~5% for the II-B isolates, and ~7% for the III isolates was observed. The inability of genomovar II isolates to produce mortalities in rainbow trout was unanticipated based on previous studies, but may be due to a number of factors including rainbow trout source and water chemistry. The source of fish and/or the presence of sub-optimal environment may influence the susceptibility of rainbow trout to different F. columnare genomovars.

  10. Oxidative stress in juvenile chinook salmon, Oncorhynchus tshawytscha (Walbaum)

    USGS Publications Warehouse

    Welker, T.L.; Congleton, J.L.

    2004-01-01

    Juvenile chinook salmon, Oncorhynchus tshawytscha (Walbaum), were held in 8-11??C freshwater, starved for 3 days and subjected to a low-water stressor to determine the relationship between the general stress response and oxidative stress. Lipid peroxidation (LPO) levels (lipid hydroperoxides) were measured in kidney, liver and brain samples taken at the beginning of the experiment (0-h unstressed controls) and at 6, 24 and 48 h after application of a continuous low-water stressor. Tissue samples were also taken at 48 h from fish that had not been exposed to the stressor (48-h unstressed controls). Exposure to the low-water stressor affected LPO in kidney and brain tissues. In kidney, LPO decreased 6 h after imposition of the stressor; similar but less pronounced decreases also occurred in the liver and brain. At 48 h, LPO increased (in comparison with 6-h stressed tissues) in the kidney and brain. In comparison with 48-h unstressed controls, LPO levels were higher in the kidney and brain of stressed fish. Although preliminary, results suggest that stress can cause oxidative tissue damage in juvenile chinook salmon. Measures of oxidative stress have shown similar responses to stress in mammals; however, further research is needed to determine the extent of the stress-oxidative stress relationship and the underlying physiological mechanisms in fish.

  11. Modeling silver binding to gills of rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Janes, N.; Playle, R.C.

    1995-11-01

    Rainbow trout (Oncorhynchus mykiss, 1--3 g) were exposed to {approximately} 1.0 {micro}M silver (Ag) ({approximately} 11 {micro}g {center_dot} L{sup {minus}1} Ag) for 2 to 3 h in synthetic soft water (Ca, Na {approximately} 300 {micro}M, pH 6.5--7.5) to which was added Ca, Na, H{sup +}, dissolved organic carbon (DOC), Cl, or thiosulfate (S{sub 2}O{sub 3}). Gills were extracted and gill Ag concentrations were measured using graphite-furnace atomic absorption spectrophotometry. The concentration of cations (Ca, Na, H{sup +}) and complexing agents (DOC, Cl, S{sub 2}O{sub 3}) needed to keep Ag off the gills were used to calculate conditional equilibrium binding constants (K) at the gills. Log K for Ag-gill binding was 10.0, with approximately 1.3 nmol Ag binding sites per fish. All experimentally determined log K values were entered into an aquatic chemistry equilibrium model, MINEQL{sup +}, to predict Ag binding at trout gills. For a series of natural waters, model-predicted gill Ag concentrations correlated well with observed gill Ag concentrations, with one exception, very hard city of Waterloo tapwater. This exception may indicate a kinetic constraint on the thermodynamic basis of the model.

  12. Sexual difference in PCB concentrations of coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Madenjian, Charles P.; Schrank, Candy S.; Begnoche, Linda J.; Elliott, Robert F.; Quintal, Richard T.

    2010-01-01

    We determined polychlorinated biphenyl (PCB) concentrations in 35 female coho salmon (Oncorhynchus kisutch) and 60 male coho salmon caught in Lake Michigan (Michigan and Wisconsin, United States) during the fall of 1994 and 1995. In addition, we determined PCB concentrations in the skin-on fillets of 26 female and 19 male Lake Michigan coho salmon caught during the fall of 2004 and 2006. All coho salmon were age-2 fish. These fish were caught prior to spawning, and therefore release of eggs could not account for sexual differences in PCB concentrations because female coho salmon spawn only once during their lifetime. To investigate whether gross growth efficiency (GGE) differed between the sexes, we applied bioenergetics modeling. Results showed that, on average, males were 19% higher in PCB concentration than females, based on the 1994–1995 dataset. Similarly, males averaged a 20% higher PCB concentration in their skin-on fillets compared with females. According to the bioenergetics modeling results, GGE of adult females was less than 1% higher than adult male GGE. Thus, bioenergetics modeling could not explain the 20% higher PCB concentration exhibited by the males. Nonetheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations.

  13. Proteomic Analysis of Chinook Salmon (Oncorhynchus tshawytscha) Ovarian Fluid

    PubMed Central

    Johnson, Sheri L.; Villarroel, Marsha; Rosengrave, Patrice; Carne, Alan; Kleffmann, Torsten; Lokman, P. Mark; Gemmell, Neil J.

    2014-01-01

    The ovarian, or coelomic, fluid that is released with the egg mass of many fishes is increasingly found to play an important role in several biological processes crucial for reproductive success. These include maintenance of oocyte fertility and developmental competence, prolonging of sperm motility, and enhancing sperm swimming speed. Here we examined if and how the proteome of chinook salmon (Oncorhynchus tshawytscha) ovarian fluid varied among females and then sought to examine the composition of this fluid. Ovarian fluid in chinook salmon was analyzed using 1D SDS PAGE and LC-MS/MS tryptic digest screened against Mascot and Sequest databases. We found marked differences in the number and concentrations of proteins in salmon ovarian fluid across different females. A total of 174 proteins were identified in ovarian fluid, 47 of which were represented by six or more peptides, belonging to one of six Gene Ontology pathways. The response to chemical stimulus and response to hypoxia pathways were best represented, accounting for 26 of the 174 proteins. The current data set provides a resource that furthers our understanding of those factors that influence successful egg production and fertilisation in salmonids and other species. PMID:25089903

  14. Talking with TV: A Guide to Starting Dialogue with Youth, 1993-1994 Edition.

    ERIC Educational Resources Information Center

    Center for Population Options, Washington, DC.

    This booklet shows parents and other adults how to use entertainment television to spark discussions with children and adolescents about sexuality, values, responsibility, communication, and other sensitive subjects (personal relationships, race and culture, drug use). First published in 1989, this booklet has been updated annually. Discussion…

  15. Advanced Light Source First-Phase Scientific Program, 1993/1994

    SciTech Connect

    Not Available

    1992-08-01

    This composite document outlines ten different experiments planned for the beamline at the Advanced Light Source. Researchers from various parts of the country have detailed their methods and equipment to be used in experiments in biology and physics. X-ray spectroscopy and microscopy are the common topics to these experiments. (GHH)

  16. Heat-related deaths--Philadelphia and United States, 1993-1994.

    PubMed

    1994-07-01

    During June 1994, temperatures across the United States were higher than usual. Since June 13, record high temperatures (above 90 F [32.2 C]) with humidities of 50%-60% have occurred in the northeastern United States (1). During July 1-14, 1993, the eastern United States also experienced a severe heat wave with high temperatures (93 F-101 F [33.9 C-38.3 C]) and high humidity (36%-58%) (2). During July 6-14, 1993, in Philadelphia, medical examiners (MEs) determined 118 deaths were heat-related*. This report describes heat-related deaths that occurred in Philadelphia during 1993 and 1994 and summarizes risk factors for heat-related illness and death. PMID:8208234

  17. The photodissociation and reaction dynamics of vibrationally excited molecules. Technical progress report, 1993--1994

    SciTech Connect

    Not Available

    1994-04-01

    Combined vibrational overtone excitation and laser induced fluorescence detection was used to study dissociation dynamics of hydroxylamine (NH{sub 2}OH), laser induced grating experiments on water were analyzed, discovering the important role that electrostriction and thermal relaxation play, and a new apparatus for preparing vibrationally excited molecules with simulated Raman excitation was completed and the first measurements made. Role of vibrational excitation in photodissociation dynamics was studied using a vibrational state preparation technique, such as vibrational overtone excitation or stimulated Raman excitation, to create molecules with particular nuclear motions and then excite that molecule to a dissociative electronic state. Because the vibrational excitation alters the dissociation dynamics in the excited state, both by providing access to different portions of the excited state surface and by altering the motion of the system on the surface, it is usually refered to as vibrationally mediated photodissociation.

  18. Research and Clinical Center for Child Development Annual Report, 1993-1994, No. 17.

    ERIC Educational Resources Information Center

    Wakai, Kunio, Ed.; Chen, Shing-jen, Ed.

    This annual report discusses several topics related to the work of the Research and Clinical Center for Child Development. Six topics are covered in the report. The articles are: (1) "Development of Intentional Behavior in Early Infancy" (Hongtu Chen); (2) "An Investigation of the Differences of Social Space in the Playroom: Through Analysis by…

  19. Proceedings of the Midwest Philosophy of Education Society, 1993-1994.

    ERIC Educational Resources Information Center

    Stickel, George W., Ed.; Owen, David B., Ed.

    These proceedings are composed of papers presented at the 1993 and 1994 Annual Meetings of the Midwest Philosophy of Education Society. The collection is divided into four parts. Part 1 includes: "Failure, Philosophy of Education, and the Music of the Spheres" (David B. Owen); "What Has Philosophy of Education Come To?" (Lawrence J. Dennis). Part…

  20. Project Data-Tech. Final Evaluation Report, 1993-1994. OER Report.

    ERIC Educational Resources Information Center

    Roman, Elliott M.

    Project Data-Tech was an Elementary and Secondary Education Act Title VII-funded project in its fifth and last year of operation at a high school in Brooklyn (New York). The program served a total of 131 Haitian- and Spanish-speaking students, most of whom were of limited English proficiency, 54 fewer than in the previous year. Participating…

  1. The Journal of the Imagination in Language Learning, 1993-1994.

    ERIC Educational Resources Information Center

    Coreil, Clyde, Ed.; Napoliello, Mihri

    1994-01-01

    Articles in these two issues are as follows: "Imagination and Memory: Friends or Enemies" (Earl W. Stevick); "Imagination in Second Language Acquisition" (James J. Asher); "Where the Magic Lies" (Interview with Carolyn Graham); "Drawing on Experience: The Interview" (with John Dumicich); "What Color is Your Picnic Basket?" (Interview with Susan…

  2. Venus Data Analysis Program: Directory of Research Projects (1993-1994)

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This directory provides information about the scientific investigations funded by the NASA Venus Data Analysis Program (VDAP) during fiscal year 1993. The VDAP Directory consists of summary sheets from the proposals that were selected by NASA for funding in FY 93. Each summary sheet indicates the title, principal investigator, institution of the investigation, and information related to the objectives of the research activities proposed for FY 93. The objective of the VDAP Program is to advance our understanding of the nature and evolution of Venus. VDAP supports scientific investigation using data obtained from the Magellan, Pioneer Venus, and other Venus missions, as well as earth-based observations that contribute to understanding the physical and evolutionary properties of Venus. The program intends to enhance the scientific return from these missions by broadening the participation in the analysis of Venus data. Categories of research funded by VDAP are atmosphere, ionosphere, geology, geophysics, and mapping. The directory is intended to provide the science community with an overview of the research projects supported by this program. Research activities identified in this directory were selected for funding in FY 93 on the basis of scientific peer review conducted by the VDAP Review Panel.

  3. The Western Pond Turtle; Habitat and History, 1993-1994 Final Report.

    SciTech Connect

    Holland, Dan C.

    1994-08-01

    The western pond turtle is known from many areas of Oregon. The majority of sightings and other records occur in the major drainages of the Klamath, Rogue, Umpqua, Willamette and Columbia River systems. A brief overview is presented of the evolution of the Willamette-Puget Sound hydrographic basin. A synopsis is also presented of the natural history of the western pond turtle, as well as, the status of this turtle in the Willamette drainage basin. The reproductive ecology and molecular genetics of the western pond turtle are discussed. Aquatic movements and overwintering of the western pond turtle are evaluated. The effect of introduced turtle species on the status of the western pond turtle was investigated in a central California Pond. Experiments were performed to determine if this turtle could be translocated as a mitigation strategy.

  4. A pilot marine monitoring program in Cook Inlet, Alaska 1993--1994

    SciTech Connect

    Brown, J.S.; Boehm, P.D.; Hyland, J.L.

    1995-12-31

    Under the mandate of the Oil Pollution Act of 1990 (OPA`90) the Cook Inlet Regional Citizens Advisory Council (CIRCAC) sponsored the initiation of a pilot monitoring program in Cook Inlet, Alaska, The objectives of the pilot monitoring program were to provide baseline data on petroleum hydrocarbon concentrations in sediments and biota of Cook Inlet, and to evaluate the effectiveness of selected monitoring techniques in detecting petroleum hydrocarbon inputs from industry based sources. A sampling program was initiated in 1993 that included petroleum industry, specific sites and reference sites. Sample measurements included polynuclear aromatic hydrocarbons (PAH) in sediments, caged mussels, and semipermeable membrane devices (SPMDs), sediment toxicity using the amphipod, Ampelisca abdita, and estimates of population size and physiological condition of indigenous bivalves. Results of the 1993 sampling program indicated that (1) background levels of petrogenic, pyrogenic, and diagenetic hydrocarbons were present in sediments and indigenous bivalves, and (2) that limited amphipod toxicity and variations in bivalve measurements did not correlate with the hydrocarbons in the sediments. Modifications to the 1993 program were instituted for the 1994 sampling and included, the selection of new industry specific sites, discontinued use of caged bivalves, and design changes to SPMDs to enhance sensitivity. The results of the 1994 sampling program, and comparisons with the 1993 data are presented.

  5. Semi-autonomous robots for reactor containments. Annual summary report, [1993--1994

    SciTech Connect

    Not Available

    1994-05-06

    During 1993, the activity at the University was split into two primary groups. One group provided direct support for the development and testing of the RVIR vehicle. This effort culminated in a demonstration of the vehicle at ORNL during December. The second group of researchers focused attention on pushing the technology forward in the areas of radiation imaging, navigation, and sensing modalities. A major effort in technology transfer took place during this year. All of these efforts reflected in the periodic progress reports which are attached. During 1994, our attention will change from the Nuclear Energy program to the Environmental Restoration and Waste Management office. The immediate needs of the Robotics Technology Development Program within the Office of Technology Development of EM drove this change in target applications. The University will be working closely with the national laboratories to further develop and transfer existing technologies to mobile platforms which are currently being designed and employed in seriously hazardous environments.

  6. Fish Research Project Oregon; Umatilla Hatchery Monitoring and Evaluation, 1993-1994 Annual Report.

    SciTech Connect

    Hayes, Michael C.; Onjukka, Sam T.; Focher, Shannon M.

    1995-01-01

    This report covers the first three years of comprehensive monitoring and evaluation of the Umatilla Hatchery. Because the hatchery and the evaluation study and the fish health monitoring investigations are in the early stages of implementation, much of the information contained in this report is preliminary. The majority of the data that is crucial for evaluating the success of the hatchery program, the data on post-release performance and survival, is yet unavailable. In addition, several years of data are necessary to make conclusions about rearing performance at Umatilla Hatchery. The conclusions drawn in this report should be viewed as preliminary and should be used in conjunction with additional information as it becomes available.

  7. Kokanee Stocking and Monitoring, Flathead Lake, 1993-1994 Annual Report.

    SciTech Connect

    Deleray, Mark; Fredenberg, Wade; Hansen, Barry

    1995-07-01

    One mitigation goal of the Hungry Horse Dam fisheries mitigation program, funded by the Bonneville Power Administration, is to replace lost production of 100,000 adult kokanee in Flathead Lake. The mitigation program calls for a five-year test to determine if kokanee can be reestablished in Flathead Lake. The test consists. of annual stocking of one million hatchery-raised yearling kokanee. There are three benchmarks for judging the success of the kokanee reintroduction effort: (1) Post-stocking survival of 30 percent of planted kokanee one year after stocking; (2) Yearling to adult survival of 10 percent (100,000 adult salmon); (3) Annual kokanee harvest of 50,000 or more fish per year by 1998, with an average length of 11 inches or longer for harvested fish, and fishing pressure of 100,000 angler hours or more. Kokanee were the primary sport fish species in the Flathead Lake fishery in the early 1900s, and up until the late 1980s when the population rapidly declined in numbers and then disappeared. Factors identified which influenced the decline of kokanee are the introduction of opossum shrimp (Mysis relicta), hydroelectric operations, overharvest through angling, and competition and/or predation by lake trout (Salvelinus namaycush) and lake whitefish (Coregonur clupeaformis). The purpose of this report was to summarize the stocking program and present monitoring results from the 1993 and 1994 field seasons. In June 1993, roughly 210,000 yearling kokanee were stocked into two bays on the east shore of Flathead Lake. Following stocking, we observed a high incidence of stocked kokanee in stomach samples from lake trout captured in areas adjacent to the stocking sites and a high percentage of captured lake trout containing kokanee. Subsequent monitoring concluded that excessive lake trout predation precluded significant survival of kokanee stocked in 1993. In June 1994, over 802,000 kokanee were stocked into Big Arm Bay. The combination of near optimum water temperatures, an upsurge in the abundance of Duphniu rhorum, and saturation planting in an area believed to have lower lake trout densities was expected to maximize short-term survival of stocked kokanee. A net-pen experiment demonstrated that yearling hatchery kokanee, in the absence of predation, adjusted to conditions in Flathead Lake and utilized available zooplankton during June and July without substantial poststocking mortality. Kokanee captured after several months in the lake exhibited good growth and condition. We concluded that the food supply in Big Arm Bay was not limiting survival of stocked kokanee. The 1994 monitoring objective was to quantify lake trout predation of kokanee in Big Arm Bay in the first eight weeks following stocking. There were three components needed to quantify predation; estimated number of lake trout in Big Arm Bay, average number of kokanee consumed by lake trout, and estimated time required for lake trout to digest kokanee. As in the previous year, the monitoring results from the 1994 kokanee plant demonstrated that lake trout predation is the primary factor reducing survival of stocked kokanee. We estimated that lake trout consumed a minimum of 232,000 kokanee in Big Arm Bay during the first eight weeks following stocking. This represents 29 percent of kokanee planted. The consumption estimate was based on a hydroacoustic estimate for lake trout abundance (7,850 fish over 300 mm in total length), an incidence of kokanee per lake trout stomach sample which ranged from 2.99 to 0.22 fish, and a gastric evacuation rate of 47 hours for lake trout to digest consumed kokanee. Due to hydroacoustic limitations in identifying bottom-oriented lake trout, we underestimated the true abundance of lake trout, which led to an underestimate of kokanee mortality. By fall of 1994, we estimated that an additional 12.7 percent of surviving kokanee matured, based on observations of similar-sized fish in the hatchery. Thus, up to 72,000 additional fish were removed from the population due to early maturation. Adding the loss due to predation in the first eight weeks (232,000) to the loss due to early maturation (72,000), we accounted for mortality of at least 304,000 (38 percent) of the original 802,000 fish planted. These estimates did not account for additional losses, including predation outside Big Arm Bay, predation in the months following July, and predation from species other than lake trout, such as bull trout and northern squawfish. We documented lake trout predation of kokanee from June through October, and predation by fish species other than lake trout. One of the program goals is to achieve post-stocking survival of 30 percent one year after planting. Based on observations of the 1994 program, it is unlikely we will achieve this level of survival from the 1994 plant.

  8. Wisconsin Integrated and Applied Curricula Project. Year One: 1993-1994.

    ERIC Educational Resources Information Center

    Gilbertson, Alan; And Others

    These materials were developed as part of Wisconsin's tech prep initiative. The 25-page report describes how approximately 500 secondary and postsecondary educators who would be responsible for the initial development, implementation, and assessment of the state's grade 11-14 integrated/applied curricula attended a 2-day training workshop in…

  9. 1993-1994 Final technical report for establishing the SECME Model in the District of Columbia

    SciTech Connect

    Vickers, R.G.

    1995-12-31

    This is the final report for a program to establish the SECME Model in the District of Columbia. This program has seen the development of a partnership between the District of Columbia Public Schools, the University of the District of Columbia, the Department of Energy, and SECME. This partnership has demonstrated positive achievement in mathematics and science education and learning in students within the District of Columbia.

  10. Surfactant-enhanced alkaline flooding for light oil recovery. [Annual report], 1993--1994

    SciTech Connect

    Wasan, D.T.

    1995-03-01

    In this report, we present the results of our experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, we have (1) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (2) investigated the kinetics of oil removal from a silica surface, and (3) developed a theoretical interfacial activity model for determining equilibrium interfacial tension. The results of the studies conducted during the course of this project are presented.

  11. Literacy across the Curriculum: Connecting Literacy in the Schools, Community and Workplace, 1993-1994.

    ERIC Educational Resources Information Center

    Literacy across the Curriculum, 1994

    1994-01-01

    This packet contains four sets of newsletters. Some of the topics covered in the Spring 1993 edition include the following: the rhetoric of crisis discredited, ethics in business-education partnerships, teaching about editorials, the politics of workplace literacy, women and literacy programs in Canada, and a list of resources on native literacy.…

  12. Accountability as Measured by Employer Satisfaction in Hawaii's Tourist/Hospitality Industry: 1993-1994.

    ERIC Educational Resources Information Center

    Broadbent, William A.

    During 1993 and 94, the University of Hawaii performed a study of local organizations in the tourist/hospitality industry, assessing employer satisfaction with the graduates and products of the public school system and community colleges. Specifically, the study aimed to determine if participants of training programs were making a successful…

  13. Assessment of Smolt Condition for Travel Time Analysis, 1993-1994 Annual Report.

    SciTech Connect

    Schrock, Robin M; Beeman, John W; VanderKooi, Scott P

    1999-02-01

    The assessment of smolt condition for travel time analysis (ASCTTA) project provided information on the level of smoltification in Columbia River hatchery and wild salmonid stocks to the Fish Passage Center (FPC), for the primary purpose of in-river management of flows.

  14. Habitat Evaluation Procedures (HEP) Report; Willow Creek, Technical Report 1993-1994.

    SciTech Connect

    Beilke, Susan

    1994-09-01

    The Willow Creek site is one of the most significant remaining areas of typical native Willamette Valley habitats, with a variety of wetlands, grasslands, and woodlands. A diverse array of native flora and fauna, with significant wildlife habitats, is present on the site. Wildlife diversity is high, and includes species of mammals, songbirds, raptors, reptiles, amphibians, and one rare invertebrate. Over 200 species of native plants have been identified (including populations of six rare, threatened, or endangered species), along with significant remnants of native plant communities. Willow Creek is located in Lane County, Oregon, on the western edge of the City of Eugene (see Figure 1). The city limit of Eugene passes through the site, and the site is entirely within the Eugene Urban Growth Boundary (UGB). At present, only lands to the east and northeast of the site are developed to full urban densities. Low density rural residential and agricultural land uses predominate on lands to the northwest and south. A partially completed light industrial/research office park is located to the northwest. Several informal trails lead south from West 18th at various points into the site. The area encompasses a total of approximately 349 acres under several ownerships, in sections 3 and 4 of Township 18 South, Range 4 West. wildlife habitat values resulting from the purchase of this site will contribute toward the goal of mitigating for habitat lost as outlined in the Bonneville Power Administration's (BPA) Mitigation and Enhancement Plan for the Willamette River Basin. Under this Plan, mitigation goals were developed as a result of the loss of wildlife habitat due to the development and operation of Federal hydro-electric facilities in the Willamette River Basin. Results of the HEP will be used to: (1) determine the current status and habitat enhancement potential of the site consistent with wildlife mitigation goals and objectives; and (2) develop a management plan for the area. The BPA is considering exercising their option to purchase the Bailey Hill property, acquiring additional properties now owned by The Nature Conservancy, and/or funding enhancement activities for the entire site in order to receive credit under the Mitigation and Enhancement Plan for the Willamette River Basin.

  15. Atomic Safety and Licensing Board Panel Biennial Report, Fiscal Years 1993--1994. Volume 6

    SciTech Connect

    1995-08-01

    In Fiscal Year 1993, the Atomic Safety and Licensing Board Panel (``the Panel``) handled 30 proceedings. In Fiscal Year 1994, the Panel handled 36 proceedings. The cases addressed issues in the construction, operation, and maintenance of commercial nuclear power reactors and other activities requiring a license form the Nuclear Regulatory Commission. This report sets out the Panel`s caseload during the year and summarizes, highlight, and analyzes how the wide- ranging issues raised in those proceedings were addressed by the Panel`s judges and licensing boards.

  16. Low-temperature catalytic gasification of wet industrial wastes. FY 1993--1994 interim report

    SciTech Connect

    Elliott, D.C.; Hart, T.R.; Neuenschwander, G.G.; Deverman, G.S.; Werpy, T.A.; Phelps, M.R.; Baker, E.G.; Sealock, L.J. Jr.

    1995-03-01

    Process development research is continuing on a low-temperature, catalytic gasification system that has been demonstrated to convert organics in water (dilute or concentrated) to useful and environmentally safe gases. The system, licensed under the trade name Thermochemical Environmental Energy System (TEESO), treats a wide variety of feedstocks ranging from hazardous organics in water to waste sludges from food processing. The current research program is focused on the use of continuous-feed, tubular reactors systems for testing catalysts and feedstocks in the process. A range of catalysts have been tested, including nickel and other base metals, as well as ruthenium and other precious metals. Results of extensive testing show that feedstocks, ranging from 2% para-cresol in water to potato waste and spent grain, can be processed to > 99% reduction of chemical oxygen demand (COD). The product fuel gas contains from 40% up to 75% methane, depending on the feedstock. The balance of the gas is mostly carbon dioxide with < 5% hydrogen and usually < 1% ethane and higher hydrocarbons. The byproduct water stream carries residual organics from 10 to 1,000 mg/l COD, depending on the feedstock. The level of development of TEES has progressed to the initial phases of industrial process demonstration. Testing of industrial waste streams is under way at both the bench scale and engineering scale of development.

  17. Strong interactions studies with medium energy probes. Progress report, 1993--1994

    SciTech Connect

    Seth, K.K.

    1994-09-01

    This progress report refers to the period August 1993 to September 1994, which includes the second year of the three year period December 1, 1992--November 30, 1995 of our existing research contract. The budget proposal for the third year, December 1, 1994 to November 30, 1995 as originally approved, is also presented. As anticipated in our 1992--1995 proposal, Fermilab E760/E835 on high precision charmonium spectroscopy has remained a major part of our preoccupation and commitment during the last year, and it will remain so in the forthcoming year. In early 1994 we joined the collaboration of the Brookhaven experiment E852 on the spectroscopy of states with exotic quantum numbers. The first successful three month run of E852 was completed on July 31 and preliminary data analysis has been started. Some new commitments have resulted from this collaboration and a separate proposal for supplemental financial support is being prepared for them. At Los Alamos our experiment {number_sign}1274 on search of extremely neutron rich exotic nuclei by pion absorption began making initial measurements a month ago and is expected to take data during the period October 15--November 30, 1994. In addition to the above on-going programs, our Bates proposal (94-01) for a definitive measurement of the quenching of the longitudinal response in quasi-free scattering of electrons from nuclei has been approved with high priority for 600 hours of beam time, and we expect to start the experiment in late 1995.

  18. Long depletion time of enrofloxacin in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Lucchetti, Dario; Fabrizi, Laura; Guandalini, Emilio; Podestà, Elisabetta; Marvasi, Luigi; Zaghini, Anna; Coni, Ettore

    2004-10-01

    The international production of farmed fish has been growing continuously over recent years. Until now few veterinary drugs have been approved by the European Union for use in aquaculture, and this has favored the off-label use of products authorized for use in food-producing animal species different from fishes among fish farmers. Adequate field studies are lacking, especially for those species called minor species which are consumed extensively only in some European countries. In the present investigation we studied the depletion of the fluoroquinolone antibacterial enrofloxacin over time in a minor species, the rainbow trout (Oncorhynchus mykiss), reared on a real fish farm and treated with medicated feed (10 mg kg of trout body weight(-1) day(-1)). Edible tissue samples (muscle plus skin in natural proportions) and fish bone samples were analyzed for enrofloxacin and for its major metabolite, ciprofloxacin, by high-performance liquid chromatography with fluorescence detection at different times after the end of treatment. Our results show that at 500 degrees C-day (in which degree-days are calculated by multiplying the mean daily water temperature by the total number of days on which the temperature was measured), which is the minimum withdrawal period established by European Economic Commission Directive No. 82/2001 for any type of product administered off-label, edible trout tissues might still contain about 170 microg of enrofloxacin kg(-1), whereas the maximum residue level for enrofloxacin plus ciprofloxacin is set at 100 microg kg(-1). To our knowledge, no studies of the depletion of enrofloxacin in rainbow trout have been performed. On the basis of the data obtained in the present study, we suggest a more appropriate withdrawal time of 816 degrees C-day for the sum of enrofloxacin plus ciprofloxacin levels in rainbow trout muscle plus skin tissues. PMID:15388452

  19. Dorsal hump morphology in pink salmon (Oncorhynchus gorbuscha).

    PubMed

    Susuki, Kenta; Ichimura, Masaki; Koshino, Yosuke; Kaeriyama, Masahide; Takagi, Yasuaki; Adachi, Shinji; Kudo, Hideaki

    2014-05-01

    Mature male Pacific salmon (Genus Oncorhynchus) develop a dorsal hump, as a secondary male sexual characteristic, during the spawning period. Previous gross anatomical studies have indicated that the dorsal humps of salmon are mainly composed of cartilaginous tissue (Davidson [1935] J Morphol 57:169-183.) However, the histological and biochemical characteristics of such humps are poorly understood. In this study, the detailed microstructures and components of the dorsal humps of pink salmon were analyzed using histochemical techniques and electrophoresis. In mature males, free interneural spines and neural spines were located in a line near to the median septum of the dorsal hump. No cartilaginous tissue was detected within the dorsal hump. Fibrous and mucous connective tissues were mainly found in three regions of the dorsal hump: i) the median septum, ii) the distal region, and iii) the crescent-shaped region. Both the median septum and distal region consisted of connective tissue with a high water content, which contained elastic fibers and hyaluronic acid. It was also demonstrated that the lipid content of the dorsal hump connective tissue was markedly decreased in the mature males compared with the immature and maturing males. Although, the crescent-shaped region of the hump consisted of connective tissue, it did not contain elastic fibers, hyaluronic acid, or lipids. In an ultrastructural examination, it was found that all of the connective tissues in the dorsal hump were composed of collagen fibers. Gel electrophoresis of collagen extracts from these tissues found that the collagen in the dorsal hump is composed of Type I collagen, as is the case in salmon skin. These results indicate that in male pink salmon the dorsal hump is formed as a result of an increase in the amount of connective tissue, rather than cartilage, and the growth of free interneural spines and neural spines.

  20. Renal excretion in coho salmon (Oncorhynchus kisutch) after acute exposure to 3-trifluoromethyl-4-nitrophenol

    USGS Publications Warehouse

    Hunn, J.B.; Allen, J.L.

    1975-01-01

    COHO SALMON (ONCORHYNCHUS KISUTCH) EXPOSED TO AN ACUTE, SUBLETHAL CONCENTRATION OF 3-TRIFLUOROMETHLY 1-4 NITROPHENOL (TFM) EXHIBITED AN INCREASED OUTPUT OF URINE WHEN COMPARED WITH CONTROLS, BUT THE URINARY EXCRETION OF NA, K, CA, MG AND C1 WAS NOT AFFECTED. ABOUT 35 TIMES MORE CONJUGATED TFM THAN FREE TFM WAS EXCRETED DURING THE 24-HOUR STUDY PERIOD.

  1. Effects of sex steroids on indices of protein turnover in rainbow trout (Oncorhynchus mykiss) white muscle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of 17-estradiol (E2), testosterone, and 5a-dihydrotestosterone (DHT) on protein turnover and proteolytic gene expression were determined in rainbow trout (Oncorhynchus mykiss) primary myocytes and white muscle tissue. E2 reduced rates of protein synthesis and increased rates of protein degr...

  2. Sensory analysis of rainbow trout, oncorhynchus mykiss, fed enriched black soldier fly prepupae, hermetia illucens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A growth trial and fillet sensory analysis were conducted to examine the effects of replacing dietary fish meal with black soldier fly (BSF) prepupae, Hermetia illucens, in rainbow trout, Oncorhynchus mykiss. A practical-type trout diet was formulated to contain 45% protein; four test diets were dev...

  3. Effects of incubation temperatures on embryonic and larval survival in rainbow trout, Oncorhynchus mykiss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incubation temperature is commonly used by hatcheries to manipulate hatch date in salmonids including rainbow trout (Oncorhynchus mykiss). Target dates for hatching often change during the incubation period and require a sudden adjustment in temperature. Although there are many studies charac...

  4. Observations on side-swimming rainbow trout Oncorhynchus mykiss in water recirculation aquaculture systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRAS), it was observed that rainbow trout Oncorhynchus mykiss in all WRAS exhibited a higher-than-normal prevalence of side-swimming (i.e. controlled, forward swimming, but with misaligned orientation suc...

  5. Shedding of Renibacterium salmoninarum by infected chinook salmon Oncorhynchus tschawytscha

    USGS Publications Warehouse

    McKibben, C.L.; Pascho, R.J.

    1999-01-01

    Laboratory studies of the transmission and pathogenesis of Renibacterium salmoninarum may describe more accurately what is occurring in the natural environment if test fish are infected by waterborne R. salmoninarum shed from infected fish. To quantify bacterial shedding by chinook salmon Oncorhynchus tschawytscha at 13??C in freshwater, groups of fish were injected intraperitoneally with R. salmoninarum at either 1.3 x 106 colony forming units (CFU) fish-1 (high-dose injection group) or 1.5 x 103 CFU fish-1 (low-dose injection group). R. salmoninarum infection levels were measured in the exposed fish by the enzyme-linked immunosorbent assay (BKD-ELISA). At regular intervals for 30 d, the numbers of R. salmoninarum shed by the injected fish were calculated on the basis of testing water samples by the membrane filtration-fluorescent antibody test (MF-FAT) and bacteriological culture. Mean BKD-ELISA optical densities (ODs) for fish in the low-dose injection group were not different from those of control fish [p > 0.05), and no R. salmoninarum were detected in water samples taken up to 30 d after injection of fish in the low-dose group. By 12 d after injection a proportion of the fish from the high-dose infection group had high (BKD-ELISA OD ??? 1.000) to severe (BKD-ELISA OD ??? 2.000) R. salmoninarum infection levels, and bacteria were detected in the water by both tests. However, measurable levels of R. salmoninarum were not consistently detected in the water until a proportion of the fish maintained high to severe infection levels for an additional 8 d. The concentrations of R salmoninarum in the water samples ranged from undetectable up to 994 cells ml-1 on the basis of the MF-FAT, and up to 1850 CFU ml-1 on the basis of bacteriological culture. The results suggest that chinook salmon infected with R. salmoninarum by injection of approximately 1 x 106 CFU fish-1 can be used as the source of infection in cohabitation challenges beginning 20 darter injection.

  6. Muscle wound healing in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Schmidt, J G; Andersen, E W; Ersbøll, B K; Nielsen, M E

    2016-01-01

    We followed the progression of healing of deep excisional biopsy punch wounds over the course of 365 days in rainbow trout (Oncorhynchus mykiss) by monitoring visual wound healing and gene expression in the healing muscle at regular intervals (1, 3, 7, 14, 38 and 100 days post-wounding). In addition, we performed muscle texture analysis one year after wound infliction. The selected genes have all previously been investigated in relation to vertebrate wound healing, but only few specifically in fish. The selected genes were interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β1 and -β3, matrix metalloproteinase (MMP) -9 and -13, inducible nitric oxide synthase (iNOS), fibronectin (FN), tenascin-C (TN-C), prolyl 4-hydroxylase α1-chain (P4Hα1), lysyl oxidase (LOX), collagen type I α1-chain (ColIα1), CD41 and CD163. Wound healing progressed slowly in the presented study, which is at least partially due to the low temperature of about 8.5 °C during the first 100 days. The inflammation phase lasted more than 14 days, and the genes relating to production and remodeling of new extracellular matrix (ECM) exhibited a delayed but prolonged upregulation starting 1-2 weeks post-wounding and lasting until at least 100 days post-wounding. The gene expression patterns and histology reveal limited capacity for muscle regeneration in rainbow trout, and muscle texture analyses one year after wound infliction confirm that wounds heal with fibrosis. At 100 dpw epidermis had fully regenerated, and dermis partially regenerated. Scales had not regenerated even after one year. CD163 is a marker of "wound healing"-type M2c macrophages in mammals. M2 macrophage markers are as yet poorly described in fish. The pattern of CD163 expression in the present study is consistent with the expected timing of presence of M2c macrophages in the wound. CD163 may thus potentially prove a valuable marker of M2 macrophages - or a subset hereof - in fish. We subjected a group of fish to

  7. Carnobacterium maltaromaticum infections in feral Oncorhynchus spp. (Family Salmonidae) in Michigan.

    PubMed

    Loch, Thomas P; Kumar, Rakesh; Xu, Wei; Faisal, Mohamed

    2011-10-01

    Members of the genus Oncorhynchus were introduced from the Pacific Northwest to the Laurentian Great Lakes basin and now constitute one of its most commercially and ecologically valuable fisheries. Recently, infections by a group of Gram-positive atypical lactobacilli belonging to the genus Carnobacterium have been detected in feral and captive Oncorhynchus spp. broodstock, some of which were associated with mortalities. Out of 1564 rainbow and steelhead trout (O. mykiss), coho salmon (O. kisutch), and Chinook salmon (O. tshawytscha) that were bacteriologically examined, 57 Carnobacterium spp. isolates were recovered from the kidneys, spleen, swimbladder, and/or external ulcerations of 51 infected fish. Phenotypic and biochemical characterization, as well as partial 16S rDNA sequencing and phylogenetic analyses of 30 representative isolates identified 29 as Carnobacterium maltaromaticum and 1 as C. divergens, though some phenotypic and genotypic heterogeneity was observed. Infections with C. maltaromaticum were associated with signitures typical of pseudokidney disease, but on occasion were also observed in fish displaying the gross and histopathological changes characteristic of nephrocalcinosis. While C. maltaromaticum infections were found to be widespread in both feral and farmed spawning populations of Oncorhynchus spp. residing within the Great Lakes basin, infection prevalence varied significantly according to fish species and strain, gender, and across time, but not by sampling location according to logistic regression analysis. The findings of this study further underscore the presence of phenotypic variations among Carnobacterium maltaromaticum strains that necessitate genotypic analysis to achieve definitive identification.

  8. Linking marine and freshwater growth in western Alaska Chinook salmon Oncorhynchus tshawytscha

    USGS Publications Warehouse

    Ruggerone, G.T.; Nielsen, J.L.; Agler, B.A.

    2009-01-01

    The hypothesis that growth in Pacific salmon Oncorhynchus spp. is dependent on previous growth was tested using annual scale growth measurements of wild Chinook salmon Oncorhynchus tshawytscha returning to the Yukon and Kuskokwim Rivers, Alaska, from 1964 to 2004. First-year marine growth in individual O. tshawytscha was significantly correlated with growth in fresh water. Furthermore, growth during each of 3 or 4 years at sea was related to growth during the previous year. The magnitude of the growth response to the previous year's growth was greater when mean year-class growth during the previous year was relatively low. Length (eye to tail fork, LETF) of adult O. tshawytscha was correlated with cumulative scale growth after the first year at sea. Adult LETF was also weakly correlated with scale growth that occurred during freshwater residence 4 to 5 years earlier, indicating the importance of growth in fresh water. Positive growth response to previous growth in O. tshawytscha was probably related to piscivorous diet and foraging benefits of large body size. Faster growth among O. tshawytscha year classes that initially grew slowly may reflect high mortality in slow growing fish and subsequent compensatory growth in survivors. Oncorhynchus tshawytscha in this study exhibited complex growth patterns showing a positive relationship with previous growth and a possible compensatory response to environmental factors affecting growth of the age class.

  9. Spatial and temporal spawning dynamics of native westslope cutthroat trout, Oncorhynchus clarkii lewisi, introduced rainbow trout, Oncorhynchus mykiss, and their hybrids

    USGS Publications Warehouse

    Muhlfeld, C.C.; McMahon, T.E.; Belcer, D.; Kershner, J.L.

    2009-01-01

    We used radiotelemetry to assess spatial and temporal spawning distributions of native westslope cutthroat trout (Oncorhynchus clarkii lewisi; WCT), introduced rainbow trout (Oncorhynchus mykiss; RBT), and their hybrids in the upper Flathead River system, Montana (USA) and British Columbia (Canada), from 2000 to 2007. Radio-tagged trout (N = 125) moved upriver towards spawning sites as flows increased during spring runoff and spawned in 29 tributaries. WCT migrated greater distances and spawned in headwater streams during peak flows and as flows declined, whereas RBT and RBT hybrids (backcrosses to RBT) spawned earlier during increasing flows and lower in the system. WCT hybrids (backcrosses to WCT) spawned intermediately in time and space to WCT and RBT and RBT hybrids. Both hybrid groups and RBT, however, spawned over time periods that produced temporal overlap with spawning WCT in most years. Our data indicate that hybridization is spreading via long-distance movements of individuals with high amounts of RBT admixture into WCT streams and stepping-stone invasion at small scales by later generation backcrosses. This study provides evidence that hybridization increases the likelihood of reproductive overlap in time and space, promoting extinction by introgression, and that the spread of hybridization is likely to continue if hybrid source populations are not reduced or eliminated.

  10. Using broad landscape level features to predict redd densities of steelhead trout (Oncorhynchus mykiss) and Chinook Salmon (Oncorhynchus tshawytscha) in the Methow River watershed, Washington

    USGS Publications Warehouse

    Romine, Jason G.; Perry, Russell W.; Connolly, Patrick J.

    2013-01-01

    We used broad-scale landscape feature variables to model redd densities of spring Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) in the Methow River watershed. Redd densities were estimated from redd counts conducted from 2005 to 2007 and 2009 for steelhead trout and 2005 to 2009 for spring Chinook salmon. These densities were modeled using generalized linear mixed models. Variables examined included primary and secondary geology type, habitat type, flow type, sinuosity, and slope of stream channel. In addition, we included spring effect and hatchery effect variables to account for high densities of redds near known springs and hatchery outflows. Variables were associated with National Hydrography Database reach designations for modeling redd densities within each reach. Reaches were assigned a dominant habitat type, geology, mean slope, and sinuosity. The best fit model for spring Chinook salmon included sinuosity, critical slope, habitat type, flow type, and hatchery effect. Flow type, slope, and habitat type variables accounted for most of the variation in the data. The best fit model for steelhead trout included year, habitat type, flow type, hatchery effect, and spring effect. The spring effect, flow type, and hatchery effect variables explained most of the variation in the data. Our models illustrate how broad-scale landscape features may be used to predict spawning habitat over large areas where fine-scale data may be lacking.

  11. Evaluation of an Experimental Re-introduction of Sockeye Salmon into Skaha Lake; Year 3 of 3; Addendum to the Assessment of Juvenile Oncorhynchus nerka (Sockeye and Kokane) Rearing Conditions of Skaha and Osoyoos Lakes 2002 Section of the 2002 Technical Report, 2003 Technical Report.

    SciTech Connect

    Wright, Howie; Lawrence, Shayla; Rebellato, Betty

    2004-01-01

    The purpose of this addendum is, first, to provide and discuss disease agent survey results that were not available for inclusion in the Disease Risk Assessment portion of the YEAR 3 report at the time of its writing, and second, to make recommendations stemming from these results. The first set of results deals with live box exposure tests conducted using juvenile sentinel rainbow trout in the spring of 2002 to detect Myxosoma cerebralis and Ceratomyxa shasta. The second set of results deals with similar exposure tests conducted in the spring of 2003. The latter tests were initially intended to occur in the fall of 2002 but had to be re-scheduled to the spring of 2003 because suitably aged sentinel rainbow trout for the exposures were not available in the fall of 2002. The methods used for the live box exposure tests were essentially the same as those described in the YEAR 3 report. Fish were again exposed at the same four sites above McIntyre Dam and at the same four sites below the dam. As mentioned in the YEAR 3 report, the spring 2002 exposure lasted for 21 days (May 6 to 27). The spring 2003 exposure also lasted for 21 days (April 22 to May 13). The number of fish in the spring 2003 tests was, however, reduced to approximately half the number used in previous tests in order to reduce the chances of dissolved oxygen problems, suspected to have occurred in earlier tests in some of the live boxes. As before, fish that survived the live box exposures were transferred to Skaha Hatchery where they were held for sufficient time to permit any infections with M. cerebralis and C. shasta to develop and to permit for spore development in these pathogens. Assays for the pathogens were carried out as previously described. Detection of M. cerebralis was based on detecting its spores following the trypsin/pepsin digestion method. Detection of C. shasta was based on a polymerase chain reaction (PCR) test, but smears of fresh intestinal tissues (one fish per smear) were also prepared so that positive PCR findings could be confirmed by the microscopic observation of C. shasta spores. Except as just mentioned, appropriate tissues from the fish were in most cases pooled (maximum of five fish per pool) for the assays.

  12. First isolation of Pseudocohnilembus persalinus (Ciliophora: Scuticociliatida) from freshwater-reared rainbow trout, Oncorhynchus mykiss.

    PubMed

    Jones, Simon R M; Prosperi-Porta, Gina; LaPatra, Scott E

    2010-10-01

    Ciliated protists were isolated from the ovarian fluid of apparently healthy adult rainbow trout (Oncorhynchus mykiss) maintained in freshwater. The organism was identified as Pseudocohnilembus persalinus based on morphometric and morphological analysis of silver-stained specimens obtained from culture and on analysis of ribosomal RNA gene sequences. The cytochrome c oxidase subunit 1 gene sequence of this organism also was characterized. This ciliate has been reported previously as free living only in saline environments and as an endosymbiont in a marine teleost, the olive flounder (Paralichthys olivaceus). A cyst-like stage may have facilitated the novel occurrence of this organism as an endosymbiont in rainbow trout.

  13. Secondary sexual characters and sperm traits in coho salmon Oncorhynchus kisutch.

    PubMed

    Pitcher, T E; Doucet, S M; Beausoleil, J-M J; Hanley, D

    2009-05-01

    A study was undertaken to examine secondary sexual characters (spawning colouration and overall body size) in relation to sperm metrics in one alternative reproductive tactic of coho salmon Oncorhynchus kisutch: large hooknose males that spawn in dominance-based hierarchies. Males with less intense red spawning colouration had higher sperm velocities than males with darker red spawning colouration. There was no relationship between male body size and sperm metrics. These results suggest that within an alternative reproductive tactic, variation in sperm competition intensity may select for a trade-off between investment in sexual colouration and sperm quality.

  14. Life-history organization of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri) in Yellowstone Lake

    USGS Publications Warehouse

    Gresswell, Robert E.; Liss, W.J.; Larson, Gary L.

    1994-01-01

    Life-history organization of the cutthroat trout (Oncorhynchus clarki) may be viewed at various levels, including species, subspecies, metapopulation, population, or individual. Each level varies in spatial scale and temporal persistence, and components at each level continually change with changes in environment. Cutthroat trout are widely distributed throughout the western United States, occurring in such diverse environments as coastal rivers of the Pacific Northwest and interior streams of the Great Basin. During its evolution the species has organized into 14 subspecies with many different life-history characteristics and habitat requirements. Within subspecies, organization is equally complex. For example, life-history traits, such as average size and age, migration strategy, and migration timing, vary among individual spawning populations of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri) in tributary streams of Yellowstone Lake. Understanding the effects of human perturbations on life-history organization is critical for management of the cutthroat trout and other polytypic salmonid species. Loss of diversity at any hierarchical level jeopardizes the long-term ability of the species to adapt to changing environments, and it may also lead to increased fluctuations in abundance and yield and increase the risk of extinction.

  15. Comparative mapping reveals quantitative trait loci that affect spawning time in coho salmon (Oncorhynchus kisutch)

    PubMed Central

    Araneda, Cristian; Díaz, Nelson F.; Gomez, Gilda; López, María Eugenia; Iturra, Patricia

    2012-01-01

    Spawning time in salmonids is a sex-limited quantitative trait that can be modified by selection. In rainbow trout (Oncorhynchus mykiss), various quantitative trait loci (QTL) that affect the expression of this trait have been discovered. In this study, we describe four microsatellite loci associated with two possible spawning time QTL regions in coho salmon (Oncorhynchus kisutch). The four loci were identified in females from two populations (early and late spawners) produced by divergent selection from the same base population. Three of the loci (OmyFGT34TUF, One2ASC and One19ASC) that were strongly associated with spawning time in coho salmon (p < 0.0002) were previously associated with QTL for the same trait in rainbow trout; a fourth loci (Oki10) with a suggestive association (p = 0.00035) mapped 10 cM from locus OmyFGT34TUF in rainbow trout. The changes in allelic frequency observed after three generations of selection were greater than expected because of genetic drift. This work shows that comparing information from closely-related species is a valid strategy for identifying QTLs for marker-assisted selection in species whose genomes are poorly characterized or lack a saturated genetic map. PMID:22888302

  16. Use of streambed substrate as refuge by steelhead or rainbow trout Oncorhynchus mykiss during simulated freshets.

    PubMed

    Ligon, F K; Nakamoto, R J; Harvey, B C; Baker, P F

    2016-04-01

    A flume was used to estimate the carrying capacity of streambed substrates for juvenile steelhead or rainbow trout Oncorhynchus mykiss seeking refuge from simulated freshets. The simulated freshets had mean water column velocities of c. 1·1 m s(-1). The number of O. mykiss finding cover within the interstices of the substrate was documented for different substrate sizes and levels of embeddedness. The availability of suitable refuges determined the carrying capacity of the substrate for O. mykiss. For the size of the O. mykiss tested [mean ± s.d. fork length (L(F)) = 122 ± 12.6 mm], the number of interstices with depths ≥200 mm measured with a 14.0 mm diameter flexible plastic tube was the best predictor of the number of O. mykiss able to find cover (r(2)  = 0.75). Oncorhynchus mykiss seeking refuge from freshets may need deeper interstices than those seeking concealment at autumn or winter base flows. The availability of interstices suitable as refuge from high flows may determine autumn and winter carrying capacity. PMID:26932205

  17. Abnormal swimming behavior and increased deformities in rainbow trout Oncorhynchus mykiss cultured in low exchange water recirculation aquaculture systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two studies were conducted to determine if accumulating water quality parameters would negatively impact rainbow trout Oncorhynchus mykiss health and welfare within water recirculation aquaculture systems (WRAS) that were operated at low and near-zero water exchange, with and without ozonation, and ...

  18. Effect of anthocyanidins on myogenic differentiation in induced and non-induced primary myoblasts from rainbow trout (Oncorhynchus mykiss).

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to test whether an anthocyanidin mixture (peonidin, cyanidin and pelargonidin chloride) modulates myogenesis in both induced and non-induced myogenic cells from juvenile rainbow trout (Oncorhynchus mykiss). We evaluated three different anthocyanidin concentrations (1X, 2.5X and...

  19. Effects of frying in various cooking oils on fatty acid content of farmed rainbow trout (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our goal was to describe the effects of frying with various oils on the fatty acid content of rainbow trout. Four different oils were evaluated (peanut oil, high oleic sunflower oil, corn oil, and canola oil). Farmed rainbow trout (Oncorhynchus mykiss) fillets were sliced into three portions and eac...

  20. Identification of Estrogen-responsive Vitelline Envelope Protein Fragments from Rainbow Trout (Oncorhynchus mykiss) Plasma Using Mass Spectrometry

    EPA Science Inventory

    Plasma protein biomarkers associated with exposure of rainbow trout (Oncorhynchus mykiss) to 17β-estradiol were isolated and identified using novel sample preparation techniques and state-of-the-art mass spectrometry and bioinformatics approaches. Juvenile male and female trout ...

  1. Preliminary examination of oxidative stress in juvenile spring Chinook salmon (Oncorhynchus tshawytscha) of wild origin sampled from transport barges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Migrating juvenile wild Chinook salmon (Oncorhynchus tshawytscha), collected and loaded onto transport barges at Lower Granite Dam on the Snake River, were sampled from barges at John Day Dam, 348 km downstream, at five-day intervals beginning late April and ending late May. An increase in lipid per...

  2. 50 CFR 226.210 - Central California Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the USGS publication and... ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.210 Central California... (Oncorhynchus kisutch). Critical habitat is designated to include all river reaches accessible to listed...

  3. 50 CFR 226.210 - Central California Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the USGS publication and... ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.210 Central California... (Oncorhynchus kisutch). Critical habitat is designated to include all river reaches accessible to listed...

  4. 50 CFR 226.210 - Central California Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the USGS publication and... ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.210 Central California... (Oncorhynchus kisutch). Critical habitat is designated to include all river reaches accessible to listed...

  5. 50 CFR 226.210 - Central California Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the USGS publication and... ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.210 Central California... (Oncorhynchus kisutch). Critical habitat is designated to include all river reaches accessible to listed...

  6. 50 CFR 226.210 - Central California Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the USGS publication and... ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.210 Central California... (Oncorhynchus kisutch). Critical habitat is designated to include all river reaches accessible to listed...

  7. Continuous Exposure to Infectious Pancreatic Necrosis Virus (IPNV) During Early Life Stages of Rainbow Trout, Oncorhynchus mykiss, Walbaum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rainbow trout (Oncorhynchus mykiss, Walbaum) were exposed continuously to infectious pancreatic necrosis virus (IPNV) at 0, 10, 1,000, or 10,000 pfu/L of water to estimate the effects of chronic IPNV exposure on early life stages. Fish density averaged 35 fish/L (low) or 140 fish/L (high), and wate...

  8. Continuous exposure to infectious pancreatic necrosis virus during early life stages of rainbow trout, Oncorhynchus mykiss(Walbaum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rainbow trout (Oncorhynchus mykiss, Walbaum) were exposed continuously to infectious pancreatic necrosis virus (IPNV) at 0, 10, 1,000, or 100,000 pfu/L of water to estimate the effects of chronic IPNV exposure on early life stages. Fish density averaged 35 fish/L or 140 fish/L, with a tank flow rat...

  9. Acute handling disturbance modulates plasma insulin-like growth factor binding proteins in rainbow trout (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of acute stressor exposure on proximal (growth hormone; GH) and distal (insulin-like growth factor-I; IGF-I and IGF-binding proteins) components of the somatotropic axis are poorly understood in finfish. We exposed rainbow trout (Oncorhynchus mykiss) to a 5-minute handling disturbance to...

  10. A second generation integrated map of the rainbow trout (Oncorhynchus mykiss) genome: analysis of synteny with model fish genomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper we generated DNA fingerprints and end sequences from bacterial artificial chromosomes (BACs) from two new libraries to improve the first generation integrated physical and genetic map of the rainbow trout (Oncorhynchus mykiss) genome. The current version of the physical map is compose...

  11. Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993-1994

    USGS Publications Warehouse

    Squillace, P.T.; Zogorski, J.S.; Wilber, W.G.; Price, C.V.

    1997-01-01

    The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE), is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient groundwater from urban areas that were collected during 1993-94 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Samples were collected from 5 drinking-water wells, 12 springs, and 1g3 monitoring wells in urban areas. No MTBE was detected in drinking-water wells. At a reporting level of 0.2 ??g/L, MTBE was detected most frequently in shallow groundwater from urban areas (27% of 210 wells and springs sampled in 8 areas) as compared to shallow groundwater from agricultural areas (1.3% of 549 wells sampled in 21 areas) or deeper groundwater from major aquifers (1.0% of 412 wells sampled in 9 areas). Only 3% of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 ??g/L, which is the estimated lower limit of the United States Environmental Protection Agency draft lifetime drinking water health advisory. Because MTBE is persistent and mobile in groundwater) it can move from shallow to deeper aquifers with time. In shallow urban groundwater, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylenes (BTEX) compounds which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in groundwater include point sources, such as leaking storage tanks, and nonpoint sources, such as recharge of precipitation and storm-water runoff.

  12. Federal Funds for Research and Development. Fiscal Years 1993, 1994, and 1995. Volume 43. Detailed Statistical Tables.

    ERIC Educational Resources Information Center

    Meeks, Ronald L.; And Others

    Data in the tables of this publication were derived from the Survey of Federal Funds for Research and Development. They reflect research and development funding (R&D) levels as reported by 32 federal agencies from March through October 1994. The agencies reported their data as obligations and outlays incurred, or expected to be incurred,…

  13. Effect of Flap Deflection on Section Characteristics of S813 Airfoil; Period of Performance: 1993--1994

    SciTech Connect

    Somers, D. M.

    2005-01-01

    The effect of small deflections of a 30% chord, simple flap on the section characteristics of a tip airfoil, the S813, designed for 20- to 30-meter, stall-regulated, horizontal-axis wind turbines has been evaluated theoretically. The decrease in maximum lift coefficient due to leading-edge roughness increases in magnitude with increasing, positive flap deflection and with decreasing Reynolds number.

  14. Advanced turbine technology applications project (ATTAP): Hybrid vehicle turbine engine technology support (HVTE-TS): Annual report, 1993-1994

    SciTech Connect

    1996-03-01

    This is the sixth of a series of reports documenting work performed on the ATTAP/HVTETS. This is a combined report to cover work performed in both 1993 and 1994. Progress is reported on ceramic component design and characterization, powertrain development, component rig testing and performance and durability testing.

  15. Professional Development: International and National Perspectives. Four Presentations from AAHE's National Conference on School/College Collaboration, 1993-1994.

    ERIC Educational Resources Information Center

    Darling-Hammond, Linda; Sato, Nancy; Paine, Lynn; Snowball, Diane

    The four papers presented here address teacher development from an international viewpoint. In "Professional Development and Standards" (Linda Darling-Hammond) it is suggested that U.S. educators engage in new kinds of collaborations with universities, and it proposes a shift from information transmittal to "co-construction" of knowledge state…

  16. International Council for Laboratory Animal Science: International activities. Institute of Laboratory Animal Resources annual report, 1993--1994

    SciTech Connect

    Not Available

    1994-09-01

    In late 1987, the Interagency Research Animal Committee (IRAC) requested that the Institute of Laboratory Animal Resources (ILAR), National Research Council (NRC), National Academy of Sciences, reestablish US national membership in the International Council for Laboratory Animal Science (ICLAS). The ICLAS is the only worldwide organization whose goal is to foster the humane use of animals in medical research and testing. ILAR`s Mission Statement reflects its commitment to producing highly respected documents covering a wide range of scientific issues, including databases in genetic stocks, species specific management guides, guidelines for humane care of animals, and position papers on issues affecting the future of the biological sciences. As such, ILAR is recognized nationally and internationally as an independent, scientific authority in the development of animal sciences in biomedical research.

  17. Results of the basewide monitoring program at Wright-Patterson Air Force Base, Ohio, 1993-1994

    USGS Publications Warehouse

    Schalk, C.W.; Cunningham, W.L.

    1996-01-01

    Geologic and hydrologic data were collected at Wright-Patterson Air Force Base (WPAFB), Ohio, as part of Basewide Monitoring Program (BMP) that began in 1992. The BMP was designed as a long-term project to character ground-water and surface-water quality (including streambed sediments), describe water-quality changes as water enters, flows across, and exits the Base, and investigate the effects of activities at WPAFB on regional water quality. Ground water, surface ware, and streambed sediment were sampled in four rounds between August 1993 and September 1994 to provide the analytical data needed to address the objectives of the BMP. Surface-water-sampling rounds were designed to include most of the seasonal hydrologic conditions encountered in southwestern Ohio, including baseflow conditions and spring runoff. Ground-water-sampling rounds were scheduled for times of recession and recharfe. Ground-water data were used to construct water-table, potentiometric, and vertical gradient maps of the WPAFB area. Water levels have not changed significantly since 1987, but the effects of pumping on and near the Base can have a marked effect on water levels in localized areas. Ground-ware gradients generally were downward throughout Area B (the southwestern third of the Base) and in the eastern third of Areas A and C (the northeastern two-thirds of the Base), and were upward in the vicinity of Mad River. Stream-discharge measurements verified these gradients. Many of the U.S. Environmental Protection Agency maximum contaminant level (MCL) exceedances of inorganic constituents in ground water were associated with water from the bedrock. Exceedances of concentrations of chromium and nickel were found consistently in five wells completed in the glacial aquifer beneath the Base. Five organic compounds [trichloroethylene (TCE), tetrachloroethylene (PCE), vinyl chloride, benzene, and bis(2-ethylhexyl) phthalate] were detected at concentrations that exceeded MCLs; all of the TCE, PCE, and vinyl chloride exceedances were in water from glacial aquifer, whereas the benzene exceedance and most of the bis(2-ethylhexyl) phthalate exceedances were in water from the bedrock. TCE (16 exceedances) and PCE (11 exceedances) most frequently exceeded the MCLs and were detected in the most samples. A decrease in concentrations of inorganic and organic compounds with depth suggest that many constituents detected in ground-water samples are associated partly with human activities, in addition to their natural occurrence. Included in the list of these constituents are nickel, chromium, copper, lead vanadium, zinc, bromide, and nitrate. Many constituents are not found at depths greater than 60 to 80 feet, possibly indicating that human effects on ground-water quality are limited to shallow flow systems. Organic compounds detected in shallow or intermediate-depth wells were aligned mostly with flowpaths that pass through or near identified hazardous-waste sites. Few organic contaminants were detected in surface water. The only organic compound to exceed MCLs for drinking water was bis(2-ethylhexyl) phthalate, but it was detected at concentrations just above the MCL. Inorganic constituents detected at concentration exceeding MCLs include beryllium (twice), lead (once), thallium (once), and gross alpha radiation (once). No polycyclic aromatic (PAHs) were detected in surface-water samples. The highest concentrations of contaminants detected during a storm event were in samples from upgradient locations, indicating that off-Base sources may contribute to surface-water contamination. Inorganic and organic contaminants were found in streambed sediments at WPAFB, primarily in Areas A and C. Trace metals such as lead, mercury, arsenic, and cadmium were detected at 16 locations at concentrations considered 'elevated' according to a ranking scheme for sediments. PAHS were the organic compounds detected most frequently and in highest concentrations organo

  18. Washington State Even Start 1993-1994: Final Evaluation. A Report to the Office of Adult Literacy.

    ERIC Educational Resources Information Center

    Iglitzin, Lynne; Wandschneider, Mary

    All 18 Washington State Even Start sites participated in the program's evaluation. Site coordinators administered the assessment and evaluation measures to the adults served by the program and to teachers working with children at both entry and exit from the program. An indepth study was conducted of 134 families for whom there were complete sets…

  19. Fisheries Habitat Evaluation on Tributaries of the Coeur d`Alene Indian Reservation : 1993, 1994 Annual Report.

    SciTech Connect

    Woodward-Lillengreen, Kelly L.; Vitale, Angelo; Peters, Ronald L.

    1996-09-01

    Bull trout and cutthroat trout are two salmonid species native to the Lake Coeur d`Alene drainage. Historically these species were a critical component of the Coeur d`Alene Tribe`s annual subsistence requirements. Since 1932, the cutthroat trout population has declined significantly in the Coeur d`Alene system. The present ecosystem bears little resemblance to habitat composition, diversity and structure of the historic ecosystem. The purpose of this study was to conduct baseline stream and biological surveys of four drainages located within the Coeur d`alene Reservation and make recommendations on ways to increase the westslope cutthroat and bull trout populations on the Reservation. Data indicated that habitat degradation, specifically, water quantity and lack of habitat complexity, was limiting westslope cutthroat and bull trout populations on the Reservation. Population data indicated that cutthroat trout populations were low when compared to other similar drainages. Surveys revealed a conspicuous absence of bull trout. Recommendations included: conducting extensive habitat restoration in the study drainages; developing alternate harvest opportunities to reduce pressure on wild stocks; purchasing critical watershed areas for fisheries habitat protection; constructing and operating a trout production facility; and, implementing a five-year monitoring program to evaluate the program effectiveness.

  20. Differences in neurobehavioral responses of chinook salmon (Oncorhynchus tshawytscha) and rainbow trout (Oncorhynchus mykiss) exposed to copper and cobalt: Behavioral avoidance

    SciTech Connect

    Hansen, J.A.; Marr, J.C.A.; Lipton, J.; Cacela, D.; Bergman, H.L.

    1999-09-01

    Behavioral avoidance of copper (Cu), cobalt (Co), and a Cu and Co mixture in soft water differed greatly between rainbow trout (Oncorhynchus mykiss) and chinook salmon (O. tshawytscha). Chinook salmon avoided at least 0.7 {micro}g Cu/L, 24 {micro}g Co/L, and the mixture of 1.0 {micro}g Cu/L and 0.9 {micro}g Co/L, whereas rainbow trout avoided at least 1.6 {micro}g Cu/L, 180 {micro}g Co/L, and the mixture of 2.6 {micro}g Cu/L and 2.4 {micro}g Co/L. Chinook salmon were also more sensitive to the toxic effects of Cu in that they failed to avoid {ge}44 {micro}g Cu/L, whereas rainbow trout failed to avoid {ge}180 {micro}g Cu/L. Furthermore, following acclimation to 2 {micro}g Cu/L, rainbow trout avoided 4 {micro}g Cu/L and preferred clean water, but chinook salmon failed to avoid any Cu concentrations and did not prefer clean water. The failure to avoid high concentrations of metals by both species suggests that the sensory mechanism responsible for avoidance responses was impaired. Exposure to Cu concentrations that were not avoided could result in lethality from prolonged Cu exposure or in impairment of sensory-dependent behaviors that are essential for survival and reproduction.

  1. Virus diseases of fish

    USGS Publications Warehouse

    Watson, Stanley W.

    1954-01-01

    The degenerative or non-neoplastic diseases of possible virus origin give the fish-culturist the most concern because of the severe mortalities resulting from infection. Epizootics of this nature have been reported in carp (Cyprinus carpio) and rainbow trout (Salmo gairdneri) in Europe, in acara (Geophagus brasiliensis) in South America, in kokanee, (Oncorhynchus nerka kennerlyi) and in sockeye salmon (Oncorhynchus nerka nerka) in the State of Washington. It has been demonstrated that each epizootic was caused by an infectious filterable agent, probably a virus.

  2. Cholinergic and behavioral neurotoxicity of carbaryl and cadmium to larval rainbow trout (oncorhynchus mykiss)

    USGS Publications Warehouse

    Beauvais, S.L.; Jones, S.B.; Parris, J.T.; Brewer, S.K.; Little, E.E.

    2001-01-01

    Pesticides and heavy metals are common environmental contaminants that can cause neurotoxicity to aquatic organisms, impairing reproduction and survival. Neurotoxic effects of cadmium and carbaryl exposures were estimated in larval rainbow trout (RBT; Oncorhynchus mykiss) using changes in physiological endpoints and correlations with behavioral responses. Following exposures, RBT were videotaped to assess swimming speed. Brain tissue was used to measure cholinesterase (ChE) activity, muscarinic cholinergic receptor (MChR) number, and MChR affinity. ChE activity decreased with increasing concentrations of carbaryl but not of cadmium. MChR were not affected by exposure to either carbaryl or cadmium. Swimming speed correlated with ChE activity in carbaryl-exposed RBT, but no correlation occurred in cadmium-exposed fish. Thus, carbaryl exposure resulted in neurotoxicity reflected by changes in physiological and behavioral parameters measured, while cadmium exposure did not. Correlations between behavior and physiology provide a useful assessment of neurotoxicity. ?? 2001 Academic Press.

  3. Amoebic gill infection in coho salmon Oncorhynchus kisutch farmed in Korea.

    PubMed

    Kim, Wi-Sik; Kong, Kyoung-Hui; Kim, Jong-Oh; Oh, Myung-Joo

    2016-08-31

    About 70% mortality occurred in cultured coho salmon Oncorhynchus kisutch at a marine farm in the South Sea of Korea in 2014. Diseased fish showed greyish or pale patches on the gills, with no internal signs of disease. No bacteria or viruses were isolated from diseased fish, but numerous amoebae were found on the gills. Histopathological examinations revealed extensive hyperplastic epithelium and lamellar fusion in the gills. Numerous amoebae were seen between gill filaments. The amoebae had a 630 bp partial 18S rRNA gene fragment specific to Neoparamoeba perurans. Phylogenetic analysis based on partial 18S rRNA gene nucleotide sequences revealed that this Korean amoeba belonged to the N. perurans group. This is the first report of N. perurans infection in Korea. PMID:27596862

  4. Family size and effective population size in a hatchery stock of coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Simon, R.C.; McIntyre, J.D.; Hemmingsen, A.R.

    1986-01-01

    Means and variances of family size measured in five year-classes of wire-tagged coho salmon (Oncorhynchus kisutch) were linearly related. Population effective size was calculated by using estimated means and variances of family size in a 25-yr data set. Although numbers of age 3 adults returning to the hatchery appeared to be large enough to avoid inbreeding problems (the 25-yr mean exceeded 4500), the numbers actually contributing to the hatchery production may be too low. Several strategies are proposed to correct the problem perceived. Argument is given to support the contention that the problem of effective size is fairly general and is not confined to the present study population.

  5. Accumulation and depletion kinetics of erythromycin in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Vendrell, Daniel; Serarols, Lidia; Balcázar, José Luis; de Blas, Ignacio; Gironés, Olivia; Múzquiz, José Luis; Ruiz-Zarzuela, Imanol

    2012-06-01

    Erythromycin is an antimicrobial agent recommended for the control and treatment of diseases caused by gram-positive bacteria. Few studies, however, have determined the metabolic and pharmacokinetic aspects of this antimicrobial agent in fish. The aim of the present study, therefore, was to determine the accumulation and depletion time of erythromycin after administration of medicated feed containing 52 mg kg(-1) body weight day(-1) for 8 days in rainbow trout (Oncorhynchus mykiss). Results were analyzed following the European Agency for Evaluation of Medicinal Products guidelines. We measured a withdrawal time of 187°C-day (°C-day=water temperature×days), lower than the value (500°C-day) recommended by Council Directive 2004/28/EC for veterinary medicinal products. Our results provide data to establish therapeutic regimens for the use of erythromycin in aquaculture. PMID:22436556

  6. Comparative cardiovascular effects of four fishery anesthetics in spinally transected rainbow trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    Fredricks, K.T.; Gingerich, W.H.; Fater, D.C.

    1993-01-01

    1. We compared the effects of four anesthetics on heart rate, dorsal and ventral aortic blood pressure, and electrocardiograms of rainbow trout (Oncorhynchus mykiss). 1. Exposure to the local anesthetics tricaine methanesulfonate (MS-222) and benzocaine hydrochloride (BZH) produced minimal cardiovascular alterations. Mean dorsal aortic pressure (DAP) decreased during exposure to MS-222, and mean DAP and mean ventral aortic pressure (VAP) increased 15% during recovery from BZH. 3. Exposure to the general anesthetic 2-phenoxyethanol (2-PE) or the hypnotic agent etomidate (ET) dramatically decreased heart rate and blood pressures and altered EKG patterns. 4. During recovery, VAP and DAP increased above baseline for an extended period. Heart rate and EKG patterns rapidly returned to normal.

  7. Atmospheric depression-mediated water temperature changes affect the vertical movement of chum salmon Oncorhynchus keta.

    PubMed

    Kitagawa, Takashi; Hyodo, Susumu; Sato, Katsufumi

    2016-08-01

    The Sanriku coastal area, Japan, is one of the southern-most natural spawning regions of chum salmon Oncorhynchus keta. Here, we report their behavioral response to changes in ambient temperature after the passage of an atmospheric depression during the early spawning season. Before the passage, all electrically tagged fish moved vertically for several hours to depths below the shallow thermocline at >100 m. However, during the atmospheric depression, the salmon shortened the duration of their vertical movements and spent most time at the surface. The water column was homogenous at <150 m deep except for the surface. The descending behavior may have been discontinued because the cooler water below the thermocline was no longer in a thermally defined layer, due to strong vertical mixing by high wave action. Instead, they likely spent time within the cooler water temperatures at the surface of bays to minimize metabolic energy cost during migration.

  8. Stress of formalin treatment in juvenile spring chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Salmo gairdneri)

    USGS Publications Warehouse

    Wedemeyer, Gary; Yasutake, W.T.

    1973-01-01

    The physiological stress of 200 ppm formalin treatments at 10 C is more severe in the juvenile steelhead trout (Salmo gairdneri) than in the spring chinook salmon (Oncorhynchus tshawytscha). In the steelhead, a marked hypochloremia follows a 1-hr treatment and recovery requires about 24 hr. During longer treatments, hypercholesterolemia together with reduced regulatory precision, hypercortisolemia, alkaline reserve depletion, and hypocapnia unaccompanied by a fall in blood pH occur — suggestive of compensated respiratory alkalosis. In the spring chinook, hypochloremia and reduced plasma cholesterol regulatory precision are the significant treatment side effects but recovery requires only a few hours.Formalin treatments also cause epithelial separation, hypertrophy, and necrosis in the gills of both fishes but again, consistent with the physiological dysfunctions, these are more severe in the steelhead.

  9. Dietary effects of Spirulina platensis on hematological and serum biochemical parameters of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Yeganeh, Sakineh; Teimouri, Mahdi; Amirkolaie, Abdolsamad Keramat

    2015-08-01

    This study evaluated the effects of diets containing 0, 2.5, 5, 7.5 and 10% of Spirulina platensis on hematological and serum biochemical parameters of rainbow trout (Oncorhynchus mykiss). Fish (n=180; 101±8 g) were randomly divided into fifteen 300 L fiberglass tanks in triplicates for a period of ten weeks. The RBC, WBC, hemoglobin, total protein and albumin levels increased significantly in the groups supplemented with S. platensis. Dietary inclusion of S. platensis had no significant effects on hematocrit, cholesterol, triglyceride and lactate of the blood. HDL-cholesterol was larger in rainbow trout fed 10% S. platensis in comparison with the other diets, whereas LDL-cholesterol significantly decreased with increasing of S. platensis inclusion. Cortisol and glucose significantly decreased with increasing of S. platensis inclusion. The present results demonstrate that inclusion of 10% S. platensis can be introduced as an immunostimulant in rainbow trout diets.

  10. Recent physical connections may explain weak genetic structure in western Alaskan chum salmon (Oncorhynchus keta) populations

    PubMed Central

    Garvin, Michael R; Kondzela, Christine M; Martin, Patrick C; Finney, Bruce; Guyon, Jeffrey; Templin, William D; DeCovich, Nick; Gilk-Baumer, Sara; Gharrett, Anthony J

    2013-01-01

    Low genetic divergence at neutral loci among populations is often the result of high levels of contemporary gene flow. Western Alaskan summer-run chum salmon (Oncorhynchus keta) populations demonstrate weak genetic structure, but invoking contemporary gene flow as the basis for the low divergence is problematic because salmon home to their natal streams and some of the populations are thousands of kilometers apart. We used genotypes from microsatellite and single nucleotide polymorphism loci to investigate alternative explanations for the current genetic structure of chum salmon populations from western Alaska. We also estimated current levels of gene flow among Kuskokwim River populations. Our results suggest that weak genetic structure is best explained by physical connections that occurred after the Holocene Thermal Maximum among the Yukon, Kuskokwim, and Nushagak drainages that allowed gene flow to occur among now distant populations. PMID:23919176

  11. Dietary effects of Spirulina platensis on hematological and serum biochemical parameters of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Yeganeh, Sakineh; Teimouri, Mahdi; Amirkolaie, Abdolsamad Keramat

    2015-08-01

    This study evaluated the effects of diets containing 0, 2.5, 5, 7.5 and 10% of Spirulina platensis on hematological and serum biochemical parameters of rainbow trout (Oncorhynchus mykiss). Fish (n=180; 101±8 g) were randomly divided into fifteen 300 L fiberglass tanks in triplicates for a period of ten weeks. The RBC, WBC, hemoglobin, total protein and albumin levels increased significantly in the groups supplemented with S. platensis. Dietary inclusion of S. platensis had no significant effects on hematocrit, cholesterol, triglyceride and lactate of the blood. HDL-cholesterol was larger in rainbow trout fed 10% S. platensis in comparison with the other diets, whereas LDL-cholesterol significantly decreased with increasing of S. platensis inclusion. Cortisol and glucose significantly decreased with increasing of S. platensis inclusion. The present results demonstrate that inclusion of 10% S. platensis can be introduced as an immunostimulant in rainbow trout diets. PMID:26267095

  12. Geographic distribution of chromosome and microsatellite DNA polymorphisms in Oncorhynchus mykiss native to western Washington

    USGS Publications Warehouse

    Ostberg, C.O.; Thorgaard, G.H.

    1999-01-01

    Chromosome studies of native populations of Oncorhynchus mykiss (steelhead and rainbow trout) in western Washington and southern British Columbia revealed the presence of two evolutionarily distinct chromosome lineages. Populations between, and including, the Elwha River, Washington, and Chilliwack River, British Columbia, contained 2n = 60 chromosomes. Populations on the central Washington coast contained 2n = 58 chromosomes. The north Washington coast and western Strait of Juan de Fuca contained individuals with 58, 59, or 60 chromosomes, suggesting this is a transition zone between 58 and 60 chromosome groups. The differences in chromosomal structure between 2n = 58 and 2n = 60 groups are presumably a Robertsonian rearrangement and an inversion. Allelic variation at three microsatellite loci (One ??6, One ??11 and Omy 77) also was examined, and no significant variation was detected among the 58 and 60 chromosome races. A hypothesis is presented concerning the origin of the 60 chromosome lineage.

  13. Experimental hexamitiasis in juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdner)

    USGS Publications Warehouse

    1965-01-01

    An exogenous strain of cultured Hexamita salmonis (Moore) was employed to induce trophic hexamitiasis in otherwise disease-free juveniles of coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri). Mortality and growth were the parameters used to detect the effects of hexamitiasis on the two species. Two levels of each of the three experimental factors under study, Hexamita infection, species of fish, and density of fish, were arranged in a three-way factorial design. Replicate lots involved a total of 1,440 fish held under controlled laboratory conditions.Comparisons of growth and mortality indicate that infection with H. salmonis over a period of 8 weeks is innocuous to coho salmon. Steelhead trout suffered a low, but statistically significant mortality which subsided after the sixth week; growth rate was not affected.

  14. [CATALITICAL PROPERTIES OF LIVER MONOAMINE OXIDASE IN THE CHUM SALMON ONCORHYNCHUS KETA].

    PubMed

    Basova, I N; Basova, N E; Yagodina, O V

    2015-01-01

    The substrate and inhibitory specificity of mitochondrial monoamine oxidase (MAO) in the liver of males of the summer form of the chum salmon Oncorhynchus keta was studied. As to the spectrum of deaminated substrates, the hepatic MAO of the chum salmon is similar to MAO of most terrestrial mammals, for eight classical MAO substrates similarity in their substrate characteristics were found. Analysis of the antimonoamine oxidase activity of two derivaties of 2-propinilamine, five derivatives of acridine as well as of pyronine G revealed significant qualitative and quantitative differences as compared to the hepatic enzyme of tuna and whitefish. The compounds tested manifested themselves as irreversible inhibitors of chum salmon's hepatic MAO possessing various efficacy, but lacking the selectivity of action as dependent on the deaminated substrate. The obtained data on the substrate and inhibitory analysis provide an indirect evidence for the presence of a single molecular form of MAO in the chum salmon liver.

  15. SalmonDB: a bioinformatics resource for Salmo salar and Oncorhynchus mykiss

    PubMed Central

    Di Génova, Alex; Aravena, Andrés; Zapata, Luis; González, Mauricio; Maass, Alejandro; Iturra, Patricia

    2011-01-01

    SalmonDB is a new multiorganism database containing EST sequences from Salmo salar, Oncorhynchus mykiss and the whole genome sequence of Danio rerio, Gasterosteus aculeatus, Tetraodon nigroviridis, Oryzias latipes and Takifugu rubripes, built with core components from GMOD project, GOPArc system and the BioMart project. The information provided by this resource includes Gene Ontology terms, metabolic pathways, SNP prediction, CDS prediction, orthologs prediction, several precalculated BLAST searches and domains. It also provides a BLAST server for matching user-provided sequences to any of the databases and an advanced query tool (BioMart) that allows easy browsing of EST databases with user-defined criteria. These tools make SalmonDB database a valuable resource for researchers searching for transcripts and genomic information regarding S. salar and other salmonid species. The database is expected to grow in the near feature, particularly with the S. salar genome sequencing project. Database URL: http://genomicasalmones.dim.uchile.cl/ PMID:22120661

  16. The stress of Formalin treatments in rainbow trout (Salmo gairdneri) and coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Wedemeyer, Gary

    1971-01-01

    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.

  17. Oral pharmacological treatments for parasitic diseases of rainbow trout Oncorhynchus mykiss. II. Gyrodactylus sp.

    PubMed

    Tojo, J L; Santamarina, M T

    1998-07-30

    A total of 24 drugs were evaluated as regards their efficacy for oral treatment of gyrodactylosis in rainbow trout Oncorhynchus mykiss. In preliminary trials, all drugs were supplied to infected fish at 40 g per kg of feed for 10 d. Twenty-two of the drugs tested (aminosidine, amprolium, benznidazole, bithionol, chloroquine, diethylcarbamazine, flubendazole, levamisole, mebendazole, metronidazole, niclosamide, nitroxynil, oxibendazole, parbendazole, piperazine, praziquantel, ronidazole, secnidazole, tetramisole, thiophanate, toltrazuril and trichlorfon) were ineffective. Triclabendazole and nitroscanate completely eliminated the infection. Triclabendazole was effective only at the screening dosage (40 g per kg of feed for 10 d), while nitroscanate was effective at dosages as low as 0.6 g per kg of feed for 1 d. PMID:9745715

  18. Whole body and tissue blood volumes of two strains of rainbow trout (Oncorhynchus mykiss )

    USGS Publications Warehouse

    Gingerich, W.H.; Pityer, R.A.; Rach, J.J.

    1990-01-01

    1. Estimates of apparent packed cell, plasma and total blood volumes for the whole body and for 13 selected tissues were compared between Kamloops and Wytheville strains of rainbow trout (Oncorhynchus mykiss) by the simultaneous injection of two vascular tracers, radiolabeled trout erythrocytes (51Cr-RBC) and radioiodated bovine serum albumin (125I-BSA). 2. Whole body total blood volume, plasma volume and packed cell volume were slightly, but not significantly greater in the Wytheville trout, whereas, the apparent plasma volumes and total blood volumes in 4 of 13 tissues were significantly greater in the Kamloops strain. 3. Differences were most pronounced in highly perfused organs, such as the liver and kidney and in organs of digestion such as the stomach and intestines. 4. Differences in blood volumes between the two strains may be related to the greater permeability of the vascular membranes in the Kamloops strain fish.

  19. Nutritional factors in the biochemical pathology of Corynebacterial kidney disease in the coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Wedemeyer, Gary A.; Ross, A.J.

    1973-01-01

    The influence of diet ingredient on the morbidity and biochemical pathogenesis of corynebacterial kidney disease was investigated using juvenile coho salmon (Oncorhynchus kisutch) fed the Abernathy dry ration made up with either corn gluten or cottonseed meal (isoprotein, isocaloric substitution). Evaluation of incidence of infection, pituitary activation and aspects of carbohydrate metabolism, acid-base balance, renal function, and hematopoietic activity showed that the actual disease incidence was about the same for both diets but the nonspecific stress of infection was more severe in fish fed the corn gluten.Discriminant function calculations combining four physiological parameters gave a probability of 0.86 for successfully diagnosing infected fish on the basis of these blood chemistry tests.

  20. Effect of copper sulphate on the antioxidant parameters in the rainbow trout fry, Oncorhynchus mykiss.

    PubMed

    Yonar, M E; Ispir, U; Mişe Yonar, S; Kirici, M

    2016-01-01

    The aim of this study was to evaluate antioxidant responses of rainbow trout (Oncorhynchus mykiss) exposed to different concentrations of copper sulphate (CuSO4). Fish were exposed to 0 (Group I-control), 5 (Group II), 15 (Group III) and 30 µg/L (Group IV) concentrations of CuSO4 for 14 days. Liver and gills samples were collected at the end of the experiment, and analysed for their oxidant-antioxidant status, including the malondialdehyde (MDA) level, the catalase (CAT) and glutathione peroxidase (GSH-Px) activities as well as the reduced glutathione (GSH) concentration. Results obtained showed that the levels of MDA increased in tissues of fish. Compared to control, GSH level and GSH-Px and CAT activities were significantly reduced in the fish that were exposed to different concentrations of CuSO4. The result demonstrated that CuSO4 has an oxidative-stress-inducing potential in fish. PMID:27262803

  1. Some physiological aspects of sublethal heat stress in the juvenile steelhead trout (Salmo gairdneri) and coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Wedemeyer, Gary

    1973-01-01

    A rapid (3 min) but sublethal temperature increase from 10 to 20 imposed a greater stress on juvenile coho salmon (Oncorhynchus kisutch) than on juvenile steelhead trout (Salmo gairdneri). Both species suffered hyperglycemia, hypocholesterolemia, increased blood hemoglobin, and decreased blood sugar regulatory precision, but the steelhead recovered more quickly. Acid–base equilibrium was essentially unaffected, and only the coho suffered any significant interrenal vitamin C depletion. Vitamin C normalization required about 24 hr.

  2. Enzymatic Digestion of Eye and Brain Tissues of Sockeye and Coho Salmon, and Dusky Rockfish Commercially Harvested in Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potential feed ingredients with high lipid content were made by enzymatic digestion followed by centrifugation of eye tissue from dusky rockfish (Sebastes ciliatos), coho salmon (Oncorhynchus kisutch), and sockeye salmon (Oncorhynchus nerka) and brain tissue from sockeye salmon. Materials with high ...

  3. Evaluation of angler effort and harvest of rainbow trout (Oncorhynchus mykiss), Lake Scanewa, Washington, 2010

    USGS Publications Warehouse

    Liedtke, Theresa L.; Kock, Tobias J.; Ekstrom, Brian K.; Tomka, Ryan G.; Rondorf, Dennis W.

    2011-01-01

    A creel evaluation was conducted in Lake Scanewa, a reservoir on the Cowlitz River, to monitor catch rates of rainbow trout (Oncorhynchus mykiss) and determine if the trout fishery was having negative impacts on juvenile anadromous salmon (Oncorhynchus spp.) in the system. The trout fishery, which is supported by releases of 20,000 fish (2 fish per pound) per year from June to August, was developed to mitigate for the construction of the Cowlitz Falls Dam in 1994. The trout fishery has a target catch rate of at least 0.50 fish per hour. Interviews with 1,214 anglers during the creel evaluation found that most anglers targeted rainbow trout (52 percent) or Chinook and coho salmon (48 percent). The interviewed anglers caught a total of 1,866 fish, most of which were rainbow trout (1,213 fish; 78 percent) or coho salmon (311 fish; 20 percent). We estimated that anglers spent 17,365 hours fishing in Lake Scanewa from June to November 2010. Catch rates for boat anglers (1.39 fish per hour) exceeded the 0.50 fish per hour target, whereas catch rates for shore anglers (0.35 fish per hour) fell short of the goal. The combined catch rates for all trout anglers in the reservoir were 0.96 fish per hour. We estimated that anglers harvested 7,584 (95 percent confidence interval = 2,795-12,372 fish) rainbow trout during the study period and boat anglers caught more fish than shore anglers (5,975 and 1,609 fish, respectively). This estimate suggests that more than 12,000 of the 20,000 rainbow trout released into Lake Scanewa during 2010 were not harvested, and could negatively impact juvenile salmon in the reservoir through predation or competition. We examined 1,236 stomach samples from rainbow trout and found that 2.1 percent (26 fish) of these samples contained juvenile fish. Large trout (greater than 300 millimeters) had a higher incidence of predation than small trout (less than 300 millimeters; 8.50 and 0.06 percent, respectively). A total of 39 fish were found in rainbow

  4. Effect of dietary aloe vera on growth and lipid peroxidation indices in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Golestan, Ghazale; Salati, Amir Parviz; Keyvanshokooh, Saeed; Zakeri, Mohammad; Moradian, Hossein

    2015-01-01

    Aloe vera has been used worldwide in pharmaceutical, food and cosmetic industries due to the plethora of biological activities of its constituents. This study was done to evaluate the effects of dietary aloe vera on growth and lipid peroxidation in rainbow trout (Oncorhynchus mykiss). A total number of 480 O. mykiss (mean weight 9.50 ± 0.85 g) were randomized into four experimental groups including one control and three experimental groups that aloe vera was incorporated in their diet at 0.5, 1.0 and 2.0 g kg(-1). Trial was done for eight weeks. Then biometry and blood sampling were done. Plasma malondialdehyde, ferric reducing ability of plasma and growth index were estimated at the end of study. The results showed that aloe vera extract did not affect growth indices. Malondialdehyde was increased in the experimental group compared to the control group but ferric reducing ability of plasma showed a decrease in experimental groups (p < 0.05) compared to the control group. Our findings showed that dietary aloe vera have adverse effects on antioxidant defense system in O. mykiss.

  5. Puffy skin disease (PSD) in rainbow trout, Oncorhynchus mykiss (Walbaum): a case definition.

    PubMed

    Maddocks, C E; Nolan, E T; Feist, S W; Crumlish, M; Richards, R H; Williams, C F

    2015-07-01

    Puffy skin disease (PSD) is a disease that causes skin pathology in rainbow trout, Oncorhynchus mykiss (Walbaum). Incidence of PSD in UK fish farms and fisheries has increased sharply in the last decade, with growing concern from both industry sectors. This paper provides the first comprehensive case definition of PSD, combining clinical and pathological observations of diseased rainbow trout from both fish farms and fisheries. The defining features of PSD, as summarized in the case definition, were focal lateral flank skin lesions that appeared as cutaneous swelling with pigment loss and petechiae. These were associated with lethargy, poor body condition, inappetance and low level mortality. Epidermal hyperplasia and spongiosis, oedema of the dermis stratum spongiosum and a mild diffuse inflammatory cellularity were typical in histopathology of skin. A specific pathogen or aetiology was not identified. Prevalence and severity of skin lesions was greatest during late summer and autumn, with the highest prevalence being 95%. Atypical lesions seen in winter and spring were suggestive of clinical resolution. PSD holds important implications for both trout aquaculture and still water trout fisheries. This case definition will aid future diagnosis, help avoid confusion with other skin conditions and promote prompt and consistent reporting.

  6. Characterizing creosote immunotoxicity in rainbow trout, Oncorhynchus mykiss: A mesocosm study

    SciTech Connect

    Karrow, N.A.; Dixon, D.G.; Bols, N.C.; Whyte, J.J.; Magdic, S.; Boermans, H.J.; Solomon, K.R.

    1995-12-31

    Immunocompetence was assessed in rainbow trout Oncorhynchus mykiss exposed on days 103 to 131 of a mesocosm study using initial liquid creosote concentrations of 0, 5, 9, 17, 31 and 56 ul/l. Oxidative burst, phagocytic activity, and lymphocyte blastogenic response were measured, as indicators of exposure, using pronephros leukocytes. Peripheral blood was used to measure surface immunoglobulin-positive (slg{sup +}) leukocyte count and lysozyme activity. Tissue residue and water concentration were used as dose surrogates. Pronephros leukocyte phagocytic activity and oxidative burst exhibited a significant dose-response relationship, as measured by flow cytometry. Oxidative burst was inhibited, while phagocytic activity was enhanced. A concentration dependent reduction in the number of slg + peripheral blood leukocytes was also observed using flow cytometry. Although no measurable change in lymphocyte proliferation was detected in response to phytohaemagglutinin (PHA) and concanavalin-A (ConA), lipopolysaccharide (LPS) induced blastogenesis was significantly inhibited. No change in lysozyme activity was observed at 28 d. The results from this study indicate that sediment bound creosote has the potential to alter immune response. Polycyclic aromatic hydrocarbons (PAHs), a major constituent of liquid creosote, are the suspected immunoalterating agents. PAHs are known to predispose fish to disease resulting from their immunosuppressive potentiality.

  7. Over the falls? Rapid evolution of ecotypic differentiation in steelhead/rainbow trout (Oncorhynchus mykiss).

    PubMed

    Pearse, Devon E; Hayes, Sean A; Bond, Morgan H; Hanson, Chad V; Anderson, Eric C; Macfarlane, R Bruce; Garza, John Carlos

    2009-01-01

    Adaptation to novel habitats and phenotypic plasticity can be counteracting forces in evolution, but both are key characteristics of the life history of steelhead/rainbow trout (Oncorhynchus mykiss). Anadromous steelhead reproduce in freshwater river systems and small coastal streams but grow and mature in the ocean. Resident rainbow trout, either sympatric with steelhead or isolated above barrier dams or waterfalls, represent an alternative life-history form that lives entirely in freshwater. We analyzed population genetic data from 1486 anadromous and resident O. mykiss from a small stream in coastal California with multiple barrier waterfalls. Based on data from 18 highly variable microsatellite loci (He = 0.68), we conclude that the resident population above one barrier, Big Creek Falls, is the result of a recent anthropogenic introduction from the anadromous population of O. mykiss below the falls. Furthermore, fish from this above-barrier population occasionally descend over the falls and have established a genetically differentiated below-barrier subpopulation at the base of the falls, which appears to remain reproductively isolated from their now-sympatric anadromous ancestors. These results support a hypothesis of rapid evolution of a purely resident life history in the above-barrier population in response to strong selection against downstream movement. PMID:19561050

  8. Coho Salmon (Oncorhynchus kisutch) Prefer and Are Less Aggressive in Darker Environments.

    PubMed

    Gaffney, Leigh P; Franks, Becca; Weary, Daniel M; von Keyserlingk, Marina A G

    2016-01-01

    Fish are capable of excellent vision and can be profoundly influenced by the visual properties of their environment. Ambient colours have been found to affect growth, survival, aggression and reproduction, but the effect of background darkness (i.e., the darkness vs. lightness of the background) on preference and aggression has not been evaluated systematically. One-hundred Coho salmon (Oncorhynchus kisutch), a species that is increasing in popularity in aquaculture, were randomly assigned to 10 tanks. Using a Latin-square design, every tank was bisected to allow fish in each tank to choose between all the following colour choices (8 choices in total): black vs. white, light grey, dark grey, and a mixed dark grey/black pattern, as well as industry-standard blue vs. white, light grey, dark grey, and black. Fish showed a strong preference for black backgrounds over all other options (p < 0.01). Across tests, preference strength increased with background darkness (p < 0.0001). Moreover, having darker backgrounds in the environment resulted in less aggressive behaviour throughout the tank (p < 0.0001). These results provide the first evidence that darker tanks are preferred by and decrease aggression in salmonids, which points to the welfare benefits of housing farmed salmon in enclosures containing dark backgrounds. PMID:27028731

  9. Effect of catch-and-release angling on growth and survival of rainbow trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    Pope, K.L.; Wilde, G.R.; Knabe, D.W.

    2007-01-01

    Catch-and-release angling is popular in many parts of the world and plays an increasingly important role in fish conservation efforts. Although survival rates associated with catch-and-release angling are well documented for many species, sublethal effects have been less studied. An experiment was conducted to directly assess the effects of catch-and-release angling on growth and survival of rainbow trout, Oncorhynchus mykiss (Walbaum). Catch-and-release events were simulated in laboratory tanks maintained at 15-16 ??C with hooks manually placed in pre-designated locations in the mouths of the fish. There were no differences in standard length (P = 0.59) or wet weight (P = 0.81) gained between caught and uncaught fish over a 1-month angling and recovery period. Survival was 96.99 ?? 0.06% for rainbow trout caught and released, and did not vary with number (one, two or four) of captures. Thus, catch-and-release angling appears to have little effect on growth and mortality of rainbow trout hooked in the mouth. ?? 2007 The Authors. Journal compilation 2007 Blackwell Publishing Ltd.

  10. Effects of atrazine on hepatic metabolism and endocrine homeostasis in rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Salaberria, Iurgi Hansen, Bjorn Henrik; Asensio, Vega; Olsvik, Pal A.; Andersen, Rolf A.; Jenssen, Bjorn Munro

    2009-01-01

    The herbicide atrazine (ATZ) is one of the most widely used pesticides in the world and is now under scrutiny for its alleged capacity to disrupt the endocrine system. Exhibiting negligible interaction with the estrogen receptor (ER), ATZ's mode of action remains to be elucidated. ATZ may act as an inducer of the enzyme aromatase, which converts androgens to estrogens, although other mechanisms should also be taken into consideration such as impairment of hepatic metabolism. Therefore we administered juvenile rainbow trout (Oncorhynchus mykiss) a dose of either 2 or 200 {mu}g ATZ/kg, or of carrier control phosphate buffered saline (PBS) and we measured plasma concentrations of testosterone (T), 17beta-estradiol (E2) and vitellogenin (Vtg) 6 days after exposure. Simultaneously we analyzed hepatic gene expression of cytochrome P450 (CYP) 1A and pi-class glutathione S-transferase (GST-P), and catalase (CAT) activity. Although sex steroid levels showed no significant alterations, we found a dose-dependent increase in Vtg and a concomitant decrease in CYP1A. There was no effect of ATZ on GST-P mRNA levels but GST-P was positively correlated with CYP1A. Also, CYP1A was negatively correlated with liver CAT and E2, and varied with T concentrations in a hormetic manner. The results showed that ATZ can alter hepatic metabolism, induce estrogenic effects and oxidative stress in vivo, and that these effects are linked.

  11. Acute effects of chlorinated resin acid exposure on juvenile rainbow trout, Oncorhynchus mykiss

    SciTech Connect

    Kennedy, C.J.; Sweeting, R.M.; Farrell, A.P.; McKeown, B.A.; Johansen, J.A.

    1995-06-01

    The effects of an acute exposure to either 14-monochlorodehydroabietic acid (MCDHAA) or 12,14-dichlorodehydroabietic acid (DCDHAA) were examined in juvenile rainbow trout, Oncorhynchus mykiss. The experimentally determined 96-h LC50 values (and their 95% confidence limits) were 1.03 (0.72, 1.48) and 0.91 (0.70, 1.21) mg/L, for MCDHAA and DCDHAA, respectively. To measure effects on several biochemical parameters, swimming performance, and disease resistance, juvenile trout were exposed for 24 h to sublethal concentrations of one or the other resin acid in an intermittent-flow respirometer. Hematocrit, plasma lactate, and liver protein were significantly affected by exposure to the highest dose (80% of the 96-h LC50 value) of either of the resin acids. Plasma cortisol levels were 14- and 3-fold higher than were controls. Resistance to infection by Aeromonas salmonicida was significantly reduced; the cumulative percent mortalities due to furunculosis in fish exposed to MCDHAA or DCDHAA reached 20 and 26%, respectively. Swimming performance, measured as critical swimming speed (mean values 6.32 {+-} 0.20 and 5.93 {+-} 0.15 body lengths per second for MCDHAA and DCDHAA, respectively), was not significantly affected by resin acid exposure.

  12. Altered burst swimming in rainbow trout Oncorhynchus mykiss exposed to natural and synthetic oestrogens.

    PubMed

    Osachoff, H L; Osachoff, K N; Wickramaratne, A E; Gunawardane, E K; Venturini, F P; Kennedy, C J

    2014-08-01

    Juvenile rainbow trout Oncorhynchus mykiss were exposed to two concentrations each of 17β-oestradiol (E2; natural oestrogen hormone) or 17α-ethinyl oestradiol (EE2; a potent synthetic oestrogen hormone) to evaluate their potential effects on burst-swimming performance. In each of six successive burst-swimming assays, burst-swimming speed (Uburst ) was lower in fish exposed to 0.5 and 1 µg l(-1) E2 and EE2 for four days compared with control fish. A practice swim (2 days prior to exposure initiation) in control fish elevated initial Uburst values, but this training effect was not evident in the 1 µg l(-1) EE2-exposed fish. Several potential oestrogen-mediated mechanisms for Uburst reductions were investigated, including effects on metabolic products, osmoregulation and blood oxygen-carrying capacity. Prior to burst-swimming trials, fish exposed to E2 and EE2 for 4 days had significantly reduced erythrocyte numbers and lower plasma glucose concentrations. After six repeated burst-swimming trials, plasma glucose, lactate and creatinine concentrations were not significantly different among treatment groups; however, plasma Cl(-) concentrations were significantly reduced in E2- and EE2-treated fish. In summary, E2 and EE2 exposure altered oxygen-carrying capacity ([erythrocytes]) and an osmoregulatory-related variable ([Cl(-) ]), effects that may underlie reductions in burst-swimming speed, which will have implications for fish performance in the wild. PMID:24930959

  13. Chronic stress of rainbow trout Oncorhynchus mykiss at high altitude: a field study.

    PubMed

    Hunt von Herbing, I; Pan, T-C F; Méndez-Sánchez, F; Garduño-Paz, M; Hernández-Gallegos, O; Ruiz-Gómez, M L; Rodríguez-Vargas, G

    2015-07-01

    The stress response of Oncorhynchus mykiss in high-altitude farms in central Mexico was investigated over two seasons: the cool (9·1-13·7° C) dry winter season, and the warmer (14·7-15·9° C), wetter summer season. Fish were subjected to an acute stress test followed by sampling of six physiological variables: blood cortisol, glucose, lactate, total antioxidant capacity, haemoglobin concentration and per cent packed cell volume (VPC %). Multivariate analyses revealed that lactate and total antioxidant capacity were significantly higher in the summer, when water temperatures were warmer and moderate hypoxia (4·9-5·3 mg l(-1) ) prevailed. In contrast, plasma cortisol was significantly higher in the winter (mean ± s.e.: 76·7 ± 4·0 ng ml(-1) ) when temperatures were cooler and dissolved oxygen levels higher (6·05-7·9 mg l(-1) ), than in the summer (22·7 ± 3·8 ng ml(-1) ). Haemoglobin concentrations (mg dl(-1) ) were not significantly different between seasons, but VPC % was significantly higher in the summer (50%) than in the winter (35%). These results suggest that in summer, effects of high altitude on farmed fish are exacerbated by stresses of high temperatures and hypoxia, resulting in higher blood lactate, increased total antioxidant capacity and elevated VPC % levels. PMID:26148653

  14. An experimental vaccine against Aeromonas hydrophila can induce protection in rainbow trout, Oncorhynchus mykiss (Walbaum)

    USGS Publications Warehouse

    LaPatra, S.E.; Plant, K.P.; Alcorn, S.; Ostland, V.; Winton, J.

    2010-01-01

    A candidate vaccine against Aeromonas hydrophila in rainbow trout, Oncorhynchus mykiss, was developed using a bacterial lysate. To test the strength of protection, A. hydrophila challenge models were compared using injection into both the intraperitoneal (IP) cavity and the dorsal sinus (DS) with selected doses of live bacteria washed in saline or left untreated. Unlike the IP route, injection into the DS with either saline washed or unwashed cells resulted in consistent cumulative mortality and a dose response that could be used to establish a standard challenge having an LD50 of approximately 3 × 107 colony forming units per fish. Survivors of the challenge suffered significantly lower mortality upon re-challenge than naïve fish, suggesting a high level of acquired resistance was elicited by infection. Passive immunization using serum from hyper-immunized fish also resulted in significantly reduced mortality indicating protection can be transferred and that some portion of resistance may be antibody mediated. Vaccination of groups of rainbow trout with A. hydrophila lysate resulted in significant protection against a high challenge dose but only when injected along with Freund’s complete adjuvant. At a low challenge dose, mortality in all groups was low, but the bacterial lysate alone appeared to offer some protection.

  15. Fluvial rainbow trout contribute to the colonization of steelhead (Oncorhynchus mykiss) in a small stream

    USGS Publications Warehouse

    Weigel, Dana E.; Connolly, Patrick J.; Powell, Madison S.

    2013-01-01

    Life history polymorphisms provide ecological and genetic diversity important to the long term persistence of species responding to stochastic environments. Oncorhynchus mykiss have complex and overlapping life history strategies that are also sympatric with hatchery populations. Passive integrated transponder (PIT) tags and parentage analysis were used to identify the life history, origin (hatchery or wild) and reproductive success of migratory rainbow/steelhead for two brood years after barriers were removed from a small stream. The fluvial rainbow trout provided a source of wild genotypes to the colonizing population boosting the number of successful spawners. Significantly more parr offspring were produced by anadromous parents than expected in brood year 2005, whereas significantly more parr offspring were produced by fluvial parents than expected in brood year 2006. Although hatchery steelhead were prevalent in the Methow Basin, they produced only 2 parr and no returning adults in Beaver Creek. On average, individual wild steelhead produced more parr offspring than the fluvial or hatchery groups. Yet, the offspring that returned as adult steelhead were from parents that produced few parr offspring, indicating that high production of parr offspring may not be related to greater returns of adult offspring. These data in combination with other studies of sympatric life histories of O. mykiss indicate that fluvial rainbow trout are important to the conservation and recovery of steelhead and should be included in the management and recovery efforts.

  16. Genotyping by sequencing resolves shallow population structure to inform conservation of Chinook salmon (Oncorhynchus tshawytscha)

    PubMed Central

    Larson, Wesley A; Seeb, Lisa W; Everett, Meredith V; Waples, Ryan K; Templin, William D; Seeb, James E

    2014-01-01

    Recent advances in population genomics have made it possible to detect previously unidentified structure, obtain more accurate estimates of demographic parameters, and explore adaptive divergence, potentially revolutionizing the way genetic data are used to manage wild populations. Here, we identified 10 944 single-nucleotide polymorphisms using restriction-site-associated DNA (RAD) sequencing to explore population structure, demography, and adaptive divergence in five populations of Chinook salmon (Oncorhynchus tshawytscha) from western Alaska. Patterns of population structure were similar to those of past studies, but our ability to assign individuals back to their region of origin was greatly improved (>90% accuracy for all populations). We also calculated effective size with and without removing physically linked loci identified from a linkage map, a novel method for nonmodel organisms. Estimates of effective size were generally above 1000 and were biased downward when physically linked loci were not removed. Outlier tests based on genetic differentiation identified 733 loci and three genomic regions under putative selection. These markers and genomic regions are excellent candidates for future research and can be used to create high-resolution panels for genetic monitoring and population assignment. This work demonstrates the utility of genomic data to inform conservation in highly exploited species with shallow population structure. PMID:24665338

  17. Nutrient content in the muscle and skin of fillets from farmed rainbow trout (Oncorhynchus mykiss).

    PubMed

    Rebolé, A; Velasco, S; Rodríguez, M L; Treviño, J; Alzueta, C; Tejedor, J L; Ortiz, L T

    2015-05-01

    The nutrient content in the muscle and edible skin parts of rainbow trout (Oncorhynchus mykiss) fillets, sampled at two growth stages, was evaluated. The average concentrations of protein and essential amino acids were higher in the muscle than in the skin. The chemical scores reached a value of 1.0 for the amino acids in the muscle and ranged from 0.40 (tryptophan) to 0.94 (threonine) in the skin. The average lipid content and the saturated fatty acids/polyunsaturated fatty acids and n-6/n-3 ratios were higher in the skin than in the muscle, whereas the proportion of docosahexaenoic acid (C22:6 n-3) was higher in the muscle. Significant differences were found for the essential minerals analysed, except for Cu. The concentrations of Na, K and Mg were higher and those of Ca, P, Fe, Mn and Zn were lower in the muscle than in the skin. Significant effects of the fish growth on the composition were detected.

  18. Variability in expression of anadromy by female Oncorhynchus mykiss within a river network

    USGS Publications Warehouse

    Mills, Justin S.; Dunham, Jason B.; Reeves, Gordon H.; McMillan, John R.; Zimmerman, Christian E.; Jordan, Chris E.

    2012-01-01

    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.

  19. Individual condition and stream temperature influence early maturation of rainbow and steelhead trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    McMillan, John R.; Dunham, J.B.; Reeves, G.H.; Mills, J.S.; Jordan, C.E.

    2012-01-01

    Alternative male phenotypes in salmonine fishes arise from individuals that mature as larger and older anadromous marine-migrants or as smaller and younger freshwater residents. To better understand the processes influencing the expression of these phenotypes we examined the influences of growth in length (fork length) and whole body lipid content in rainbow trout (Oncorhynchus mykiss). Fish were sampled from the John Day River basin in northeast Oregon where both anadromous ("steelhead") and freshwater resident rainbow trout coexist. Larger males with higher lipid levels had a greater probability of maturing as a resident at age-1+. Among males, 38% were maturing overall, and the odds ratios of the logistic model indicated that the probability of a male maturing early as a resident at age-1+ increased 49% (95% confidence interval (CI) = 23-81%) for every 5 mm increase in length and 33% (95% CI = 10-61%) for every 0.5% increase in whole body lipid content. There was an inverse association between individual condition and water temperature as growth was greater in warmer streams while whole body lipid content was higher in cooler streams. Our results support predictions from life history theory and further suggest that relationships between individual condition, maturation, and environmental variables (e.g., water temperature) are shaped by complex developmental and evolutionary influences.

  20. Individual condition and stream temperature influence early maturation of rainbow and steelhead trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    McMillan, J.R.; Dunham, J.B.; Reeves, G.H.; Mills, J.S.; Jordan, C.E.

    2012-01-01

    Alternative male phenotypes in salmonine fishes arise from individuals that mature as larger and older anadromous marine-migrants or as smaller and younger freshwater residents. To better understand the processes influencing the expression of these phenotypes we examined the influences of growth in length (fork length) and whole body lipid content in rainbow trout (Oncorhynchus mykiss). Fish were sampled from the John Day River basin in northeast Oregon where both anadromous ("steelhead") and freshwater resident rainbow trout coexist. Larger males with higher lipid levels had a greater probability of maturing as a resident at age-1+. Among males, 38% were maturing overall, and the odds ratios of the logistic model indicated that the probability of a male maturing early as a resident at age-1+ increased 49% (95% confidence interval (CI) = 23-81%) for every 5 mm increase in length and 33% (95% CI = 10-61%) for every 0. 5% increase in whole body lipid content. There was an inverse association between individual condition and water temperature as growth was greater in warmer streams while whole body lipid content was higher in cooler streams. Our results support predictions from life history theory and further suggest that relationships between individual condition, maturation, and environmental variables (e. g., water temperature) are shaped by complex developmental and evolutionary influences. ?? 2011 Springer Science+Business Media B.V.

  1. Costs of living for juvenile Chinook salmon (Oncorhynchus tshawytscha) in an increasingly warming and invaded world

    USGS Publications Warehouse

    Kuehne, Lauren M.; Olden, Julian D.; Duda, Jeffrey J.

    2012-01-01

    Rapid environmental change in freshwater ecosystems has created a need to understand the interactive effects of multiple stressors, with temperature and invasive predators identified as key threats to imperiled fish species. We tested the separate and interactive effects of water temperature and predation by non-native smallmouth bass (Micropterus dolomieu) on the lethal (mortality) and sublethal (behavior, physiology, and growth) effects for juvenile Chinook salmon (Oncorhynchus tshawytscha) in seminatural stream channel experiments. Over 48 h trials, there was no difference in direct predation with warmer temperatures, but significant interactive effects on sublethal responses of juvenile salmon. Warmer temperatures resulted in significantly stronger and more variable antipredator responses (surface shoaling and swimming activity), while physiological indicators (plasma glucose, plasma cortisol) suggested suppression of physiological mechanisms in response to the combined stressors. These patterns corresponded with additive negative growth in predation, temperature, and combined treatments. Our results suggest that chronic increases in temperature may not increase direct predation over short periods, but can result in significant sublethal costs with negative implications for long-term development, disease resistance, and subsequent size-selective mortality of Pacific salmon.

  2. Epizootic ameloblastomas in Chinook salmon (Oncorhynchus tshawytscha) of the northwestern United States.

    PubMed

    Grim, K C; Wolfe, M J; Edwards, M; Kaufman, J; Onjukka, S; Moran, P; Wolf, J C

    2009-07-01

    Abnormal growths were observed on the lips and in the oral cavities of 2- and 3-year-old Chinook salmon (Oncorhynchus tshawytscha) maintained in one freshwater and one saltwater captive fish-rearing facility in the Columbia River (Pacific Northwest). Initially presenting as bilaterally symmetrical, red, irregular plaques on oral mucosal surfaces, the lesions developed progressively into large, disfiguring masses. Of the 502 natural parr collected for captive broodstock, 432 (86%) displayed these tumors, whereas cohort salmon (i.e., same year classes) in these same facilities remained unaffected. Morphologically similar neoplasms were collected occasionally from adult Chinook salmon that had returned to their natal streams. Histologic features of the tumors suggested that they were derived from the portion of dental lamina destined to form tooth root sulci; therefore, these neoplasms were diagnosed as ameloblastomas. The lesions also resembled archived specimens of Chinook salmon oral tumors, which had been described decades earlier. Etiologic investigations performed during the current outbreak included bacteriologic, virologic, genetic, ultrastructural analyses, and cohabitation exposure studies. Results of these efforts did not indicate an obvious genetic basis for this syndrome, attempts to isolate potentially causative viruses or bacteria were negative, and disease transmission to naïve fish was unsuccessful. A few intracytoplasmic hexagonal structures, possibly consistent with viral particles (approximately 100 nm), were observed ultrastructurally in a tumor cell from 1 of 6 specimens submitted for transmission electron microscopy. Although the presence of these particles does not constitute sufficient evidence for causality, an infectious or multifactorial etiology seems plausible.

  3. Body morphology differs in wild juvenile Chinook salmon Oncorhynchus tshawytscha in the Willamette River, Oregon, USA

    USGS Publications Warehouse

    Billman, E.J.; Whitman, L.D.; Schroeder, R.K.; Sharpe, C.S.; Noakes, David L. G.; Schreck, Carl B.

    2014-01-01

    Body morphology of juvenile Chinook salmon Oncorhynchus tshawytscha in the upper Willamette River, Oregon, U.S.A., was analysed to determine if variation in body shape is correlated with migratory life-history tactics followed by juveniles. Body shape was compared between migrating juveniles that expressed different life-history tactics, i.e. autumn migrants and yearling smolts, and among parr sampled at three sites along a longitudinal river gradient. In the upper Willamette River, the expression of life-history tactics is associated with where juveniles rear in the basin with fish rearing in downstream locations generally completing ocean ward migrations earlier in life than fish rearing in upstream locations. The morphological differences that were apparent between autumn migrants and yearling smolts were similar to differences between parr rearing in downstream and upstream reaches, indicating that body morphology is correlated with life-history tactics. Autumn migrants and parr from downstream sampling sites had deeper bodies, shorter heads and deeper caudal peduncles compared with yearling smolts and parr from the upstream sampling site. This study did not distinguish between genetic and environmental effects on morphology; however, the results suggest that downstream movement of juveniles soon after emergence is associated with differentiation in morphology and with the expression of life-history variation.

  4. Characterization and application of a quantitative DNA marker that discriminates sex in chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Clifton, D.R.; Rodriguez, R.J.

    1997-01-01

    A qualitative male-specific DNA marker (OT-24) was amplified by spPCR (single-primer polymerase chain reaction) from chinook salmon (Oncorhynchus tshawytscha) DNA along with several non-sex-linked products. The termini of the male-specific product were sequenced, and a pair of PeR primers were constructed for marker-specific PCR amplification. Dual primer PCR (dpPCR), with the marker-specific primers, amplified a product from both nudes and females. The amount of dpPCR product amplified from males was at least 100-fold greater than that from females. The quantitative difference between males and females was consistent among geographically distinct populations from western U.S. rivers. In addition, DNA sequence analysis indicated that OT-24 was highly conserved among geographically distinct salmon populations. The qualitative spPCR product segregated through several genetic crosses indicating equal sex ratios among progeny. Identification of the male and female juveniles by dpPCR was consistent with the spPCR analysis. There was no tissue specificity observed by spPCR or dpPCR analysis of this marker. A rapid DNA extraction method and dpPCR analysis were used to nonlethally determine sex ratios in wild spring chinook salmon adults, withheld for genetic and behavioral studies, prior to their development of gross sexual differences in their external morphology.

  5. Characterization and application of a quantitative DNA marker that discriminates sex in Chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Clifton, D.R.; Rodriguez, R.J.

    1997-01-01

    A qualitative male-specific DNA marker (OT-24) was amplified by spPCR (single-primer polymerase chain reaction) from chinook salmon (Oncorhynchus tshawytscha) DNA along with several non-sex-linked products. The termini of the male-specific product were sequenced, and a pair of PeR primers were constructed for marker-specific PCR amplification. Dual primer PCR (dpPCR), with the marker-specific primers, amplified a product from both nudes and females. The amount of dpPCR product amplified from males was at least 100-fold greater than that from females. The quantitative difference between males and females was consistent among geographically distinct populations from western U.S. rivers. In addition, DNA sequence analysis indicated that OT-24 was highly conserved among geographically distinct salmon populations. The qualitative spPCR product segregated through several genetic crosses indicating equal sex ratios among progeny. Identification of the male and female juveniles by dpPCR was consistent with the spPCR analysis. There was no tissue specificity observed by spPCR or dpPCR analysis of this marker. A rapid DNA extraction method and dpPCR analysis were used to nonlethally determine sex ratios in wild spring chinook salmon adults, withheld for genetic and behavioral studies, prior to their development of gross sexual differences in their external morphology.

  6. Estimating westslope cutthroat trout (Oncorhynchus clarkii lewisi) movements in a river network using strontium isoscapes

    USGS Publications Warehouse

    Muhlfeld, Clint C.; Simon R. Thorrold,; Thomas E. McMahon,; Marotz, Brian

    2012-01-01

    We used natural variation in the strontium concentration (Sr:Ca) and isotope composition (87Sr:86Sr) of stream waters and corresponding values recorded in otoliths of westslope cutthroat trout (Oncorhynchus clarkii lewisi) to examine movements during their life history in a large river network. We found significant spatial differences in Sr:Ca and 87Sr:86Sr values (strontium isoscapes) within and among numerous spawning and rearing streams that remained relatively constant seasonally. Both Sr:Ca and 87Sr:86Sr values in the otoliths of juveniles collected from nine natal streams were highly correlated with those values in the ambient water. Strontium isoscapes measured along the axis of otolith growth revealed that almost half of the juveniles had moved at least some distance from their natal streams. Finally, otolith Sr profiles from three spawning adults confirmed homing to natal streams and use of nonoverlapping habitats over their migratory lifetimes. Our study demonstrates that otolith geochemistry records movements of cutthroat trout through Sr isoscapes and therefore provides a method that complements and extends the utility of conventional tagging techniques in understanding life history strategies and conservation needs of freshwater fishes in river networks.

  7. Purification and characteristics of trypsin from masu salmon (Oncorhynchus masou) cultured in fresh-water.

    PubMed

    Kanno, Gaku; Yamaguchi, Takahito; Kishimura, Hideki; Yamaha, Etsurou; Saeki, Hiroki

    2010-09-01

    Trypsin from the pyloric ceca of masu salmon (Oncorhynchus masou) cultured in fresh water was purified by a series of chromatographies including Sephacryl S-200, Sephadex G-50 and diethylaminoethyl cellulose to obtain a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and native PAGE. The molecular mass of the purified trypsin was estimated to be approximately 24,000 Da by SDS-PAGE. The enzyme activity was strongly inhibited by phenylmethylsulfonyl fluoride, soybean trypsin inhibitor, and N ( alpha )-p-tosyl-L: -lysine chloromethyl ketone. Masu salmon trypsin was stabilized by calcium ion. The optimum pH of the masu salmon trypsin was around pH 8.5, and the trypsin was unstable below pH 5.0. The optimum temperature of the masu salmon trypsin was around 60 degrees C, and the trypsin was stable below 50 degrees C, like temperate-zone and tropical-zone fish trypsins. The N-terminal 20 amino acid sequence of the masu salmon trypsin was IVGGYECKAYSQPHQVSLNS, and its charged amino acid content was lower than those of trypsins from frigid-zone fish and similar to those of trypsins from temperate-zone and tropical-zone fish. In the phylogenetic tree, the masu salmon trypsin was classified into the group of the temperate-zone fish trypsin.

  8. Innate and adaptive immune responses in migrating spring-run adult chinook salmon, Oncorhynchus tshawytscha.

    PubMed

    Dolan, Brian P; Fisher, Kathleen M; Colvin, Michael E; Benda, Susan E; Peterson, James T; Kent, Michael L; Schreck, Carl B

    2016-01-01

    Adult Chinook salmon (Oncorhynchus tshawytscha) migrate from salt water to freshwater streams to spawn. Immune responses in migrating adult salmon are thought to diminish in the run up to spawning, though the exact mechanisms for diminished immune responses remain unknown. Here we examine both adaptive and innate immune responses as well as pathogen burdens in migrating adult Chinook salmon in the Upper Willamette River basin. Messenger RNA transcripts encoding antibody heavy chain molecules slightly diminish as a function of time, but are still present even after fish have successfully spawned. In contrast, the innate anti-bacterial effector proteins present in fish plasma rapidly decrease as spawning approaches. Fish also were examined for the presence and severity of eight different pathogens in different organs. While pathogen burden tended to increase during the migration, no specific pathogen signature was associated with diminished immune responses. Transcript levels of the immunosuppressive cytokines IL-10 and TGF beta were measured and did not change during the migration. These results suggest that loss of immune functions in adult migrating salmon are not due to pathogen infection or cytokine-mediated immune suppression, but is rather part of the life history of Chinook salmon likely induced by diminished energy reserves or hormonal changes which accompany spawning.

  9. Latitudinal variation in sexual size dimorphism of sea-run masu salmon, Oncorhynchus masou.

    PubMed

    Tamate, Tsuyoshi; Maekawa, Koji

    2006-01-01

    Sexual size dimorphism (SSD), a difference in body size between the sexes, occurs in many animal species. Although the larger sex is often considered invariable within species, patterns of selection may result in interpopulation variation or even reversal of SSD. We evaluated correlations between latitude and female body size, male body size, and relative body size (male body size/female body size) in 22 populations (ranging from 37 degrees N to 49 degrees N) of sea-run masu salmon (Oncorhynchus masou) that spawn in rivers along the Sea of Japan coast. Male size and the relative body size increased with latitude, but female size did not correlate with latitude. In addition, increase in male size with latitude was sufficient to result in a reversal of SSD, the switch-point being around 45 degrees N. We suggest that the positive correlation between latitude and male size is due to increasing operational sex ratios or sexual selection on sea-run male body size that result from sex-biased patterns of anadromy. In conclusion, our study provides the first example of predictable geographic variation in SSD shaped by apparent patterns of sexual selection.

  10. Use of a genetic marker to examine genetic interaction among subpopulations of pink salmon (Oncorhynchus gorbuscha).

    PubMed

    Gharrett, A J; Lane, S; McGregor, A J; Taylor, S G

    2001-01-01

    In 1979 and 1981, a genetic marker was bred into one of the five identifiable subpopulations of pink salmon [Oncorhynchus gorbuscha (Walbaum)] in the Auke Lake drainage in Southeast Alaska. As a result of the marking effort, the frequencies of two malate dehydrogenase (MDH-B1, 2*) alleles were changed in the marked subpopulation, but not in other subpopulations that spawn at different times or places. Between 1983 and 1989, the marker allele frequencies were monitored in many of these subpopulations and in early- and late-run pink salmon spawning in nearby Waydelich Creek, located approximately 1 km away. Changes in allele frequencies at MDH-B1, 2*, used to obtain direct estimates of average migration rates (m) from the marked to the unmarked subpopulations, revealed little or no introgression into early subpopulations or into nearby Waydelich Creek. Moreover, spatially distinct late-run Auke Creek subpopulations were not immediately overrun by the more abundant marked subpopulation. These observations suggest that genetic isolation exists between temporally distinct spawning runs and that small temporal and spatial (or ecological) differences contribute to population structure. These observations should be considered in taking actions that affect conservation and harvest management or extensive culture of salmonids.

  11. Bacterial infections of Chinook salmon, Oncorhynchus tshawytscha (Walbaum), returning to gamete collecting weirs in Michigan.

    PubMed

    Loch, T P; Scribner, K; Tempelman, R; Whelan, G; Faisal, M

    2012-01-01

    Herein, we describe the prevalence of bacterial infections in Chinook salmon, Oncorhynchus tshawytscha (Walbaum), returning to spawn in two tributaries within the Lake Michigan watershed. Ten bacterial genera, including Renibacterium, Aeromonas, Carnobacterium, Serratia, Proteus, Pseudomonas, Hafnia, Salmonella, Shewanella and Morganella, were detected in the kidneys of Chinook salmon (n = 480) using culture, serological and molecular analyses. Among these, Aeromonas salmonicida was detected at a prevalence of ∼15%. Analyses revealed significant interactions between location/time of collection and gender for these infections, whereby overall infection prevalence increased greatly later in the spawning run and was significantly higher in females. Renibacterium salmoninarum was detected in fish kidneys at an overall prevalence of >25%. Logistic regression analyses revealed that R. salmoninarum prevalence differed significantly by location/time of collection and gender, with a higher likelihood of infection later in the spawning season and in females vs. males. Chi-square analyses quantifying non-independence of infection by multiple pathogens revealed a significant association between R. salmoninarum and motile aeromonad infections. Additionally, greater numbers of fish were found to be co-infected by multiple bacterial species than would be expected by chance alone. The findings of this study suggest a potential synergism between bacteria infecting spawning Chinook salmon.

  12. Release of persistent organic contaminants from carcasses of Lake Ontario Chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    O'Toole, Shaun; Metcalfe, Chris; Craine, Ian; Gross, Mart

    2006-03-01

    About 20,000 Chinook salmon (Oncorhynchus tshawytscha) from Lake Ontario enter the Credit River, Ontario, Canada every fall to spawn and die. In this study, samples of muscle and eggs collected from female Chinook salmon entering the Credit River contained total PCBs, DDT compounds and other organochlorine (OC) compounds at mug/kg concentrations. Semi-permeable membrane devices (SPMDs) were deployed at a reference site above the spawning grounds and at two downstream sites at intervals over a 14-month period that spanned two spawning runs. There was an increase in the concentrations of total PCBs, total DDT and other classes of OCs in the SPMDs deployed at the two downstream sites during and after both spawning runs; indicating that the decay of salmon releases contaminants into the river. Based upon the concentrations of contaminants in the salmon tissues, approximately 75 g of total PCBs and 35 g of total DDT compounds would be transported annually into the Credit River from this source.

  13. Qualitative modification of muscle metabolic organization with thermal acclimation of rainbow trout, Oncorhynchus mykiss.

    PubMed

    Guderley, H; Gawlicka, A

    1992-08-01

    Rainbow trout (Oncorhynchus mykiss) were acclimated to 4 and 18°C and fed at rations levels which led to an equal change in mass at these temperatures during the six week acclimation. Thermal acclimation markedly modified the metabolic organization of red and white muscle. Cold-acclimated fish had activities of β-hydroxyacyl CoA dehydrogenase in both red and white muscle that were twice those of warm-acclimated fish. By contrast, the activities of cytochrome oxidase were unchanged by thermal acclimation. Thus, the capacity for β-oxidation of lipids is specifically enhanced in the muscle of cold-acclimated trout. In white muscle, citrate synthase and phosphofructokinase activities were also enhanced by cold acclimation (increases of 125% and 35% respectively), while cytochrome oxidase levels were unchanged. The non-parallel changes in the activities of mitochondrial enzymes strongly suggest that trout muscle mitochondria undergo qualitative reorganization during cold acclimation. The relative activities of mitochondrial enzymes suggest that mitochondria from red muscle have a threefold greater capacity to oxidize lipids than those from white muscle. PMID:24214209

  14. Comparison of biochemical parameters of rainbow trout (Oncorhynchus mykiss) reared in two different trout farms'

    NASA Astrophysics Data System (ADS)

    Karatas, Tayfun

    2016-04-01

    The aim of this study was to compare biochemical parameters of cultured rainbow trouts (Oncorhynchus mykiss, Walbaum, 1972) reared in two different trout farms' (Agri and Erzurum). The average weights of fish were 150±10gr for first station (Agri), 230±10gr for second station (Erzurum). Fishes used in research were randomly caught from pools, and fifteen pieces were used for each group. Fishes were fed with commercial trout feed with 45-50% crude protein twice a day. The levels of AST, ALT, LDL, total cholesterol and triglyceride in the second station (Erzurum) were found to be higher (p<0.05) than that of first station (Agri). Whereas, the levels of HDL in the second station (Erzurum) were found to be lower (p<0.05) than that of first station (Agri). Differences in the levels of total cholesterol and AST, ALT, HDL, LDL, triglyceride may be associated with size, sex, sexual maturity and environmental conditions (temperature, pH, hardness and dissolved oxygen).

  15. An integrated linkage map reveals candidate genes underlying adaptive variation in Chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    McKinney, G J; Seeb, L W; Larson, W A; Gomez-Uchida, D; Limborg, M T; Brieuc, M S O; Everett, M V; Naish, K A; Waples, R K; Seeb, J E

    2016-05-01

    Salmonids are an important cultural and ecological resource exhibiting near worldwide distribution between their native and introduced range. Previous research has generated linkage maps and genomic resources for several species as well as genome assemblies for two species. We first leveraged improvements in mapping and genotyping methods to create a dense linkage map for Chinook salmon Oncorhynchus tshawytscha by assembling family data from different sources. We successfully mapped 14 620 SNP loci including 2336 paralogs in subtelomeric regions. This improved map was then used as a foundation to integrate genomic resources for gene annotation and population genomic analyses. We anchored a total of 286 scaffolds from the Atlantic salmon genome to the linkage map to provide a framework for the placement 11 728 Chinook salmon ESTs. Previously identified thermotolerance QTL were found to colocalize with several candidate genes including HSP70, a gene known to be involved in thermal response, as well as its inhibitor. Multiple regions of the genome with elevated divergence between populations were also identified, and annotation of ESTs in these regions identified candidate genes for fitness related traits such as stress response, growth and behaviour. Collectively, these results demonstrate the utility of combining genomic resources with linkage maps to enhance evolutionary inferences. PMID:26490135

  16. Discovery and characterization of single nucleotide polymorphisms in coho salmon, Oncorhynchus kisutch.

    PubMed

    Starks, Hilary A; Clemento, Anthony J; Garza, John Carlos

    2016-01-01

    Molecular population genetic analyses have become an integral part of ecological investigation and population monitoring for conservation and management. Microsatellites have been the molecular marker of choice for such applications over the last several decades, but single nucleotide polymorphism (SNP) markers are rapidly expanding beyond model organisms. Coho salmon (Oncorhynchus kisutch) is native to the north Pacific Ocean and its tributaries, where it is the focus of intensive fishery and conservation activities. As it is an anadromous species, coho salmon typically migrate across multiple jurisdictional boundaries, complicating management and requiring shared data collection methods. Here, we describe the discovery and validation of a suite of novel SNPs and associated genotyping assays which can be used in the genetic analyses of this species. These assays include 91 that are polymorphic in the species and one that discriminates it from a sister species, Chinook salmon. We demonstrate the utility of these SNPs for population assignment and phylogeographic analyses, and map them against the draft trout genome. The markers constitute a large majority of all SNP markers described for coho salmon and will enable both population- and pedigree-based analyses across the southern part of the species native range. PMID:25965351

  17. Innate and adaptive immune responses in migrating spring-run adult chinook salmon, Oncorhynchus tshawytscha.

    PubMed

    Dolan, Brian P; Fisher, Kathleen M; Colvin, Michael E; Benda, Susan E; Peterson, James T; Kent, Michael L; Schreck, Carl B

    2016-01-01

    Adult Chinook salmon (Oncorhynchus tshawytscha) migrate from salt water to freshwater streams to spawn. Immune responses in migrating adult salmon are thought to diminish in the run up to spawning, though the exact mechanisms for diminished immune responses remain unknown. Here we examine both adaptive and innate immune responses as well as pathogen burdens in migrating adult Chinook salmon in the Upper Willamette River basin. Messenger RNA transcripts encoding antibody heavy chain molecules slightly diminish as a function of time, but are still present even after fish have successfully spawned. In contrast, the innate anti-bacterial effector proteins present in fish plasma rapidly decrease as spawning approaches. Fish also were examined for the presence and severity of eight different pathogens in different organs. While pathogen burden tended to increase during the migration, no specific pathogen signature was associated with diminished immune responses. Transcript levels of the immunosuppressive cytokines IL-10 and TGF beta were measured and did not change during the migration. These results suggest that loss of immune functions in adult migrating salmon are not due to pathogen infection or cytokine-mediated immune suppression, but is rather part of the life history of Chinook salmon likely induced by diminished energy reserves or hormonal changes which accompany spawning. PMID:26581919

  18. Changes in Size and Age of Chinook Salmon Oncorhynchus tshawytscha Returning to Alaska.

    PubMed

    Lewis, Bert; Grant, W Stewart; Brenner, Richard E; Hamazaki, Toshihide

    2015-01-01

    The average sizes of Pacific salmon have declined in some areas in the Northeast Pacific over the past few decades, but the extent and geographic distribution of these declines in Alaska is uncertain. Here, we used regression analyses to quantify decadal trends in length and age at maturity in ten datasets from commercial harvests, weirs, and spawner abundance surveys of Chinook salmon Oncorhynchus tshawytscha throughout Alaska. We found that on average these fish have become smaller over the past 30 years (~6 generations), because of a decline in the predominant age at maturity and because of a decrease in age-specific length. The proportion of older and larger 4-ocean age fish in the population declined significantly (P < 0.05) in all stocks examined by return year or brood year. Our analyses also indicated that the age-specific lengths of 4-ocean fish (9 of 10 stocks) and of 3-ocean fish (5 of 10 stocks) have declined significantly (P < 0.05). Size-selective harvest may be driving earlier maturation and declines in size, but the evidence is not conclusive, and additional factors, such as ocean conditions or competitive interactions with other species of salmon, may also be responsible. Regardless of the cause, these wide-spread phenotypic shifts influence fecundity and population abundance, and ultimately may put populations and associated fisheries at risk of decline. PMID:26090990

  19. Loma salmonae (Protozoa: Microspora) infections in seawater reared coho salmon Oncorhynchus kisutch

    USGS Publications Warehouse

    Kent, M.L.; Elliott, D.G.; Groff, J.M.; Hedrick, R.P.

    1989-01-01

    Loma salmonae (Putz et al., 1965) infections were observed in five groups of coho salmon, Oncorhynchus kisutch, reared in seawater net-pens in Washington State, U.S.A. in 1984–1986. Ultrastructural characteristics, size of spores, tissues and host infected, and geographical location identified the microsporidium as Loma salmonae. Preserved spores measured 4.4×2.3 (4–5.6×2–2.4) μm and exhibited 14–17 turns of the polar filament. Infections were evident in the gills of some fish before seawater entry, but few parasites were observed and they caused little tissue damage. Infections observed in fish after transfer to seawater were associated with significant pathological changes in the gills. A mixed inflammatory infiltrate was associated with ruptured microsporidian xenomas within the vessels and interstitium of the primary lamellae. Microsporidian spores were dispersed throughout the lesions and were often seen inside phagocytes. The parasite was also observed in the heart, spleen, kidney and pseudobranchs; however, the inflammatory lesions were common only in the heart.Monthly examination of fish after transfer to seawater showed peak prevalences (33–65%) of gill infections during the summer. Although moribund fish were often infected with other pathogens, the high prevalence of L. salmonae infections and the severity of the lesions it caused, suggested that this parasite significantly contributed to the recurrent summer mortalities observed at this net-pen site.

  20. Using nitrogen stable isotopes to detect longdistance movement in a threatened cutthroat trout (Oncorhynchus clarkii utah)

    USGS Publications Warehouse

    Sepulveda, A.J.; Colyer, W.T.; Lowe, W.H.; Vinson, M.R.

    2009-01-01

    Interior cutthroat trout occupy small fractions of their historic ranges and existing populations often are relegated to headwater habitats. Conservation requires balancing protection for isolated genetically pure populations with restoration of migratory life histories by reconnecting corridors between headwater and mainstem habitats. Identification of alternative life history strategies within a population is critical to these efforts. We tested the application of nitrogen stable isotopes to discern fluvial from resident Bonneville cutthroat trout (BCT; Oncorhynchus clarkii utah) in a headwater stream. Fluvial BCT migrate from headwater streams with good water quality to mainstem habitats with impaired water quality. Resident BCT remain in headwater streams. We tested two predictions: (i) fluvial BCT have a higher ??15N than residents, and (ii) fluvial BCT ??15N reflects diet and ??15N enrichment characteristics of mainstem habitats. We found that fluvial ??15N was greater than resident ??15N and that ??15N was a better predictor of life history than fish size. Our data also showed that fluvial and resident BCT had high diet overlap in headwater sites and that ??15N of lower trophic levels was greater in mainstem sites than in headwater sites. We conclude that the high ??15N values of fluvial BCT were acquired in mainstem sites.

  1. Immunohistochemical evaluation of experimental Vagococcus salmoninarum infection in rainbow trout (Oncorhynchus mykiss, Walbaum 1792).

    PubMed

    Yardimci, B; Didinen, B I; Onuk, E E; Metin, S; Ciftci, A; Kubilay, A; Pekmezci, G Z; Eralp, H

    2016-05-01

    The aim of this study was to investigate the pathogenesis and histopathological and immunohistochemical findings in rainbow trout (Oncorhynchus mykiss) following experimental vagococcosis. For this purpose, 60 rainbow trout were used. The experimental study used the pathogen Vagococcus salmoninarum. The fish were intraperitoneally (IP) administered with an inoculate containing 0.1 mL of the bacteria, resulting in a dose of 1.2 × 10(9) cfu mL(-1) per fish. For histopathological observations, tissue samples were taken from fish that died during the experiment and fish that survived until the end of the trial (60th day). All the tissue samples were immunohistochemically stained by the avidin-biotin-peroxidase complex and immunofluorescence methods using polyclonal antibody to detect V. salmoninarum antigens. In immunoperoxidase staining, positive reactions to bacterial antigens were most commonly seen in the kidney, heart and liver. In the immunofluorescence analysis, the distribution of antigens in the tissue and organs was similar to that observed with the immunoperoxidase staining. The results reveal an important correlation between histochemical and immunohistochemical staining in demonstrating the distribution of V. salmoninarum antigens in the affected tissues.

  2. Over the falls? Rapid evolution of ecotypic differentiation in steelhead/rainbow trout (Oncorhynchus mykiss).

    PubMed

    Pearse, Devon E; Hayes, Sean A; Bond, Morgan H; Hanson, Chad V; Anderson, Eric C; Macfarlane, R Bruce; Garza, John Carlos

    2009-01-01

    Adaptation to novel habitats and phenotypic plasticity can be counteracting forces in evolution, but both are key characteristics of the life history of steelhead/rainbow trout (Oncorhynchus mykiss). Anadromous steelhead reproduce in freshwater river systems and small coastal streams but grow and mature in the ocean. Resident rainbow trout, either sympatric with steelhead or isolated above barrier dams or waterfalls, represent an alternative life-history form that lives entirely in freshwater. We analyzed population genetic data from 1486 anadromous and resident O. mykiss from a small stream in coastal California with multiple barrier waterfalls. Based on data from 18 highly variable microsatellite loci (He = 0.68), we conclude that the resident population above one barrier, Big Creek Falls, is the result of a recent anthropogenic introduction from the anadromous population of O. mykiss below the falls. Furthermore, fish from this above-barrier population occasionally descend over the falls and have established a genetically differentiated below-barrier subpopulation at the base of the falls, which appears to remain reproductively isolated from their now-sympatric anadromous ancestors. These results support a hypothesis of rapid evolution of a purely resident life history in the above-barrier population in response to strong selection against downstream movement.

  3. Effects of Watercress (Nasturtium nasturtium) extract on selected immunological parameters of rainbow trout (Oncorhynchus mykiss)

    PubMed Central

    Asadi, M.S.; Mirvaghefei, A.R.; Nematollahi, M.A.; Banaee, M.; Ahmadi, K.

    2012-01-01

    Watercress (Nasturtium nasturtium) is a medical plant containing diverse chemically-active substances with biological properties. The present study was conducted to investigate the immunomodulatory effects of watercress extract on immunological and hematological parameters of rainbow trout (Oncorhynchus mykiss). Fish were fed for 21 days with diet supplemented with 0.1% and 1% of watercress extract per 1 kg food and with a normal diet as control. Hematological parameters such as red blood cells (RBC) and white blood cells (WBC), hematocrit (Hct), hemoglobin (Hb), RBC index like mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) as well as immunological parameters such as peroxidase, lysozyme and complement activities, total protein, albumin and globulin levels were measured after 21 days of watercress extract treatment. The results indicated that oral administration of 1 % watercress extract in fish may enhance some hematological and immunological parameters including Hb and MCHC, lysozyme and complement activities, total protein and globulin levels, compared to the controls after 21 days of experimental period. In conclusion, on the basis of these results, oral administration of watercress extract may be useful to improve fish’s immune system. PMID:26623289

  4. Characterization of aroma-active compounds in rainbow trout (Oncorhynchus mykiss) eliciting an off-odor.

    PubMed

    Selli, Serkan; Rannou, Cecile; Prost, Carole; Robin, Joel; Serot, Thierry

    2006-12-13

    The aroma-active and off-flavor compounds of cooked rainbow trout (Oncorhynchus mykiss) were analyzed by sensory and instrumental analyses. Sensory analysis shows that the aromatic extract obtained by vacuum steam distillation was representative of rainbow trout odor. To obtain more information on odorants of volatile compounds, analyses were conducted on two gas chromatography columns of different polarities (DB-5 and DB-Wax). The results of the gas chromatography-olfactometry analysis showed that 38 odorous compounds were perceived when the DB-5 column was used and 36 with the DB-Wax column. Of these, 31 with the DB-5 and 28 with the DB-Wax were identified. (E)-2-Nonenal, 2-ethyl-1-hexanol, 2-methylisoborneol, geosmin, 2-methylnaphthalene, and 8-heptadecene were described as off-flavor compounds by the sniffing assessors. The most powerful off-flavor compounds identified in the extract were 2-methylisoborneol and geosmin, which were described as strong musty and earthy odors, respectively.

  5. Using parentage analysis to estimate rates of straying and homing in Chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    Ford, Michael J; Murdoch, Andrew; Hughes, Michael

    2015-03-01

    We used parentage analysis based on microsatellite genotypes to measure rates of homing and straying of Chinook salmon (Oncorhynchus tshawytscha) among five major spawning tributaries within the Wenatchee River, Washington. On the basis of analysis of 2248 natural-origin and 11594 hatchery-origin fish, we estimated that the rate of homing to natal tributaries by natural-origin fish ranged from 0% to 99% depending on the tributary. Hatchery-origin fish released in one of the five tributaries homed to that tributary at a far lower rate than the natural-origin fish (71% compared to 96%). For hatchery-released fish, stray rates based on parentage analysis were consistent with rates estimated using physical tag recoveries. Stray rates among major spawning tributaries were generally higher than stray rates of tagged fish to areas outside of the Wenatchee River watershed. Within the Wenatchee watershed, rates of straying by natural-origin fish were significantly affected by spawning tributary and by parental origin: progeny of naturally spawning hatchery-produced fish strayed at significantly higher rates than progeny whose parents were themselves of natural origin. Notably, none of the 170 offspring that were products of mating by two natural-origin fish strayed from their natal tributary. Indirect estimates of gene flow based on FST statistics were correlated with but higher than the estimates from the parentage data. Tributary-specific estimates of effective population size were also correlated with the number of spawners in each tributary. PMID:25626589

  6. Cryopreservation of sperm from the endangered formosan landlocked salmon (Oncorhynchus masou formosanus).

    PubMed

    Gwo, J C; Ohta, H; Okuzawa, K; Wu, H C

    1999-02-01

    The Formosan landlocked salmon (Oncorhynchus masou formosanus) are at a high risk of extinction, and the sustained maintenance of the population will soon depend on aquaculture systems, which use cryopreservation of spermatozoa to increase genetic diversity. We investigated the effectiveness of dimethyl sulfoxide (DMSO), dimethyl-acetamide (DMA), and methanol as cryoprotectants in combination with 300 mM glucose as extender on the freezing of Formosan landlocked salmon spermatozoa. We also evaluated the morphological changes of Formosan landlocked salmon spermatozoa after their immediate dilution in the 300 mM glucose-DMSO extender and after freeze-thawing. The spermatozoa frozen with DMSO as a cryoprotectant showed significantly higher post-thaw motility and fertility than spermatozoa frozen with DMA or methanol. The fertilization capacity of frozen-thawed Formosan landlocked salmon was comparable to that of fresh spermatozoa. Intersubspecies fertilization trials between cryopreserved Formosan landlocked salmon spermatozoa and Amago salmon eggs showed high fertilization rates. Based on the findings, the potential value of using sperm bank to safeguard this endangered species is discussed.

  7. Adaptive genetic markers discriminate migratory runs of Chinook salmon (Oncorhynchus tshawytscha) amid continued gene flow

    PubMed Central

    O'Malley, Kathleen G; Jacobson, Dave P; Kurth, Ryon; Dill, Allen J; Banks, Michael A

    2013-01-01

    Neutral genetic markers are routinely used to define distinct units within species that warrant discrete management. Human-induced changes to gene flow however may reduce the power of such an approach. We tested the efficiency of adaptive versus neutral genetic markers in differentiating temporally divergent migratory runs of Chinook salmon (Oncorhynchus tshawytscha) amid high gene flow owing to artificial propagation and habitat alteration. We compared seven putative migration timing genes to ten microsatellite loci in delineating three migratory groups of Chinook in the Feather River, CA: offspring of fall-run hatchery broodstock that returned as adults to freshwater in fall (fall run), spring-run offspring that returned in spring (spring run), and fall-run offspring that returned in spring (FRS). We found evidence for significant differentiation between the fall and federally listed threatened spring groups based on divergence at three circadian clock genes (OtsClock1b, OmyFbxw11, and Omy1009UW), but not neutral markers. We thus demonstrate the importance of genetic marker choice in resolving complex life history types. These findings directly impact conservation management strategies and add to previous evidence from Pacific and Atlantic salmon indicating that circadian clock genes influence migration timing. PMID:24478800

  8. Metabolism and elimination of benzocaine by rainbow-trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    Meinertz, J.R.; Gingerich, W.H.; Allen, J.L.

    1991-01-01

    1. Branchial and urinary elimination of benzocaine residues was evaluated in adult rainbow trout, oncorhynchus mykiss, given a single dorsal aortic dose of c-14-benzocaine hydrochloride.^2. Branchial elimination of benzocaine residues was rapid and accounted for 59.2% Of the dose during the first 3 h after dosing. Renal elimination of radioactivity was considerably slower; the kidney excreted 2.7% Dose within 3 h and 9.0% Within 24 h. Gallbladder bile contained 2.0% Dose 24 h after injection.^3. Of the radioactivity in radiochromatograms from water taken 3 min after injection, 87.3% Was benzocaine and 12.7% Was n-acetylated benzocaine. After 60 min, 32.7% Was benzocaine and 67.3% Was n-acetylated benzocaine.^4. Of the radioactivity in radiochromatograms from urine taken 1 h after dosing, 7.6% Was para-aminobenzoic acid, 59.7% Was n-acetylated para-aminobenzoic acid, 19.5% Was benzocaine, and 8.0% Was n-acetylated benzocaine. The proportion of the radioactivity in urine changed with time so that by 20 h, 1.0% Was para-aminobenzoic acid and 96.6% Was n-acetylated para-aminobenzoic acid.^5. Benzocaine and a more hydrophobic metabolite, n-acetylated benzocaine, were eliminated primarily through the gills; renal and biliary pathways were less significant elimination routes for benzocaine residues.

  9. Immunocytochemical localization of carbonic anhydrase in the pseudobranch tissue of the rainbow trout Oncorhynchus mykiss

    PubMed Central

    Rahim, S. M.; Mazlan, A. G.; Simon, K. D.; Delaunoy, J. P.; Laurent, P.

    2014-01-01

    Pseudobranch function has long interested scientists, but its role has yet to be elucidated. Several studies have suggested that pseudobranchs serve respiratory, osmoregulatory, and sensory functions. This work investigated the immunolocalization of pseudobranch carbonic anhydrase (CA) in the teleost fish species rainbow trout (Oncorhynchus mykiss) to clarify its physiological function. CA was purified from rainbow trout gills O. mykiss and specific antibodies were raised. Immunoblotting between tissue homogenates of pseudobranch and gill CA antibodies showed specific immunostaining with only one band corresponding to CA in the pseudobranch homogenate. Results of immunohistochemical technique revealed that CA was distributed within pseudobranch cells and more precisely in the apical parts (anti-vascular) of cells. The basal (vascular) parts of cells, tubular system, blood capillaries, and pillar cells were not immunostained. Immunocytochemistry confirmed these results and showed that some CA enzyme was cytoplasmic and the remainder was linked to membranous structures. The results also showed that the lacunar tissue layers did not display immunoperoxidase activity. Our results indicated that pseudobranch CA may have a function related to the extracellular medium wherein CA intervenes with the mechanism of stimulation of afferent nerve fibers. PMID:24510712

  10. Electronic tags and genetics explore variation in migrating steelhead kelts (oncorhynchus mykiss), Ninilchik river, Alaska

    USGS Publications Warehouse

    Nielsen, J.L.; Turner, S.M.; Zimmerman, C.E.

    2011-01-01

    Acoustic and archival tags examined freshwater and marine migrations of postspawn steelhead kelts (Oncorhynchus mykiss) in the Ninilchik River, Alaska, USA. Postspawn steelhead were captured at a weir in 2002-2005. Scale analysis indicated multiple migratory life histories and spawning behaviors. Acoustic tags were implanted in 99 kelts (2002-2003), and an array of acoustic receivers calculated the average speed of outmigration, timing of saltwater entry, and duration of residency in the vicinity of the river mouth. Ocean migration data were recovered from two archival tags implanted in kelts in 2004 (one male and one female). Archival tags documented seasonal differences in maximum depth and behavior with both fish spending 97% of time at sea <6 m depth (day and night). All study fish were double tagged with passive integrated transponder (PIT) tags implanted in the body cavity. Less than 4% of PIT tags were retained in postspawn steelhead. Molecular genetics demonstrated no significant differences in genetic population structure across years or among spawning life history types, suggesting a genetically panmictic population with highly diverse life history characteristics in the Ninilchik River.

  11. Gene expression in the liver of rainbow trout, Oncorhynchus mykiss, during the stress response

    USGS Publications Warehouse

    Momoda, T.S.; Schwindt, A.R.; Feist, G.W.; Gerwick, L.; Bayne, C.J.; Schreck, C.B.

    2007-01-01

    To better appreciate the mechanisms underlying the physiology of the stress response, an oligonucleotide microarray and real-time RT-PCR (QRT-PCR) were used to study gene expression in the livers of rainbow trout (Oncorhynchus mykiss). For increased confidence in the discovery of candidate genes responding to stress, we conducted two separate experiments using fish from different year classes. In both experiments, fish exposed to a 3??h stressor were compared to control (unstressed) fish. In the second experiment some additional fish were exposed to only 0.5??h of stress and others were sampled 21??h after experiencing a 3??h stressor. This 21??h post-stress treatment was a means to study gene expression during recovery from stress. The genes we report as differentially expressed are those that responded similarly in both experiments, suggesting that they are robust indicators of stress. Those genes are a major histocompatibility complex class 1 molecule (MHC1), JunB, glucose 6-phosphatase (G6Pase), and nuclear protein 1 (Nupr1). Interestingly, Nupr1 gene expression was still elevated 21??h after stress, which indicates that recovery was incomplete at that time. ?? 2007 Elsevier Inc. All rights reserved.

  12. Shifting Thresholds: Rapid Evolution of Migratory Life Histories in Steelhead/Rainbow Trout, Oncorhynchus mykiss.

    PubMed

    Phillis, Corey C; Moore, Jonathan W; Buoro, Mathieu; Hayes, Sean A; Garza, John Carlos; Pearse, Devon E

    2016-01-01

    Expression of phenotypic plasticity depends on reaction norms adapted to historic selective regimes; anthropogenic changes in these selection regimes necessitate contemporary evolution or declines in productivity and possibly extinction. Adaptation of conditional strategies following a change in the selection regime requires evolution of either the environmentally influenced cue (e.g., size-at-age) or the state (e.g., size threshold) at which an individual switches between alternative tactics. Using a population of steelhead (Oncorhynchus mykiss) introduced above a barrier waterfall in 1910, we evaluate how the conditional strategy to migrate evolves in response to selection against migration. We created 9 families and 917 offspring from 14 parents collected from the above- and below-barrier populations. After 1 year of common garden-rearing above-barrier offspring were 11% smaller and 32% lighter than below-barrier offspring. Using a novel analytical approach, we estimate that the mean size at which above-barrier fish switch between the resident and migrant tactic is 43% larger than below-barrier fish. As a result, above-barrier fish were 26% less likely to express the migratory tactic. Our results demonstrate how rapid and opposing changes in size-at-age and threshold size contribute to the contemporary evolution of a conditional strategy and indicate that migratory barriers may elicit rapid evolution toward the resident life history on timescales relevant for conservation and management of conditionally migratory species. PMID:26585381

  13. The immunoglobulin repertoire of the rainbow trout (Oncorhynchus mykiss): definition of nine Igh-V families.

    PubMed

    Roman, T; Charlemagne, J

    1994-01-01

    An Igh-V library was constructed from the head kidney cytoplasmic RNA of an 8.5-month-old non-immunized rainbow trout, Oncorhynchus mykiss, using the 5' RACE polymerase chain reaction. Six new Igh-V segments were identified, bringing to nine the number of Igh-V families actually defined in that species. A phylogenetic analysis shows that these nine Igh-V families can be classified into three major groups. The first includes the Igh-V1, Igh-V3, Igh-V4, and Igh-V7 families, and is homologous to the human and mouse Group III Igh-V families. The second includes the Igh-V5, Igh-V8, and Igh-V9 families and is more closely related to the Group I and Group II human and mouse Igh-V families. The third group includes the Igh-V2 and Igh-V6 families, which are not closely related to any other vertebrate Igh-V gene. Six Igh-J segments were characterized. They can recombine with Igh-V segments belonging to different families and there is a high level of junctional diversity between the Igh-V and Igh-J segments. PMID:8039829

  14. The effect of creosote on vitellogenin production in rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Sherry, J.P.; Whyte, J.J.; Karrow, N.A.; Gamble, A.; Boerman, H.J.; Bol, N.C.; Dixon, D.G.; Solomon, K.R.

    2006-01-01

    As part of a broader investigation into the effects of creosote treatments on the aquatic biota in pond microcosms, we examined the possible implications for vitellogenin (Vtg) production in Oncorhynchus mykiss [rainbow trout (RT)]. Vtg is the precursor of egg yolk protein and has emerged as a useful biomarker of exposure to estrogenic substances. Our a priori intent was to assess the ability of the creosote treatments (nominal cresoste concentrations were 0, 3, and 10 ??l/L immediately after the last subsurface addition) to induce estrogenic responses in RT. The data showed no evidence of an estrogenic response in the treated fish. During the course of the experiment, however, the fish matured and began to produce Vtg, probably in response to endogenous estrogen. A posteriori analysis of the Vtg data from the maturing fish showed that after 28 days, the plasma Vtg concentrations were about 15-fold lower in fish from the creosote-treated microcosms compared with fish from the reference microcosm. Although the experiment design does not permit mechanistic insights, our observation suggests that exposure of female fish to PAH mixtures such as creosote can impair the production of Vtg with possible health implications for embryos and larvae. ?? 2006 Springer Science+Business Media, Inc.

  15. Stressor timing, not cortisol, is an important embryo viability determinant in female rainbow trout Oncorhynchus mykiss.

    PubMed

    Medeiros, L R; Elliott, M; Nagler, J J

    2016-02-01

    The objective of this study was to determine whether the timing of elevated cortisol levels in adult female rainbow trout Oncorhynchus mykiss, achieved by silastic implants within the body cavity, had an effect on embryo viability. Cortisol-implanted fish experienced a significant increase in circulating levels of plasma cortisol compared with sham-implanted fish, and plasma cortisol remained elevated relative to sham-implanted fish for 4 months in each of the three treatment groups (0-4, 4-8 and 8-12 months). There were no significant differences in embryo viability, egg diameters or plasma 17β-oestradiol levels between the cortisol and sham-implanted treatments in any of the groups. There was a significant difference in the number of subfertile females (<80% embryo viability) when the three treatments were compared. The majority of the females (75%) implanted immediately postspawn (0-4 months) produced subfertile eggs, which was significantly higher than those treated 4-8 (33%) or 8-12 (17%) months postspawn. These results imply that silastic implantation can affect oocyte development, independent of plasma cortisol levels, leading to a reduction in embryo viability.

  16. Quantitative threat analysis for management of an imperiled species: Chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    Hoekstra, Jonathan M; Bartz, Krista K; Ruckelshaus, Mary H; Moslemi, Jennifer M; Harms, Tamara K

    2007-10-01

    Chinook salmon (Oncorhynchus tshawytscha) have declined dramatically across the Pacific Northwest because of multiple human impacts colloquially characterized as the four "H's": habitat degradation, harvest, hydroelectric and other dams, and hatchery production. We use this conceptual framework to quantify the relative importance of major threats to the current status of 201 Chinook populations. Current status is characterized by two demographic indices: population density and trend. We employ path analytic models and information theoretic methods for multi-model inference. Our results indicate that dams most strongly affect variation in population density, while harvest and hatchery production most strongly affect variation in population trend. Comparable results arise when the sample size of the analysis is reduced to 22 Chinook populations within a smaller region typical of the scale at which salmon recovery planning is conducted. Results from these threat analyses suggest that recovery strategies targeting specific demographic indices, and those considering natural and human-mediated interdependencies of major threats, are most likely to succeed. PMID:17974341

  17. Innate and adaptive immune responses in migrating spring-run adult chinook salmon, Oncorhynchus tshawytscha

    USGS Publications Warehouse

    Dolan, Brian P.; Fisher, Kathleen M.; Colvin, Michael E.; Benda, Susan E.; Peterson, James T.; Kent, Michael L.; Schreck, Carl B.

    2016-01-01

    Adult Chinook salmon (Oncorhynchus tshawytscha) migrate from salt water to freshwater streams to spawn. Immune responses in migrating adult salmon are thought to diminish in the run up to spawning, though the exact mechanisms for diminished immune responses remain unknown. Here we examine both adaptive and innate immune responses as well as pathogen burdens in migrating adult Chinook salmon in the Upper Willamette River basin. Messenger RNA transcripts encoding antibody heavy chain molecules slightly diminish as a function of time, but are still present even after fish have successfully spawned. In contrast, the innate anti-bacterial effector proteins present in fish plasma rapidly decrease as spawning approaches. Fish also were examined for the presence and severity of eight different pathogens in different organs. While pathogen burden tended to increase during the migration, no specific pathogen signature was associated with diminished immune responses. Transcript levels of the immunosuppressive cytokines IL-10 and TGF beta were measured and did not change during the migration. These results suggest that loss of immune functions in adult migrating salmon are not due to pathogen infection or cytokine-mediated immune suppression, but is rather part of the life history of Chinook salmon likely induced by diminished energy reserves or hormonal changes which accompany spawning.

  18. p,p'-DDE depresses the immune competence of chinook salmon (Oncorhynchus tshawytscha) leukocytes

    USGS Publications Warehouse

    Misumi, Ichiro; Vella, Anthony T.; Leong, Jo-Ann C.; Nakanishi, Teruyuki; Schreck, Carl B.

    2005-01-01

    p,p′-DDE, the main metabolite of DDT, is still detected in aquatic environments throughout the world. Here, the effects and mechanisms by which p,p′-DDE exposure might affect the immune system of chinook salmon (Oncorhynchus tshawytscha) was studied. Isolated salmon splenic and pronephric leukocytes were incubated with different concentrations of p,p′-DDE, and cell viability, induction of apoptosis, and mitogenic responses were measured by flow cytometry and Alamar Blue assay. p,p′-DDE significantly reduced cell viability and proliferation and increased apoptosis. The effect of p,p′-DDE on pronephric leukocytes was more severe than on splenic leukocytes, likely because pronephric leukocytes had a higher proportion of granulocytes, cells that appear more sensitive to p,p′-DDE. The effect of p,p′-DDE on leukocytes appeared to vary between developmental stages or seasonal differences. The mitogenic response of leukocytes of chinook salmon exposed to p,p′-DDE in vivo exhibited a biphasic dose–response relationship. Only leukocytes isolated from salmon treated with 59 ppm p,p′-DDE had a significantly lower percentage of Ig+ blasting cells than controls, although the response was biphasic. These results support the theory that exposure to chemical contaminants could lead to an increase in disease susceptibility and mortality of fish due to immune suppression.

  19. Development and pharmacokinetic evaluation of erythromycin lipidic formulations for oral administration in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Serdoz, Francesca; Voinovich, Dario; Perissutti, Beatrice; Grabnar, Iztok; Hasa, Dritan; Ballestrazzi, Rodolfo; Coni, Ettore; Pellegrini, Enrico

    2011-08-01

    The aim of this work was to enhance the bioavailability of erythromycin base when administered orally in rainbow trout (Oncorhynchus mykiss). Since erythromycin is normally given in the form of medicated feed, in this study three new types of feed formulation were developed. A self-emulsifying system and two types of double microemulsions (O/W/O) were prepared, characterized and adsorbed on a commercial extruded diet for fish. The emulsified systems were based on saturated polyglycolized glycerides and mono- and diglycerides of medium-chain fatty acids (as oily phase), Tween 80 (as surfactant) and, in the case of double microemulsions, distilled water. The systems differed in percentage composition and for the amount and position of erythromycin in different phases. The three medicated feed were then administered orally by means of a gastric probe to rainbow trout and their relative bioavailability was estimated in comparison with that obtained after oral administration of feed with erythromycin powder. For each medicated feed, 80 fish were tested. Finally, plasma profiles of erythromycin after single administration of medicated feeds were used to predict profiles obtainable by administering once-daily medicated feeds for 7 consecutive days. The results proved that the feeds containing microemulsified erythromycin provided largely superior oral bioavailability and the advantage of obtaining the same efficacy against bacterial infections with a much lower dose of drug.

  20. Recovery of Barotrauma Injuries in Chinook Salmon, Oncorhynchus tshawytscha from Exposure to Pile Driving Sound

    PubMed Central

    Casper, Brandon M.; Popper, Arthur N.; Matthews, Frazer; Carlson, Thomas J.; Halvorsen, Michele B.

    2012-01-01

    Juvenile Chinook salmon, Oncorhynchus tshawytscha, were exposed to simulated high intensity pile driving signals to evaluate their ability to recover from barotrauma injuries. Fish were exposed to one of two cumulative sound exposure levels for 960 pile strikes (217 or 210 dB re 1 µPa2·s SELcum; single strike sound exposure levels of 187 or 180 dB re 1 µPa2⋅s SELss respectively). This was followed by an immediate assessment of injuries, or assessment 2, 5, or 10 days post-exposure. There were no observed mortalities from the pile driving sound exposure. Fish exposed to 217 dB re 1 µPa2·s SELcum displayed evidence of healing from injuries as post-exposure time increased. Fish exposed to 210 dB re 1 µPa2·s SELcum sustained minimal injuries that were not significantly different from control fish at days 0, 2, and 10. The exposure to 210 dB re 1 µPa2·s SELcum replicated the findings in a previous study that defined this level as the threshold for onset of injury. Furthermore, these data support the hypothesis that one or two Mild injuries resulting from pile driving exposure are unlikely to affect the survival of the exposed animals, at least in a laboratory environment. PMID:22745794

  1. Shifting Thresholds: Rapid Evolution of Migratory Life Histories in Steelhead/Rainbow Trout, Oncorhynchus mykiss.

    PubMed

    Phillis, Corey C; Moore, Jonathan W; Buoro, Mathieu; Hayes, Sean A; Garza, John Carlos; Pearse, Devon E

    2016-01-01

    Expression of phenotypic plasticity depends on reaction norms adapted to historic selective regimes; anthropogenic changes in these selection regimes necessitate contemporary evolution or declines in productivity and possibly extinction. Adaptation of conditional strategies following a change in the selection regime requires evolution of either the environmentally influenced cue (e.g., size-at-age) or the state (e.g., size threshold) at which an individual switches between alternative tactics. Using a population of steelhead (Oncorhynchus mykiss) introduced above a barrier waterfall in 1910, we evaluate how the conditional strategy to migrate evolves in response to selection against migration. We created 9 families and 917 offspring from 14 parents collected from the above- and below-barrier populations. After 1 year of common garden-rearing above-barrier offspring were 11% smaller and 32% lighter than below-barrier offspring. Using a novel analytical approach, we estimate that the mean size at which above-barrier fish switch between the resident and migrant tactic is 43% larger than below-barrier fish. As a result, above-barrier fish were 26% less likely to express the migratory tactic. Our results demonstrate how rapid and opposing changes in size-at-age and threshold size contribute to the contemporary evolution of a conditional strategy and indicate that migratory barriers may elicit rapid evolution toward the resident life history on timescales relevant for conservation and management of conditionally migratory species.

  2. Some blood chemistry values for the juvenile coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Wedemeyer, Gary; Chatterton, K.

    1971-01-01

    Overlapping Gaussian distribution curves were resolved into normal ranges for 1800 clinical test values obtained from caudal arterial blood or plasma of more than 1000 juvenile coho salmon (Oncorhynchus kisutch) held under defined conditions of diet and temperature. Estimated normal blood chemistry ranges were bicarbonate, 9.5–12.6 mEq/liter; blood urea nitrogen (BUN), 0.9–3.4 mg/100 ml; chloride, 122–136 mEq/liter; cholesterol, 88–262 mg/100 ml;pCO2, 2.6–6.1 mm Hg (10 C); glucose, 41–135 mg/100 ml; hematocrit, 32.5–52.5%; hemoglobin, 6.5–9.9 g/100 ml; total protein, 1.4–4.3 g/100 ml; blood pH (10 C), 7.51–7.83. The calculated range of normal acid–base balance vs. water temperature is also presented.

  3. Effects of Watercress (Nasturtium nasturtium) extract on selected immunological parameters of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Asadi, M S; Mirvaghefei, A R; Nematollahi, M A; Banaee, M; Ahmadi, K

    2012-01-01

    Watercress (Nasturtium nasturtium) is a medical plant containing diverse chemically-active substances with biological properties. The present study was conducted to investigate the immunomodulatory effects of watercress extract on immunological and hematological parameters of rainbow trout (Oncorhynchus mykiss). Fish were fed for 21 days with diet supplemented with 0.1% and 1% of watercress extract per 1 kg food and with a normal diet as control. Hematological parameters such as red blood cells (RBC) and white blood cells (WBC), hematocrit (Hct), hemoglobin (Hb), RBC index like mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) as well as immunological parameters such as peroxidase, lysozyme and complement activities, total protein, albumin and globulin levels were measured after 21 days of watercress extract treatment. The results indicated that oral administration of 1 % watercress extract in fish may enhance some hematological and immunological parameters including Hb and MCHC, lysozyme and complement activities, total protein and globulin levels, compared to the controls after 21 days of experimental period. In conclusion, on the basis of these results, oral administration of watercress extract may be useful to improve fish's immune system.

  4. Inhibition of fish pathogens by the microbiota from rainbow trout (Oncorhynchus mykiss, Walbaum) and rearing environment.

    PubMed

    Araújo, Carlos; Muñoz-Atienza, Estefanía; Nahuelquín, Yanina; Poeta, Patrícia; Igrejas, Gilberto; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M

    2015-04-01

    This work reports the isolation and taxonomic identification of the cultivable total microbiota (TM) and Lactic Acid Bacteria (LAB) from rainbow trout (Oncorhynchus mykiss, Walbaum) and rearing environment from selected stages of the life-cycle, and the evaluation of the LAB antimicrobial activity against the main fish pathogens. TM and LAB isolates were randomly selected and identified by 16S rRNA and/or superoxide dismutase gene sequencing. Although a great diversity in the TM was observed, Enterobacteriaceae and Aeromonadaceae were clearly prevalent, while the genus Lactococcus was the predominant LAB. From a total of 1620 randomly selected LAB, 1159 isolates (71.5%) showed antimicrobial activity. From these, 248 isolates (21.4%) selected for their activity against, at least, four fish pathogens, were taxonomically identified, being Lactococcus lactis the most common species (164 isolates, 66.1%). Interestingly, 88 isolates (35.5%), including 55 L. lactis isolates, exerted activity against four strains of the rainbow trout pathogen Lactococcus garvieae. Our results demonstrate that rainbow trout and rearing environment are potential sources for the isolation of LAB, mainly lactococci, active against L. garvieae and other fish pathogens. Moreover, this is the first study describing the cultivable TM and LAB from rainbow trout intestine and rearing environment along the fish life-cycle. The host-derived LAB active against fish pathogens comprise potential candidates as probiotics in rainbow trout farming as an alternative or complementary strategy to antibiotics and vaccines for disease prevention.

  5. Immunocytochemical localization of carbonic anhydrase in the pseudobranch tissue of the rainbow trout Oncorhynchus mykiss.

    PubMed

    Rahim, S M; Mazlan, A G; Simon, K D; Delaunoy, J P; Laurent, P

    2014-02-01

    Pseudobranch function has long interested scientists, but its role has yet to be elucidated. Several studies have suggested that pseudobranchs serve respiratory, osmoregulatory, and sensory functions. This work investigated the immunolocalization of pseudobranch carbonic anhydrase (CA) in the teleost fish species rainbow trout (Oncorhynchus mykiss) to clarify its physiological function. CA was purified from rainbow trout gills O. mykiss and specific antibodies were raised. Immunoblotting between tissue homogenates of pseudobranch and gill CA antibodies showed specific immunostaining with only one band corresponding to CA in the pseudobranch homogenate. Results of immunohistochemical technique revealed that CA was distributed within pseudobranch cells and more precisely in the apical parts (anti-vascular) of cells. The basal (vascular) parts of cells, tubular system, blood capillaries, and pillar cells were not immunostained. Immunocytochemistry confirmed these results and showed that some CA enzyme was cytoplasmic and the remainder was linked to membranous structures. The results also showed that the lacunar tissue layers did not display immunoperoxidase activity. Our results indicated that pseudobranch CA may have a function related to the extracellular medium wherein CA intervenes with the mechanism of stimulation of afferent nerve fibers. PMID:24510712

  6. Compensatory growth response of rainbow trout Oncorhynchus mykiss Walbaum following short starvation periods

    NASA Astrophysics Data System (ADS)

    Azodi, Maryam; Ebrahimi, Eisa; Farhadian, Omidvar; Mahboobi-Soofiani, Nasrollah; Morshedi, Vahid

    2015-07-01

    This sixty-day study was performed to determine the effects of short-term starvation and re-feeding cycles on growth, feeding performances and body composition of rainbow trout ( Oncorhynchus mykiss). Three hundred trout fingerlings with an average initial weight of 17.5±0.06 g were randomly distributed in 15 circular fiberglass tanks. The fish were exposed to 5 different feeding regimes; control: continuously fed twice daily to apparent satiation; T1: starved for 1 day and re-fed for 2 days; T2: starved for 1 day and re-fed for 4 days; T3: starved for 3 days and re-fed for 12 days; T4: starved for 4 days and re-fed for 16 days. At the end of the experiment, growth performance, feed utilization, whole body ash and moisture contents were not significantly ( P>0.05) different among the treatments. However, whole body protein content in T3 was significantly higher than other treatments ( P<0.05). A significant difference in whole body fat content was observed between T3 and the control group at the end of the experiment ( P<0.05). In conclusion this experiment suggests that feeding schedules involving starvation (1-4 days) and re-feeding cycles are a promising feed management tool for rainbow trout culture.

  7. Effects of copper on immune system parameters of rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Dethloff, G.M.; Bailey, H.C.

    1998-09-01

    Agricultural, urban, industrial, and mining sources release metals into waterways. The effects of sublethal concentrations of metals on integrated physiological processes in fish, such as immunocompetency, are not well understood. The objective of this study was to determine the physiological effects of a range of sublethal copper concentrations on Shasta-strain rainbow trout (Oncorhynchus mykiss) exposed in soft water. Trout were sampled after 3, 7, 14, and 21 d of exposure to copper. The percentage of monocytes was consistently elevated at 26.9 {micro}g Cu/L, and the percentage of lymphocytes was decreased. A consistent increase in the percentage of neutrophils occurred at 26.9 and 6.4 {micro}g Cu/L. Respiratory burst activity was decreased for all concentrations at all sampling days, but a significant reduction occurred only at 14 and 21 d of exposure to copper. B-like cell proliferation was decreased by exposure to the higher copper concentrations. Proliferation results, however, had high variability. T-like cell proliferation and phagocytosis were not altered. Hepatic copper concentration was consistently elevated in trout exposed to 26.9 {micro}g Cu/L; no correlation was found between hepatic copper concentration and the immune system responses investigated. Consistent alterations in immunological parameters suggest that these parameters could serve as indicators of chronic metal toxicity in natural systems.

  8. Nutrient content in the muscle and skin of fillets from farmed rainbow trout (Oncorhynchus mykiss).

    PubMed

    Rebolé, A; Velasco, S; Rodríguez, M L; Treviño, J; Alzueta, C; Tejedor, J L; Ortiz, L T

    2015-05-01

    The nutrient content in the muscle and edible skin parts of rainbow trout (Oncorhynchus mykiss) fillets, sampled at two growth stages, was evaluated. The average concentrations of protein and essential amino acids were higher in the muscle than in the skin. The chemical scores reached a value of 1.0 for the amino acids in the muscle and ranged from 0.40 (tryptophan) to 0.94 (threonine) in the skin. The average lipid content and the saturated fatty acids/polyunsaturated fatty acids and n-6/n-3 ratios were higher in the skin than in the muscle, whereas the proportion of docosahexaenoic acid (C22:6 n-3) was higher in the muscle. Significant differences were found for the essential minerals analysed, except for Cu. The concentrations of Na, K and Mg were higher and those of Ca, P, Fe, Mn and Zn were lower in the muscle than in the skin. Significant effects of the fish growth on the composition were detected. PMID:25529727

  9. Inhibition of fish pathogens by the microbiota from rainbow trout (Oncorhynchus mykiss, Walbaum) and rearing environment.

    PubMed

    Araújo, Carlos; Muñoz-Atienza, Estefanía; Nahuelquín, Yanina; Poeta, Patrícia; Igrejas, Gilberto; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M

    2015-04-01

    This work reports the isolation and taxonomic identification of the cultivable total microbiota (TM) and Lactic Acid Bacteria (LAB) from rainbow trout (Oncorhynchus mykiss, Walbaum) and rearing environment from selected stages of the life-cycle, and the evaluation of the LAB antimicrobial activity against the main fish pathogens. TM and LAB isolates were randomly selected and identified by 16S rRNA and/or superoxide dismutase gene sequencing. Although a great diversity in the TM was observed, Enterobacteriaceae and Aeromonadaceae were clearly prevalent, while the genus Lactococcus was the predominant LAB. From a total of 1620 randomly selected LAB, 1159 isolates (71.5%) showed antimicrobial activity. From these, 248 isolates (21.4%) selected for their activity against, at least, four fish pathogens, were taxonomically identified, being Lactococcus lactis the most common species (164 isolates, 66.1%). Interestingly, 88 isolates (35.5%), including 55 L. lactis isolates, exerted activity against four strains of the rainbow trout pathogen Lactococcus garvieae. Our results demonstrate that rainbow trout and rearing environment are potential sources for the isolation of LAB, mainly lactococci, active against L. garvieae and other fish pathogens. Moreover, this is the first study describing the cultivable TM and LAB from rainbow trout intestine and rearing environment along the fish life-cycle. The host-derived LAB active against fish pathogens comprise potential candidates as probiotics in rainbow trout farming as an alternative or complementary strategy to antibiotics and vaccines for disease prevention. PMID:25464142

  10. Hepatic gene expression in rainbow trout (Oncorhynchus mykiss) exposed to different hydrocarbon mixtures.

    PubMed

    Hook, Sharon E; Lampi, Mark A; Febbo, Eric J; Ward, Jeff A; Parkerton, Thomas F

    2010-09-01

    Traditional biomarkers for hydrocarbon exposure are not induced by all petroleum substances. The objective of this study was to determine if exposure to a crude oil and different refined oils would generate a common hydrocarbon-specific response in gene expression profiles that could be used as generic biomarkers of hydrocarbon exposure. Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to the water accommodated fraction (WAF) of either kerosene, gas oil, heavy fuel oil, or crude oil for 96 h. Tissue was collected for RNA extraction and microarray analysis. Exposure to each WAF resulted in a different list of differentially regulated genes, with few genes in common across treatments. Exposure to crude oil WAF changed the expression of genes including cytochrome P4501A (CYP1A) and glutathione-S-transferase (GST) with known roles in detoxification pathways. These gene expression profiles were compared to others from previous experiments that used a diverse suite of toxicants. Clustering algorithms successfully identified gene expression profiles resulting from hydrocarbon exposure. These preliminary analyses highlight the difficulties of using single genes as diagnostic of petroleum hydrocarbon exposures. Further work is needed to determine if multivariate transcriptomic-based biomarkers may be a more effective tool than single gene studies for exposure monitoring of different oils.

  11. Behaviour of rainbow trout ( Oncorhynchus mykiss) under defensible and indefensible patterns of food delivery

    NASA Astrophysics Data System (ADS)

    Saeed Heydarnejad, M.; Purser, G. J.

    2010-07-01

    The goal of this study was to investigate the behaviour of rainbow trout ( n=30), Oncorhynchus mykiss, in small raceways when either self-feeders (T2) or hand-feeding (t2) were used. The method of food delivery in T2 was defensible while that of t2 was indefensible. Fish in both raceways were subjected to restricted feeding (RF) for 25 days. Food was available in the morning (09:00-10:00) in the downstream area and in the afternoon (16:00-17:00) in the upstream area of the raceways. The results showed that the behaviour of rainbow trout was significantly different under interference competition (T2) for food compared with that under scramble competition (t2). RF in T2 fish limited food availability to meal times when feeding rewards were available while t2 fish only responded to the location of food delivery. The aggressive fish in T2 were dominant, and t2 fish at high densities showed intense social interactions under the indefensible pattern of food distribution; these interactions did not dampen to a minimum level to suppress the development of dominance hierarchies. Further, the stocking density did not break down the dominance hierarchies between the T2 fish. This suggests that decreased efficiency in the search for food or inefficient foraging, induced by interference competition at high densities, affected the behaviour of rainbow trout.

  12. Effect of hypoxia on specific dynamic action and postprandial cardiovascular physiology in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Eliason, Erika J; Farrell, Anthony P

    2014-05-01

    Fish routinely encounter hypoxic environments, which may have detrimental effects on digestion and performance. The present study measured oxygen consumption (MO2), gastrointestinal blood flow (GBF), cardiac output (Vb) and heart rate (f(H)) in rainbow trout Oncorhynchus mykiss at 10°C-11.5°C while exposed to a 1.5-h step-wise hypoxia treatment (80%, 60% and 40% saturation=16.7, 12.6 and 8.4 kPa, respectively), which began 4 h after being fed 1% of their body mass. GBF and f(H) significantly decreased by 41 and 25%-29%, respectively, at the most severe hypoxia step (40% saturation), while MO2 and Vb were maintained throughout the entire hypoxia exposure. Thus, GBF and f(H) were more sensitive to hypoxia than MO2 or Vb in digesting rainbow trout. Subsequent to the hypoxic exposure, the fish were returned to normoxia and monitored for a total of 50h after feeding. While the magnitude of SDA was unaffected, peak postprandial MO2 was reduced by 17%, and the duration of specific dynamic action (SDA) was prolonged by 6h in hypoxia-treated fish when compared to control fish. In conclusion, digestive performance was compromised both during and after the hypoxic exposure, which could lead to negative effects on growth.

  13. Coho Salmon (Oncorhynchus kisutch) Prefer and Are Less Aggressive in Darker Environments

    PubMed Central

    Gaffney, Leigh P.; Franks, Becca; Weary, Daniel M.; von Keyserlingk, Marina A. G.

    2016-01-01

    Fish are capable of excellent vision and can be profoundly influenced by the visual properties of their environment. Ambient colours have been found to affect growth, survival, aggression and reproduction, but the effect of background darkness (i.e., the darkness vs. lightness of the background) on preference and aggression has not been evaluated systematically. One-hundred Coho salmon (Oncorhynchus kisutch), a species that is increasing in popularity in aquaculture, were randomly assigned to 10 tanks. Using a Latin-square design, every tank was bisected to allow fish in each tank to choose between all the following colour choices (8 choices in total): black vs. white, light grey, dark grey, and a mixed dark grey/black pattern, as well as industry-standard blue vs. white, light grey, dark grey, and black. Fish showed a strong preference for black backgrounds over all other options (p < 0.01). Across tests, preference strength increased with background darkness (p < 0.0001). Moreover, having darker backgrounds in the environment resulted in less aggressive behaviour throughout the tank (p < 0.0001). These results provide the first evidence that darker tanks are preferred by and decrease aggression in salmonids, which points to the welfare benefits of housing farmed salmon in enclosures containing dark backgrounds. PMID:27028731

  14. Mechanisms of fenthion activation in rainbow trout (Oncorhynchus mykiss) acclimated to hypersaline environments

    SciTech Connect

    Lavado, Ramon Rimoldi, John M.; Schlenk, Daniel

    2009-03-01

    Previous studies in rainbow trout have shown that acclimation to hypersaline environments enhances the toxicity to thioether organophosphate and carbamate pesticides. In order to determine the role of biotransformation in this process, the metabolism of the thioether organophosphate biocide, fenthion was evaluated in microsomes from gills, liver and olfactory tissues in rainbow trout (Oncorhynchus mykiss) acclimated to freshwater and 17 per mille salinity. Hypersalinity acclimation increased the formation of fenoxon and fenoxon sulfoxide from fenthion in liver microsomes from rainbow trout, but not in gills or in olfactory tissues. NADPH-dependent and independent hydrolysis was observed in all tissues, but only NADPH-dependent fenthion cleavage was differentially modulated by hypersalinity in liver (inhibited) and gills (induced). Enantiomers of fenthion sulfoxide (65% and 35% R- and S-fenthion sulfoxide, respectively) were formed in liver and gills. The predominant pathway of fenthion activation in freshwater appears to be initiated through initial formation of fenoxon which may be subsequently converted to the most toxic metabolite fenoxon R-sulfoxide. However, in hypersaline conditions both fenoxon and fenthion sulfoxide formation may precede fenoxon sulfoxide formation. Stereochemical evaluation of sulfoxide formation, cytochrome P450 inhibition studies with ketoconazole and immunoblots indicated that CYP3A27 was primarily involved in the enhancement of fenthion activation in hypersaline-acclimated fish with limited contribution of FMO to initial sulfoxidation.

  15. Epizootiology and histopathology of Parvicapsula sp. in coho salmon Oncorhynchus kisutch

    USGS Publications Warehouse

    Yasutake, William T.; Elliott, Diane G.

    2003-01-01

    The epizootiology and histopathology of the myxosporean Parvicapsula sp. was studied during monthly health surveys of 4 groups of coho salmon Oncorhynchus kisutch at a commercial farm in Puget Sound, Washington, USA, from 1984 to 1986. No Parvicapsula sp. was detected in histological samples taken from juvenile fish in fresh water, but the parasite was detected in fish from all groups 2 to 8 mo after transfer to seawater net pens. Groups placed in seawater net pens in November and December had a higher prevalence of infection, and a longer period of continuous detected infection, than those introduced into net pens in May. For the groups transferred to seawater in November and December, the highest infection prevalence (45 to 90%) was detected during the following March and April. Among 13 tissues examined histologically, only the pseudobranch and kidney were positive for Parvicapsula sp., with 26 (62%) of 42 positive fish showing infections only in the pseudobranch, 5 (12%) showing infections only in the kidney, and 11 (26%) showing infections in both organs. Both the pseudobranch and kidney were apparent primary infection sites, but pseudobranch infections appeared to persist longer in a population. Pseudobranch infections were frequently heavy and associated with extensive inflammation and necrosis of filament and lamellar tissues. The kidney had been the only infection site reported for Parvicapsula sp. in previous studies of coho salmon.

  16. Genetic stock identification of immature chum salmon ( Oncorhynchus keta) in the western Bering Sea, 2004

    NASA Astrophysics Data System (ADS)

    Kang, Minho; Kim, Suam; Low, Loh-Lee

    2016-03-01

    Genetic stock identification studies have been widely applied to Pacific salmon species to estimate stock composition of complex mixed-stock fisheries. In a September-October 2004 survey, 739 chum salmon ( Oncorhynchus keta) specimens were collected from 23 stations in the western Bering Sea. We determined the genetic stock composition of immature chum salmon based on the previous mitochondria DNA baseline. Each regional estimate was computed based on the conditional maximum likelihood method using 1,000 bootstrap resampling and then pooled to the major regional groups: Korea - Japan - Primorie (KJP) / Russia (RU) / Northwest Alaska (NWA) / Alaska Peninsula - Southcentral Alaska - Southeast Alaska - British Columbia - Washington (ONA). The stock composition of immature chum salmon in the western Bering Sea was a mix of 0.424 KJP, 0.421 RU, 0.116 NWA, and 0.039 ONA stocks. During the study period, the contribution of Asian chum salmon stocks gradually changed from RU to KJP stock. In addition, North American populations from NWA and ONA were small but present near the vicinity of the Russian coast and the Commander Islands, suggesting that the study areas in the western Bering Sea were an important migration route for Pacific chum salmon originating both from Asia and North America during the months of September and October. These results make it possible to better understand the chum salmon stock composition of the mixed-stock fisheries in the western Bering Sea and the stock-specific distribution pattern of chum salmon on the high-seas.

  17. Effects of diesel on survival, growth, and gene expression in rainbow trout (Oncorhynchus mykiss) fry.

    PubMed

    Mos, Lizzy; Cooper, Glenn A; Serben, Kerrie; Cameron, Marc; Koop, Ben F

    2008-04-01

    Diesel spills are all too frequent disturbances of freshwater ecosystems, largely as a result of the quantities transported and consumed. Assessing the risk that such events may pose to aquatic life remains a difficult process, because of the complexity of this hydrocarbon mixture and our limited knowledge of its toxicity. A diesel spike experiment with rainbow trout (Oncorhynchus mykiss) fry was carried out to fill this knowledge gap. Survival, growth, and gene expression changes were assessed and toxicity thresholds were determined. Whereas the biological end points were consistent in the determination of (sub)lethal doses, microarrays supplied additional information on the mechanism of toxicity (oxygen deprivation) and potential long-term effects (feminization, immune system alterations) of diesel exposure on salmonids. Hemoglobins, prostaglandins, cytochromes, and gluthathion-S-transferases were among the molecular biomarkers proposed for use in future risk assessments based on microarray results. By bridging traditional toxicity testing with recent microarray technologies, this study shows the potential of genomics tools in ecotoxicity studies as well as industrial applications, including risk assessment, in the near future.

  18. A novel role for pigment genes in the stress response in rainbow trout (Oncorhynchus mykiss)

    PubMed Central

    Khan, Uniza Wahid; Øverli, Øyvind; Hinkle, Patricia M.; Pasha, Farhan Ahmad; Johansen, Ida Beitnes; Berget, Ingunn; Silva, Patricia I. M.; Kittilsen, Silje; Höglund, Erik; Omholt, Stig W.; Våge, Dag Inge

    2016-01-01

    In many vertebrate species visible melanin-based pigmentation patterns correlate with high stress- and disease-resistance, but proximate mechanisms for this trait association remain enigmatic. Here we show that a missense mutation in a classical pigmentation gene, melanocyte stimulating hormone receptor (MC1R), is strongly associated with distinct differences in steroidogenic melanocortin 2 receptor (MC2R) mRNA expression between high- (HR) and low-responsive (LR) rainbow trout (Oncorhynchus mykiss). We also show experimentally that cortisol implants increase the expression of agouti signaling protein (ASIP) mRNA in skin, likely explaining the association between HR-traits and reduced skin melanin patterning. Molecular dynamics simulations predict that melanocortin 2 receptor accessory protein (MRAP), needed for MC2R function, binds differently to the two MC1R variants. Considering that mRNA for MC2R and the MC1R variants are present in head kidney cells, we hypothesized that MC2R activity is modulated in part by different binding affinities of the MC1R variants for MRAP. Experiments in mammalian cells confirmed that trout MRAP interacts with the two trout MC1R variants and MC2R, but failed to detect regulation of MC2R signaling, possibly due to high constitutive MC1R activity. PMID:27373344

  19. Sources of variation in counts of meristic features of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri)

    USGS Publications Warehouse

    Kruse, C.G.; Hubert, W.A.; Rahel, F.J.

    1996-01-01

    We determined variability in counts of meristic features (pyloric caceae, vertebrae, pelvic fin rays, gill-rakers, basibranchial teeth, scales above the lateral line, and scales in the lateral series) of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri) by 3 independent readers, by the same reader on 3 different occasions, and among fish from 12 sampling sites within a 650-km2 watershed. Genetic purity of the cutthroat trout was determined by electrophoretic analysis. Significant differences in meristic counts were observed among 3 readers and among sampling sites, but not among 3 occasions by a single reader. Scale counts were within the reported range for Yellowstone cutthroat trout, but counts of other structures (pyloric caceae, gillrakers, vertebrae) were as similar to rainbow trout as to Yellowstone cutthroat trout. Meristic counts identified the fish as cutthroat trout; however, variation among readers and sampling sites as well as within the species, limits their use when identifying genetically pure cutthroat trout or assessing possible integration with rainbow trout.

  20. Impacts of multispecies parasitism on juvenile coho salmon (Oncorhynchus kisutch) in Oregon

    USGS Publications Warehouse

    Ferguson, Jayde A.; Romer, Jeremy; Sifneos, Jean C.; Madsen, Lisa; Schreck, Carl B.; Glynn, Michael; Kent, Michael L.

    2011-01-01

    We are studying the impacts of parasites on threatened stocks of Oregon coastal coho salmon (Oncorhynchus kisutch). In our previous studies, we have found high infections of digeneans and myxozoans in coho salmon parr from the lower main stem of West Fork Smith River (WFSR), Oregon. In contrast parr from tributaries of this river, and outmigrating smolts, harbor considerably less parasites. Thus, we have hypothesized that heavy parasite burdens in parr from this river are associated with poor overwintering survival. The objective of the current study was to ascertain the possible effects these parasites have on smolt fitness. We captured parr from the lower main stem and tributaries of WFSR and held them in the laboratory to evaluate performance endpoints of smolts with varying degrees of infection by three digeneans (Nanophyetus salmincola, Apophallus sp., and neascus) and one myxozoan (Myxobolus insidiosus). The parameters we assessed were weight, fork length, growth, swimming stamina, and gill Na+,K+-ATPase activity. We repeated our study on the subsequent year class and with hatchery reared coho salmon experimentally infected with N. salmincola. The most significant associations between parasites and these performance or fitness endpoints were observed in the heavily infected groups from both years. We found that all parasite species, except neascus, were negatively associated with fish fitness. This was corroborated for N. salmincola causing reduced growth with our experimental infection study. Parasites were most negatively associated with growth and size, and these parameters likely influenced the secondary findings with swimming stamina and ATPase activity levels.

  1. Multiple biomarkers responses in juvenile rainbow trout, Oncorhynchus mykiss, after acute exposure to a fungicide propiconazole.

    PubMed

    Li, Zhi-Hua; Zlabek, Vladimir; Velisek, Josef; Grabic, Roman; Machova, Jana; Kolarova, Jitka; Li, Ping; Randak, Tomas

    2013-03-01

    In this study, the toxic effects of propiconazole (PCZ), a triazole fungicide present in aquatic environment, were studied in juvenile rainbow trout, Oncorhynchus mykiss, by acute toxicity test with the concentration of 5.04 mg/L (96 h LC50). Morphological indices, hematological parameters, liver xenobiotic-metabolizing response, and tissue antioxidant status were evaluated. Compared with the control group, fish exposed to PCZ showed significantly higher Leuko, PCV, MCHC, and hepatic EROD, and significantly lower MCV. CF and HSI were not significantly different among groups. SOD, CAT, GPx, and GR activities increased significantly in liver of experimental groups, but decreased significantly in gill. In general, antioxidant enzyme activity in intestine was less evident than in liver. Oxidative stress indices (levels of LPO and CP) were significantly higher in gill. Additionally, through chemometrics of all parameters measured in this study, two groups with 67.29% of total accumulated variance were distinguished. In short, the physiological and biochemical responses in different tissues of fish indicated that PCZ-induced the stressful environmental conditions. But according to PCZ residual status in the natural environment, more long-term experiments at lower concentrations will be necessary in the future. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.

  2. Altered burst swimming in rainbow trout Oncorhynchus mykiss exposed to natural and synthetic oestrogens.

    PubMed

    Osachoff, H L; Osachoff, K N; Wickramaratne, A E; Gunawardane, E K; Venturini, F P; Kennedy, C J

    2014-08-01

    Juvenile rainbow trout Oncorhynchus mykiss were exposed to two concentrations each of 17β-oestradiol (E2; natural oestrogen hormone) or 17α-ethinyl oestradiol (EE2; a potent synthetic oestrogen hormone) to evaluate their potential effects on burst-swimming performance. In each of six successive burst-swimming assays, burst-swimming speed (Uburst ) was lower in fish exposed to 0.5 and 1 µg l(-1) E2 and EE2 for four days compared with control fish. A practice swim (2 days prior to exposure initiation) in control fish elevated initial Uburst values, but this training effect was not evident in the 1 µg l(-1) EE2-exposed fish. Several potential oestrogen-mediated mechanisms for Uburst reductions were investigated, including effects on metabolic products, osmoregulation and blood oxygen-carrying capacity. Prior to burst-swimming trials, fish exposed to E2 and EE2 for 4 days had significantly reduced erythrocyte numbers and lower plasma glucose concentrations. After six repeated burst-swimming trials, plasma glucose, lactate and creatinine concentrations were not significantly different among treatment groups; however, plasma Cl(-) concentrations were significantly reduced in E2- and EE2-treated fish. In summary, E2 and EE2 exposure altered oxygen-carrying capacity ([erythrocytes]) and an osmoregulatory-related variable ([Cl(-) ]), effects that may underlie reductions in burst-swimming speed, which will have implications for fish performance in the wild.

  3. NORs inheritance analysis in crossings including individuals from two stocks of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Porto-Foresti, Fábio; Oliveira, Claudio; Tabata, Yara Aiko; Rigolino, Marcos Guilherme; Foresti, Fausto

    2002-01-01

    Silver nitrate staining of rainbow trouts (Oncorhynchus mykiss) chromosomes, for the identification of the nucleolar organizing regions (NORs), revealed that in individuals from Núcleo Experimental de Salmonicultura de Campos do Jordão (Brazil) NORs were located in the long arms of submetacentric pair while in specimens from Mount Shasta (USA) NORs were located in the short arms of a submetacentric pair. Cytogenetic analysis of the offspring, obtained through artificial crosses including individuals from both stocks, allowed the identification of NORs in two submetacentric chromosomes, one in the short arms and the other in the long arms, confirming the effectiveness of the hybridization process. Complementary results obtained using the FISH technique with 18S and 5S rDNA probes showed that NOR-bearing chromosomes exhibited a cluster of 5S genes located in tandem with the 18S gene cluster in both stocks. The results allow us to suggest that the difference in NOR-bearing chromosomes found between the two stocks is likely to be due to pericentric inversion involving the chromosome segment where 18S and 5S rDNA genes are located. The presence of ribosomal genes in the long arms of a submetacentric chromosome is apparently a particular characteristic of the rainbow trout stock of Campos do Jordão and might be used as a chromosome marker in studies of controlled crosses in this species.

  4. A novel role for pigment genes in the stress response in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Khan, Uniza Wahid; Øverli, Øyvind; Hinkle, Patricia M; Pasha, Farhan Ahmad; Johansen, Ida Beitnes; Berget, Ingunn; Silva, Patricia I M; Kittilsen, Silje; Höglund, Erik; Omholt, Stig W; Våge, Dag Inge

    2016-01-01

    In many vertebrate species visible melanin-based pigmentation patterns correlate with high stress- and disease-resistance, but proximate mechanisms for this trait association remain enigmatic. Here we show that a missense mutation in a classical pigmentation gene, melanocyte stimulating hormone receptor (MC1R), is strongly associated with distinct differences in steroidogenic melanocortin 2 receptor (MC2R) mRNA expression between high- (HR) and low-responsive (LR) rainbow trout (Oncorhynchus mykiss). We also show experimentally that cortisol implants increase the expression of agouti signaling protein (ASIP) mRNA in skin, likely explaining the association between HR-traits and reduced skin melanin patterning. Molecular dynamics simulations predict that melanocortin 2 receptor accessory protein (MRAP), needed for MC2R function, binds differently to the two MC1R variants. Considering that mRNA for MC2R and the MC1R variants are present in head kidney cells, we hypothesized that MC2R activity is modulated in part by different binding affinities of the MC1R variants for MRAP. Experiments in mammalian cells confirmed that trout MRAP interacts with the two trout MC1R variants and MC2R, but failed to detect regulation of MC2R signaling, possibly due to high constitutive MC1R activity. PMID:27373344

  5. Post-release behavior and movement patterns of Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) after capture using alternative commercial fish gear, lower Columbia River, Washington and Oregon, 2013

    USGS Publications Warehouse

    Liedtke, Theresa L.; Kock, Tobias J.; Evans, Scott D.; Hansen, Gabriel S.; Rondorf, Dennis W.

    2014-01-01

    In 2011 and 2012, WDFW conducted post-release mortality studies of steelhead (Oncorhynchus mykiss), Chinook salmon (Oncorhynchus tshawytscha), and coho salmon (Oncorhynchus kisutch) that were captured using beach or purse seines. These studies were comprised of two groups of fish tagged with passive integrated transponder tags (PIT tags): (1) treatment fish that were captured by one of the gear types 9–25 river kilometers (rkm) downstream of Bonneville Dam (rkm 234); and (2) control fish that were captured at the Adult Fish Facility near the Washington shore fish ladder at Bonneville Dam, and then transported and released 8 rkm downstream of the Bonneville Dam. Fish were confirmed to have survived if they moved upstream and were detected on PIT-tag antennas at or upstream of Bonneville Dam, were recovered at hatcheries or at the dam, or were captured by commercial or sport fishers. Post-release survival estimates were higher for steelhead (89–98 percent) than for Chinook salmon and coho salmon (50–90 percent; Washington Department of Fish and Wildlife, unpub. data, 2014). However, some Chinook salmon and coho salmon return to hatcheries, or spawn in the mainstem Columbia River and in tributaries downstream of Bonneville Dam. The proportion of Chinook salmon and coho salmon in the treatment group that were destined for areas downstream of Bonneville Dam likely was higher than in the control group because the control fish were collected as they were attempting to pass the dam. If this assertion was true, mortality would have been overestimated in these studies, so WDFW developed a study plan to determine the post-release movements and intended location of Chinook salmon and coho salmon collected with beach and purse seines in the lower Columbia River.

  6. Morphological and molecular characterisation of Gyrodactylus salmonis (Platyhelminthes, Monogenea) isolates collected in Mexico from rainbow trout (Oncorhynchus mykiss Walbaum).

    PubMed

    Rubio-Godoy, Miguel; Paladini, Giuseppe; Freeman, Mark A; García-Vásquez, Adriana; Shinn, Andrew P

    2012-05-25

    Gyrodactylus salmonis (Yin et Sproston, 1948) isolates collected from feral rainbow trout, Oncorhynchus mykiss (Walbaum) in Veracruz, southeastern Mexico are described. Morphological and molecular variation of these isolates to G. salmonis collected in Canada and the U.S.A. is characterised. Morphologically, the marginal hook sickles of Mexican isolates of G. salmonis closely resemble those of Canadian specimens - their shaft and hook regions align closely with one another; only features of the sickle base and a prominent bridge to the toe permit their separation. The 18S sequence determined from the Mexican specimens was identical to two variable regions of SSU rDNA obtained from a Canadian population of G. salmonis. Internal transcribed spacer (ITS) regions (spanning ITS1, 5.8S and ITS2) of Mexican isolates of G. salmonis are identical to ITS sequences of an American population of G. salmonis and to Gyrodactylus salvelini Kuusela, Ziętara et Lumme, 2008 from Finland. Analyses of the ribosomal RNA gene of Mexican isolates of G. salmonis show 98-99% similarity to those of Gyrodactylus gobiensis Gläser, 1974, Gyrodactylus salaris Malmberg, 1957, and Gyrodactylus rutilensis Gläser, 1974. Mexican and American isolates of G. salmonis are 98% identical, as assessed by sequencing the mitochondrial cox1 gene. Oncorhynchus mykiss is one of the most widely-dispersed fish species in the world and has been shown to be an important vector for parasite/disease transmission. Considering that Mexican isolates of G. salmonis were collected well outside the native distribution range of all salmonid fish, we discuss the possibility that the parasites were translocated with their host through the aquacultural trade. In addition, this study includes a morphological review of Gyrodactylus species collected from rainbow trout and from other salmonid fish of the genus Oncorhynchus which occur throughout North America.

  7. Novel molecular markers differentiate Oncorhynchus mykiss (rainbow trout and steelhead) and the O. clarki (cutthroat trout) subspecies

    USGS Publications Warehouse

    Ostberg, C.O.; Rodriguez, R.J.

    2002-01-01

    A suite of 26 PCR-based markers was developed that differentiates rainbow (Oncorhynchus mykiss) and coastal cutthroat trout (O. clarki clarki). The markers also differentiated rainbow from other cutthroat trout subspecies (O. clarki), and several of the markers differentiated between cutthroat trout subspecies. This system has numerous positive attributes, including: nonlethal sampling, high species-specificity and products that are easily identified and scored using agarose gel electrophoresis. The methodology described for developing the markers can be applied to virtually any system in which numerous markers are desired for identifying or differentiating species or subspecies.

  8. Growth of age-0 steelhead (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) in the Pine River watershed, Alcona County, Michigan

    SciTech Connect

    Bellgraph, Brian J.; Thompson, Bradley E.; Hayes, Daniel B.; Riley, Timothy S.

    2006-12-01

    We sampled ten sites within the Pine River watershed, Alcona County, Michigan. In 2001, age-0 steelhead (Oncorhynchus mykiss) were collected to determine growth rates. In 2002, emergence dates of steelhead were determined by observational studies and age-0 steelhead and brook trout (Salvelinus fontinalis) were collected to determine growth rates. Steelhead emergence occurred from late June to mid-July 2002. Growth rates of both species varied among branches within the watershed (P<0.05). Steelhead growth varied from 0.24 to 0.42 mm/day and brook trout growth varied from 0.22 to 0.37 mm/day.

  9. Antibody-producing cells correlated to body weight in juvenile chinook salmon (Oncorhynchus tshawytscha) acclimated to optimal and elevated temperatures

    USGS Publications Warehouse

    Harrahy, L.N.M.; Schreck, C.B.; Maule, A.G.

    2001-01-01

    The immune response of juvenile chinook salmon (Oncorhynchus tshawytscha) ranging in weight from approximately 10 to 55 g was compared when the fish were acclimated to either 13 or 21?? C. A haemolytic plaque assay was conducted to determine differences in the number of antibody-producing cells (APC) among fish of a similar age but different body weights. Regression analyses revealed significant increases in the number of APC with increasing body weight when fish were acclimated to either water temperature. These results emphasise the importance of standardising fish weight in immunological studies of salmonids before exploring the possible effects of acclimation temperatures. ?? 2001 Academic Press.

  10. Effects of freshwater exposure to arsenic trioxide on the parr-smolt transformation of coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Nichols, J.W.; Wedemeyer, G.A.; Mayer, F.L.; Dickhoff, Walton W.; Gregory, S.V.; Yasutake, W.T.; Smith, S.D.

    1984-01-01

    The effects of chronic (6 months) exposure to arsenic trioxide in fresh water on the Parr-smolt transformation of coho salmon (Oncorhynchus kisutch) were evaluated. Exposure to 300 μg As/L (as As2O3) appeared to delay the onset of the normal increase in plasma thyroxine concentration and cause a transient reduction of gill Na+,K+-ATPase activity. Fish exposed to 300 μg As/L also migrated to the sea less successfully than did nonexposed smolts, but there were no effects on the survival and growth of smolts held in 28‰ salt water for 6 months.

  11. Temperature seasonality during fry out-migration influences the survival of hatchery-reared chum salmon Oncorhynchus keta.

    PubMed

    Morita, K; Nakashima, A

    2015-10-01

    Among years, fry-to-adult survival of hatchery-reared chum salmon Oncorhynchus keta was positively correlated with the length (in days) of the fry out-migration period with temperatures suitable for migration. Furthermore, survival decreased with increasing difference in mean temperature between May and June. Thus, prolonged out-migration periods increased the probability of survival from fry to adult, lending support to the hypothesis that long migration periods decrease the risk of mortality (bet-hedging), and increase the probability of migration when environmental conditions in fresh water and the ocean are suitable (match-mismatch).

  12. Transcription profiling in environmental diagnostics: health assessments in Columbia River basin steelhead (Oncorhynchus mykiss).

    PubMed

    Connon, Richard E; D'Abronzo, Leandro S; Hostetter, Nathan J; Javidmehr, Alireza; Roby, Daniel D; Evans, Allen F; Loge, Frank J; Werner, Inge

    2012-06-01

    The health condition of out-migrating juvenile salmonids can influence migration success. Physical damage, pathogenic infection, contaminant exposure, and immune system status can affect survival probability. The present study is part of a wider investigation of out-migration success in juvenile steelhead (Oncorhynchus mykiss) and focuses on the application of molecular profiling to assess sublethal effects of environmental stressors in field-collected fish. We used a suite of genes in O. mykiss to specifically assess responses that could be directly related to steelhead health condition during out-migration. These biomarkers were used on juvenile steelhead captured in the Snake River, a tributary of the Columbia River, in Washington, USA, and were applied on gill and anterior head kidney tissue to assess immune system responses, pathogen-defense (NRAMP, Mx, CXC), general stress (HSP70), metal-binding (metallothionein-A), and xenobiotic metabolism (Cyp1a1) utilizing quantitative polymerase chain reaction (PCR) technology. Upon capture, fish were ranked according to visual external physical conditions into good, fair, poor, and bad categories; gills and kidney tissues were then dissected and preserved for gene analyses. Transcription responses were tissue-specific for gill and anterior head kidney with less significant responses in gill tissue than in kidney. Significant differences between the condition ranks were attributed to NRAMP, MX, CXC, and Cyp1a1 responses. Gene profiling correlated gene expression with pathogen presence, and results indicated that gene profiling can be a useful tool for identifying specific pathogen types responsible for disease. Principal component analysis (PCA) further correlated these responses with specific health condition categories, strongly differentiating good, poor, and bad condition ranks. We conclude that molecular profiling is an informative and useful tool that could be applied to indicate and monitor numerous population

  13. Does feed composition affect oxidation of rainbow trout (Oncorhynchus mykiss) during frozen storage?

    PubMed

    Baron, Caroline P; Hyldig, Grethe; Jacobsen, Charlotte

    2009-05-27

    Rainbow trout ( Oncorhynchus mykiss ) were fed a diet containing either fish oil or rapeseed oil and with or without 200 mg/kg carotenoid (either astaxanthin or canthaxanthin). A total of six diets were obtained: (1) fish oil/astaxanthin; (2) vegetable oil/astaxanthin; (3) fish oil/canthaxanthin; (4) vegetable oil/canthaxanthin; (5) fish oil/no pigment; and (6) vegetable oil/no pigment. The fish were slaughtered and stored in polyethylene bags individually as butterfly fillets for up to 22 months at -20 °C. The composition of the fish muscle at slaughter and during frozen storage was evaluated by sampling after 4, 8, 13, 18, and 22 months. The carotenoid content in the muscle was found to be approximately 9-10 mg/kg of fish for both carotenoids. Primary oxidation lipid products (peroxides) as well as secondary oxidation products (volatiles) were measured. In addition, the level of protein carbonyl groups and the content of tocopherols and carotenoids in the muscle were also measured. To estimate the overall changes in sensory properties of the different samples during storage, a trained sensory panel also evaluated the samples. Both the sensory panel and the chemical analysis revealed that in this investigation fish fed fish oil were slightly more oxidized than fish fed vegetable oil. Results showed that canthaxanthin effectively protected both protein and lipid against oxidation during frozen storage. In contrast, astaxanthin did not seem to have a clear and systematic effect. Results indicated that the feed composition influenced the fish muscle composition and subsequently the oxidative stability of the fish during frozen storage. Besides, other constituents in the feed might influence deposition of antioxidants in the tissue and consequently affect the oxidative stability of the muscle.

  14. Genetic Architecture of Migration-Related Traits in Rainbow and Steelhead Trout, Oncorhynchus mykiss

    PubMed Central

    Hecht, Benjamin C.; Thrower, Frank P.; Hale, Matthew C.; Miller, Michael R.; Nichols, Krista M.

    2012-01-01

    Although migration plays a critical role in the evolution and diversification of species, relatively little is known of the genetic architecture underlying this life history in any species. Rainbow and steelhead trout (Oncorhynchus mykiss) naturally segregate for both resident and migratory life-history types, respectively, as do other members of the salmonid family of fishes. Using an experimental cross derived from wild resident rainbow and wild migratory steelhead trout from Southeast Alaska and high throughput restriction-site associated DNA (RAD) tag sequencing, we perform a quantitative trait locus (QTL) analysis to identify the number, position, and relative contribution of genetic effects on a suite of 27 physiological and morphological traits associated with the migratory life history in this species. In total, 37 QTL are localized to 19 unique QTL positions, explaining 4–13.63% of the variation for 19 of the 27 migration-related traits measured. Two chromosomal positions, one on chromosome Omy12 and the other on Omy14 each harbor 7 QTL for migration-related traits, suggesting that these regions could harbor master genetic controls for the migratory life-history tactic in this species. Another QTL region on Omy5 has been implicated in several studies of adaptive life histories within this species and could represent another important locus underlying the migratory life history. We also evaluate whether loci identified in this out-crossed QTL study colocalize to genomic positions previously identified for associations with migration-related traits in a doubled haploid mapping family. PMID:22973549

  15. Effects of deltamethrin on excitability and contractility of the rainbow trout (Oncorhynchus mykiss) heart.

    PubMed

    Haverinen, Jaakko; Vornanen, Matti

    2014-01-01

    Pyrethroids are extensively used for the control of pest insects and disease vectors. Pyrethroid use is regarded safe due to their selective toxicity: they are effective against insects but relatively harmless to mammals and birds. Unfortunately, pyrethroids are very toxic to fishes. The high toxicity of pyrethroids to fishes is only partly explained by slow elimination rate of toxins, suggesting that high affinity binding to their molecular targets, the Na(+) channels, is involved. This study tests the hypothesis that Na(+) channels of the fish heart are targets to a type II pyrethroid, deltamethrin (DM), and therefore pyrethroids are cardiotoxic to fishes. In ventricular myocytes of the rainbow trout (Oncorhynchus mykiss) heart DM (10(-7)-3·10(-5) M) modified Na(+) current by slowing inactivation and shifting the reversal potential of the current to the left. Maximally 31±2% of the cardiac Na(+) channels were modified by DM and the half-maximal effect occurred at the concentration of 2.1 μM. The effect of DM on trout cardiac Na(+) channels is stronger and occurs about an order of magnitude lower in concentration in comparison to the orthologous mammalian Na(+) channels. In sinoatrial preparations of the trout heart DM (10 μM) caused irregularities in rate, rhythm and force of the heartbeat indicating that DM can be arrhythmogenic for the trout heart. Consistent with this, DM (>0.1 μM) induced spontaneous action potentials in otherwise quiescent ventricular myocytes. DM (10 μM) did not affect calcium current or inward rectifier and delayed rectifier potassium currents. Collectively, these findings indicate that DM exerts cardiotoxic effects in trout, and suggest that the high sensitivity of fishes to pyrethroid toxicity might be partially due to the high affinity of fish Na(+) channels to pyrethroids. PMID:24100050

  16. Quantitative evaluation of macrophage aggregates in brook trout Salvelinus fontinalis and rainbow trout Oncorhynchus mykiss

    USGS Publications Warehouse

    Schwindt, Adam R.; Truelove, Nathan; Schreck, Carl B.; Fournie, John W.; Landers, Dixon H.; Kent, Michael L.

    2006-01-01

    Macrophage aggregates (MAs) occur in various organs of fishes, especially the kidney, liver and spleen, and contain melanin, ceroid/lipofuscin and hemosiderin pigments. They have been used as indicators of a number of natural and anthropogenic stressors. Macrophage aggregates occur in salmonids but are poorly organized, irregularly shaped, and are generally smaller than those in derived teleosts. These features complicate quantification, and thus these fishes have seldom been used in studies correlating MAs with environmental stressors. To alleviate these complications, we developed color filtering algorithms for use with the software package ImagePro Plus® (Media Cybernetics) that select and quantify pigmented area (i.e. colors ranging from gold to brown to black) in tissue sections. Image analysis results compared well with subjective scoring when tested on brook trout Salvelinus fontinalis and rainbow trout Oncorhynchus mykiss captured from high-elevation lakes or hatcheries. Macrophage aggregate pigments correlated positively with age and negatively with condition factor. Within individual fish, pigmentation correlated positively among organs, suggesting that the kidney, liver or spleen are suitable indicator organs. In age-matched fishes, MA pigments were not different between hatcheries and lakes in the organs examined. Between lakes, differences in pigments were observed in the kidney and spleen, but were not explained by age, condition factor, sex or maturation state. Our results indicate that quantification of the area occupied by MA pigments is an efficient and accurate means of evaluating MAs in salmonid organs and that organ pigmentation correlates with age and condition factor, as seen in studies with more derived fishes. 

  17. The interactive toxicity of cadmium, copper, and zinc to Ceriodaphnia dubia and rainbow trout (Oncorhynchus mykiss).

    PubMed

    Naddy, Rami B; Cohen, Adam S; Stubblefield, William A

    2015-04-01

    Traditionally, aquatic toxicity studies examine the toxicity of a single chemical to an organism. Organisms in nature, however, may be exposed to multiple toxicants. Given this is a more realistic exposure scenario in situ, the authors sought to understand the interactive toxicity of multiple metals to aquatic organisms. The authors performed a series of studies using equitoxic mixtures of cadmium, copper, and zinc to 2 aquatic organisms, rainbow trout (Oncorhynchus mykiss) and the waterflea, Ceriodaphnia dubia. Single metal toxicity tests were conducted to determine the acute median lethal concentration (LC50) values for O. mykiss and short-term, chronic median effective concentration (EC50) values for C. dubia. All 3 metals were then combined in equitoxic concentrations for subsequent mixture studies using a toxic unit (TU) approach (i.e., 1 TU = EC50 or LC50). For C. dubia, the mixture study showed greater-than-additive effects in hard water (TU-based EC50 = 0.74 TU), but less-than-additive effects in soft water (TU-based EC50 = 1.93 TU). The mixture effects for O. mykiss showed less-than-additive effects in both hard and soft waters, with TU-based LC50 values of 2.33 total TU and 2.22 total TU, respectively. These data are useful in helping understand metal mixture toxicity in aquatic systems and indicate that although in most situations the assumption of additivity of metal mixture toxicity is valid, under certain conditions it may not be sufficiently protective.

  18. Orally administered erythromycin in rainbow trout (Oncorhynchus mykiss): residues in edible tissues and withdrawal time.

    PubMed

    Esposito, Annarita; Fabrizi, Laura; Lucchetti, Dario; Marvasi, Luigi; Coni, Ettore; Guandalini, Emilio

    2007-03-01

    Aquaculture production has notably increased in the last decades, mainly thanks to intensive farming. Together with market globalization, this gives rise to the spreading of several fish diseases, thus increasing the demand for veterinary drugs for aquatic species. Nonetheless, very few chemicals are registered for use in aquaculture, and fish farmers are often forced to resort to off-label use of drugs authorized for other food-producing animal species. Rainbow trout is the major farmed fish species in Italy and the second one in Europe. Erythromycin is the antibiotic of choice against gram-positive cocci, the major concern for trout farming, but it is not yet registered for aquaculture use in most European countries. The aim of this study was to follow the depletion of erythromycin in rainbow trout (Oncorhynchus mykiss), after its administration at 100 mg kg(-1) trout body weight day(-1) for 21 days through medicated feed (water temperature, 11.5 degrees C). Erythromycin residues in fish muscle plus skin in natural proportion were determined by a validated liquid chromatography-electrospray ionization-tandem mass spectrometry method. Interpolation of our data, following European Agency for the Evaluation of Medicinal Products guidelines, gives a withdrawal time of 255 degrees C-days ( degrees C-day = water temperature x days), thus showing that the general value (500 degrees C-day) recommended by the Council Directive (EEC) no. 82/2001 for off-label drug use in aquaculture would be too conservative in this case, with excessive costs for the farmers. Our study provides preliminary data for a more prudent use of erythromycin in rainbow trout, suggesting a possible withdrawal time after treatment. PMID:17194823

  19. Gene Flow between Sympatric Life History Forms of Oncorhynchus mykiss Located above and below Migratory Barriers

    PubMed Central

    Van Doornik, Donald M.; Berejikian, Barry A.; Campbell, Lance A.

    2013-01-01

    Oncorhynchus mykiss have a diverse array of life history types, and understanding the relationship among types is important for management of the species. Patterns of gene flow between sympatric freshwater resident O. mykiss, commonly known as rainbow trout, and anadromous O. mykiss, commonly known as steelhead, populations are complex and poorly understood. In this study, we attempt to determine the occurrence and pathways of gene flow and the degree of genetic similarity between sympatric resident and anadromous O. mykiss in three river systems, and investigate whether resident O. mykiss are producing anadromous offspring in these rivers, two of which have complete barriers to upstream migration. We found that the population structure of the O. mykiss in these rivers appears to be influenced more by the presence of a barrier to upstream migration than by life history type. The sex ratio of resident O. mykiss located above a barrier, and smolts captured in screw traps was significantly skewed in favor of females, whereas the reverse was true below the barriers, suggesting that male resident O. mykiss readily migrate downstream over the barrier, and that precocious male maturation may be occurring in the anadromous populations. Through paternity analyses, we also provide direct confirmation that resident O. mykiss can produce offspring that become anadromous. Most (89%) of the resident O. mykiss that produced anadromous offspring were males. Our results add to the growing body of evidence that shows that gene flow does readily occur between sympatric resident and anadromous O. mykiss life history types, and indicates that resident O. mykiss populations may be a potential repository of genes for the anadromous life history type. PMID:24224023

  20. Effects of aquaculture production noise on hearing, growth, and disease resistance of rainbow trout Oncorhynchus mykiss

    USGS Publications Warehouse

    Wysocki, L.E.; Davidson, J. W.; Smith, M.E.; Frankel, A.S.; Ellison, W.T.; Mazik, P.M.; Popper, A.N.; Bebak, J.

    2007-01-01

    Intensive aquaculture production often utilizes equipment (e.g., aerators, air and water pumps, harvesters, blowers, filtration systems, and maintenance machinery) that increases noise levels in fish culture tanks. Consequently, chronic exposure to elevated noise levels in tanks could negatively impact cultured species. Possible effects include impairment of the auditory system, increased stress, and reduced growth rates. The objective of this study was to evaluate the long-term effects of sound exposure on the hearing sensitivity, growth, and survival of cultured rainbow trout (Oncorhynchus mykiss). Two cohorts of rainbow trout were cultured for 8??months in replicated tanks consisting of three sound treatments: 115, 130, or 150 decibels referenced at 1 micropascal (dB re 1????Pa root mean square [RMS]) levels. Auditory evoked potential (AEP) recordings revealed no significant differences in hearing thresholds resulting from exposure to increased ambient sound levels. Although there was no evident noise-induced hearing loss, there were significant differences in hearing thresholds between the two fish cohorts examined. No statistical effect of sound treatment was found for growth rate and mortality within each fish cohort. There was no significant difference in mortality between sound treatments when fish were exposed to the pathogen Yersinia ruckeri, but there was significantly different mortality between cohorts. This study indicated that rainbow trout hearing sensitivity, growth, survival, stress, and disease susceptibility were not negatively impacted by noise levels common to recirculating aquaculture systems. These findings should not be generalized to all cultured fish species, however, because many species, including catfish and cyprinids, have much greater hearing sensitivity than rainbow trout and could be affected differently by noise. ?? 2007 Elsevier B.V. All rights reserved.

  1. Ontogenetic changes in photoreceptor opsin gene expression in coho salmon (Oncorhynchus kisutch, Walbaum).

    PubMed

    Temple, S E; Veldhoen, K M; Phelan, J T; Veldhoen, N J; Hawryshyn, C W

    2008-12-01

    Pacific salmonids start life in fresh water then migrate to the sea, after a metamorphic event called smoltification, later returning to their natal freshwater streams to spawn and die. To accommodate changes in visual environments throughout life history, salmon may adjust their spectral sensitivity. We investigated this possibility by examining ontogenetic and thyroid hormone (TH)-induced changes in visual pigments in coho salmon (Oncorhynchus kisutch, Walbaum). Using microspectrophotometry, we measured the spectral absorbance (quantified by lambda(max)) of rods, and middle and long wavelength-sensitive (MWS and LWS) cones in three age classes of coho, representing both freshwater and marine phases. The lambda(max) of MWS and LWS cones differed among freshwater (alevin and parr) and ocean (smolt) phases. The lambda(max) of rods, on the other hand, did not vary, which is evidence that vitamin A(1)/A(2) visual pigment chromophore ratios were similar among freshwater and ocean phases when sampled at the same time of year. Exogenous TH treatment long wavelength shifted the lambda(max) of rods, consistent with an increase in A(2). However, shifts in cones were greater than predicted for a change in chromophore ratio. Real-time quantitative RT-PCR demonstrated that at least two RH2 opsin subtypes were expressed in MWS cones, and these were differentially expressed among alevin, parr and TH-treated alevin groups. Combined with changes in A(1)/A(2) ratio, differential expression of opsin subtypes allows coho to alter the spectral absorbance of their MWS and LWS cones by as much as 60 and 90 nm, respectively. To our knowledge, this is the largest spectral shift reported in a vertebrate photoreceptor.

  2. Behavioral plasticity in rainbow trout (Oncorhynchus mykiss) with divergent coping styles: when doves become hawks.

    PubMed

    Ruiz-Gomez, Maria de Lourdes; Kittilsen, Silje; Höglund, Erik; Huntingford, Felicity A; Sørensen, Christina; Pottinger, Thomas G; Bakken, Morten; Winberg, Svante; Korzan, Wayne J; Overli, Oyvind

    2008-09-01

    Consistent and heritable individual differences in reaction to challenges, often referred to as stress coping styles, have been extensively documented in vertebrates. In fish, selection for divergent post-stress plasma cortisol levels in rainbow trout (Oncorhynchus mykiss) has yielded a low (LR) and a high responsive (HR) strain. A suite of behavioural traits is associated with this physiological difference, with LR (proactive) fish feeding more rapidly after transfer to a new environment and being socially dominant over HR (reactive) fish. Following transport from the UK to Norway, a switch in behavioural profile occurred in trout from the 3rd generation; HR fish regained feeding sooner than LR fish in a novel environment and became dominant in size-matched HR-LR pairs. One year after transport, HR fish still fed sooner, but no difference in social dominance was found. Among offspring of transported fish, no differences in feeding were observed, but as in pre-transported 3rd generation fish, HR fish lost fights for social dominance against size-matched LR opponents. Transported fish and their offspring retained their distinctive physiological profile throughout the study; HR fish showed consistently higher post-stress cortisol levels at all sampling points. Altered risk-taking and social dominance immediately after transport may be explained by the fact that HR fish lost more body mass during transport than did LR fish. These data demonstrate that some behavioural components of stress coping styles can be modified by experience, whereas behavioural plasticity is limited by genetic effects determining social position early in life story.

  3. Behavioural thermoregulation by subyearling fall (autumn) Chinook salmon oncorhynchus tshawytscha in a reservoir

    USGS Publications Warehouse

    Tiffan, K.F.; Kock, T.J.; Connor, W.P.; Steinhorst, R.K.; Rondorf, D.W.

    2009-01-01

    This study investigated behavioural thermoregulation by subyearling fall (autumn) Chinook salmon Oncorhynchus tshawytscha in a reservoir on the Snake River, Washington, U.S.A. During the summer, temperatures in the reservoir varied from 23?? C on the surface to 11?? C at 14 m depth. Subyearlings implanted with temperature-sensing radio transmitters were released at the surface at temperatures >20?? C during three blocks of time in summer 2004. Vertical profiles were taken to measure temperature and depth use as the fish moved downstream over an average of 5??6-7??2 h and 6??0-13??8 km. The majority of the subyearlings maintained average body temperatures that differed from average vertical profile temperatures during most of the time they were tracked. The mean proportion of the time subyearlings tracked within the 16-20?? C temperature range was larger than the proportion of time this range was available, which confirmed temperature selection opposed to random use. The subyearlings selected a depth and temperature combination that allowed them to increase their exposure to temperatures of 16-20?? C when temperatures 20?? C were available at lower and higher positions in the water column. A portion of the subyearlings that selected a temperature c. 17??0?? C during the day, moved into warmer water at night coincident with an increase in downstream movement rate. Though subyearlings used temperatures outside of the 16-20?? C range part of the time, behavioural thermoregulation probably reduced the effects of intermittent exposure to suboptimal temperatures. By doing so, it might enhance growth opportunity and life-history diversity in the population of subyearlings studied.

  4. Effect of starvation on global gene expression and proteolysis in rainbow trout (Oncorhynchus mykiss)

    PubMed Central

    Salem, Mohamed; Silverstein, Jeff; Rexroad, Caird E; Yao, Jianbo

    2007-01-01

    Background Fast, efficiently growing animals have increased protein synthesis and/or reduced protein degradation relative to slow, inefficiently growing animals. Consequently, minimizing the energetic cost of protein turnover is a strategic goal for enhancing animal growth. Characterization of gene expression profiles associated with protein turnover would allow us to identify genes that could potentially be used as molecular biomarkers to select for germplasm with improved protein accretion. Results We evaluated changes in hepatic global gene expression in response to 3-week starvation in rainbow trout (Oncorhynchus mykiss). Microarray analysis revealed a coordinated, down-regulated expression of protein biosynthesis genes in starved fish. In addition, the expression of genes involved in lipid metabolism/transport, aerobic respiration, blood functions and immune response were decreased in response to starvation. However, the microarray approach did not show a significant increase of gene expression in protein catabolic pathways. Further studies, using real-time PCR and enzyme activity assays, were performed to investigate the expression of genes involved in the major proteolytic pathways including calpains, the multi-catalytic proteasome and cathepsins. Starvation reduced mRNA expression of the calpain inhibitor, calpastatin long isoform (CAST-L), with a subsequent increase in the calpain catalytic activity. In addition, starvation caused a slight but significant increase in 20S proteasome activity without affecting mRNA levels of the proteasome genes. Neither the mRNA levels nor the activities of cathepsin D and L were affected by starvation. Conclusion These results suggest a significant role of calpain and 20S proteasome pathways in protein mobilization as a source of energy during fasting and a potential association of the CAST-L gene with fish protein accretion. PMID:17880706

  5. Environmental adaptation in Chinook salmon (Oncorhynchus tshawytscha) throughout their North American range.

    PubMed

    Hecht, Benjamin C; Matala, Andrew P; Hess, Jon E; Narum, Shawn R

    2015-11-01

    Landscape genomics is a rapidly growing field with recent advances in both genotyping efficiency and statistical analyses that provide insight towards local adaptation of populations under varying environmental and selective pressure. Chinook salmon (Oncorhynchus tshawytscha) are a broadly distributed Pacific salmon species, occupying a diversity of habitats throughout the northeastern Pacific with pronounced variation in environmental and climate features but little is understood regarding local adaptation in this species. We used a multivariate method, redundancy analysis (RDA), to identify polygenic correlations between 19,703 SNP loci and a suite of environmental variables in 46 collections of Chinook salmon (1956 total individuals) distributed throughout much of its North American range. Models in RDA were conducted on both rangewide and regional scales by hierarchical partitioning of the populations into three distinct genetic lineages. Our results indicate that between 5.8 and 21.8% of genomic variation can be accounted for by environmental features, and 566 putatively adaptive loci were identified as targets of environmental adaptation. The most influential drivers of adaptive divergence included precipitation in the driest quarter of the year (Rangewide and North Coastal Lineage, anova P = 0.002 and 0.01, respectively), precipitation in the wettest quarter of the year (Interior Columbia River Stream-Type Lineage, anova P = 0.03), variation in mean diurnal range in temperature (South Coastal Lineage, ANOVA P = 0.005), and migration distance (Rangewide, anova P = 0.001). Our results indicate that environmental features are strong drivers of adaptive genomic divergence in this species, and provide a foundation to investigate how Chinook salmon might respond to global environmental change. PMID:26465117

  6. Biomagnification and tissue distribution of perfluoroalkyl substances (PFASs) in market-size rainbow trout (Oncorhynchus mykiss).

    PubMed

    Goeritz, Ina; Falk, Sandy; Stahl, Thorsten; Schäfers, Christoph; Schlechtriem, Christian

    2013-09-01

    The present study investigated the biomagnification potential as well as the substance and tissue-specific distribution of perfluoroalkyl substances (PFASs) in market-size rainbow trout (Oncorhynchus mykiss). Rainbow trout with an average body weight of 314 ± 21 g were exposed to perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) in the diet for 28 d. The accumulation phase was followed by a 28-d depuration phase, in which the test animals were fed with nonspiked trout feed. On days 0, 7, 14, 28, 31, 35, 42, and 56 of the present study, fish were sampled from the test basin for PFAS analysis. Biomagnification factors (BMFs) for all test compounds were determined based on a kinetic approach. Distribution factors were calculated for each test compound to illustrate the disposition of PFASs in rainbow trout after 28 d of exposure. Dietary exposure of market-size rainbow trout to PFASs did not result in biomagnification; BMF values were calculated as 0.42 for PFOS, >0.23 for PFNA, >0.18 for PFHxS, >0.04 for PFOA, and >0.02 for PFBS, which are below the biomagnification threshold of 1. Liver, blood, kidney, and skin were identified as the main target tissues for PFASs in market-size rainbow trout. Evidence was shown that despite relative low PFAS contamination, the edible parts of the fish (the fillet and skin) can significantly contribute to the whole-body burden.

  7. Tissue distribution and residue depletion of metronidazole in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Mitrowska, Kamila; Pekala, Agnieszka; Posyniak, Andrzej

    2015-01-01

    Tissue distribution and residue depletion of metronidazole (MNZ) was studied in rainbow trout (Oncorhynchus mykiss) following oral administration of MNZ in feed at the average dose of 25 mg kg(-1) body weight day(-1) for 7 days at 11 ± 2°C. The MNZ concentration in feed was 0.25% while daily feed intake was 1% of body weight. The concentrations of MNZ and its main metabolite, hydroxymetronidazole (MNZOH), in fish tissues were determined by LC-MS/MS. The drug was well distributed in tissues with maximum concentrations on day 1 post-administration. At this time, the mean MNZ concentrations in muscle, skin, kidney, liver and gill were 14,999, 20,269, 15,070, 10,102 and 16,467 µg kg(-1) respectively. MNZ was converted into MNZOH with the ratio of MNZOH:MNZ up to 7% in all fish tissues throughout the withdrawal period. This shows that MNZ itself is the main residue in rainbow trout. MNZ was detected at the level close to the decision limit (0.20 µg kg(-1)) in muscle, skin and muscle with adhering skin up to 42 days, while in kidney, liver and gill it was up to 28 days post-administration. MNZOH was eliminated more rapidly from fish tissues and it was present in muscle alone up to 21 days. The elimination half-lives of MNZ and MNZOH in rainbow trout tissues were 1.83-2.53 and 1.24-2.12 days, respectively. When muscle without skin was analysed, higher MNZ and MNZOH concentrations were detected, and for a longer period of time, than in muscle with adhering skin. Thus muscle alone could be more appropriate for the effective residue control of MNZ in rainbow trout. For the same reason, it is also essential to ensure direct cooling immediately after sampling, since MNZ and its metabolite degrade in fish muscle and skin stored in non-freezing conditions.

  8. Nutritional regulation of long-chain PUFA biosynthetic genes in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Gregory, Melissa K; Collins, Robert O; Tocher, Douglas R; James, Michael J; Turchini, Giovanni M

    2016-05-28

    Most studies on dietary vegetable oil in rainbow trout (Oncorhynchus mykiss) have been conducted on a background of dietary EPA (20 : 5n-3) and DHA (22 : 6n-3) contained in the fishmeal used as a protein source in aquaculture feed. If dietary EPA and DHA repress their endogenous synthesis from α-linolenic acid (ALA, 18 : 3n-3), then the potential of ALA-containing vegetable oils to maintain tissue EPA and DHA has been underestimated. We examined the effect of individual dietary n-3 PUFA on the expression of the biosynthetic genes required for metabolism of ALA to DHA in rainbow trout. A total of 720 juvenile rainbow trout were allocated to twenty-four experimental tanks and assigned one of eight diets. The effect of dietary ALA, EPA or DHA, in isolation or in combination, on hepatic expression of fatty acyl desaturase (FADS)2a(Δ6), FADS2b(Δ5), elongation of very long-chain fatty acid (ELOVL)5 and ELOVL2 was examined after 3 weeks of dietary intervention. The effect of these diets on liver and muscle phospholipid PUFA composition was also examined. The expression levels of FADS2a(Δ6), ELOVL5 and ELOVL2 were highest when diets were high in ALA, with no added EPA or DHA. Under these conditions ALA was readily converted to tissue DHA. Dietary DHA had the largest and most consistent effect in down-regulating the gene expression of all four genes. The ELOVL5 expression was the least responsive of the four genes to dietary n-3 PUFA changes. These findings should be considered when optimising aquaculture feeds containing vegetable oils and/or fish oil or fishmeal to achieve maximum DHA synthesis.

  9. Migratory Patterns of Chinook Salmon Oncorhynchus tshawytscha Returning to a Large, Free-flowing River Basin

    USGS Publications Warehouse

    Eiler, John H.; Evans, Allison N.; Schreck, Carl B.

    2015-01-01

    Upriver movements were determined for Chinook salmon Oncorhynchus tshawytscha returning to the Yukon River, a large, virtually pristine river basin. These returns have declined dramatically since the late 1990s, and information is needed to better manage the run and facilitate conservation efforts. A total of 2,860 fish were radio tagged during 2002–2004. Most (97.5%) of the fish tracked upriver to spawning areas displayed continual upriver movements and strong fidelity to the terminal tributaries entered. Movement rates were substantially slower for fish spawning in lower river tributaries (28–40 km d-1) compared to upper basin stocks (52–62 km d-1). Three distinct migratory patterns were observed, including a gradual decline, pronounced decline, and substantial increase in movement rate as the fish moved upriver. Stocks destined for the same region exhibited similar migratory patterns. Individual fish within a stock showed substantial variation, but tended to reflect the regional pattern. Differences between consistently faster and slower fish explained 74% of the within-stock variation, whereas relative shifts in sequential movement rates between “hares” (faster fish becoming slower) and “tortoises” (slow but steady fish) explained 22% of the variation. Pulses of fish moving upriver were not cohesive. Fish tagged over a 4-day period took 16 days to pass a site 872 km upriver. Movement rates were substantially faster and the percentage of atypical movements considerably less than reported in more southerly drainages, but may reflect the pristine conditions within the Yukon River, wild origins of the fish, and discrete run timing of the returns. Movement data can provide numerous insights into the status and management of salmon returns, particularly in large river drainages with widely scattered fisheries where management actions in the lower river potentially impact harvests and escapement farther upstream. However, the substantial variation

  10. Chronic toxicity of 14 phthalate esters to Daphnia magna and rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Rhodes, J.E.; Adams, W.J.; Biddinger, G.R.; Robillard, K.A.; Gorsuch, J.W.

    1995-11-01

    Chronic toxicity studies were performed with commercial phthalate esters and Daphnia magna (14 phthalates) and rainbow trout (Oncorhynchus mykiss) (six phthalates). For the lower-molecular-weight phthalate esters--dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and butylbenzyl phthalate (BBP)--the results of the studies indicated a general trend in which toxicity for both species increased as water solubility decreased. The geometric mean maximum acceptable toxicant concentration(GM-MATC) for D. magna ranged from 0.63 to 34.8 mg/L. For the higher-molecular-weight phthalate esters--dihexyl phthalate (DHP), butyl 2-ethylhexyl phthalate (BOP), di-(n-hexyl, n-octyl, n-decyl) phthalate (610P), di-(2-ethylhexyl) phthalate (DEHP), diisooctyl phthalate (DIOP), diisononyl phthalate (DINP), di-(heptyl, nonyl, undecyl) phthalate (711P), diisodecyl phthalate (DIDP), diundecyl phthalate (DUP), and ditridecyl phthalate (DTDP)--the GM-MATC values ranged from 0.042 to 0.15 mg/L. Survival was equally sensitive and sometimes more sensitive than reproduction. The observed toxicity to daphnids with most of the higher-molecular-weight phthalate esters appeared to be due to surface entrapment or a mode of toxicity that is not due to exposure to dissolved aqueous-phase chemical. Early life-stage toxicity studies with rainbow trout indicated that survival (DMP) and growth (DBP) were affected at 24 and 0.19 mg/L, respectively. This pattern of observed toxicity with the lower-molecular-weight phthalate esters and not the higher-molecular-weight phthalate esters is consistent with previously reported acute toxicity studies for several aquatic species.

  11. Pesticides and PCBs in Pacific salmon (Oncorhynchus tshawytscha and O. kisutch) from Puget Sound, Washington

    SciTech Connect

    O`Neill, S.M.; West, J.E.

    1995-12-31

    The Washington Department of Fish and Wildlife initiated a long-term study to monitor levels of contaminants in two species of Pacific salmon (Oncorhynchus tshawytscha and O. kisutch) and other marine fishes of Puget Sound. The study is one component of the Puget Sound Ambient Monitoring Program (PSAMP), a multi-agency effort to assess the environmental health of Puget Sound. Here the authors summarize results from their ongoing study of O. tshawytscha and O. kisutch. Samples of muscle tissue were collected for chemical analyses from adult salmon that were purchased from licensed fish buyers or treaty tribal fisherman. From 1992 through 1994, both salmon species were sampled at seven fishing areas in marine waters and river mouths of Puget Sound. 4,4-DDE and 4,4-DDD, metabolites of the pesticide DDT, and polychlorinated biphenyls (PCBS) were consistently detected in both species and were consistently higher in O. tshawytscha. Low to moderate concentrations of DDT metabolites (3 to 59 ug/kg wet weight) were detected in the salmon samples but were seldom detected in other fish species sampled by PSAMP. Total PCBs concentrations (Arochlor 1254 + 1260) ranged from 10 to 211 ug/kg wet weight in 0. tshawytscha, with many samples containing PCBs concentrations similar to those detected in benthic flatfish, (Pleuronectes vetulus), sampled from urbanized embayments. A stepwise linear regression model was used to identify parameters correlated with accumulation of PCBs and DDT metabolites in salmon. In addition to species differences, factors such as fish age, percent lipids and sampling location may affect the accumulation of these contaminants. Results of this study are contrasted with contaminant levels previously reported for Canadian and Alaskan Pacific salmon. Possible sources of contaminants are outlined.

  12. Characterization of three novel beta-defensin antimicrobial peptides in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Casadei, Elisa; Wang, Tiehui; Zou, Jun; González Vecino, Jose L; Wadsworth, Simon; Secombes, Christopher J

    2009-10-01

    An initial bioinformatics investigation followed by cloning and sequencing analysis, has led to the identification of three novel members (omDB-2, omDB-3, omBD-4) of the beta-defensin family in rainbow trout (Oncorhynchus mykiss). The contiguous sequences could be translated to give predicted peptides of 62 (omDB-2), 63 (omDB-3) and 68 (omDB-4) amino acids (aa) in length, with mature peptides of 43 (omDB-2), 39 (omDB-3) and 42 (omDB-4) aa, with no obvious proregion present. Analysis of the gene organization found that all three new genes contained three exons divided by two introns, as seen in defensin genes of other fish species. Constitutive expression of all the trout defensins was detected by RT-PCR in a wide range of mucosal and systemic tissues from healthy fish, with omDB-3 and omDB-4 showing the highest expression levels. Following bacterial challenge in vivo, the defensin genes were induced at the three mucosal sites examined (skin, gill, gut), with levels of omDB-2 and omDB-3 increased some 16-fold in gut and gill respectively. Using polyinosinic polycytosinic RNA (polyI:C) as a viral mimic, all of the four trout beta-defensin genes were induced in head kidney primary leucocyte cultures at 4h post-stimulation, with omDB-1 and omDB-3 particularly highly expressed. These data suggest that beta-defensins are likely an important component of the innate defences of fish, and reveal an added level of antimicrobial peptide complexity in fish to that known previously. PMID:19709750

  13. The effect of peptidoglycan enriched diets on antimicrobial peptide gene expression in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Casadei, Elisa; Bird, Steve; Vecino, Jose L González; Wadsworth, Simon; Secombes, Christopher J

    2013-02-01

    The aim of this study was to investigate the effect of feeding rainbow trout (Oncorhynchus mykiss) peptidoglycan (PG) enriched diets on antimicrobial peptide (AMP) gene expression. Fish were divided into 5 groups and fed diets containing 0, 5, 10, 50 and 100 mg PG/Kg, and sampled 1, 7 and 14 days later. The expression of eight AMP genes (four defensins, two cathelicidins and two liver expressed AMPs) was determined in skin, gill, gut and liver, tissues important for first lines of defence or production of acute phase proteins. Up-regulation of many AMPs was found after feeding the PG enriched diets, with sequential expression seen over the time course studied, where defensins were typically expressed early and cathelicidins and LEAPs later on. A number of clear differences in AMP responsiveness between the tissues examined were also apparent. Of the four PG concentrations used, 5 mg PG/Kg did not always elicit AMP gene induction or to the same degree as seen with the other diets. The three higher dose groups generally showed similar trends although differences in fold change were more pronounced in the 50 and 100 mg PG/Kg groups. Curiously several AMPs were down-regulated after 14 days of feeding in gills, gut and liver. Nevertheless, overall the PG enriched diets had a positive effect on AMP expression. Further investigations now need to be undertaken to confirm whether this higher AMP gene expression correlates with protection against common bacterial diseases and if PG enriched diets have value as a means to temporarily boost the piscine immune system. PMID:23220715

  14. Proteomic analysis of rainbow trout (Oncorhynchus mykiss) intestinal epithelia: physiological acclimation to short-term starvation.

    PubMed

    Baumgarner, Bradley L; Bharadwaj, Anant S; Inerowicz, Dorota; Goodman, Angela S; Brown, Paul B

    2013-03-01

    The intestinal epithelia form the first line of defense against harmful agents in the gut lumen of most monogastric vertebrates, including teleost fishes. Previous investigations into the effect of starvation on the intestinal epithelia of teleost fishes have focused primarily on changes in morphological characteristics and targeted molecular analysis of specific enzymes. The goal of this study was to use a comprehensive approach to help reveal how the intestinal epithelia of carnivorous teleost fishes acclimate to short-term nutrient deprivation. We utilized two-dimensional gel electrophoresis (2-DE) to conduct the proteomic analysis of the mucosal and epithelial layer of the anterior gut intestinal tract (GIT) from satiation fed vs. 4 week starved rainbow trout (Oncorhynchus mykiss). A total of 40 proteins were determined to be differentially expressed and were subsequently picked for in-gel trypsin digestion. Peptide mass fingerprint analysis was conducted using matrix assisted laser desorption time-of-flight/time-of-flight. Nine of the 11 positively identified proteins were directly related to innate immunity. The expression of α-1 proteinase inhibitor decreased in starved vs. fed fish. Also, the concentration of one leukocyte elastase inhibitor (LEI) isomer decreased in starved fish, though the concentration of another LEI isomer increased in due to starvation. In addition, starvation promoted an increased concentration of the important xenobiotic-transporter p-glycoprotein. Finally, starvation resulted in a significant increase in type II keratin E2. Overall, our results indicate that starvation promoted a reduced capacity to inhibit enzymatic stress but increased xenobiotic resistance and paracellular permeability of epithelial cells in the anterior intestine of rainbow trout.

  15. Distribution of T Cells in Rainbow Trout (Oncorhynchus mykiss) Skin and Responsiveness to Viral Infection.

    PubMed

    Leal, Esther; Granja, Aitor G; Zarza, Carlos; Tafalla, Carolina

    2016-01-01

    Although the skin constitutes the first line of defense against waterborne pathogens, there is a great lack of information regarding the skin associated lymphoid tissue (SALT) and whether immune components of the skin are homogeneously distributed through the surface of the fish is still unknown. In the current work, we have analyzed the transcription of several immune genes throughout different rainbow trout (Oncorhynchus mykiss) skin areas. We found that immunoglobulin and chemokine gene transcription levels were higher in a skin area close to the gills. Furthermore, this skin area as well as other anterior sections also transcribed significantly higher levels of many different immune genes related to T cell immunity such as T cell receptor α (TCRα), TCRγ, CD3, CD4, CD8, perforin, GATA3, Tbet, FoxP3, interferon γ (IFNγ), CD40L and Eomes in comparison to posterior skin sections. In agreement with these results, immunohistochemical analysis revealed that anterior skin areas had a higher concentration of CD3(+) T cells and flow cytometry analysis confirmed that the percentage of CD8(+) T lymphocytes was also higher in anterior skin sections. These results demonstrate for the first time that T cells are not homogeneously distributed throughout the teleost skin. Additionally, we studied the transcriptional regulation of these and additional T cell markers in response to a bath infection with viral hemorrhagic septicemia virus (VHSV). We found that VHSV regulated the transcription of several of these T cell markers in both the skin and the spleen; with some differences between anterior and posterior skin sections. Altogether, our results point to skin T cells as major players of teleost skin immunity in response to waterborne viral infections. PMID:26808410

  16. [Heritability of body weight and fork length for Oncorhynchus masou masou].

    PubMed

    Zhang, Yu-Yong; Jia, Zhi-Ying; Bai, Qing-Li; Chen, Shu-Qiang; Shi, Lian-Yu; Wang, Bing-Qian

    2013-02-01

    Body weight and body length have been considered as the most important production traits for the fish genetic improvement. For cold-water fish, body length was usually substituted by fork length. In order to estimate the heritability of body weight and fork length of the sixth generation Oncorhynchus masou masou, which was introduced into China, the method of unbalanced nest design and an artificial insemination technigue were used. Twenty-nine full-sib families and fourteen half-sib families were obtained. Body weight and fork length of O. masou masou were measured in 12 and 24 months after fertilization. Based on full-sib and half-sib families data, the causal components of phenotypic variance were calculated. The results showed that, (1) during the whole growth phase of O. masou masou, the coefficient variation (CV) of fork length was higher than body weight, and CV of 12-month old was higher than that of 24-month old; (2) body weight and fork length of O. masou masou among sires and dams among sires were significant difference (P<0.01) both at 12 months and at 24 months; (3) the maternal component estimates were significantly larger than those of paternal ones for body weight and fork length traits both at 12 months and at 24 months; (4) for 12 months of O. masou masou the heritabilities of body weight and fork length were 0.41~0.51 and 0.46~0.54, respectively. For 24 months the values were 0.55~0.60 and 0.53~0.59, respectively; and (5) it was concluded that the heritability of growth traits in O. masou masou was relatively high and this highlights the potential to improve its growth through selective breeding. This study shows important data supporting for further genetic improvement of O. masou masou. PMID:23448933

  17. Experimental evaluation of rainbow trout Oncorhynchus mykiss predation on longnose dace Rhinichthys cataractae

    USGS Publications Warehouse

    Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.

    2014-01-01

    Laboratory and in-stream enclosure experiments were used to determine whether rainbow trout Oncorhynchus mykiss influence survival of longnose dace Rhinichthys cataractae. In the laboratory, adult rainbow trout preyed on longnose dace in 42% of trials and juvenile rainbow trout did not prey on longnose dace during the first 6 h after rainbow trout introduction. Survival of longnose dace did not differ in the presence of adult rainbow trout previously exposed to active prey and those not previously exposed to active prey ( = 0.28, P = 0.60). In field enclosures, the number of longnose dace decreased at a faster rate in the presence of rainbow trout relative to controls within the first 72 h, but did not differ between moderate and high densities of rainbow trout (F2,258.9 = 3.73, P = 0.03). Additionally, longnose dace were found in 7% of rainbow trout stomachs after 72 h in enclosures. Rainbow trout acclimated to the stream for longer periods had a greater initial influence on the number of longnose dace remaining in enclosures relative to those acclimated for shorter periods regardless of rainbow trout density treatment (F4,148.5 = 2.50, P = 0.04). More research is needed to determine how predation rates will change in natural environments, under differing amounts of habitat and food resources and in the context of whole assemblages. However, if rainbow trout are introduced into the habitat of longnose dace, some predation on longnose dace is expected, even when rainbow trout have no previous experience with active prey.

  18. Intersex occurrence in rainbow trout (Oncorhynchus mykiss) male fry chronically exposed to ethynylestradiol.

    PubMed

    Depiereux, Sophie; Liagre, Mélanie; Danis, Lorraine; De Meulder, Bertrand; Depiereux, Eric; Segner, Helmut; Kestemont, Patrick

    2014-01-01

    This study aimed to investigate the male-to-female morphological and physiological transdifferentiation process in rainbow trout (Oncorhynchus mykiss) exposed to exogenous estrogens. The first objective was to elucidate whether trout develop intersex gonads under exposure to low levels of estrogen. To this end, the gonads of an all-male population of fry exposed chronically (from 60 to 136 days post fertilization--dpf) to several doses (from environmentally relevant 0.01 µg/L to supra-environmental levels: 0.1, 1 and 10 µg/L) of the potent synthetic estrogen ethynylestradiol (EE2) were examined histologically. The morphological evaluations were underpinned by the analysis of gonad steroid (testosterone, estradiol and 11-ketotestosterone) levels and of brain and gonad gene expression, including estrogen-responsive genes and genes involved in sex differentiation in (gonads: cyp19a1a, ER isoforms, vtg, dmrt1, sox9a2; sdY; cyp11b; brain: cyp19a1b, ER isoforms). Intersex gonads were observed from the first concentration used (0.01 µg EE2/L) and sexual inversion could be detected from 0.1 µg EE2/L. This was accompanied by a linear decrease in 11-KT levels, whereas no effect on E2 and T levels was observed. Q-PCR results from the gonads showed downregulation of testicular markers (dmrt1, sox9a2; sdY; cyp11b) with increasing EE2 exposure concentrations, and upregulation of the female vtg gene. No evidence was found for a direct involvement of aromatase in the sex conversion process. The results from this study provide evidence that gonads of male trout respond to estrogen exposure by intersex formation and, with increasing concentration, by morphological and physiological conversion to phenotypic ovaries. However, supra-environmental estrogen concentrations are needed to induce these changes. PMID:25033040

  19. Functional Identification of Dendritic Cells in the Teleost Model, Rainbow Trout (Oncorhynchus mykiss)

    PubMed Central

    Bassity, Elizabeth; Clark, Theodore G.

    2012-01-01

    Dendritic cells are specialized antigen presenting cells that bridge innate and adaptive immunity in mammals. This link between the ancient innate immune system and the more evolutionarily recent adaptive immune system is of particular interest in fish, the oldest vertebrates to have both innate and adaptive immunity. It is unknown whether dendritic cells co-evolved with the adaptive response, or if the connection between innate and adaptive immunity relied on a fundamentally different cell type early in evolution. We approached this question using the teleost model organism, rainbow trout (Oncorhynchus mykiss), with the aim of identifying dendritic cells based on their ability to stimulate naïve T cells. Adapting mammalian protocols for the generation of dendritic cells, we established a method of culturing highly motile, non-adherent cells from trout hematopoietic tissue that had irregular membrane processes and expressed surface MHCII. When side-by-side mixed leukocyte reactions were performed, these cells stimulated greater proliferation than B cells or macrophages, demonstrating their specialized ability to present antigen and therefore their functional homology to mammalian dendritic cells. Trout dendritic cells were then further analyzed to determine if they exhibited other features of mammalian dendritic cells. Trout dendritic cells were found to have many of the hallmarks of mammalian DCs including tree-like morphology, the expression of dendritic cell markers, the ability to phagocytose small particles, activation by toll-like receptor-ligands, and the ability to migrate in vivo. As in mammals, trout dendritic cells could be isolated directly from the spleen, or larger numbers could be derived from hematopoietic tissue and peripheral blood mononuclear cells in vitro. PMID:22427987

  20. Nutritional regulation of long-chain PUFA biosynthetic genes in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Gregory, Melissa K; Collins, Robert O; Tocher, Douglas R; James, Michael J; Turchini, Giovanni M

    2016-05-28

    Most studies on dietary vegetable oil in rainbow trout (Oncorhynchus mykiss) have been conducted on a background of dietary EPA (20 : 5n-3) and DHA (22 : 6n-3) contained in the fishmeal used as a protein source in aquaculture feed. If dietary EPA and DHA repress their endogenous synthesis from α-linolenic acid (ALA, 18 : 3n-3), then the potential of ALA-containing vegetable oils to maintain tissue EPA and DHA has been underestimated. We examined the effect of individual dietary n-3 PUFA on the expression of the biosynthetic genes required for metabolism of ALA to DHA in rainbow trout. A total of 720 juvenile rainbow trout were allocated to twenty-four experimental tanks and assigned one of eight diets. The effect of dietary ALA, EPA or DHA, in isolation or in combination, on hepatic expression of fatty acyl desaturase (FADS)2a(Δ6), FADS2b(Δ5), elongation of very long-chain fatty acid (ELOVL)5 and ELOVL2 was examined after 3 weeks of dietary intervention. The effect of these diets on liver and muscle phospholipid PUFA composition was also examined. The expression levels of FADS2a(Δ6), ELOVL5 and ELOVL2 were highest when diets were high in ALA, with no added EPA or DHA. Under these conditions ALA was readily converted to tissue DHA. Dietary DHA had the largest and most consistent effect in down-regulating the gene expression of all four genes. The ELOVL5 expression was the least responsive of the four genes to dietary n-3 PUFA changes. These findings should be considered when optimising aquaculture feeds containing vegetable oils and/or fish oil or fishmeal to achieve maximum DHA synthesis. PMID:26987422

  1. Social stress modulates the cortisol response to an acute stressor in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Jeffrey, J D; Gollock, M J; Gilmour, K M

    2014-01-15

    In rainbow trout (Oncorhynchus mykiss) of subordinate social status, circulating cortisol concentrations were elevated under resting conditions but the plasma cortisol and glucose responses to an acute stressor (confinement in a net) were attenuated relative to those of dominant trout. An in vitro head kidney preparation, and analysis of the expression of key genes in the stress axis prior to and following confinement in a net were then used to examine the mechanisms underlying suppression of the acute cortisol stress response in trout experiencing chronic social stress. With porcine adrenocorticotropic hormone (ACTH) as the secretagogue, ACTH-stimulated cortisol production was significantly lower for head kidney preparations from subordinate trout than for those from dominant trout. Dominant and subordinate fish did not, however, differ in the relative mRNA abundance of melanocortin-2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) or cytochrome P450 side chain cleavage enzyme (P450scc) within the head kidney, although the relative mRNA abundance of these genes was significantly higher in both dominant and subordinate fish than in sham trout (trout that did not experience social interactions but were otherwise treated identically to the dominant and subordinate fish). The relative mRNA abundance of all three genes was significantly higher in trout exposed to an acute net stressor than under control conditions. Upstream of cortisol production in the stress axis, plasma ACTH concentrations were not affected by social stress, nor was the relative mRNA abundance of the binding protein for corticotropin releasing factor (CRF-BP). The relative mRNA abundance of CRF in the pre-optic area of subordinate fish was significantly higher than that of dominant or sham fish 1h after exposure to the stressor. Collectively, the results indicate that chronic social stress modulates cortisol production at the level of the interrenal cells, resulting in an attenuated

  2. Linking personality to larval energy reserves in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Andersson, Madelene Åberg; Höglund, Erik

    2012-01-01

    There is a surging interest in the evolution, ecology and physiology of personality differences. However, most of the studies in this research area have been performed in adult animals. Trait variations expressed early in development and how they are related to the ontogeny of an animal's personality are far less studied. Genetic differences as well as environmental factors causing functional variability of the central serotonergic system have been related to personality differences in vertebrates, including humans. Such gene-environment interplay suggests that the central serotonergic system plays an important role in the ontogeny of personality traits. In salmonid fishes, the timing of emergence from spawning nests is related to energy reserves, aggression, and social dominance. However, it is currently unknown how the size of the yolk reserve is reflected on aggression and dominance, or if these traits are linked to differences in serotonergic transmission in newly emerged larvae. In this study we investigated the relationship between yolk reserves, social dominance, and serotonergic transmission in newly emerged rainbow trout (Oncorhynchus mykiss) larvae. This was conducted by allowing larvae with the same emergence time, but with different yolk sizes, to interact in pairs for 24 h. The results show that individuals with larger yolks performed more aggressive acts, resulting in a suppression of aggression in individuals with smaller yolks. A higher brain serotonergic activity confirmed subordination in larvae with small yolks. The relationship between social dominance and yolk size was present in siblings, demonstrating a link between interfamily variation in energy reserves and aggression, and suggests that larger yolk reserves fuel a more aggressive personality during the initial territorial establishment in salmonid fishes. Furthermore, socially naïve larvae with big yolks had lower serotonin levels, suggesting that other factors than the social environment

  3. Oil dispersion increases the apparent bioavailability and toxicity of diesel to rainbow trout (Oncorhynchus mykiss).

    PubMed

    Schein, Allison; Scott, Jason A; Mos, Lizzy; Hodson, Peter V

    2009-03-01

    Diesel is a complex mixture containing polycyclic aromatic hydrocarbons, which persist after a spill, pass readily from water into tissues, and are toxic to early life stages of fish. The bioavailability and chronic toxicity of hydrocarbons dissolved into water from floating diesel (water-accommodated fraction) and chemically dispersed diesel (chemically enhanced water-accommodated fraction) were measured by the extent of ethoxyresorufin-O-deethylase (EROD) induction in juvenile rainbow trout (Oncorhynchus mykiss) and by the severity of blue sac disease in embryos. The water-accommodated fraction of floating diesel was virtually nontoxic to embryos at nominal concentrations up to 1,000 mg/L, causing only small weight changes. Liver EROD induction in juvenile trout was only observed at the highest nominal water-accommodated fraction concentration (10,000 mg/L). Chemical dispersion increased the bioavailability and toxicity of diesel to trout by 100-fold. Diesel chemically enhanced water-accommodated fraction induced EROD activity, caused blue sac disease, and impaired development and growth of embryonic trout at nominal concentrations as low as 10 mg/L; 88% mortality occurred at 100 mg/L. However, when total hydrocarbon concentrations were measured, differences between dispersed and undispersed diesel disappeared, with a median lethal concentration of 8 mg/L of total hydrocarbons and sublethal median effective concentrations ranging from 1.3 to 6.1 mg/L. Dispersion of diesel by high-energy mechanical mixing was recently reported to cause acute lethality to juvenile trout between 40 and 200 mg/L. Therefore, dispersion of oil by any means increases the bioavailability and apparent toxicity of diesel to fish embryos without changing the toxicity of its components. Nevertheless, in an actual spill, dispersion of diesel increases the effects of oil on fish populations.

  4. Distribution of T Cells in Rainbow Trout (Oncorhynchus mykiss) Skin and Responsiveness to Viral Infection

    PubMed Central

    Leal, Esther; Granja, Aitor G.; Zarza, Carlos; Tafalla, Carolina

    2016-01-01

    Although the skin constitutes the first line of defense against waterborne pathogens, there is a great lack of information regarding the skin associated lymphoid tissue (SALT) and whether immune components of the skin are homogeneously distributed through the surface of the fish is still unknown. In the current work, we have analyzed the transcription of several immune genes throughout different rainbow trout (Oncorhynchus mykiss) skin areas. We found that immunoglobulin and chemokine gene transcription levels were higher in a skin area close to the gills. Furthermore, this skin area as well as other anterior sections also transcribed significantly higher levels of many different immune genes related to T cell immunity such as T cell receptor α (TCRα), TCRγ, CD3, CD4, CD8, perforin, GATA3, Tbet, FoxP3, interferon γ (IFNγ), CD40L and Eomes in comparison to posterior skin sections. In agreement with these results, immunohistochemical analysis revealed that anterior skin areas had a higher concentration of CD3+ T cells and flow cytometry analysis confirmed that the percentage of CD8+ T lymphocytes was also higher in anterior skin sections. These results demonstrate for the first time that T cells are not homogeneously distributed throughout the teleost skin. Additionally, we studied the transcriptional regulation of these and additional T cell markers in response to a bath infection with viral hemorrhagic septicemia virus (VHSV). We found that VHSV regulated the transcription of several of these T cell markers in both the skin and the spleen; with some differences between anterior and posterior skin sections. Altogether, our results point to skin T cells as major players of teleost skin immunity in response to waterborne viral infections. PMID:26808410

  5. The effects of copper on blood and biochemical parameters of rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Dethloff, G.M.; Schlenk, D.; Khan, S.; Bailey, H.C.

    1999-01-01

    Metals are released into aquatic systems from many sources, often at sublethal concentrations. The effects of sublethal concentrations of metals on fish are not entirely understood. The objective of this study was to determine the hematological and biochemical effects of a range of copper concentrations (6.4, 16.0, 26.9 ??g Cu/L) on rainbow trout (Oncorhynchus mykiss) over a prolonged period of time. Trout were exposed to copper, and, at intervals of 3, 7, 14, and 21 days, selected parameters were evaluated. Hemoglobin, hematocrit, plasma glucose, and plasma cortisol levels were elevated in trout exposed to 26.9 ??g Cu/L at day 3 and then returned to levels comparable to control fish. Plasma protein and lactate levels were not significantly altered in trout from any copper treatment. Hepatic copper concentration and hepatic metallothionein mRNA expression were consistently elevated in trout exposed to 26.9 ??g Cu/L. Both of these parameters stabilized by day 3, with only hepatic copper concentration showing a further increase at day 21. Hepatic copper concentration and hepatic metallothionein mRNA expression appear to be robust indicators of copper exposure. Most blood-based parameters evaluated appear to be associated with a transitory, nonspecific stress response. The return of elevated hematological and biochemical parameters to control levels after 3 days and thestabilization of hepatic metallothionein mRNA expression and copper concentration over a similar time period suggested acclimation to dissolved copper at 26.9 ??g/L. Further analysis of the data on blood-based parameters indicated that certain parameters (hemoglobin, hematocrit, plasma glucose, plasma cortisol) may be useful in field monitoring.

  6. Genetics of Microenvironmental Sensitivity of Body Weight in Rainbow Trout (Oncorhynchus mykiss) Selected for Improved Growth

    PubMed Central

    Janhunen, Matti; Kause, Antti; Vehviläinen, Harri; Järvisalo, Otso

    2012-01-01

    Microenvironmental sensitivity of a genotype refers to the ability to buffer against non-specific environmental factors, and it can be quantified by the amount of residual variation in a trait expressed by the genotype’s offspring within a (macro)environment. Due to the high degree of polymorphism in behavioral, growth and life-history traits, both farmed and wild salmonids are highly susceptible to microenvironmental variation, yet the heritable basis of this characteristic remains unknown. We estimated the genetic (co)variance of body weight and its residual variation in 2-year-old rainbow trout (Oncorhynchus mykiss) using a multigenerational data of 45,900 individuals from the Finnish national breeding programme. We also tested whether or not microenvironmental sensitivity has been changed as a correlated genetic response when genetic improvement for growth has been practiced over five generations. The animal model analysis revealed the presence of genetic heterogeneity both in body weight and its residual variation. Heritability of residual variation was remarkably lower (0.02) than that for body weight (0.35). However, genetic coefficient of variation was notable in both body weight (14%) and its residual variation (37%), suggesting a substantial potential for selection responses in both traits. Furthermore, a significant negative genetic correlation (−0.16) was found between body weight and its residual variation, i.e., rapidly growing genotypes are also more tolerant to perturbations in microenvironment. The genetic trends showed that fish growth was successfully increased by selective breeding (an average of 6% per generation), whereas no genetic change occurred in residual variation during the same period. The results imply that genetic improvement for body weight does not cause a concomitant increase in microenvironmental sensitivity. For commercial production, however, there may be high potential to simultaneously improve weight gain and increase its

  7. The Olfactory Transcriptome and Progression of Sexual Maturation in Homing Chum Salmon Oncorhynchus keta

    PubMed Central

    Palstra, Arjan P.; Fukaya, Kosuke; Chiba, Hiroaki; Dirks, Ron P.; Planas, Josep V.; Ueda, Hiroshi

    2015-01-01

    Reproductive homing migration of salmonids requires accurate interaction between the reception of external olfactory cues for navigation to the spawning grounds and the regulation of sexual maturation processes. This study aimed at providing insights into the hypothesized functional link between olfactory sensing of the spawning ground and final sexual maturation. We have therefore assessed the presence and expression levels of olfactory genes by RNA sequencing (RNAseq) of the olfactory rosettes in homing chum salmon Oncorhynchus keta Walbaum from the coastal sea to 75 km upstream the rivers at the pre-spawning ground. The progression of sexual maturation along the brain-pituitary-gonadal axis was assessed through determination of plasma steroid levels by time-resolved fluoroimmunoassays (TR-FIA), pituitary gonadotropin subunit expression and salmon gonadotropin-releasing hormone (sgnrh) expression in the brain by quantitative real-time PCR. RNAseq revealed the expression of 75 known and 27 unknown salmonid olfactory genes of which 13 genes were differentially expressed between fish from the pre-spawning area and from the coastal area, suggesting an important role of these genes in homing. A clear progression towards final maturation was characterised by higher plasma 17α,20β-dihydroxy-4-pregnen-3-one (DHP) levels, increased pituitary luteinizing hormone β subunit (lhβ) expression and sgnrh expression in the post brain, and lower plasma testosterone (T) and 17β-estradiol (E2) levels. Olfactomedins and ependymin are candidates among the differentially expressed genes that may connect olfactory reception to the expression of sgnrh to regulate final maturation. PMID:26397372

  8. Evaluating Adaptive Divergence Between Migratory and Nonmigratory Ecotypes of a Salmonid Fish, Oncorhynchus mykiss

    PubMed Central

    Hale, Matthew C.; Thrower, Frank P.; Berntson, Ewann A.; Miller, Michael R.; Nichols, Krista M.

    2013-01-01

    Next-generation sequencing and the application of population genomic and association approaches have made it possible to detect selection and unravel the genetic basis to variable phenotypic traits. The use of these two approaches in parallel is especially attractive in nonmodel organisms that lack a sequenced and annotated genome, but only works well when population structure is not confounded with the phenotype of interest. Herein, we use population genomics in a nonmodel fish species, rainbow trout (Oncorhynchus mykiss), to better understand adaptive divergence between migratory and nonmigratory ecotypes and to further our understanding about the genetic basis of migration. Restriction site-associated DNA (RAD) tag sequencing was used to identify single-nucleotide polymorphisms (SNPs) in migrant and resident O. mykiss from two systems, one in Alaska and the other in Oregon. A total of 7920 and 6755 SNPs met filtering criteria in the Alaska and Oregon data sets, respectively. Population genetic tests determined that 1423 SNPs were candidates for selection when loci were compared between resident and migrant samples. Previous linkage mapping studies that used RAD DNA tag SNPs were available to determine the position of 1990 markers. Several significant SNPs are located in genome regions that contain quantitative trait loci for migratory-related traits, reinforcing the importance of these regions in the genetic basis of migration/residency. Annotation of genome regions linked to significant SNPs revealed genes involved in processes known to be important in migration (such as osmoregulatory function). This study adds to our growing knowledge on adaptive divergence between migratory and nonmigratory ecotypes of this species; across studies, this complex trait appears to be controlled by many loci of small effect, with some in common, but many loci not shared between populations studied. PMID:23797103

  9. Genetic variation underlying resistance to infectious hematopoietic necrosis virus in a steelhead trout (Oncorhynchus mykiss) population

    USGS Publications Warehouse

    Brieuc, Marine S. O.; Purcell, Maureen K.; Palmer, Alexander D.; Naish, Kerry A.

    2015-01-01

    Understanding the mechanisms of host resistance to pathogens will allow insights into the response of wild populations to the emergence of new pathogens. Infectious hematopoietic necrosis virus (IHNV) is endemic to the Pacific Northwest and infectious to Pacific salmon and trout (Oncorhynchus spp.). Emergence of the M genogroup of IHNV in steelhead trout O. mykiss in the coastal streams of Washington State, between 2007 and 2011, was geographically heterogeneous. Differences in host resistance due to genetic change were hypothesized to be a factor influencing the IHNV emergence patterns. For example, juvenile steelhead trout losses at the Quinault National Fish Hatchery (QNFH) were much lower than those at a nearby facility that cultures a stock originally derived from the same source population. Using a classical quantitative genetic approach, we determined the potential for the QNFH steelhead trout population to respond to selection caused by the pathogen, by estimating the heritability for 2 traits indicative of IHNV resistance, mortality (h2 = 0.377 (0.226 - 0.550)) and days to death (h2 = 0.093 (0.018 - 0.203)). These results confirm that there is a genetic basis for resistance and that this population has the potential to adapt to IHNV. Additionally, genetic correlation between days to death and fish length suggests a correlated response in these traits to selection. Reduction of genetic variation, as well as the presence or absence of resistant alleles, could affect the ability of populations to adapt to the pathogen. Identification of the genetic basis for IHNV resistance could allow the assessment of the susceptibility of other steelhead populations.

  10. Cold-acclimation leads to differential regulation of the steelhead trout (Oncorhynchus mykiss) coronary microcirculation

    PubMed Central

    Costa, Isabel A. S. F.; Hein, Travis W.

    2015-01-01

    The regulation of vascular resistance in fishes has largely been studied using isolated large conductance vessels, yet changes in tissue perfusion/vascular resistance are primarily mediated by the dilation/constriction of small arterioles. Thus we adapted mammalian isolated microvessel techniques for use in fish and examined how several agents affected the tone/resistance of isolated coronary arterioles (<150 μm ID) from steelhead trout (Oncorhynchus mykiss) acclimated to 1, 5, and 10°C. At 10°C, the vessels showed a concentration-dependent dilation to adenosine (ADE; 61 ± 8%), sodium nitroprusside (SNP; 35 ± 10%), and serotonin (SER; 27 ± 2%) (all values maximum responses). A biphasic response (mild contraction then dilation) was observed in vessels exposed to increasing concentrations of epinephrine (EPI; 34 ± 9% dilation) and norepinephrine (NE; 32 ± 7% dilation), whereas the effect was less pronounced with bradykinin (BK; 12.5 ± 3.5% constriction vs. 6 ± 6% dilation). Finally, a mild constriction was observed after exposure to acetylcholine (ACh; 6.5 ± 1.4%), while endothelin (ET)-1 caused a strong dose-dependent increase in tone (79 ± 5% constriction). Acclimation temperature had varying effects on the responsiveness of vessels. The dilations induced by EPI, ADE, SER, and SNP were reduced/eliminated at 5°C and/or 1°C as compared with 10°C. In contrast, acclimation to 5 and 1°C increased the maximum constriction induced by ACh and the sensitivity of vessels to ET-1 (but not the maximum response) at 1°C was greater. Acclimation temperature had no effect on the response to NE, and responsiveness to BK was variable. PMID:25715834

  11. Determination of Quantitative Trait Loci (QTL) for Early Maturation in Rainbow Trout (Oncorhynchus mykiss)

    PubMed Central

    Haidle, Lisa; Janssen, Jennifer E.; Gharbi, Karim; Moghadam, Hooman K.; Ferguson, Moira M.

    2008-01-01

    To identify quantitative trait loci (QTL) influencing early maturation (EM) in rainbow trout (Oncorhynchus mykiss), a genome scan was performed using 100 microsatellite loci across 29 linkage groups. Six inter-strain paternal half-sib families using three inter-strain F1 brothers (approximately 50 progeny in each family) derived from two strains that differ in the propensity for EM were used in the study. Alleles derived from both parental sources were observed to contribute to the expression of EM in the progeny of the brothers. Four genome-wide significant QTL regions (i.e., RT-8, -17, -24, and -30) were observed. EM QTL detected on RT-8 and -24 demonstrated significant and suggestive QTL effects in both male and female progeny. Furthermore, within both male and female full-sib groupings, QTL on RT-8 and -24 were detected in two or more of the five parents used. Significant genome-wide and several strong chromosome-wide QTL for EM localized to different regions in males and females, suggesting some sex-specific control. Namely, QTL detected on RT-13, -15, -21, and -30 were associated with EM only in females, and those on RT-3, -17, and -19 were associated with EM only in males. Within the QTL regions identified, a comparison of syntenic EST markers from the rainbow trout linkage map with the zebrafish (Danio rerio) genome identified several putative candidate genes that may influence EM. Electronic supplementary material The online version of this article (doi:10.1007/s10126-008-9098-5) contains supplementary material, which is available to authorized users. PMID:18491191

  12. Sediment Dynamics and Southern Steelhead Habitat (Oncorhynchus mykiss) in the Matilija Creek Watershed, Southern California

    NASA Astrophysics Data System (ADS)

    Minear, J. T.; Kondolf, G. M.

    2003-12-01

    Matilija Creek, one of two principal forks of the Ventura River, drains 142 km2 in the Transverse Ranges of southern California. Thanks to rapid tectonic uplift and weak clastic rocks, sediment yields exceed 1200 m3/km2 annually. Matilija Dam was built in 1947 with an initial capacity of 8 million m3 and is now nearly full of sediment. The dam is structurally unsafe, blocks anadromous fish migration, and is being considered for removal. The Ventura River has one of the southernmost runs of steelhead trout (Oncorhynchus mykiss), with an average of approximately 2,500 annually migrating up Matilija Creek before the dam was built. The high sediment yields and highly variable flow regime have raised questions about the interactions among high flows, sediment transfer from lower order tributaries to the third order channels used by the fish, and fish life history. Previous studies in Southern California have documented sediment yields (especially following debris flows and fires, and mostly in the San Gabriel Mountains), but the interaction of geomorphic processes and aquatic habitat in this highly episodic environment is not well understood. We used a combination of mapping and survey techniques, sediment traps, grain size analysis, lithologic analysis and scour rods to study intra-annual geomorphic processes and sediment dynamics affecting Southern Steelhead habitat in the Matilija Creek area in 16 study pools over the 2002 and 2003 flow seasons (dry and "normal", respectively) and found little sediment was deposited or scoured from pools. However, other processes not previously recognized significantly affected the steelhead habitat in the study pools including tufa cementation (carbonate deposition) and alder root growth in spawning gravels, as well as seasonal desiccation of some reaches. Removal of Matilija Dam will reopen suitable habitat to steelhead trout, but managers should recognize that habitat quality is likely to vary considerably from year

  13. The influence of social status on hepatic glucose metabolism in rainbow trout Oncorhynchus mykiss.

    PubMed

    Gilmour, Kathleen M; Kirkpatrick, Sheryn; Massarsky, Andrey; Pearce, Brenda; Saliba, Sarah; Stephany, Céleste-Élise; Moon, Thomas W

    2012-01-01

    The effects of chronic social stress on hepatic glycogen metabolism were examined in rainbow trout Oncorhynchus mykiss by comparing hepatocyte glucose production, liver glycogen phosphorylase (GP) activity, and liver β-adrenergic receptors in dominant, subordinate, control, fasted, and cortisol-treated fish. Hepatocyte glucose production in subordinate fish was approximately half that of dominant fish, reflecting hepatocyte glycogen stores in subordinate trout that were just 16% of those in dominant fish. Fasting and/or chronic elevation of cortisol likely contributed to these differences based on similarities among subordinate, fasted, and cortisol-treated fish. However, calculation of the "glycogen gap"--the difference between glycogen stores used and glucose produced--suggested an enhanced gluconeogenic potential in subordinate fish that was not present in fasted or cortisol-treated trout. Subordinate, fasted, and cortisol-treated trout also exhibited similar GP activities (both total activity and that of the active or a form), and these activities were in all cases significantly lower than those in control trout, perhaps reflecting an attempt to protect liver glycogen stores or a modified capacity to activate GP. Dominant trout exhibited the lowest GP activities (20%-24% of the values in control trout). Low GP activities, presumably in conjunction with incoming energy from feeding, allowed dominant fish to achieve the highest liver glycogen concentrations (double the value in control trout). Liver membrane β-adrenoceptor numbers (assessed as the number of (3)H-CGP binding sites) were significantly lower in subordinate than in dominant trout, although this difference did not translate into attenuated adrenergic responsiveness in hepatocyte glucose production in vitro. Transcriptional regulation, likely as a result of fasting, was indicated by significantly lower β(2)-adrenoceptor relative mRNA levels in subordinate and fasted trout. Collectively, the data

  14. Breeding site selection by coho salmon (Oncorhynchus kisutch) in relation to large wood additions and factors that influence reproductive success

    USGS Publications Warehouse

    Clark, Steven M.; Dunham, Jason B.; McEnroe, Jeffery R.; Lightcap, Scott W.

    2014-01-01

    The fitness of female Pacific salmon (Oncorhynchus spp.) with respect to breeding behavior can be partitioned into at least four fitness components: survival to reproduction, competition for breeding sites, success of egg incubation, and suitability of the local environment near breeding sites for early rearing of juveniles. We evaluated the relative influences of habitat features linked to these fitness components with respect to selection of breeding sites by coho salmon (Oncorhynchus kisutch). We also evaluated associations between breeding site selection and additions of large wood, as the latter were introduced into the study system as a means of restoring habitat conditions to benefit coho salmon. We used a model selection approach to organize specific habitat features into groupings reflecting fitness components and influences of large wood. Results of this work suggest that female coho salmon likely select breeding sites based on a wide range of habitat features linked to all four hypothesized fitness components. More specifically, model parameter estimates indicated that breeding site selection was most strongly influenced by proximity to pool-tail crests and deeper water (mean and maximum depths). Linkages between large wood and breeding site selection were less clear. Overall, our findings suggest that breeding site selection by coho salmon is influenced by a suite of fitness components in addition to the egg incubation environment, which has been the emphasis of much work in the past.

  15. Patterns of variation and covariation in the shapes of mandibular bones of juvenile salmonids in the genus Oncorhynchus.

    PubMed

    Kimmel, Charles B; Watson, Sawyer; Couture, Ryan B; McKibben, Natasha S; Nichols, James T; Richardson, Shannon E; Noakes, David L G

    2015-01-01

    What is the nature of evolutionary divergence of the jaw skeleton within the genus Oncorhynchus? How can two associated bones evolve new shapes and still maintain functional integration? Here, we introduce and test a "concordance" hypothesis, in which an extraordinary matching of the evolutionary shape changes of the dentary and angular articular serves to preserve their fitting together. To test this hypothesis, we examined morphologies of the dentary and angular articular at parr (juvenile) stage, and at three levels of biological organization—between salmon and trout, between sister species within both salmon and trout, and among three types differing in life histories within one species, Oncorhynchus mykiss. The comparisons show bone shape divergences among the groups at each level; morphological divergence between salmon and trout is marked even at this relatively early life history stage. We observed substantial matching between the two mandibular bones in both pattern and amount of shape variation, and in shape covariation across species. These findings strongly support the concordance hypothesis, and reflect functional and/or developmental constraint on morphological evolution. We present evidence for developmental modularity within both bones. The locations of module boundaries were predicted from the patterns of evolutionary divergences, and for the dentary, at least, would appear to facilitate its functional association with the angular articular. The modularity results suggest that development has biased the course of evolution.

  16. Assessing the suitability of a partial water reuse system for rearing juvenile Chinook salmon Oncorhynchus tshawytscha for stocking in Washington State

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Health and welfare of juvenile Chinook salmon Oncorhynchus tshawytsha reared in a pilot circular tank-based partial water reuse system in Washington State were evaluated in comparison to fish from the same spawn reared in a flow-through raceway, in order to assess the suitability of using water reus...

  17. Molecular cloning and expression analysis of rainbow trout (Oncorhynchus mykiss)CCAAT/enhancer binding protein genes and their responses to induction by GH in vitro and in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CCAAT/enhancer-binding proteins (C/EBPs) are transcription factors consisting of six isoforms and play diverse physiological roles in vertebrates. In rainbow trout (Oncorhynchus mykiss), in addition to the reported C/EBPbeta1,we have isolated cDNA of four other isoforms, C/EBPalpha, C/EBPbeta2, C/E...

  18. The effects of ozonation on performance, health and welfare of rainbow trout Oncorhynchus mykiss in low-exchange water recirculation aquaculture systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A controlled four-month trial was conducted to compare the effects of ozonation (oxidation-reduction potential setpoint = 250 mV) versus no ozonation on rainbow trout Oncorhynchus mykiss performance, health, and welfare in replicated WRAS operated at low exchange rates (0.26% of the total recirculat...

  19. Impact of carbon dioxide level, water velocity, strain, and feeding regimen on growth and fillet attributes of cultured rainbow trout (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production and management variables such as carbon dioxide (CO2) level, water velocity, and feeding frequency influence the growth and fillet attributes of rainbow trout (Oncorhynchus mykiss), as well as cost of production. More information is needed to determine the contributions of these variables...

  20. Growth, immune responses and intestinal morphology of rainbow trout (Oncorhynchus mykiss) supplemented with commercial probiotics.

    PubMed

    Ramos, M A; Gonçalves, J F M; Batista, S; Costas, B; Pires, M A; Rema, P; Ozório, R O A

    2015-07-01

    The influence of two commercial probiotics on the growth, innate immune parameters and intestinal morphology of rainbow trout (Oncorhynchus mykiss) juveniles (initial weight: 16.4 ± 0.4 g) was evaluated. Two probiotic types: A, multi-species (Bacillus sp., Pedicoccus sp., Enterococcus sp., Lactobacillus sp.) and B, mono-species (Pediococcus acidilactici) were tested at two levels each (A1: 1.5 g kg(-1), 8.6 × 10(5) CFU g(-1); A2: 3 g kg(-1), 1.6 × 10(6) CFU g(-1); B1: 0.1 g kg(-1), 2.6 × 10(4) CFU g(-1); B2: 0.2 g kg(-1), 7.2 × 10(4) CFU g(-1)) versus an unsupplemented diet (C). Diets were distributed to sextuplicate tanks, three times a day to visual satiation for 8 weeks. Growth performance and immune responses (plasma lysozyme, ACH50, peroxidase and head kidney respiratory burst) were determined at 4 and 8 weeks of feeding. Body composition and intestine morphology were determined at the end of the feeding trial. At 8 weeks, the lower dose of multi-species probiotic (A1) improved growth rate, while both probiotic types improved feed conversion rate compared to the control animals, at the lower dose of multi-species (A1) and at the higher dose of mono-species (B2) probiotics. Body composition did not vary between treatments. At 4 weeks, ACH50 activity was significantly higher in fish fed higher dose of B probiotic (B2, 123.7 ± 50.6 vs 44.1 ± 7.7 U.ml(-1) in control). At 8 weeks, lysozyme activity was higher in fish fed A1 (13.1 ± 5.2 μg ml(-1)) diet compared to fish fed control diet (7.8 ± 1 μg ml(-1)). Plasma peroxidase and head-kidney respiratory burst did not differ among the dietary treatments. Villi length and integrity and goblet cell counting of a cross section of the anterior intestine were not significantly different between groups. Results suggest benefits in zootechnical performance and immune humoral responses using both probiotic types, in a dose dependent manner, without apparent alterations in intestinal morphology.

  1. Oxygen uptake in Pacific salmon Oncorhynchus spp.: when ecology and physiology meet.

    PubMed

    Eliason, E J; Farrell, A P

    2016-01-01

    Over the past several decades, a substantial amount of research has examined how cardiorespiratory physiology supports the diverse activities performed throughout the life cycle of Pacific salmon, genus Oncorhynchus. Pioneering experiments emphasized the importance of aerobic scope in setting the functional thermal tolerance for activity in fishes. Variation in routine metabolism can have important performance and fitness consequences as it is related to dominance, aggression, boldness, territoriality, growth rate, postprandial oxygen consumption, life history, season, time of day, availability of shelter and social interactions. Wild fishes must perform many activities simultaneously (e.g. swim, obtain prey, avoid predators, compete, digest and reproduce) and oxygen delivery is allocated among competing organ systems according to the capacity of the heart to deliver blood. For example, salmonids that are simultaneously swimming and digesting trade-off maximum swimming performance in order to support the oxygen demands of digestion. As adult Pacific salmonids cease feeding in the ocean prior to their home migration, endogenous energy reserves and cardiac capacity are primarily partitioned among the demands for swimming upriver, sexual maturation and spawning behaviours. Furthermore, the upriver spawning migration is under strong selection pressure, given that Pacific salmonids are semelparous (single opportunity to spawn). Consequently, these fishes optimize energy expenditures in a number of ways: strong homing, precise migration timing, choosing forward-assist current paths and exploiting the boundary layer to avoid the strong currents in the middle of the river, using energetically efficient swimming speeds, and recovering rapidly from anaerobic swimming. Upon arrival at the spawning ground, remaining energy can be strategically allocated to the various spawning behaviours. Strong fidelity to natal streams has resulted in reproductively isolated populations that

  2. Identification, characterization and genetic mapping of TLR1 loci in rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Palti, Y.; Rodriguez, M.F.; Gahr, S.A.; Purcell, M.K.; Rexroad, C. E.; Wiens, G.D.

    2010-01-01

    Induction of innate immune pathways is critical for early anti-microbial defense but there is limited understanding of how teleosts recognize microbial molecules and activate these pathways. In mammals, Toll-like receptors (TLR) 1 and 2 form a heterodimer involved in recognizing peptidoglycans and lipoproteins of microbial origin. Herein, we identify and describe the rainbow trout (Oncorhynchus mykiss) TLR1 gene ortholog and its mRNA expression. Two TLR1 loci were identified from a rainbow trout bacterial artificial chromosome (BAC) library using DNA sequencing and genetic linkage analyses. Full length cDNA clone and direct sequencing of four BACs revealed an intact omTLR1 open reading frame (ORF) located on chromosome 14 and a second locus on chromosome 25 that contains a TLR1 pseudogene. The duplicated trout loci exhibit conserved synteny with other fish genomes that extends beyond the TLR1 gene sequences. The omTLR1 gene includes a single large coding exon similar to all other described TLR1 genes, but unlike other teleosts it also has a 5??? UTR exon and intron preceding the large coding exon. The omTLR1 ORF is predicted to encode an 808 amino-acid protein with 69% similarity to the Fugu TLR1 and a conserved pattern of predicted leucine-rich repeats (LRR). Phylogenetic analysis grouped omTLR1 with other fish TLR1 genes on a separate branch from the avian TLR1 and mammalian TLR1, 6 and 10. omTLR1 expression levels in rainbow trout anterior kidney leukocytes were not affected by the human TLR2/6 and TLR2/1 agonists diacylated lipoprotein (Pam2CSK4) and triacylated lipoprotein (Pam3CSK4). However, due to the lack of TLR6 and 10 genes in teleost genomes and up-regulation of TLR1 mRNA in response to LPS and bacterial infection in other fish species we hypothesize an important role for omTLR1 in anti-microbial immunity. Therefore, the identification of a TLR2 ortholog in rainbow trout and the development of assays to measure ligand binding and downstream signaling

  3. Identification, characterization and genetic mapping of TLR1 loci in rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Palti, Yniv; Rodriguez, M. Fernanda; Gahr, Scott A.; Purcell, Maureen K.; Rexroad, Caird E.; Wiens, Gregory D.

    2010-01-01

    Induction of innate immune pathways is critical for early anti-microbial defense but there is limited understanding of how teleosts recognize microbial molecules and activate these pathways. In mammals, Toll-like receptors (TLR) 1 and 2 form a heterodimer involved in recognizing peptidoglycans and lipoproteins of microbial origin. Herein, we identify and describe the rainbow trout (Oncorhynchus mykiss) TLR1 gene ortholog and its mRNA expression. Two TLR1 loci were identified from a rainbow trout bacterial artificial chromosome (BAC) library using DNA sequencing and genetic linkage analyses. Full length cDNA clone and direct sequencing of four BACs revealed an intact omTLR1 open reading frame (ORF) located on chromosome 14 and a second locus on chromosome 25 that contains a TLR1 pseudogene. The duplicated trout loci exhibit conserved synteny with other fish genomes that extends beyond the TLR1 gene sequences. The omTLR1 gene includes a single large coding exon similar to all other described TLR1 genes, but unlike other teleosts it also has a 5' UTR exon and intron preceding the large coding exon. The omTLR1 ORF is predicted to encode an 808 amino-acid protein with 69% similarity to the Fugu TLR1 and a conserved pattern of predicted leucine-rich repeats (LRR). Phylogenetic analysis grouped omTLR1 with other fish TLR1 genes on a separate branch from the avian TLR1 and mammalian TLR1, 6 and 10. omTLR1 expression levels in rainbow trout anterior kidney leukocytes were not affected by the human TLR2/6 and TLR2/1 agonists diacylated lipoprotein (Pam2CSK4) and triacylated lipoprotein (Pam3CSK4). However, due to the lack of TLR6 and 10 genes in teleost genomes and up-regulation of TLR1 mRNA in response to LPS and bacterial infection in other fish species we hypothesize an important role for omTLR1 in anti-microbial immunity. Therefore, the identification of a TLR2 ortholog in rainbow trout and the development of assays to measure ligand binding and downstream signaling are

  4. Oxygen uptake in Pacific salmon Oncorhynchus spp.: when ecology and physiology meet.

    PubMed

    Eliason, E J; Farrell, A P

    2016-01-01

    Over the past several decades, a substantial amount of research has examined how cardiorespiratory physiology supports the diverse activities performed throughout the life cycle of Pacific salmon, genus Oncorhynchus. Pioneering experiments emphasized the importance of aerobic scope in setting the functional thermal tolerance for activity in fishes. Variation in routine metabolism can have important performance and fitness consequences as it is related to dominance, aggression, boldness, territoriality, growth rate, postprandial oxygen consumption, life history, season, time of day, availability of shelter and social interactions. Wild fishes must perform many activities simultaneously (e.g. swim, obtain prey, avoid predators, compete, digest and reproduce) and oxygen delivery is allocated among competing organ systems according to the capacity of the heart to deliver blood. For example, salmonids that are simultaneously swimming and digesting trade-off maximum swimming performance in order to support the oxygen demands of digestion. As adult Pacific salmonids cease feeding in the ocean prior to their home migration, endogenous energy reserves and cardiac capacity are primarily partitioned among the demands for swimming upriver, sexual maturation and spawning behaviours. Furthermore, the upriver spawning migration is under strong selection pressure, given that Pacific salmonids are semelparous (single opportunity to spawn). Consequently, these fishes optimize energy expenditures in a number of ways: strong homing, precise migration timing, choosing forward-assist current paths and exploiting the boundary layer to avoid the strong currents in the middle of the river, using energetically efficient swimming speeds, and recovering rapidly from anaerobic swimming. Upon arrival at the spawning ground, remaining energy can be strategically allocated to the various spawning behaviours. Strong fidelity to natal streams has resulted in reproductively isolated populations that

  5. The effect of chronic chromium exposure on the health of Chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Farag, A.M.; May, T.; Marty, G.D.; Easton, M.; Harper, D.D.; Little, E.E.; Cleveland, L.

    2006-01-01

    This study was designed to determine fish health impairment of Chinook salmon (Oncorhynchus tshawytscha) exposed to chromium. Juvenile Chinook salmon were exposed to aqueous chromium concentrations (0-266 ??g l-1) that have been documented in porewater from bottom sediments and in well waters near salmon spawning areas in the Columbia River in the northwestern United States. After Chinook salmon parr were exposed to 24 and 54 ??g Cr l -1 for 105 days, neither growth nor survival of parr was affected. On day 105, concentrations were increased from 24 to 120 ??g Cr l-1 and from 54 to 266 ??g Cr l-1 until the end of the experiment on day 134. Weight of parr was decreased in the 24/120 ??g Cr l-1 treatment, and survival was decreased in the 54/266 ??g Cr l-1 treatment. Fish health was significantly impaired in both the 24/120 and 54/266 ??g Cr l-1 treatments. The kidney is the target organ during chromium exposures through the water column. The kidneys of fish exposed to the greatest concentrations of chromium had gross and microscopic lesions (e.g. necrosis of cells lining kidney tububules) and products of lipid peroxidation were elevated. These changes were associated with elevated concentrations of chromium in the kidney, and reduced growth and survival. Also, variations in DNA in the blood were associated with pathological changes in the kidney and spleen. These changes suggest that chromium accumulates and enters the lipid peroxidation pathway where fatty acid damage and DNA damage (expressed as chromosome changes) occur to cause cell death and tissue damage. While most of the physiological malfunctions occurred following parr exposures to concentrations ???120 ??g Cr l-1, nuclear DNA damage followed exposures to 24 ??g Cr l-1, which was the smallest concentration tested. The abnormalities measured during this study are particularly important because they are associated with impaired growth and reduced survival at concentrations ???120 ??g Cr l-1. Therefore, these

  6. Effects of triploidy induction on antioxidant defense status in rainbow trout (Oncorhynchus mykiss) during early development.

    PubMed

    Taghipoor, Kaveh; Keyvanshokooh, Saeed; Salati, Amir Parviz; Pasha-Zanoosi, Hossein; Babaheydari, Samad Bahrami

    2016-08-01

    The objective of the present study was to examine the antioxidant status of rainbow trout (Oncorhynchus mykiss) during the early stages of development (fertilized egg, eyed egg, alevin and fry) as an effect of triploidy induction. Eggs and milt were taken from eight females and six males. After insemination, the eggs were incubated at 10°C for 10min. Half of the fertilized eggs were then subjected to heat-shock for 10min submerged in a 28°C water bath to induce triploidy. The remainder were incubated normally and used as diploid controls. Three batches of eggs were randomly selected from each group (control and heat-shocked) and were incubated at 10-11°C under the same environmental conditions in hatchery troughs until the fry stage. Triplicate samples of fertilized eggs from each experimental group were randomly selected 1.5h post-fertilization and at the eyed egg stage of development (18 days post-fertilization, dpf). At 27 dpf, triplicate samples of alevins were chosen from each group. Based on ploidy determination experiment performed on both groups, nine diploid and nine triploid fry (76 dpf) were also selected. The triploidy induction success rate was 87.1%. Vitamin C was in lesser concentrations in fertilized eggs and eyed eggs of the heat-shock treatment group as compared with eggs of the diploid group. Alevins of the heat-shock treatment group had a lower superoxide dismutase (SOD) activity than alevins of the diploid group. Glutathione peroxidase (GPx) level was greater in fertilized eggs and alevins of the heat-shock treatment group as compared to diploids. Catalse (CAT) activity was greater in fertilized eggs, alevins and fry of the heat-shock treatment group than those of the diploid group. Malondialdehyde (MDA), as an index of lipid peroxidation, was in greater concentration in fertilized eggs of the group that was heat-shocked, but it was lesser in alevins and fry of the group in which the eggs were heat-shocked as compared to diploid counterparts

  7. Innate immune and growth promoting responses to caper (Capparis spinosa) extract in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Bilen, Soner; Altunoglu, Yasemin Celik; Ulu, Ferhat; Biswas, Gouranga

    2016-10-01

    Cytokine responses, non-specific immune activity and growth promotion effect of dietary caper (Capparis spinosa) supplementation were examined in rainbow trout (Oncorhynchus mykiss). Rainbow trout (12.04 ± 0.71 g) were fed diets containing three doses of caper methanolic extract [0 (Control), 0.1 and 0.5 g kg(-1) of feed] for 30 days. At the end of the feeding trial, expression levels of cytokine genes that included IL-1β, IL-8, TGF-β, IL-12p40, TNF-α1 and IL-10 in head kidney was analyzed using qRT-PCR, and blood and serum were collected to determine superoxide anion production (SAP), phagocytic, lysozyme and myeloperoxidase activities. Expression levels of all cytokines, except TNF-α1 were elevated in the 0.1 g kg(-1) caper extract fed fish group compared to other groups. In 0.5 g kg(-1) caper extract treated fish, only IL-12p40 and IL-10 genes were up-regulated compared to control group fish. SAP was increased in both caper extract treated groups compared to the control, and the highest level was observed in the 0.1 g kg(-1) group. Phagocytic activity in both the caper extract treated groups was increased compared to control with no differences observed between those groups. Lysozyme and myeloperoxidase activities were recorded to be the highest in the 0.1 g kg(-1) fed fish group compared to other groups. Growth promotion was affected positively when caper doses were increased. Survival rate was significantly higher in 0.1 and 0.5 g kg(-1) caper extract treated fish groups compared to control (P < 0.05) after challenged with Aeromonas hydrophila. These results indicate that caper extract stimulates innate immunity through cytokine-mediated responses and promote growth in rainbow trout.

  8. Puffy Skin Disease Is an Emerging Transmissible Condition in Rainbow Trout Oncorhynchus mykiss Walbaum

    PubMed Central

    Cano, Irene; Verner-Jeffreys, David W.; van Aerle, Ronny; Paley, Richard K.; Peeler, Edmund J.; Green, Matthew; Rimmer, Georgina S. E.; Savage, Jacqueline; Joiner, Claire L.; Bayley, Amanda E.; Mewett, Jason; Hulland, Jonathan; Feist, Stephen W.

    2016-01-01

    The transmission of puffy skin disease (PSD) to rainbow trout Oncorhynchus mykiss Walbaum was tested in the laboratory by conducting co-habitation challenges with puffy skin (PS)-affected fish (Trojans) collected from the field. Two separate challenges were conducted using Trojans sourced from two different sites and diploid (first trial) or triploid (second trial) naïve fish. PSD-specific clinical signs were observed in both groups of naïve fish, with 66% of the fish sampled during the challenges showing signs of varying severity. The first clinical features of PSD were presented as white oval skin patches on one or both flanks 15–21 days post-challenge (dpc). The extent of the lesions ranged from 10 to 90% of the body surface, depending on the severity of the lesion. Both the severity and number of affected fish increased during the challenge. Macroscopically, oedema of the skin and multifocal petechial haemorrhaging were observed towards the end of the trials. Abnormal fish behaviour consisting of “flashing” and excessive mucous production was noted from 15 dpc onwards. Fish with severe PSD lesions also displayed inappetence and associated emaciation. Rodlet cells were observed in 41% of the fresh skin scrapes analysed from the second trial. Histologically epidermal oedema was observed in 31% of the naive fish showing gross pathology, with additional 12% displaying epidermal hyperplasia, mostly observed at the end of the challenge. Other concomitant features of the PSD lesions in challenged fish were epithelial erosion and sloughing, and occasionally mild or focal inflammation. No consistent pathology of internal organs was observed. The parasites Ichthyophthirius multifiliis and Ichthyobodo necator were observed in skin samples of a proportion of naïve challenged fish and in Trojans but not in control fish. The presence of these and other known fish pathogens in the skin of PSD-fish was confirmed by high-throughput sequencing analysis. In summary, we

  9. Innate immune and growth promoting responses to caper (Capparis spinosa) extract in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Bilen, Soner; Altunoglu, Yasemin Celik; Ulu, Ferhat; Biswas, Gouranga

    2016-10-01

    Cytokine responses, non-specific immune activity and growth promotion effect of dietary caper (Capparis spinosa) supplementation were examined in rainbow trout (Oncorhynchus mykiss). Rainbow trout (12.04 ± 0.71 g) were fed diets containing three doses of caper methanolic extract [0 (Control), 0.1 and 0.5 g kg(-1) of feed] for 30 days. At the end of the feeding trial, expression levels of cytokine genes that included IL-1β, IL-8, TGF-β, IL-12p40, TNF-α1 and IL-10 in head kidney was analyzed using qRT-PCR, and blood and serum were collected to determine superoxide anion production (SAP), phagocytic, lysozyme and myeloperoxidase activities. Expression levels of all cytokines, except TNF-α1 were elevated in the 0.1 g kg(-1) caper extract fed fish group compared to other groups. In 0.5 g kg(-1) caper extract treated fish, only IL-12p40 and IL-10 genes were up-regulated compared to control group fish. SAP was increased in both caper extract treated groups compared to the control, and the highest level was observed in the 0.1 g kg(-1) group. Phagocytic activity in both the caper extract treated groups was increased compared to control with no differences observed between those groups. Lysozyme and myeloperoxidase activities were recorded to be the highest in the 0.1 g kg(-1) fed fish group compared to other groups. Growth promotion was affected positively when caper doses were increased. Survival rate was significantly higher in 0.1 and 0.5 g kg(-1) caper extract treated fish groups compared to control (P < 0.05) after challenged with Aeromonas hydrophila. These results indicate that caper extract stimulates innate immunity through cytokine-mediated responses and promote growth in rainbow trout. PMID:27546553

  10. A novel member of the family Hepeviridae from cutthroat trout (Oncorhynchus clarkii)

    USGS Publications Warehouse

    Batts, William; Yun, Susan; Hedrick, Ronald; Winton, James

    2011-01-01

    Beginning in 1988, the Chinook salmon embryo (CHSE-214) cell line was used to isolate a novel virus from spawning adult trout in the state of California, USA. Termed the cutthroat trout (Oncorhynchus clarkii) virus (CTV), the small, round virus was not associated with disease, but was subsequently found to be present in an increasing number of trout populations in the western USA, likely by a combination of improved surveillance activities and the shipment of infected eggs to new locations. Here, we report that the full length genome of the 1988 Heenan Lake isolate of CTV consisted of 7269 nucleotides of positive-sense, single-stranded RNA beginning with a 5' untranslated region (UTR), followed by three open reading frames (ORFs), a 3' UTR and ending in a polyA tail. The genome of CTV was similar in size and organization to that of Hepatitis E virus (HEV) with which it shared the highest nucleotide and amino acid sequence identities. Similar to the genomes of human, rodent or avian hepeviruses, ORF 1 encoded a large, non-structural polyprotein that included conserved methyltransferase, protease, helicase and polymerase domains, while ORF 2 encoded the structural capsid protein and ORF 3 the phosphoprotein. Together, our data indicated that CTV was clearly a member of the family Hepeviridae, although the level of amino acid sequence identity with the ORFs of mammalian or avian hepeviruses (13-27%) may be sufficiently low to warrant the creation of a novel genus. We also performed a phylogenetic analysis using a 262. nt region within ORF 1 for 63 isolates of CTV obtained from seven species of trout reared in various geographic locations in the western USA. While the sequences fell into two genetic clades, the overall nucleotide diversity was low (less than 8.4%) and many isolates differed by only 1-2 nucleotides, suggesting an epidemiological link. Finally, we showed that CTV was able to form persistently infected cultures of the CHSE-214 cell line that may have use

  11. Performance of juvenile steelhead trout (Oncorhynchus mykiss) produced from untreated and cryopreserved milt

    USGS Publications Warehouse

    Hayes, Michael C.; Rubin, Stephen P.; Hensleigh, Jay E.; Reisenbichler, Reginald R.; Wetzel, Lisa A.

    2005-01-01

    Despite the expanding use of milt cryopreservation in aquaculture, the performance of fish produced from this technique has not been fully explored beyond initial rearing stages. We compared the performance of juvenile steelhead Oncorhynchus mykiss produced from untreated (UM) and cryopreserved milt (CM) and reared for 4–9 months. For the 1996 brood, CM alevins were heavier (∼ 1.7%, P < 0.01) than UM alevins and length was influenced by a significant milt-by-family interaction (P < 0.03) suggesting a greater treatment effect for some families. No significant differences were found in length or weight (P > 0.05) for 1997 brood alevins and percent yolk was similar for both broods (P > 0.34). In growth and survival experiment I (GSE-I, 1996), UM and CM juveniles reared in separate tanks and fed to satiation (130 days) showed no significant differences in survival, length or weight (P > 0.05) between milt groups. In contrast, for UM and CM siblings reared in the same tank for 210 days on a low food ration (GSE-II), survival was similar (P > 0.05), but length (UM 4% > CM, P < 0.05) and possibly weight (UM 15% > CM, P = 0.08), were influenced by cryopreservation. Fish from the 1997 brood (GSE-III) were reared for 313 days in a repeat of GSE-II and no differences were found in survival (P = 0.47), length (P = 0.75) or weight (P = 0.76) suggesting considerable heterogeneity between broods. Performance of the 1996 brood was also tested for response to stress and a disease challenge. Cortisol responses of juveniles exposed to acute stress were not significantly different (P = 0.19), but mean cortisol was consistently and significantly greater (P < 0.01) for CM than UM fish exposed to a 48-h stress (increased density). After exposure to three dosages of the bacteria, Listonella anguillarum, we found similar mortality proportions (P = 0.72) for UM and CM fish. Variable juvenile performance for the parameters tested indicated significant

  12. Relative virulence of three isolates of Piscirickettsia salmonis for coho salmon Oncorhynchus kisutch

    USGS Publications Warehouse

    House, M.L.; Bartholomew, J.L.; Winton, J.R.; Fryer, J.L.

    1999-01-01

    Piscirickettsia salmonis was first recognized as the cause of mortality among pen-reared coho salmon Oncorhynchus kisutch in Chile. Since the initial isolation of this intracellular Gram-negative bacterium in 1989, similar organisms have been described from several areas of the world, but the associated outbreaks were not reported to be as serious as those that occurred in Chile. To determine if this was due to differences in virulence among isolates of P. salmonis, we conducted an experiment comparing isolates from Chile, British Columbia, Canada, and Norway (LF-89, ATL-4-91 and NOR-92, respectively). For each of the isolates, 3 replicates of 30 coho salmon were injected intraperitoneally with each of 3 concentrations of the bacterium. Negative control fish were injected with MEM-10. Mortalities were collected daily for 41 d post-injection. Piscirickettsiosis was observed in fish injected with each of the 3 isolates, and for each isolate, cumulative mortality was directly related to the concentration of bacterial cells administered. The LF-89 isolate was the most virulent, with losses reaching 97% in the 3 replicates injected with 105.0 TCID50, 91% in the replicates injected with 104.0 TCID50, and 57% in the fish injected with 103.0 TCID50. The ATL-4-91 isolate caused losses of 92% in the 3 replicates injected with 105.0 TCID50, 76% in the fish injected with 104.0 TCID50, and 32% in those injected with 103.0 TCID50. The NOR-92 isolate was the least virulent, causing 41% mortality in the replicates injected with 104.6 TCID50. At 41 d post-injection, 6% of the fish injected with 103.6 TCID50 NOR-92 had died. Mortality was only 2% in the fish injected with 102.6 TCID50 NOR-92, which was the same as the negative control group. Because the group injected with the highest concentration (104.6 TCID50) of NOR-92 was still experiencing mortality at 41 d, it was held for an additional 46 d. At 87 d post-injection, the cumulative mortality in this group had reached 70

  13. Effects of triploidy induction on antioxidant defense status in rainbow trout (Oncorhynchus mykiss) during early development.

    PubMed

    Taghipoor, Kaveh; Keyvanshokooh, Saeed; Salati, Amir Parviz; Pasha-Zanoosi, Hossein; Babaheydari, Samad Bahrami

    2016-08-01

    The objective of the present study was to examine the antioxidant status of rainbow trout (Oncorhynchus mykiss) during the early stages of development (fertilized egg, eyed egg, alevin and fry) as an effect of triploidy induction. Eggs and milt were taken from eight females and six males. After insemination, the eggs were incubated at 10°C for 10min. Half of the fertilized eggs were then subjected to heat-shock for 10min submerged in a 28°C water bath to induce triploidy. The remainder were incubated normally and used as diploid controls. Three batches of eggs were randomly selected from each group (control and heat-shocked) and were incubated at 10-11°C under the same environmental conditions in hatchery troughs until the fry stage. Triplicate samples of fertilized eggs from each experimental group were randomly selected 1.5h post-fertilization and at the eyed egg stage of development (18 days post-fertilization, dpf). At 27 dpf, triplicate samples of alevins were chosen from each group. Based on ploidy determination experiment performed on both groups, nine diploid and nine triploid fry (76 dpf) were also selected. The triploidy induction success rate was 87.1%. Vitamin C was in lesser concentrations in fertilized eggs and eyed eggs of the heat-shock treatment group as compared with eggs of the diploid group. Alevins of the heat-shock treatment group had a lower superoxide dismutase (SOD) activity than alevins of the diploid group. Glutathione peroxidase (GPx) level was greater in fertilized eggs and alevins of the heat-shock treatment group as compared to diploids. Catalse (CAT) activity was greater in fertilized eggs, alevins and fry of the heat-shock treatment group than those of the diploid group. Malondialdehyde (MDA), as an index of lipid peroxidation, was in greater concentration in fertilized eggs of the group that was heat-shocked, but it was lesser in alevins and fry of the group in which the eggs were heat-shocked as compared to diploid counterparts

  14. Predation on juvenile pacific salmon oncorhynchus spp. in downstream migrant traps in prairie creek, california

    USGS Publications Warehouse

    Duffy, W.G.; Bjorkstedt, E.P.; Ellings, C.S.

    2011-01-01

    Downstream migrant traps are a widely applied fishery management tool for sampling anadromous Pacific salmon Oncorhynchus spp. and steelhead O. mykiss smolts along theWest Coast of North America and elsewhere, yet predation on juvenile salmonids in traps has not been studied quantitatively.We assessed the frequency of occurrence and abundance of juvenile salmonids in the stomachs of coastal cutthroat trout O. clarkii clarkii, coho salmon O. kisutch, steelhead, and prickly sculpin Cottus asper (>70 mm fork length) captured in traps and in nearby stream habitats. All four predator species took juvenile salmonids with much greater frequency in traps than in stream habitats. Among free-swimming predators, only coastal cutthroat trout were observed with salmonid fry in their stomachs, but they took fewer salmonid prey and appeared to rely more heavily on insect prey than did coastal cutthroat trout captured in traps. Predators consumed up to 25% of the available prey over a broad range of prey abundances. Over the course of the study, predators consumed 2.5% of all salmonid fry captured in traps, but this fraction ranged from less than 1% to more than 10% in any given year. The number of prey taken in traps increased with predator length and with prey abundance in traps, and predation in traps peaked during the period of most intense downstream migration by salmon fry. In contrast, live-box design and trap location had little or no effect on the total number of prey taken by individual predators.We estimated that the predation mortality of juvenile salmon increased by 0.5-1.0% due to in-trap predation (i.e., a 9-10% relative increase over natural predation rates). We found no evidence that predators selected for prey on the basis of species. These results should motivate additional research on methods that reduce or eliminate predation in trap live-boxes and protocols for efficiently measuring predation associated with the trapping of downstream migrants. ?? American

  15. Puffy Skin Disease Is an Emerging Transmissible Condition in Rainbow Trout Oncorhynchus mykiss Walbaum.

    PubMed

    Cano, Irene; Verner-Jeffreys, David W; van Aerle, Ronny; Paley, Richard K; Peeler, Edmund J; Green, Matthew; Rimmer, Georgina S E; Savage, Jacqueline; Joiner, Claire L; Bayley, Amanda E; Mewett, Jason; Hulland, Jonathan; Feist, Stephen W

    2016-01-01

    The transmission of puffy skin disease (PSD) to rainbow trout Oncorhynchus mykiss Walbaum was tested in the laboratory by conducting co-habitation challenges with puffy skin (PS)-affected fish (Trojans) collected from the field. Two separate challenges were conducted using Trojans sourced from two different sites and diploid (first trial) or triploid (second trial) naïve fish. PSD-specific clinical signs were observed in both groups of naïve fish, with 66% of the fish sampled during the challenges showing signs of varying severity. The first clinical features of PSD were presented as white oval skin patches on one or both flanks 15-21 days post-challenge (dpc). The extent of the lesions ranged from 10 to 90% of the body surface, depending on the severity of the lesion. Both the severity and number of affected fish increased during the challenge. Macroscopically, oedema of the skin and multifocal petechial haemorrhaging were observed towards the end of the trials. Abnormal fish behaviour consisting of "flashing" and excessive mucous production was noted from 15 dpc onwards. Fish with severe PSD lesions also displayed inappetence and associated emaciation. Rodlet cells were observed in 41% of the fresh skin scrapes analysed from the second trial. Histologically epidermal oedema was observed in 31% of the naive fish showing gross pathology, with additional 12% displaying epidermal hyperplasia, mostly observed at the end of the challenge. Other concomitant features of the PSD lesions in challenged fish were epithelial erosion and sloughing, and occasionally mild or focal inflammation. No consistent pathology of internal organs was observed. The parasites Ichthyophthirius multifiliis and Ichthyobodo necator were observed in skin samples of a proportion of naïve challenged fish and in Trojans but not in control fish. The presence of these and other known fish pathogens in the skin of PSD-fish was confirmed by high-throughput sequencing analysis. In summary, we have

  16. Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss)

    PubMed Central

    Bouwes, Nicolaas; Weber, Nicholas; Jordan, Chris E.; Saunders, W. Carl; Tattam, Ian A.; Volk, Carol; Wheaton, Joseph M.; Pollock, Michael M.

    2016-01-01

    Beaver have been referred to as ecosystem engineers because of the large impacts their dam building activities have on the landscape; however, the benefits they may provide to fluvial fish species has been debated. We conducted a watershed-scale experiment to test how increasing beaver dam and colony persistence in a highly degraded incised stream affects the freshwater production of steelhead (Oncorhynchus mykiss). Following the installation of beaver dam analogs (BDAs), we observed significant increases in the density, survival, and production of juvenile steelhead without impacting upstream and downstream migrations. The steelhead response occurred as the quantity and complexity of their habitat increased. This study is the first large-scale experiment to quantify the benefits of beavers and BDAs to a fish population and its habitat. Beaver mediated restoration may be a viable and efficient strategy to recover ecosystem function of previously incised streams and to increase the production of imperiled fish populations. PMID:27373190

  17. Effects of temperature and growth hormone on individual growth trajectories of wild-type and transgenic coho salmon Oncorhynchus kisutch.

    PubMed

    Lõhmus, M; Björklund, M; Sundström, L F; Devlin, R H

    2010-02-01

    In this study, individual growth patterns of wild-type and growth-enhanced coho salmon Oncorhynchus kisutch at 8, 12 and 16 degrees C water temperature were followed. Despite large differences among individuals in growth rates, there was generally little variation in the shape of the growth curves among O. kisutch individuals of both genotypes and at all temperatures. Typically, individuals that were relatively large initially were also relatively large at the end of the growth period. The limitation in variation was more pronounced in the growth-enhanced O. kisutch than in the wild type, where the relative size of some individuals reared at 12 and 8 degrees C changed by the end of the trial. As a warmer temperature seems to decrease the plasticity of growth trajectories in wild-type fish, it is possible that global warming will influence the ability of wild fish to adapt their growth to changing conditions.

  18. Preliminary examination of oxidative stress in juvenile spring Chinook salmon Oncorhynchus tshawytscha of wild origin sampled from transport barges.

    PubMed

    Welker, T L; Congleton, J L

    2009-11-01

    Migrating juvenile wild Chinook salmon Oncorhynchus tshawytscha, collected and loaded onto transport barges at Lower Granite Dam on the Snake River, were sampled from barges at John Day Dam, 348 km downstream, at 5 day intervals beginning in late April and ending in late May. An increase in lipid peroxidation and decrease in vitamin E in liver were observed from early to late in the barge transportation season. These changes seemed unrelated to changes in plasma cortisol or corresponding glucose levels, which declined from early to late in the season, or the concentration of n-3 highly unsaturated fatty acid (HUFA) concentrations in tissue but may be related to water temperature, which increased during the transport season, or other changes associated with the parr-smolt transformation.

  19. Some physiological consequences of handling stress in the juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri)

    USGS Publications Warehouse

    Wedemeyer, Gary

    1972-01-01

    The stress of handling juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri) in soft water and in water with added salts was evaluated using blood and tissue chemistry fluctuations as indices of metabolic and endocrine function. Changes in plasma glucose, chloride, calcium, and cholesterol levels indicated that significant osmoregulatory and metabolic dysfunctions can occur and persist for about 24 hr after handling in soft water. Pituitary activation, as judged by lack of interrenal ascorbate depletion, did not occur. Increasing the ambient NaCl and Ca++ levels to about 100 milliosmols and 75–120 ppm, respectively, partially or completely alleviated the hyperglycemia and hypochloremia indicating that the stress of handling had been reduced.

  20. Behavioral response of young rainbow trout (Oncorhynchus mykiss) to forest fire-retardant chemicals in the laboratory

    USGS Publications Warehouse

    Wells, Jason B.; Little, Edward E.; Calfee, Robin D.

    2004-01-01

    Fire-retardant chemicals often are applied in relatively pristine and environmentally sensitive areas that are potentially inhabited by endangered or threatened aquatic species. Avoidance of contaminants is an adaptive behavior that may reduce exposure to harmful conditions. We evaluated the avoidance responses of rainbow trout (Oncorhynchus mykiss) to concentrations of fire-retardant chemicals and alternate constituent formulations ranging from 0.65 to 26 mg/L. Countercurrent avoidance chambers were used in a flow-through design with receiving water at each end and a drain at the center to create a distinct boundary between treatment water and reference water. Rainbow trout consistently avoided water treated with retardants at all concentrations tested. The magnitude of the avoidance response did not appear to follow a concentration-response relationship, but rather was an all-or-none response.

  1. Evidence That GABA Mediates Dopaminergic and Serotonergic Pathways Associated with Locomotor Activity in Juvenile Chinook Salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Clements, S.; Schreck, C.B.

    2004-01-01

    The authors examined the control of locomotor activity in juvenile salmon (Oncorhynchus tshawytscha) by manipulating 3 neurotransmitter systems-gamma-amino-n-butyric acid (GABA), dopamine, and serotonin-as well as the neuropeptide corticotropin releasing hormone (CRH). Intracerebroventricular (ICV) injections of CRH and the GABAAagonist muscimol stimulated locomotor activity. The effect of muscimol was attenuated by administration of a dopamine receptor antagonist, haloperidol. Conversely, the administration of a dopamine uptake inhibitor (4???,4??? -difluoro-3-alpha-[diphenylmethoxy] tropane hydrochloride [DUI]) potentiated the effect of muscimol. They found no evidence that CRH-induced hyperactivity is mediated by dopaminergic systems following concurrent injections of haloperidol or DUI with CRH. Administration of muscimol either had no effect or attenuated the locomotor response to concurrent injections of CRH and fluoxetine, whereas the GABAA antagonist bicuculline methiodide potentiated the effect of CRH and fluoxetine.

  2. Using otolith chemical and structural analysis to investigate reservoir habitat use by juvenile Chinook salmon Oncorhynchus tshawytscha.

    PubMed

    Bourret, S L; Kennedy, B P; Caudill, C C; Chittaro, P M

    2014-11-01

    Isotopic composition of (87) Sr:(86) Sr and natural elemental tracers (Sr, Ba, Mg, Mn and Ca) were quantified from otoliths in juvenile and adult Chinook salmon Oncorhynchus tshawytscha to assess the ability of otolith microchemistry and microstructure to reconstruct juvenile O. tshawytscha rearing habitat and growth. Daily increments were measured to assess relative growth between natal rearing habitats. Otolith microchemistry was able to resolve juvenile habitat use between reservoir and natal tributary rearing habitats (within headwater basins), but not among catchments. Results suggest that 90% (n = 18) of sampled non-hatchery adults returning to the Middle Fork Willamette River were reared in a reservoir and 10% (n = 2) in natal tributary habitat upstream from the reservoir. Juveniles collected in reservoirs had higher growth rates than juveniles reared in natal streams. The results demonstrate the utility of otolith microchemistry and microstructure to distinguish among rearing habitats, including habitats in highly altered systems. PMID:25229130

  3. The use of immobilised digestive lipase from Chinook salmon (Oncorhynchus tshawytscha) to generate flavour compounds in milk.

    PubMed

    Kurtovic, Ivan; Marshall, Susan N; Cleaver, Helen L; Miller, Matthew R

    2016-05-15

    The aim of this research was to determine the potential of immobilised digestive lipase from Chinook salmon (Oncorhynchus tshawytscha) to generate flavour compounds in milk. The lipase was immobilised on hydrophobic resin (Toyopearl® Butyl) and used to hydrolyse milk lipids in a batch reactor. The lipase was stable when immobilised and there was no significant resin fouling or enzyme inhibition between cycles. Eight cycles were achieved before the hydrolysis rate dropped significantly because of physical losses of the immobilised lipase. The immobilised lipase showed the highest specificity towards short-chain fatty acids butanoic and hexanoic acids, the main dairy product flavour and odour compounds. Based on the performance of the reactor, and the ability of the lipase to alter free fatty acid composition and sensory characteristics of milk, the immobilised salmon lipase has potential applications in developing dairy products with unique flavours. PMID:26775978

  4. Triploidy does not decrease contents of eicosapentaenoic and docosahexaenoic acids in filets of pink salmon Oncorhynchus gorbuscha.

    PubMed

    Gladyshev, Michail I; Artamonova, Valentina S; Makhrov, Alexander A; Sushchik, Nadezhda N; Kalachova, Galina S; Dgebuadze, Yury Y

    2017-02-01

    Triploid fish has become an important item of commercial aquaculture, but data on its fatty acid (FA) composition are still controversial, especially regarding essential polyunsaturated fatty acids, eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA). We studied FA composition and content of diploid and triploid pink salmon Oncorhynchus gorbuscha, reared in aquaculture in a bay of the White Sea (Russia). FA composition, measured as percentages of total FA of triploids and immature diploid females significantly differed from that of mature diploid fish. Specifically, mature diploids had higher percentage of EPA and DHA in their muscle tissue (filets) compared to that of triploids and immature diploid females. Nevertheless, the contents of EPA and DHA per mass of the filets in diploid and triploid specimens were similar. Thus, no special efforts are needed to improve EPA and DHA contents in filets of triploids. PMID:27596393

  5. Some Antioxidants and Malondialdehyde Levels in the Flesh of Rainbow Trout, (Oncorhynchus mykiss W., 1792) from Various Feeding Habitats.

    PubMed

    Ural, M S; Karatas, F; Calta, M

    2015-11-08

    The present study was aimed to find the effect of feeding habitats on the amounts of some antioxidants (vitamin A, E, C, ß-carotene and selenium) and malondialdehyde (MDA) levels in the flesh of rainbow trout (Oncorhynchus mykiss). For this purpose, vitamins (A, C and E), β-carotene amounts and malondialdehyde (MDA) levels were determined by HPLC and selenium amount was determined by fluorometric method in the flesh of rainbow trout obtained from various feeding habitats. The highest amounts of vitamins (A, C and E), β-carotene and selenium were found in the flesh of wild rainbow trout (WRT), followed by cage reared rainbow trout (CRRT) and pond reared rainbow trout (PRRT). However, the levels of MDA in the flesh of PRRT were the highest, followed by CRRT and the lowest in WRT.

  6. Phylogenetic relationships of Iranian infectious hematopoietic necrosis virus of rainbow trout (Oncorhynchus mykiss) based on the glycoprotein gene

    USGS Publications Warehouse

    Adel, Milad; Amiri, Alireza Babaalian; Dada, Maryam; Kurath, Gael; Laktarashi, Bahram; Ghajari, Amrolah; Breyta, Rachel

    2016-01-01

    Infectious hematopoietic necrosis virus (IHNV), a member of family Rhabdoviridae and genus Novirhabdoviridae, causes a highly lethal disease of salmon and trout. In Iran IHNV was first detected in 2001 on farms rearing rainbow trout (Oncorhynchus mykiss). To evaluate the genetic relationships of IHNV from northern and western Iran, the sequences of a 651-nt region of the glycoprotein gene were determined for two Iranian isolates. These sequences were analyzed to evaluate their genetic relatedness to worldwide isolates representing the five known genogroups of IHNV. Iranian isolates were most closely related to European isolates within the genogroup E rather than those of North American genogroups U, M and L, or the Asian genogroup J. It appears that Iranian IHNV was most likely introduced to Iran from a source in Europe by the movement of contaminated fish eggs.

  7. Effects of acid rock drainage on stocked rainbow trout (Oncorhynchus mykiss): an in-situ, caged fish experiment.

    PubMed

    Todd, Andrew S; McKnight, Diane M; Jaros, Chris L; Marchitto, Thomas M

    2007-07-01

    In-situ caged rainbow trout (Oncorhynchus mykiss) studies reveal significant fish toxicity and fish stress in a river impacted by headwater acid rock drainage (ARD). Stocked trout survival and aqueous water chemistry were monitored for 10 days at 3 study sites in the Snake River watershed, Colorado, U.S.A. Trout mortality was positively correlated with concentrations of metals calculated to be approaching or exceeding conservative toxicity thresholds (Zn, Mn, Cu, Cd). Significant metal accumulation on the gills of fish stocked at ARD impacted study sites support an association between elevated metals and fish mortality. Observations of feeding behavior and significant differences in fish relative weights between study site and feeding treatment indicate feeding and metals-related fish stress. Together, these results demonstrate the utility of in-situ exposure studies for stream stakeholders in quantifying the relative role of aqueous contaminant exposures in limiting stocked fish survival.

  8. Phylogenetic relationships of Iranian infectious hematopoietic necrosis virus of rainbow trout (Oncorhynchus mykiss) based on the glycoprotein gene.

    PubMed

    Adel, Milad; Amiri, Alireza Babaalian; Dadar, Maryam; Breyta, Rachel; Kurath, Gael; Laktarashi, Bahram; Ghajari, Amrolah

    2016-03-01

    Infectious hematopoietic necrosis virus (IHNV), a member of family Rhabdoviridae and genus Novirhabdoviridae, causes a highly lethal disease of salmon and trout. In Iran IHNV was first detected in 2001 on farms rearing rainbow trout (Oncorhynchus mykiss). To evaluate the genetic relationships of IHNV from northern and western Iran, the sequences of a 651-nt region of the glycoprotein gene were determined for two Iranian isolates. These sequences were analyzed to evaluate their genetic relatedness to worldwide isolates representing the five known genogroups of IHNV. Iranian isolates were most closely related to European isolates within the genogroup E rather than those of North American genogroups U, M and L, or the Asian genogroup J. It appears that Iranian IHNV was most likely introduced to Iran from a source in Europe by the movement of contaminated fish eggs. PMID:26602428

  9. Effects of acid rock drainage on stocked rainbow trout (Oncorhynchus mykiss): an in-situ, caged fish experiment.

    PubMed

    Todd, Andrew S; McKnight, Diane M; Jaros, Chris L; Marchitto, Thomas M

    2007-07-01

    In-situ caged rainbow trout (Oncorhynchus mykiss) studies reveal significant fish toxicity and fish stress in a river impacted by headwater acid rock drainage (ARD). Stocked trout survival and aqueous water chemistry were monitored for 10 days at 3 study sites in the Snake River watershed, Colorado, U.S.A. Trout mortality was positively correlated with concentrations of metals calculated to be approaching or exceeding conservative toxicity thresholds (Zn, Mn, Cu, Cd). Significant metal accumulation on the gills of fish stocked at ARD impacted study sites support an association between elevated metals and fish mortality. Observations of feeding behavior and significant differences in fish relative weights between study site and feeding treatment indicate feeding and metals-related fish stress. Together, these results demonstrate the utility of in-situ exposure studies for stream stakeholders in quantifying the relative role of aqueous contaminant exposures in limiting stocked fish survival. PMID:17180429

  10. Using hierarchical models to estimate effects of ocean anomalies on north-west Pacific Chinook salmon Oncorhynchus tshawytscha recruitment.

    PubMed

    Sharma, R; Liermann, M

    2010-11-01

    The high variability in survival over the past three decades of north-west Pacific Chinook salmon Oncorhynchus tshawytscha is summarized for 24 stocks and analysed using hierarchical Bayesian models. Results from a simple model indicate that recruitment anomalies appear to be correlated in time and space. A simple model with a covariate based on basin-scale effects (Pacific Decadal Oscillation and El Niño Southern Oscillation) and local-scale effects (sea surface temperature, SST anomaly) was introduced to explain this variability. The model still exhibited residual patterns that were removed when a random-walk component was added to the model. The analysis indicates that recruitment is negatively related to SST anomaly for all stocks and the effect of basin-scale variables is negligible. The effect of climate over the next century is expected to result in estimated recruitment declining by an average of 13% for O. tshawytscha stocks coastwide.

  11. Comparative diets of subyearling Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) in the Salmon River, New York

    USGS Publications Warehouse

    Johnson, J.H.

    2007-01-01

    Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) have established naturalized populations throughout the Great Lakes. Young-of-year of these species occur sympatrically for about one month in Lake Ontario tributaries. This study examined the diets of subyearling Chinook salmon and steelhead relative to available food in the Salmon River, New York. Terrestrial invertebrates and trichopterans were the major prey of Chinook salmon, whereas steelhead fed primarily on baetid nymphs and chironomid larvae. Diet overlap was low (0.45) between the species. The diet of Chinook was closely associated to the composition of the drift (0.88). Steelhead diet drew equally from the drift and benthos during the first year of the study, but more closely matched the benthos during the second year. Differences in prey selection, perhaps associated with differences in fish size, in addition to apparent differences in feeding mode (drift versus benthic), likely reduce competitive interactions between these species.

  12. A new measurement approach of ionizing radiation in irradiated trout (Oncorhynchus mykiss) by Randomly Polymorphic DNA-Polymerase Chain Reaction.

    PubMed

    Şakalar, Ergün; Mol, Sühendan

    2016-05-01

    Trout (Oncorhynchus mykiss) were irradiated at doses of 0.250, 0.500, 1, 3, 5, 7 and 9 kGy in gamma cell. DNAs were extracted from the irradiated samples before and after storage. 1ERP primers were designed, and RAPD-PCR (Randomly Polymorphic DNA-Polymerase Chain Reaction) was applied to make randomly amplifications on the DNA of the irradiated samples. Agarose gel profiles of irradiated fish were obtained to determine change of band profiles. In addition, DNA fragmentation occurring in each dose was determined by comet assay for the verification of methodology developed in this study. The molecular methodology was developed to estimate ionizing radiation (IR) level in irradiated fish. This methodology allows the analysis of the trout irradiated up to the dose limit of around 0.5 kGy and stored for a period of three months. PMID:27407216

  13. Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss).

    PubMed

    Bouwes, Nicolaas; Weber, Nicholas; Jordan, Chris E; Saunders, W Carl; Tattam, Ian A; Volk, Carol; Wheaton, Joseph M; Pollock, Michael M

    2016-01-01

    Beaver have been referred to as ecosystem engineers because of the large impacts their dam building activities have on the landscape; however, the benefits they may provide to fluvial fish species has been debated. We conducted a watershed-scale experiment to test how increasing beaver dam and colony persistence in a highly degraded incised stream affects the freshwater production of steelhead (Oncorhynchus mykiss). Following the installation of beaver dam analogs (BDAs), we observed significant increases in the density, survival, and production of juvenile steelhead without impacting upstream and downstream migrations. The steelhead response occurred as the quantity and complexity of their habitat increased. This study is the first large-scale experiment to quantify the benefits of beavers and BDAs to a fish population and its habitat. Beaver mediated restoration may be a viable and efficient strategy to recover ecosystem function of previously incised streams and to increase the production of imperiled fish populations. PMID:27373190

  14. Behavioural response of juvenile Chinook salmon Oncorhynchus tshawytscha during a sudden temperature increase and implications for survival

    SciTech Connect

    Bellgraph, Brian J.; McMichael, Geoffrey A.; Mueller, Robert P.; Monroe, Jennifer L.

    2010-01-01

    The behaviours of juvenile Chinook salmon Oncorhynchus tshawytscha were evaluated during a temperature increase from 8.8 to 23.2°C, which was designed to simulate unique thermal conditions present in a hydroelectric reservoir. The percent of fish with an active swimming behaviour increased from 26 to 93 % and mean opercular beat rates increased from 76 to 159 beats per minute between basal and maximum temperatures. Fish equilibrium did not change significantly throughout the experiment and relatively little mortality (12 %) occurred. Thermal stress is likely incurred by juvenile salmon experiencing a temperature change of this magnitude; however, stress induced in this study was primarily sublethal. Behavioural changes accompanying thermal stress (e.g., erratic swimming) may increase predation potential in the wild despite being sublethal during laboratory experiments.

  15. Mortality and kidney histopathology of Chinook salmon Oncorhynchus tshawytscha exposed to virulent and attenuated Renibacterium salmoninarum strains

    USGS Publications Warehouse

    O'Farrell, Caroline L.; Elliott, Diane G.; Landolt, Marsha L.

    2001-01-01

    An isolate of Renibacterium salmoninarum (strain MT 239) exhibiting reduced virulence in rainbow trout Oncorhynchus mykiss was tested for its ability to cause bacterial kidney disease (BKD) in chinook salmon Oncorhynchus tshawytscha, a salmonid species more susceptible to BKD. Juvenile chinook salmon were exposed to either 33209, the American Type Culture Collection type strain of R. salmoninarum, or to MT 239, by an intraperitoneal injection of 1 x 10(3) or 1 x 10(6) bacteria fish(-1), or by a 24 h immersion in 1 x 10(5) or 1 x 10(7) bacteria ml(-1). For 22 wk fish were held in 12 degrees C water and monitored for mortality. Fish were sampled periodically for histological examination of kidney tissues. In contrast to fish exposed to the high dose of strain 33209 by either injection or immersion, none of the fish exposed to strain MT 239 by either route exhibited gross clinical signs or histopathological changes indicative of BKD. However, the MT 239 strain was detected by the direct fluorescent antibody technique in 4 fish that died up to 11 wk after the injection challenge and in 5 fish that died up to 20 wk after the immersion challenge. Viable MT 239 was isolated in culture from 3 fish that died up to 13 wk after the immersion challenge. Total mortality in groups injected with the high dose of strain MT 239 (12%) was also significantly lower (p < 0.05) than mortality in groups injected with strain 33209 (73 %). These data indicate that the attenuated virulence observed with MT 239 in rainbow trout also occurs in a salmonid species highly susceptible to BKD. The reasons for the attenuated virulence of MT 239 were not determined but may be related to the reduced levels of the putative virulence protein p57 associated with this strain.

  16. Mortality and kidney histopathology of chinook salmon Oncorhynchus tshawytscha exposed to virulent and attenuated Renibacterium salmoninarum strains

    USGS Publications Warehouse

    O'Farrell, C. L.; Elliott, D.G.; Landolt, M.L.

    2000-01-01

    An isolate of Renibacterium salmoninarum (strain MT 239) exhibiting reduced virulence in rainbow trout Oncorhynchus mykiss was tested for its ability to cause bacterial kidney disease (BKD) in chinook salmon Oncorhynchus tshawytscha, a salmonid species more susceptible to BKD. Juvenile chinook salmon were exposed to either 33209, the American Type Culture Collection type strain of R. salmoninarum, or to MT 239, by an intraperitoneal injection of 1 ?? 103 or 1 ?? 106 bacteria fish-1, or by a 24 h immersion in 1 ?? 105 or 1 ?? 107 bacteria ml-1. For 22 wk fish were held in 12??C water and monitored for mortality. Fish were sampled periodically for histological examination of kidney tissues. In contrast to fish exposed to the high dose of strain 33209 by either injection or immersion, none of the fish exposed to strain MT 239 by either route exhibited gross clinical signs or histopathological changes indicative of BKD. However, the MT 239 strain was detected by the direct fluorescent antibody technique in 4 fish that died up to 11 wk after the injection challenge and in 5 fish that died up to 20 wk after the immersion challenge. Viable MT 239 was isolated in culture from 3 fish that died up to 13 wk after the immersion challenge. Total mortality in groups injected with the high dose of strain MT 239 (12%) was also significantly lower (p < 0.05) than mortality in groups injected with strain 33209 (73%). These data indicate that the attenuated virulence observed with MT 239 in rainbow trout also occurs in a salmonid species highly susceptible to BKD. The reasons for the attenuated virulence of MT 239 were not determined but may be related to the reduced levels of the putative virulence protein p57 associated with this strain.

  17. Freshwater movement patterns by juvenile Pacific salmon Oncorhynchus spp. before they migrate to the ocean: Oh the places you'll go!

    PubMed

    Shrimpton, J M; Warren, K D; Todd, N L; McRae, C J; Glova, G J; Telmer, K H; Clarke, A D

    2014-10-01

    Juvenile movement patterns for coho salmon Oncorhynchus kisutch and Chinook salmon Oncorhynchus tshawytscha from two large interior rivers of British Columbia, Canada, were examined. Otoliths from post-spawned fishes were collected on spawning grounds and elemental signatures were determined through transects from sectioned otoliths using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Large variations in otolith elemental signatures were found during the freshwater life stage indicative of movement downstream to rivers and tributaries that differed in elemental signature. This study highlights that downstream movements occur before migration to the ocean during the parr-smolt transformation. Extensive downstream movements of parr appear to be a successful life-history strategy based on variations observed in the otolith elemental signatures of spawners. Movements downstream in parr and the remarkable homing ability of adults also suggest that imprinting to natal streams must occur prior to the parr-smolt transformation. PMID:25053226

  18. Spawning Habitat Studies of Hanford Reach Fall Chinook Salmon (Oncorhynchus tshawytscha), Final Report.

    SciTech Connect

    Geist, David R.; Arntzen, Evan V.; Chien, Yi-Ju

    2009-03-02

    The Pacific Northwest National Laboratory conducted this study for the Bonneville Power Administration (BPA) with funding provided through the Northwest Power and Conservation Council(a) and the BPA Fish and Wildlife Program. The study was conducted in the Hanford Reach of the Columbia River. The goal of study was to determine the physical habitat factors necessary to define the redd capacity of fall Chinook salmon that spawn in large mainstem rivers like the Hanford Reach and Snake River. The study was originally commissioned in FY 1994 and then recommissioned in FY 2000 through the Fish and Wildlife Program rolling review of the Columbia River Basin projects. The work described in this report covers the period from 1994 through 2004; however, the majority of the information comes from the last four years of the study (2000 through 2004). Results from the work conducted from 1994 to 2000 were covered in an earlier report. More than any other stock of Pacific salmon, fall Chinook salmon (Oncorhynchus tshawytscha) have suffered severe impacts from the hydroelectric development in the Columbia River Basin. Fall Chinook salmon rely heavily on mainstem habitats for all phases of their life cycle, and mainstem hydroelectric dams have inundated or blocked areas that were historically used for spawning and rearing. The natural flow pattern that existed in the historic period has been altered by the dams, which in turn have affected the physical and biological template upon which fall Chinook salmon depend upon for successful reproduction. Operation of the dams to produce power to meet short-term needs in electricity (termed power peaking) produces unnatural fluctuations in flow over a 24-hour cycle. These flow fluctuations alter the physical habitat and disrupt the cues that salmon use to select spawning sites, as well as strand fish in near-shore habitat that becomes dewatered. The quality of spawning gravels has been affected by dam construction, flood protection, and

  19. Annual Performance Report 1993-1994 for the Vocational Education State Administered Program under the Carl D. Perkins Vocational and Applied Technology Education Act of 1990.

    ERIC Educational Resources Information Center

    Arkansas State Dept. of Education, Little Rock. Div. of Vocational and Technical Education.

    During the 1993-94 program year, 75% of Arkansas' grade 7 through 12 students were enrolled in at least one vocational education (VE) course. Of those students, 52,847 were either academically disadvantaged, disabled, or limited English speaking. In addition, 15,940 and 8,008 students were enrolled in VE programs at Arkansas postsecondary…

  20. Optical assessment of large marine particles: development of an imaging and analysis system for quantifying large particle distributions and fluxes. Annual report, 1993-1994

    SciTech Connect

    Walsh, I.D.; Gardner, W.D.

    1994-12-31

    The central goal of DOE`s Ocean Margin Program (OMP) is to determine whether continental shelves are quantitatively significant in removing carbon dioxide from the atmosphere and isolating it via burial in sediments or exporting it to the open ocean (Program Announcement, 1991). A major component of the OMP will be to measure carbon flux on the shelf and across the shelf to the slope and open ocean. In the first round of OMP funding we proposed to develop an optical instrument package and the analytical techniques to measure a wide spectrum of the large aggregate population of particles in the shelf/slope environment. This particle population, encompassing the ``marine snow`` size particles (diameters > 0.5 mm), is thought to be the major pathway of material flux in the ocean (McCave, 1975; Asper, 1987; Walsh and Gardner, 1992). The overall objective of this proposal was to develop an instrument package and the analytical techniques to precisely measure a wide spectrum of the large aggregate population of particles in the shelf/slope environment at a rate sufficient to integrate the observed particle distributions into the coupled physical and biogeochemical models necessary to understand the shelf and slope as a system. We envisioned three stages of development of the instrument package: (1) design, assembly, and laboratory testing of all components and the package as a whole, (2) a short period of laboratory and field testing of the instrument package to determine the best operational parameters, and (3) operations within a framework of complementary analytical sampling such as an appropriate process study funded under the OMP. The first two stages were covered by this proposal. A renewal proposal follows to cover the third stage. 6 figs.

  1. An Evaluation of Conflict Resolution Programs at the Secondary Level at the Toronto Board of Education 1993-1994: The Evolution of a Model. No. 210.

    ERIC Educational Resources Information Center

    Brown, Robert S.; And Others

    This report evaluates the second and third years of conflict resolution programs that were established at both the elementary and secondary levels during the 1991-92 school year. The programs emphasized peer mediation, in which students in conflict meet with a pair of students trained in mediation skills. The mediators attempt to open…

  2. Human health risk assessment: A case study involving heavy metal soil contamination after the flooding of the river Meuse during the winter of 1993-1994.

    PubMed

    Albering, H J; van Leusen, S M; Moonen, E J; Hoogewerff, J A; Kleinjans, J C

    1999-01-01

    At the end of December 1993 and also at the end of January 1995, the river Meuse, one of the major rivers in Europe, flooded and river banks were inundated. We investigated the possible health risks of exposure to heavy metal concentrations in river bank soils resulting from the flooding of the river Meuse at the end of 1993. Soil and deposit samples and corresponding aerable and fodder crops were collected and analyzed for heavy metals. Although the soils of the floodplain of the river Meuse appeared severely polluted mainly by Cd and Zn, the heavy metal concentrations in the crops grown on these soils were within background ranges. Incidentally, the legal standard for Cd as endorsed by the Commodities Act was exceeded in wheat crops. The main exposure pathways for the general population were through the consumption of food crops grown on the river banks and through the direct ingestion of contaminated soils. For estimating potential human exposure in relation to soil pollution, we used a multiple pathway exposure model. For estimating the actual risk, we determined metal contents of vegetables grown in six experimental gardens. From this study, it can be concluded that there is a potential health risk for the river bank inhabitants as a consequence of Pb and Cd contaminations of the floodplain soils of the river Meuse, which are frequently inundated (averaged flooding frequency once every 2 years). PMID:9872715

  3. The Dual Challenges of Generality and Specificity When Developing Environmental DNA Markers for Species and Subspecies of Oncorhynchus

    PubMed Central

    Wilcox, Taylor M.; Carim, Kellie J.; McKelvey, Kevin S.; Young, Michael K.; Schwartz, Michael K.

    2015-01-01

    Environmental DNA (eDNA) sampling is a powerful tool for detecting invasive and native aquatic species. Often, species of conservation interest co-occur with other, closely related taxa. Here, we developed qPCR (quantitative PCR) markers which distinguish westslope cutthroat trout (Oncorhynchus clarkii lewsi), Yellowstone cutthroat trout (O. clarkii bouvieri), and rainbow trout (O. mykiss), which are of conservation interest both as native species and as invasive species across each other’s native ranges. We found that local polymorphisms within westslope cutthroat trout and rainbow trout posed a challenge to designing assays that are generally applicable across the range of these widely-distributed species. Further, poorly-resolved taxonomies of Yellowstone cutthroat trout and Bonneville cutthroat trout (O. c. utah) prevented design of an assay that distinguishes these recognized taxa. The issues of intraspecific polymorphism and unresolved taxonomy for eDNA assay design addressed in this study are likely to be general problems for closely-related taxa. Prior to field application, we recommend that future studies sample populations and test assays more broadly than has been typical of published eDNA assays to date. PMID:26536367

  4. The Dual Challenges of Generality and Specificity When Developing Environmental DNA Markers for Species and Subspecies of Oncorhynchus.

    PubMed

    Wilcox, Taylor M; Carim, Kellie J; McKelvey, Kevin S; Young, Michael K; Schwartz, Michael K

    2015-01-01

    Environmental DNA (eDNA) sampling is a powerful tool for detecting invasive and native aquatic species. Often, species of conservation interest co-occur with other, closely related taxa. Here, we developed qPCR (quantitative PCR) markers which distinguish westslope cutthroat trout (Oncorhynchus clarkii lewsi), Yellowstone cutthroat trout (O. clarkii bouvieri), and rainbow trout (O. mykiss), which are of conservation interest both as native species and as invasive species across each other's native ranges. We found that local polymorphisms within westslope cutthroat trout and rainbow trout posed a challenge to designing assays that are generally applicable across the range of these widely-distributed species. Further, poorly-resolved taxonomies of Yellowstone cutthroat trout and Bonneville cutthroat trout (O. c. utah) prevented design of an assay that distinguishes these recognized taxa. The issues of intraspecific polymorphism and unresolved taxonomy for eDNA assay design addressed in this study are likely to be general problems for closely-related taxa. Prior to field application, we recommend that future studies sample populations and test assays more broadly than has been typical of published eDNA assays to date.

  5. Growth and condition of juvenile coho salmon Oncorhynchus kisutch relate positively to species richness of trophically transmitted parasites.

    PubMed

    Losee, J P; Fisher, J; Teel, D J; Baldwin, R E; Marcogliese, D J; Jacobson, K C

    2014-11-01

    The aims of this study were first, to test the hypothesis that metrics of fish growth and condition relate positively to parasite species richness (S(R)) in a salmonid host; second, to identify whether S(R) differs as a function of host origin; third, to identify whether acquisition of parasites through marine v. freshwater trophic interactions was related to growth and condition of juvenile salmonids. To evaluate these questions, species diversity of trophically transmitted parasites in juvenile coho salmon Oncorhynchus kisutch collected off the coast of the Oregon and Washington states, U.S.A. in June 2002 and 2004 were analysed. Fish infected with three or more parasite species scored highest in metrics of growth and condition. Fish originating from the Columbia River basin had lower S(R) than those from the Oregon coast, Washington coast and Puget Sound, WA. Parasites obtained through freshwater or marine trophic interactions were equally important in the relationship between S(R) and ocean growth and condition of juvenile O. kisutch salmon.

  6. The Effect of Mycotoxin Deoxynivalenol on Haematological and Biochemical Indicators and Histopathological Changes in Rainbow Trout (Oncorhynchus mykiss)

    PubMed Central

    Modra, Helena; Blahova, Jana; Franc, Ales; Fictum, Petr; Sevcikova, Marie; Svobodova, Zdenka

    2014-01-01

    Deoxynivalenol (DON), produced by the Fusarium genus, is a major contaminant of cereal grains used in the production of fish feed. The effect of mycotoxin deoxynivalenol on rainbow trout (Oncorhynchus mykiss) was studied using a commercial feed with the addition of DON in a dose of 2 mg/kg feed. The fish (n = 40) were exposed to the mycotoxin for 23 days. The trout were divided into two groups, control and experimental groups. Control groups were fed a commercial feed naturally contaminated with a low concentration of DON (225 μg/kg feed); experimental groups were fed a commercial feed with the addition of DON (1964 μg/kg feed). Plasma biochemical and haematological indices, biometric parameters, and histopathological changes were assessed at the end of the experiment. The experimental groups showed significantly lower values in MCH (P < 0.05). In biochemical indices, after 23-day exposure, a significant decrease in glucose, cholesterol (P < 0.05), and ammonia (P < 0.01) was recorded in the experimental group compared to the control group. Our assessment showed no significant changes in biometric parameters. The histopathological examination revealed disorders in the caudal kidney of the exposed fish. The obtained data show the sensitivity of rainbow trout (O. mykiss) to deoxynivalenol. PMID:24729967

  7. Clock genes localize to quantitative trait loci for stage-specific growth in juvenile coho salmon, Oncorhynchus kisutch.

    PubMed

    O'Malley, Kathleen G; McClelland, Erin K; Naish, Kerry A

    2010-01-01

    In most organisms, an internal circadian clock coordinates the expression of biological rhythms and enables individuals to anticipate and respond to the seasonally changing environment. There is remarkable conservation of function in the molecular machinery underlying this circadian clock across taxa with 4 canonical proteins interacting to form an autoregulatory feedback loop: CLOCK, CRYPTOCHROME, PERIOD, and BMAL. We mapped duplicated copies of Clock and Cryptochrome in coho salmon (Oncorhynchus kisutch) to determine if these genes localize to quantitative trait loci (QTL) for hatch timing, weight, length, and growth rate measured throughout the juvenile life-history stage. We found that Cryptochrome2b mapped to a QTL region for growth (measured at 304 days post-hatching) on linkage group OKI06. The percentage of variation (PEV) explained by this QTL was 15.2%. Cryptochrome2b was also associated with a marginally nonsignificant QTL for length (measured at 395 days post-hatching). OtsClock1b mapped to a QTL region for growth rate (PEV 10.1%) and length (PEV 10.5%) on linkage group OKI24 (measured at 479 days posthatching). Neither gene localized to QTL for hatch timing or weight. Our findings indicate that the growth rate and length QTL associated with OtsClock1b and Cryptochrome2b are development stage-specific and may result from temporally differentiated gene expression patterns.

  8. Assessment of potential impacts of major groundwater contaminants to fall chinook salmon (Oncorhynchus tshawytscha) in the Hanford Reach, Columbia River

    SciTech Connect

    Geist, D.R.; Poston, T.M.; Dauble, D.D.

    1994-10-01

    Past operations of Hanford Site facilities have contaminated the groundwater adjacent to the Hanford Reach of the Columbia River, Washington, with various chemical and radiological constituents. The groundwater is hydraulically connected to the river and contains concentrations of contaminants that sometimes exceed federal and/or state drinking water standards or standards for the protection of aquatic life. For example, concentrations of chromium in shoreline seeps and springs at most 100 Area operable units exceed concentrations found to be toxic to fish. Nitrate and tritium concentrations in shoreline seeps are generally below drinking water standards and concentrations potentially toxic to aquatic life, but nitrate concentrations may be high enough to synergistically interact with and exacerbate chromium toxicity. The Hanford Reach also supports the largest run of fall chinook salmon (Oncorhynchus tshawytscha) in the Columbia River Basin. Numbers of fall chinook salmon returning to the Hanford Reach have increased relative to other mainstem populations during the last 30 years. Groundwater discharge appears to occur near some salmon spawning areas, but contaminants are generally not detectable in surface water samples. The concentration and potential toxicity of contaminants in the interstitial waters of the substrate where fall chinook salmon embryogenesis occurs are presently unknown. New tools are required to characterize the extent of groundwater contaminant discharge to the Hanford Reach and to resolve uncertainties associated with assessment of potential impacts to fall chinook salmon.

  9. Duplicated Clock genes with unique polyglutamine domains provide evidence for nonhomologous recombination in Chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    O'Malley, K G; Banks, M A

    2008-01-01

    Circadian rhythms underlie diverse life functions ranging from cellular activities to behavior. Multiple clock genes play a central role in the generation of these rhythms. We partially characterized two copies of the Clock gene from Chinook salmon (Oncorhynchus tshawytscha), OtsClock1a and OtsClock1b. The 6,460 bp OtsClock1a sequence contains 16 exons, 15 introns and encompasses three highly conserved domains indicating it is a novel member of the bHLH-PAS superfamily of transcription factors. The second copy, OtsClock1b, consists of five exons and five introns spanning 1,945 bp. A polyglutamine repeat motif (PolyQ), characteristic of a majority of CLOCK proteins, is present in both OTSCLOCK1a and OTSCLOCK1b. However, the Chinook PolyQ domains are uniquely positioned inside the gene. Interestingly, a 1,200 bp non-coding segment located downstream of the OtsClock1a PolyQ domain is absent from OtsClock1b. This insertion/deletion is 91% similar to the Salmo salar Transferrin gene. A phylogenetic analysis of 11 CLOCK proteins shows that OtsClock1a and OtsClock1b are paralogs which likely arose subsequent to the salmonid genome-wide duplication event. Ultimately, the Chinook salmon Clock genes are key components to our understanding the genetic mechanisms underlying temporally regulated life history traits in Pacific salmonids. PMID:17503191

  10. Effects of temperature on disease progression and swimming stamina in Ichthyophonus-infected rainbow trout, Oncorhynchus mykiss (Walbaum).

    PubMed

    Kocan, R; Hershberger, P; Sanders, G; Winton, J

    2009-10-01

    Rainbow trout, Oncorhynchus mykiss, were infected with Ichthyophonus sp. and held at 10 degrees C, 15 degrees C and 20 degrees C for 28 days to monitor mortality and disease progression. Infected fish demonstrated more rapid onset of disease, higher parasite load, more severe host tissue reaction and reduced mean-day-to-death at higher temperature. In a second experiment, Ichthyophonus-infected fish were reared at 15 degrees C for 16 weeks then subjected to forced swimming at 10 degrees C, 15 degrees C and 20 degrees C. Stamina improved significantly with increased temperature in uninfected fish; however, this was not observed for infected fish. The difference in performance between infected and uninfected fish became significant at 15 degrees C (P = 0.02) and highly significant at 20 degrees C (P = 0.005). These results have implications for changes in the ecology of fish diseases in the face of global warming and demonstrate the effects of higher temperature on the progression and severity of ichthyophoniasis as well as on swimming stamina, a critical fitness trait of salmonids. This study helps explain field observations showing the recent emergence of clinical ichthyophoniasis in Yukon River Chinook salmon later in their spawning migration when water temperatures were high, as well as the apparent failure of a substantial percentage of infected fish to successfully reach their natal spawning areas.

  11. Rhesus glycoprotein and urea transporter genes are expressed in early stages of development of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Hung, Carrie C; Nawata, C Michele; Wood, Chris M; Wright, Patricia A

    2008-06-01

    The objective of this study was to determine if the genes for the putative ammonia transporters, Rhesus glycoproteins (Rh) and the facilitated urea transporter (UT) were expressed during early development of rainbow trout, Oncorhynchus mykiss Walbaum. We predicted that the Rh isoforms Rhbg, Rhcg1 and Rhcg2 would be expressed shortly after fertilization but UT expression would be delayed based on the ontogenic pattern of nitrogen excretion. Embryos were collected 3, 14 and 21 days postfertilization (dpf), whereas yolk sac larvae were sampled at 31 dpf and juveniles at 60 dpf (complete yolk absorption). mRNA levels were quantified using quantitative polymerase chain reaction and expressed relative to the control gene, elongation factor 1alpha. All four genes (Rhbg, Rhcg1, Rhcg2, UT) were detected before hatching (25-30 dpf). As predicted, the mRNA levels of the Rh genes, especially Rhcg2, were relatively high early in embryonic development (14 and 21 dpf), but UT mRNA levels remained low until after hatching (31 and 60 dpf). These findings are consistent with the pattern of nitrogen excretion in early stages of trout development. We propose that early expression of Rh genes is critical for the elimination of potentially toxic ammonia from the encapsulated embryo, whereas retention of the comparatively benign urea molecule until after hatch is less problematic for developing tissues and organ systems.

  12. Copper binding affinity of rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) gills: Implications for assessing bioavailable metal

    SciTech Connect

    MacRae, R.K.; Smith, D.E.; Swoboda-Colberg, N.; Meyer, J.S.; Bergman, H.L. . Dept. of Zoology and Physiology)

    1999-06-01

    In this study, the authors determined the conditional stability constant (log K[prime]) of copper for the gills of rainbow trout (Oncorhynchus mykiss; RBT) and brook trout (Salvelinus fontinalis; BT). Using toxicity-based complexation bioassays, which measure the effect of competing organic ligands on copper toxicity, the RBT gill copper log K[prime] range was 6.4 to 7.2. Using a Scatchard analysis of gill Cu accumulation, the RBT log K[prime] was 7.50 and the BT log K[prime] was 7.25. The close agreement in RBT log K[prime] values between these two methods suggests that measurement of gill copper accumulation is an acceptable alternative for determining a toxicity-based gill copper binding affinity. The results also suggest that there is either a single gill copper binding component or, more realistically, multiple components with similar binding properties that function collectively to define a single toxicologically relevant copper conditional stability constant. These results suggest analytical approaches to measuring bioavailable metal concentrations, such as geochemical modeling where biological ligands are included in speciation calculations, may adequately simulate complex biological ligands. A method to convert gill copper accumulation to a bioavailable water criterion is also discussed.

  13. Effects of Using Tricaine Methanesulfonate and Metomidate before Euthanasia on the Contractile Properties of Rainbow Trout (Oncorhynchus mykiss) Myocardium.

    PubMed

    Roberts, Jordan C; Syme, Douglas A

    2016-01-01

    Because many anesthetics work through depressing cell excitability, unanesthetized euthanasia has become common for research involving excitable tissues (for example muscle and nerve) to avoid these depressive effects. However, anesthetic use during euthanasia may be indicated for studies involving isolated tissues if the potential depressive effects of brief anesthetic exposure dissipate after subsequent tissue isolation, washout, and saline perfusion. We explore this here by measuring whether, when applied prior to euthanasia, standard immersion doses of 2 fish anesthetics, tricaine methanesulfonate (TMS; 100 mg/L, n = 6) and methyl 1-(1-phenylethyl)-1H-imidazole-5-carboxylate (metomidate, 10 mg/L, n = 6), have residual effects on the contractile properties (force and work output) of isolated and saline-perfused ventricular compact myocardium from rainbow trout (Oncorhynchus mykiss). Results suggest that direct exposure of muscle to immersion doses of TMS-but not metomidate-impairs muscle contractile performance. However, brief exposure (2 to 3 min) to either anesthetic during euthanasia only-providing that the agent is washed out prior to tissue experimentation-does not have an effect on the contractile properties of the myocardium. Therefore, the use of TMS, metomidate, and perhaps other anesthetics that depress cell excitability during euthanasia may be indicated when conducting research on isolated and rinsed tissues. PMID:27657711

  14. Organization and development of the mineral phase during early ontogenesis of the bony fin rays of the trout Oncorhynchus mykiss.

    PubMed

    Landis, W J; Géraudie, J

    1990-12-01

    Characterization of mineral deposition has been studied by electron optical methods during early ontogenesis of lepidotrichia, the bony fin rays, of the trout Oncorhynchus mykiss (the former Salmo gairdneri). The fin rays consist of an extracellular granular ground substance containing in part a network of collagen fibrils within the basal lamella of the fin dermoepidermal interface. Growth of individual rays proceeds in a proximodistal direction. The mineral phase appears as electron-dense needle or plate-like particles and is associated with the collagenous matrix. On analysis of progressively maturing tissue, the mineral was characterized as a poorly crystalline hydroxyapatite with Ca/P molar ratios in the range of 1.0-1.4, corresponding to distal and proximal areas, respectively. With selected-area electron diffraction and dark field imaging of lepidotrichia, the mineral particles were found to be about 3-10 nm thick and 12-20 nm in length (along their crystallographic c-axes), possibly aggregated into larger crystals 35-40 nm long observed with bright field microscopy. No definitive relation was found between either the c- or a,b-axes images of the crystals and the periodic structure of collagen, which forms the framework for mineral deposition in this and in other vertebrate calcifying tissues. PMID:2285157

  15. Cholinergic control of stanniocalcin release in the rainbow trout, Oncorhynchus mykiss, and the American eel, Anguilla rostrata.

    PubMed

    Cano, T M; Perry, S F; Fenwick, J C

    1994-04-01

    An in vivo whole animal 45Ca influx bioassay was used to study the cholinergic control of the release of stanniocalcin (STC) in the rainbow trout (Oncorhynchus mykiss) and the American eel (Anguilla rostrata). In both species calcium influx (JinCa2+) was lowered in response to hypercalcemia induced by intravascular (trout) or intraperitoneal (eel) injections of CaCl2. In trout, this response was blocked by the cholinergic antagonist atropine (0.25 mumol kg-1) and mimicked by the cholinoceptor agonist carbachol (0.25 mumol kg-1). These observations are consistent with a cholinergic stimulation of STC release in response to hypercalcemia in trout. In eels, pretreatment with atropine did not block the lowering of JinCa2+ in response to hypercalcemia. This suggests that cholinergic stimulation is not obligatory for stanniocalcin release in eels. However, carbachol treatment did elicit STC release as revealed by the lowering of JinCa2+. This response to carbachol was not observed in stanniectomized eels. Thus, in the American eel it appears that there is a potential for cholinergic control of STC release but that other factors such as the local plasma calcium concentration may also be involved, at least in response to severe acute hypercalcemia.

  16. Differentiating size-dependent responses of juvenile pink salmon (Oncorhynchus gorbuscha) to sea lice (Lepeophtheirus salmonis) infections.

    PubMed

    Sutherland, Ben J G; Jantzen, Stuart G; Sanderson, Dan S; Koop, Ben F; Jones, Simon R M

    2011-06-01

    Salmon infected with an ectoparasitic marine copepod, the salmon louse Lepeophtheirus salmonis, incur a wide variety of consequences depending upon host sensitivity. Juvenile pink salmon (Oncorhynchus gorbuscha) migrate from natal freshwater systems to the ocean at a young age relative to other Pacific salmon, and require rapid development of appropriate defenses against marine pathogens. We analyzed the early transcriptomic responses of naïve juvenile pink salmon of sizes 0.3 g (no scales), 0.7 g (mid-scale development) and 2.4 g (scales fully developed) six days after a low-level laboratory exposure to L. salmonis copepodids. All infected size groups exhibited unique transcriptional profiles. Inflammation and inhibition of cell proliferation was identified in the smallest size class (0.3 g), while increased glucose absorption and retention was identified in the middle size class (0.7 g). Tissue-remodeling genes were also up-regulated in both the 0.3 g and 0.7 g size groups. Profiles of the 2.4 g size class indicated cell-mediated immunity and possibly parasite-induced growth augmentation. Understanding a size-based threshold of resistance to L. salmonis is important for fisheries management. This work characterizes molecular responses reflecting the gradual development of innate immunity to L. salmonis between the susceptible (0.3 g) and refractory (2.4 g) pink salmon size classes. PMID:21543273

  17. Landscape scale measures of steelhead (Oncorhynchus mykiss) bioenergetic growth rate potential in Lake Michigan and comparison with angler catch rates

    USGS Publications Warehouse

    Hook, T.O.; Rutherford, E.S.; Brines, Shannon J.; Geddes, C.A.; Mason, D.M.; Schwab, D.J.; Fleischer, G.W.

    2004-01-01

    The relative quality of a habitat can influence fish consumption, growth, mortality, and production. In order to quantify habitat quality, several authors have combined bioenergetic and foraging models to generate spatially explicit estimates of fish growth rate potential (GRP). However, the capacity of GRP to reflect the spatial distributions of fishes over large areas has not been fully evaluated. We generated landscape scale estimates of steelhead (Oncorhynchus mykiss) GRP throughout Lake Michigan for 1994-1996, and used these estimates to test the hypotheses that GRP is a good predictor of spatial patterns of steelhead catch rates. We used surface temperatures (measured with AVHRR satellite imagery) and acoustically measured steelhead prey densities (alewife, Alosa pseudoharengus) as inputs for the GRP model. Our analyses demonstrate that potential steelhead growth rates in Lake Michigan are highly variable in both space and time. Steelhead GRP tended to increase with latitude, and mean GRP was much higher during September 1995, compared to 1994 and 1996. In addition, our study suggests that landscape scale measures of GRP are not good predictors of steelhead catch rates throughout Lake Michigan, but may provide an index of interannual variation in system-wide habitat quality.

  18. The Dual Challenges of Generality and Specificity When Developing Environmental DNA Markers for Species and Subspecies of Oncorhynchus.

    PubMed

    Wilcox, Taylor M; Carim, Kellie J; McKelvey, Kevin S; Young, Michael K; Schwartz, Michael K

    2015-01-01

    Environmental DNA (eDNA) sampling is a powerful tool for detecting invasive and native aquatic species. Often, species of conservation interest co-occur with other, closely related taxa. Here, we developed qPCR (quantitative PCR) markers which distinguish westslope cutthroat trout (Oncorhynchus clarkii lewsi), Yellowstone cutthroat trout (O. clarkii bouvieri), and rainbow trout (O. mykiss), which are of conservation interest both as native species and as invasive species across each other's native ranges. We found that local polymorphisms within westslope cutthroat trout and rainbow trout posed a challenge to designing assays that are generally applicable across the range of these widely-distributed species. Further, poorly-resolved taxonomies of Yellowstone cutthroat trout and Bonneville cutthroat trout (O. c. utah) prevented design of an assay that distinguishes these recognized taxa. The issues of intraspecific polymorphism and unresolved taxonomy for eDNA assay design addressed in this study are likely to be general problems for closely-related taxa. Prior to field application, we recommend that future studies sample populations and test assays more broadly than has been typical of published eDNA assays to date. PMID:26536367

  19. Endocrine control of oleic acid and glucose metabolism in rainbow trout (Oncorhynchus mykiss) muscle cells in culture.

    PubMed

    Sánchez-Gurmaches, Joan; Cruz-Garcia, Lourdes; Gutiérrez, Joaquím; Navarro, Isabel

    2010-08-01

    The effects of insulin and IGF-I on fatty acid (FA) and glucose metabolism were examined using oleic acid or glucose as tracers in differentiated rainbow trout (Oncorhynchus mykiss) myotubes. Insulin and IGF-I significantly reduced the production of CO(2) from oleic acid with respect to the control values. IGF-I also significantly reduced the production of acid-soluble products (ASP) and the concentration of FA in the medium, while cellular triacylglycerols (TAG) tended to increase. Only insulin produced a significant accumulation of glycogen inside the cells in glucose distribution experiments. Incubation with catecholamines did not affect oleic acid metabolism. Cells treated with rapamycin [a target of rapamycin (TOR) inhibitor] significantly increased the oxidation of oleic acid to CO(2) and ASP, while the accumulation of TAG diminished. Rosiglitazone (a peroxisome proliferator-activated receptor gamma agonist) and etomoxir (a CPT-1 inhibitor) produced a severe and significant reduction in the production of CO(2) and ASP. Rosiglitazone and etomoxir also produced a significant accumulation of FA outside and inside the cells, respectively. No significant effects of these drugs on glucose distribution were observed. These data indicate that insulin and IGF-I act as anabolic hormones in trout myotubes in both oleic acid and glucose metabolism, although glucose oxidation appears to be less sensitive than FA oxidation to insulin and IGF-I. The use of rapamycin, etomoxir, and rosiglitazone may help us to understand the mechanisms of regulation of lipid metabolism in fish. PMID:20484701

  20. The effect of mycotoxin deoxynivalenol on haematological and biochemical indicators and histopathological changes in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Matejova, Iveta; Modra, Helena; Blahova, Jana; Franc, Ales; Fictum, Petr; Sevcikova, Marie; Svobodova, Zdenka

    2014-01-01

    Deoxynivalenol (DON), produced by the Fusarium genus, is a major contaminant of cereal grains used in the production of fish feed. The effect of mycotoxin deoxynivalenol on rainbow trout (Oncorhynchus mykiss) was studied using a commercial feed with the addition of DON in a dose of 2 mg/kg feed. The fish (n=40) were exposed to the mycotoxin for 23 days. The trout were divided into two groups, control and experimental groups. Control groups were fed a commercial feed naturally contaminated with a low concentration of DON (225  μg/kg feed); experimental groups were fed a commercial feed with the addition of DON (1964  μg/kg feed). Plasma biochemical and haematological indices, biometric parameters, and histopathological changes were assessed at the end of the experiment. The experimental groups showed significantly lower values in MCH (P<0.05). In biochemical indices, after 23-day exposure, a significant decrease in glucose, cholesterol (P<0.05), and ammonia (P<0.01) was recorded in the experimental group compared to the control group. Our assessment showed no significant changes in biometric parameters. The histopathological examination revealed disorders in the caudal kidney of the exposed fish. The obtained data show the sensitivity of rainbow trout (O. mykiss) to deoxynivalenol. PMID:24729967

  1. The combine effects of salting and thyme oil on sensory and chemical changes of rainbow trout (Oncorhynchus mykiss) fillets

    NASA Astrophysics Data System (ADS)

    Yildiz, Pınar Oǧuzhan

    2016-04-01

    The present study aimed to investigate the combine effects of salting and thyme oil on chemical and sensory changes of rainbow trout (Oncorhynchus mykiss) during storage (4°C) was investigated over a period of 24 days. There groups were constituted: group A-control salted, group B-salted samples with 0.4% of thyme oil and group C-salted samples with 0.8% of thyme oil. Fillets were subject to chemical (thiobarbituric acid reactive substances-TBARS, total volatile base nitrogen-TVB-N) and sensory analyses on certain days (0, 3, 6, 9, 12, 15, 18, 21 and 24th days) of storage. Five experienced panelists, academic staff who were trained in sensory descriptors for fishes, were employed to evaluate the quality of trout fillets during storage. Rainbow trout fillets were assessed on the basis of appearance, taste, texture and odour characteristics using a nine point descriptive scale. TVB-N and TBARS values increased in the duration of storage time in all groups. TVB-N and TBARS values in control groups were higher than other groups. Group C samples were assessed as the most acceptable products by the panellists. Difference in chemical and sensory changes between samples was found to be significant (p<0.05) during storage period.

  2. Acute toxicity of fire-retardant and foam-suppressant chemicals to early life stages of chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Buhl, Kevin J.; Hamilton, Steven J.

    1998-01-01

    Laboratorys studies were conducted to determine the acute toxicity of three fire retardants (Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F), and two fire-suppressant foams (Phos-Chek WD-881 and Ansul Silv-Ex) to early life stages of chinook salmon, Oncorhynchus tshawytscha, in hard and soft water. Regardless of water type, swim-up fry and juveniles (60 and 90 d posthatch) exhibited similar sensitivities to each chemical and these life stages were more sensitive than eyed eggs. Foam suppressants were more toxic to each life stage than the fire retardants in both water types. The descending rank order of toxicity for these chemicals tested with swim-up fry and juveniles (range of 96-h median lethal concentrations [LC50s]) was Phos-Chek WD-881 (7–13 mg/L) > Ansul Silv-Ex (11–22 mg/L) > Phos-Chek D75-F (218–305 mg/L) > Fire-Trol GTS-R (218–412 mg/L) > Fire-Trol LCG-R (685–1,195 mg/L). Water type had a minor effect on the toxicity of these chemicals. Comparison of acute toxicity values with recommended application concentrations indicates that accidental inputs of these chemicals into stream environments would require substantial dilution (237- to 1,429-fold) to reach concentrations equivalent to their 96-h LC50s.

  3. Differential Gene Expression in Liver, Gill, and Olfactory Rosettes of Coho Salmon (Oncorhynchus kisutch) After Acclimation to Salinity

    PubMed Central

    Lavado, Ramon; Bammler, Theo K.; Gallagher, Evan P.; Stapleton, Patricia L.; Beyer, Richard P.; Farin, Federico M.; Hardiman, Gary; Schlenk, Daniel

    2015-01-01

    Most Pacific salmonids undergo smoltification and transition from freshwater to saltwater, making various adjustments in metabolism, catabolism, osmotic, and ion regulation. The molecular mechanisms underlying this transition are largely unknown. In the present study, we acclimated coho salmon (Oncorhynchus kisutch) to four different salinities and assessed gene expression through microarray analysis of gills, liver, and olfactory rosettes. Gills are involved in osmotic regulation, liver plays a role in energetics, and olfactory rosettes are involved in behavior. Between all salinity treatments, liver had the highest number of differentially expressed genes at 1616, gills had 1074, and olfactory rosettes had 924, using a 1.5-fold cutoff and a false discovery rate of 0.5. Higher responsiveness of liver to metabolic changes after salinity acclimation to provide energy for other osmoregulatory tissues such as the gills may explain the differences in number of differentially expressed genes. Differentially expressed genes were tissue- and salinity-dependent. There were no known genes differentially expressed that were common to all salinity treatments and all tissues. Gene ontology term analysis revealed biological processes, molecular functions, and cellular components that were significantly affected by salinity, a majority of which were tissue-dependent. For liver, oxygen binding and transport terms were highlighted. For gills, muscle, and cytoskeleton-related terms predominated and for olfactory rosettes, immune response-related genes were accentuated. Interaction networks were examined in combination with GO terms and determined similarities between tissues for potential osmosensors, signal transduction cascades, and transcription factors. PMID:26260986

  4. Theoretical life history responses of juvenile Oncorhynchus mykiss to changes in food availability using a dynamic state-dependent approach

    USGS Publications Warehouse

    Romine, Jason G.; Benjamin, Joseph R.; Perry, Russell W.; Casal, Lynne; Connolly, Patrick J.; Sauter, Sally S.

    2013-01-01

    Marine subsidies can play an important role in the growth, survival, and migratory behavior of rearing juvenile salmonids. Availability of high-energy, marine-derived food sources during critical decision windows may influence the timing of emigration or the decision to forego emigration completely and remain in the freshwater environment. Increasing growth and growth rate during these decision windows may result in an altered juvenile population structure, which will ultimately affect the adult population age-structure. We used a state dependent model to understand how the juvenile Oncorhynchus mykiss population structure may respond to increased availability of salmon eggs in their diet during critical decision windows. Our models predicted an increase in smolt production until coho salmon eggs comprised more than 50 percent of juvenile O. mykiss diet at the peak of the spawning run. At higher-than intermediate levels of egg consumption, smolt production decreased owing to increasing numbers of fish adopting a resident life-history strategy. Additionally, greater growth rates decreased the number of age-3 smolts and increased the number of age-2 smolts. Increased growth rates with higher egg consumption also decreased the age at which fish adopted the resident pathway. Our models suggest that the introduction of a high-energy food source during critical periods of the year could be sufficient to increase smolt production.

  5. The effects of acute waterborne exposure to sublethal concentrations of molybdenum on the stress response in rainbow trout, Oncorhynchus mykiss.

    PubMed

    Ricketts, Chelsea D; Bates, William R; Reid, Scott D

    2015-01-01

    To determine if molybdenum (Mo) is a chemical stressor, fingerling and juvenile rainbow trout (Oncorhynchus mykiss) were exposed to waterborne sodium molybdate (0, 2, 20, or 1,000 mg l-1 of Mo) and components of the physiological (plasma cortisol, blood glucose, and hematocrit) and cellular (heat shock protein [hsp] 72, hsp73, and hsp90 in the liver, gills, heart, and erythrocytes and metallothionein [MT] in the liver and gills) stress responses were measured prior to initiation of exposure and at 8, 24, and 96 h. During the acute exposure, plasma cortisol, blood glucose, and hematocrit levels remained unchanged in all treatments. Heat shock protein 72 was not induced as a result of exposure and there were no detectable changes in total hsp70 (72 and 73), hsp90, and MT levels in any of the tissues relative to controls. Both fingerling and juvenile fish responded with similar lack of apparent sensitivity to Mo exposure. These experiments demonstrate that exposure to waterborne Mo of up to 1,000 mg l(-1) did not activate a physiological or cellular stress response in fish. Information from this study suggests that Mo water quality guidelines for the protection of aquatic life are highly protective of freshwater fish, namely rainbow trout.

  6. Relationships between mesoscale morphological units, stream hydraulics and Chinook salmon ( Oncorhynchus tshawytscha) spawning habitat on the Lower Yuba River, California

    NASA Astrophysics Data System (ADS)

    Moir, Hamish J.; Pasternack, Gregory B.

    2008-08-01

    An expert-based approach was used to identify 10 morphological unit types within a reach of the gravel bed, regulated Yuba River, California, that is heavily utilized by spawning Chinook salmon ( Oncorhynchus tshawytscha). Analysis of these units was carried out using two-dimensional hydrodynamic modeling, field-based geomorphic assessment, and detailed spawning surveying. Differently classified morphological units tended to exhibit discrete hydraulic signatures. In most cases, the Froude number adequately differentiated morphological units, but joint depth-velocity distributions proved the most effective hydraulic classification approach. Spawning activity was statistically differentiated at the mesoscale of the morphological unit. Salmon preferred lateral bar, riffle, and riffle entrance units. These units had moderately high velocity (unit median > 0.45 m s - 1 ) and low depth (unit median < 0.6 m), but each exhibited a unique joint depth-velocity distribution. A large proportion of redds (79%) were associated with conditions of convective flow acceleration at riffle and riffle entrance locations. In addition to reflecting microhabitat requirements of fish, it was proposed that the hydraulic segregation of preferred from avoided or tolerated morphological units was linked to the mutual association of specific hydraulic conditions with suitable caliber sediment that promotes the provision and maintenance of spawning habitat.

  7. Patterns of variation and covariation in the shapes of mandibular bones of juvenile salmonids in the genus Oncorhynchus

    PubMed Central

    Watson, Sawyer; Couture, Ryan B.; McKibben, Natasha S.; Nichols, James T.; Richardson, Shannon E.; Noakes, David L. G.

    2016-01-01

    SUMMARY What is the nature of evolutionary divergence of the jaw skeleton within the genus Oncorhynchus? How can two associated bones evolve new shapes and still maintain functional integration? Here, we introduce and test a ‘concordance’ hypothesis, in which an extraordinary matching of the evolutionary shape changes of the dentary and angular articular serves to preserve their fitting together. To test this hypothesis, we examined morphologies of the dentary and angular articular at parr (juvenile) stage, and at three levels of biological organization – between salmon and trout, between sister species within both salmon and trout, and among three types differing in life histories within one species, O. mykiss. The comparisons show bone shape divergences among the groups at each level; morphological divergence between salmon and trout is marked even at this relatively early life history stage. We observed substantial matching between the two mandibular bones in both pattern and amount of shape variation, and in shape covariation across species. These findings strongly support the concordance hypothesis, and reflect functional and/or developmental constraint on morphological evolution. We present evidence for developmental modularity within both bones. The locations of module boundaries were predicted from the patterns of evolutionary divergences, and for the dentary, at least, would appear to facilitate its functional association with the angular articular. The modularity results suggest that development has biased the course of evolution. PMID:26372063

  8. Bioconcentration, metabolism and half-life time of the human therapeutic drug diltiazem in rainbow trout Oncorhynchus mykiss.

    PubMed

    Steinbach, Christoph; Grabic, Roman; Fedorova, Ganna; Koba, Olga; Golovko, Oksana; Grabicova, Katerina; Kroupova, Hana Kocour

    2016-02-01

    Diltiazem is a human therapeutic drug and a member of the group of calcium channel blockers having widespread use in the treatment of angina pectoris and hypertension. The objective of the present study was to assess the bioconcentration, metabolism, and half-life time of diltiazem in rainbow trout Oncorhynchus mykiss. Juvenile trout were exposed for 21 and 42 days to three nominal concentrations of diltiazem: 0.03 µg L(-1) (environmentally relevant concentration), 3 µg L(-1), and 30 µg L(-1) (sub-lethal concentrations). The bioconcentration factor (BCF) of diltiazem was relatively low (0.5-194) in analysed tissues, following the order kidney > liver > muscle > blood plasma. The half-life of diltiazem in liver, kidney, and muscle was 1.5 h, 6.2 h, and 49 h, respectively. The rate of metabolism for diltiazem in liver, kidney, muscle, and blood plasma was estimated to be 85 ± 9%, 64 ± 14%, 46 ± 6%, and 41 ± 8%, respectively. Eight diltiazem metabolites were detected. The presence of desmethyl diltiazem (M1), desacetyl diltiazem (M2), and desacetyl desmethyl diltiazem (M3) suggests that rainbow trout metabolize diltiazem mainly via desmethylation and desacetylation, similar to mammals. In addition, diltiazem undergoes hydroxylation in fish. At environmentally relevant concentrations, diltiazem and its metabolites were identified in liver and kidney, indicating the potential for uptake and metabolism in non-target organisms in the aquatic environment.

  9. Persistent organic pollutants in chinook salmon (Oncorhynchus tshawytscha): implications for resident killer whales of British Columbia and adjacent waters.

    PubMed

    Cullon, Donna L; Yunker, Mark B; Alleyne, Carl; Dangerfield, Neil J; O'Neill, Sandra; Whiticar, Michael J; Ross, Peter S

    2009-01-01

    We measured persistent organic pollutant (POP) concentrations in chinook salmon (Oncorhynchus tshawytscha) in order to characterize dietary exposure in the highly contaminated, salmon-eating northeastern Pacific resident killer whales. We estimate that 97 to 99% of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dichlorodiphenyltrichloroethane (DDT), and hexachlorocyclohexane (HCH) in returning adult chinook were acquired during their time at sea. Highest POP concentrations (including PCBs, PCDDs, PCDFs, and DDT) and lowest lipids were observed in the more southerly chinook sampled. While feeding by salmon as they enter some more POP-contaminated near-shore environments inevitably contribute to their contamination, relationships observed between POP patterns and both lipid content and delta13C also suggest a migration-related metabolism and loss of the less-chlorinated PCB congeners. This has implications for killer whales, with the more PCB-contaminated salmon stocks in the south partly explaining the 4.0 to 6.6 times higher estimated daily intake for sigmaPCBs in southern resident killer whales compared to northern residents. We hypothesize that the lower lipid content of southerly chinook stocks may cause southern resident killer whales to increase their salmon consumption by as much as 50%, which would further increase their exposure to POPs.

  10. Differential Expression of Genes that Control Respiration Contribute to Thermal Adaptation in Redband Trout (Oncorhynchus mykiss gairdneri)

    PubMed Central

    Garvin, Michael R.; Thorgaard, Gary H.; Narum, Shawn R.

    2015-01-01

    Organisms can adapt to local environmental conditions as a plastic response or become adapted through natural selection on genetic variation. The ability to adapt to increased water temperatures will be of paramount importance for many fish species as the climate continues to warm and water resources become limited. Because increased water temperatures will reduce the dissolved oxygen available for fish, we hypothesized that adaptation to low oxygen environments would involve improved respiration through oxidative phosphorylation (OXPHOS). To test this hypothesis, we subjected individuals from two ecologically divergent populations of inland (redband) rainbow trout (Oncorhynchus mykiss gairdneri) with historically different temperature regimes (desert and montane) and their F1 progeny to diel cycles of temperature stress and then examined gene expression data for 80 nuclear- and mitochondrial-encoded OXPHOS subunits that participate in respiration. Of the 80 transcripts, 7 showed ≥ 2-fold difference in expression levels in gill tissue from desert fish under heat stress whereas the montane fish had none and the F1 only had one differentially expressed gene. A structural analysis of the proteins encoded by those genes suggests that the response could coordinate the formation of supercomplexes and oligomers. Supercomplexes may increase the efficiency of respiration because complexes I, III, and IV are brought into close proximity and oligomerization of complex V alters the macrostructure of mitochondria to improve respiration. Significant differences in gene expression patterns in response to heat stress in a common environment indicate that the response was not due to plasticity but had a genetic basis. PMID:25943341

  11. The influence of hydrology and waterway distance on population structure of Chinook salmon Oncorhynchus tshawytscha in a large river.

    PubMed

    Olsen, J B; Beacham, T D; Wetklo, M; Seeb, L W; Smith, C T; Flannery, B G; Wenburg, J K

    2010-04-01

    Adult Chinook salmon Oncorhynchus tshawytscha navigate in river systems using olfactory cues that may be influenced by hydrologic factors such as flow and the number, size and spatial distribution of tributaries. Thus, river hydrology may influence both homing success and the level of straying (gene flow), which in turn influences population structure. In this study, two methods of multivariate analysis were used to examine the extent to which four indicators of hydrology and waterway distance explained population structure of O. tshawytscha in the Yukon River. A partial Mantel test showed that the indicators of hydrology were positively associated with broad-scale (Yukon basin) population structure, when controlling for the influence of waterway distance. Multivariate multiple regression showed that waterway distance, supplemented with the number and flow of major drainage basins, explained more variation in broad-scale population structure than any single indicator. At an intermediate spatial scale, indicators of hydrology did not appear to influence population structure after accounting for waterway distance. These results suggest that habitat changes in the Yukon River, which alter hydrology, may influence the basin-wide pattern of population structure in O. tshawytscha. Further research is warranted on the role of hydrology in concert with waterway distance in influencing population structure in Pacific salmon.

  12. Molecular cloning and functional analysis of nucleotide-binding oligomerization domain-containing protein 1 in rainbow trout, Oncorhynchus mykiss.

    PubMed

    Jang, Ju Hye; Kim, Hyun; Kim, Yu Jin; Cho, Ju Hyun

    2016-04-01

    NOD1 has important roles in innate immunity as sensor of microbial components derived from bacterial peptidoglycan. In this study, we identified genes encoding components of the NOD1 signaling pathway, including NOD1 (OmNOD1) and RIP2 (OmRIP2) from rainbow trout, Oncorhynchus mykiss, and investigated whether OmNOD1 has immunomodulating activity in a rainbow trout hepatoma cell line RTH-149 treated with NOD1-specific ligand (iE-DAP). The deduced amino acid sequence of OmNOD1 contained conserved CARD, NOD and LRR domains. Loss-of-function and gain-of-function experiments indicated that OmNOD1 is involved in the expression of pro-inflammatory cytokines. Silencing of OmNOD1 in RTH-149 cells treated with iE-DAP decreased the expression of IL-1β, IL-6, IL-8 and TNF-α. Conversely, overexpression of OmNOD1 resulted in up-regulation of IL-1β, IL-6, IL-8 and TNF-α expression. In addition, RIP2 inhibitor (gefitinib) significantly decreased the expression of these pro-inflammatory cytokines induced by iE-DAP in RTH-149 cells. These findings highlight the important role of NOD1 signaling pathway in fish in eliciting innate immune response.

  13. Biological control of Aeromonas salmonicida subsp. salmonicida infection in rainbow trout (Oncorhynchus mykiss) using Aeromonas phage PAS-1.

    PubMed

    Kim, J H; Choresca, C H; Shin, S P; Han, J E; Jun, J W; Park, S C

    2015-02-01

    The potential control efficacy of Aeromonas phage PAS-1 was evaluated against Aeromonas salmonicida subsp. salmonicida infection in rainbow trout (Oncorhynchus mykiss) model in this study. The phage was co-cultured with the virulent A. salmonicida subsp. salmonicida strain AS05 that possesses the type III secretion system (TTSS) ascV gene, and efficient bacteriolytic activity was observed against the bacteria. The administration of PAS-1 in rainbow trout demonstrated that the phage was cleared from the fish within 200 h post-administration, and a temporal neutralizing activity against the phage was detected in the sera of phage-administrated fish. The administration of PAS-1 (multiplicity of infection: 10 000) in A. salmonicida subsp. salmonicida infected rainbow trout model showed notable protective effects, with increased survival rates and mean times to death. These results demonstrated that Aeromonas phage PAS-1 could be considered as an alternative biological control agent against A. salmonicida subsp. salmonicida infections in rainbow trout culture.

  14. Effects of disturbance on contribution of energy sources to growth of juvenile chinook salmon (Oncorhynchus tshawytscha) in boreal streams

    USGS Publications Warehouse

    Perry, R.W.; Bradford, M.J.; Grout, J.A.

    2003-01-01

    We used stable isotopes of carbon in a growth-dependent tissue-turnover model to quantify the relative contribution of autochthonous and terrestrial energy sources to juvenile chinook salmon (Oncorhynchus tshawytscha) in five small boreal streams tributary to the upper Yukon River. We used a tissue-turnover model because fish did not grow enough to come into isotopic equilibrium with their diet. In two streams, autochthonous energy sources contributed 23 and 41% to the growth of juvenile salmon. In the other three, fish growth was largely due to terrestrial (i.e., allochthonous) energy sources. This low contribution of autochthonous energy appeared to be related to stream-specific disturbances: a recent forest fire impacted two of the streams and the third was affected by a large midsummer spate during the study. These disturbances reduced the relative abundance of herbivorous macroinvertebrates, the contribution of autochthonous material to other invertebrates, and ultimately, the energy flow between stream algae and fish. Our findings suggest that disturbances to streams can be an important mechanism affecting transfer of primary energy sources to higher trophic levels.

  15. An attenuated virus vaccine appears safe to the central nervous system of rainbow trout (Oncorhynchus mykiss) after intranasal delivery.

    PubMed

    Larragoite, Erin T; Tacchi, Luca; LaPatra, Scott E; Salinas, Irene

    2016-02-01

    Nasal vaccines are very effective but the olfactory organ provides direct access of antigens to the brain. Infectious hematopoietic necrosis virus (IHNV) is known to cause high mortalities in salmonids. The purpose of this study is to evaluate the safety of a live attenuated IHNV nasal (I.N) vaccine in rainbow trout (Oncorhynchus mykiss). In the olfactory organ, the vaccine was detected 1 and 4 days after primary I.N vaccination but not in the intramuscular (i.m) or control groups. In the brain, IHNV was detected by RT-qPCR 4 and 21 days after i.m primary vaccination. One i.m and one I.N vaccinated trout were positive at days 4 and 28 days post-boost, respectively. Presence of IHNV in the brain of i.m vaccinated fish correlated with moderate increases in IL-1β and TNF-α expression in this tissue. These results demonstrate that IHNV vaccine lasts for 4 days in the local nasal environment and that nasal vaccination appears to be safe to the CNS of rainbow trout.

  16. Factors influencing coastal cutthroat trout (Oncorhynchus clarkii clarkii) seasonal survival rates: A spatially continuous approach within stream networks

    USGS Publications Warehouse

    Berger, A.M.; Gresswell, R.E.

    2009-01-01

    Mark-recapture methods were used to examine watershed-scale survival of coastal cutthroat trout (Oncorhynchus clarkii clarkii) from two headwater stream networks. A total of 1725 individuals (???100 mm, fork length) were individually marked and monitored seasonally over a 3-year period. Differences in survival were compared among spatial (stream segment, subwatershed, and watershed) and temporal (season and year) analytical scales, and the effects of abiotic (discharge, temperature, and cover) and biotic (length, growth, condition, density, movement, and relative fish abundance) factors were evaluated. Seasonal survival was consistently lowest and least variable (years combined) during autumn (16 September - 15 December), and evidence suggested that survival was negatively associated with periods of low stream discharge. In addition, relatively low (-) and high (+) water temperatures, fish length (-), and boulder cover (+) were weakly associated with survival. Seasonal abiotic conditions affected the adult cutthroat trout population in these watersheds, and low-discharge periods (e.g., autumn) were annual survival bottlenecks. Results emphasize the importance of watershed-scale processes to the understanding of population-level survival.

  17. Effects of Renibacterium salmoninarum on olfactory organs of Chinook salmon (Oncorhynchus tshawytscha) marked with coded wire tags

    USGS Publications Warehouse

    Elliott, Diane G.; Conway, Carla M.; Bruno, D.W.; Elliott, D.G.; Nowak, B.

    2014-01-01

    Bacterial kidney disease (BKD) caused by Renibacterium salmoninarum can cause significant morbidity and mortality in Chinook salmon (Oncorhynchus tshawytscha), particularly in Chinook salmon of the stream (spring) life history type, which migrate to sea as yearlings rather than subyearlings. R. salmoninarum can be transmitted vertically from the female parent to the progeny in association with the egg, as well as horizontally from fish to fish. This study was conducted as part of a research project to investigate whether the prevalence and intensity of R. salmoninarum infections in adult spring Chinook salmon could affect the survival and pathogen prevalence and intensity in their progeny (Pascho et al., 1991, 1993; Elliott et al., 1995). Fish from two brood years (1988 and 1989) were reared at Dworshak National Fish Hatchery (Idaho, USA) for about 1-1/2 years, released as yearling smolts, and allowed to migrate to the Pacific Ocean for maturation. The majority of progeny fish were marked with coded wire tags (CWTs) about 4 months before they were released from the hatchery so that adult returns could be monitored. The CWTs were implanted in the snouts of the fish by an experienced team of fish markers using automated wire-tagging machines. The intended placement site was the cartilage, skeletal muscle or loose connective tissue of the snout.

  18. Genetic effects of ELISA-based segregation for control of bacterial kidney disease in Chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Hard, J.J.; Elliott, D.G.; Pascho, R.J.; Chase, D.M.; Park, L.K.; Winton, J.R.; Campton, D.E.

    2006-01-01

    We evaluated genetic variation in ability of Chinook salmon (Oncorhynchus tshawytscha) to resist two bacterial pathogens: Renibacterium salmoninarum, the agent of bacterial kidney disease (BKD), and Listonella anguillarum, an agent of vibriosis. After measuring R. salmoninarum antigen in 499 adults by enzyme-linked immunosorbent assay (ELISA), we mated each of 12 males with high or low antigen levels to two females with low to moderate levels and exposed subsets of their progeny to each pathogen separately. We found no correlation between R. salmoninarum antigen level in parents and survival of their progeny following pathogen exposure. We estimated high heritability for resistance to R. salmoninarum (survival h2 = 0.890 ?? 0.256 (mean ?? standard error)) independent of parental antigen level, but low heritability for resistance to L. anguillarum (h2 = 0.128 ?? 0.078). The genetic correlation between these survivals (rA = -0.204 ?? 0.309) was near zero. The genetic and phenotypic correlations between survival and antigen levels among surviving progeny exposed to R. salmoninarum were both negative (rA = -0.716 ?? 0.140; rP = -0.378 ?? 0.041), indicating that variation in antigen level is linked to survival. These results suggest that selective culling of female broodstock with high antigen titers, which is effective in controlling BKD in salmon hatcheries, will not affect resistance of their progeny. ?? 2006 NRC.

  19. Secondary contact and changes in coastal habitat availability influence the nonequilibrium population structure of a salmonid (Oncorhynchus keta)

    PubMed Central

    Petrou, E L; Hauser, L; Waples, R S; Seeb, J E; Templin, W D; Gomez-Uchida, D; Seeb, L W

    2013-01-01

    Numerous empirical studies have reported lack of migration–drift equilibrium in wild populations. Determining the causes of nonequilibrium population structure is challenging because different evolutionary processes acting at a variety of spatiotemporal scales can produce similar patterns. Studies of contemporary populations in northern latitudes suggest that nonequilibrium population structure is probably caused by recent colonization of the region after the last Pleistocene ice age ended ∼13 000 years ago. The chum salmon's (Oncorhynchus keta) range was fragmented by dramatic environmental changes during the Pleistocene. We investigated the population structure of chum salmon on the North Alaska Peninsula (NAP) and, using both empirical data and simulations, evaluated the effects of colonization timing and founder population heterogeneity on patterns of genetic differentiation. We screened 161 single nucleotide polymorphisms and found evidence of nonequilibrium population structure when the slope of the isolation-by-distance relationship was examined at incremental spatial scales. In addition, simulations suggested that this pattern closely matched models of recent colonization of the NAP by secondary contact. Our results agree with geological and archaeological data indicating that the NAP was a dynamic landscape that may have been more recently colonized than during the last deglaciation because of dramatic changes in coastal hydrology over the last several thousand years. PMID:24118255

  20. Inactivation of Listeria innocua in nisin-treated salmon (Oncorhynchus keta) and sturgeon (Acipenser transmontanus) caviar heated by radio frequency.

    PubMed

    Al-Holy, M; Ruiter, J; Lin, M; Kang, D H; Rasco, B

    2004-09-01

    Recent regulatory concerns about the presence of the pathogen Listeria monocytogenes in ready-to-eat aquatic foods such as caviar has prompted the development of postpackaging pasteurization processes. However, caviar is heat labile, and conventional pasteurization processes affect the texture, color, and flavor of these foods negatively. In this study, chum salmon (Oncorhynchus keta, 2.5% total salt) caviar or ikura and sturgeon (Acipenser transmontanus, 3.5% total salt) caviar were inoculated with three strains of Listeria innocua in stationary phase at a level of more than 10(7) CFU/g. L innocua strains were used because they exhibit an equivalent response to L monocytogenes for many physicochemical processing treatments, including heat treatment. The products were treated by immersion in 500 IU/ml nisin solution and heat processed (an 8-D process without nisin or a 4-D process with 500 IU/ml nisin) in a newly developed radio frequency (RF; 27 MHz) heating method at 60, 63, and 65 degrees C. RF heating along with nisin acted synergistically to inactivate L. innocua cells and total mesophilic microorganisms. In the RF-nisin treatment at 65 degrees C, no surviving L. innocua microbes were recovered in sturgeon caviar or ikura. The come-up times in the RF-heated product were significantly lower compared with the water bath-heated caviar at all treatment temperatures. The visual quality of the caviar products treated by RF with or without nisin was comparable to the untreated control. PMID:15453574

  1. Effects of stocking hatchery fish on the phenotype of indigenous populations in the amago salmon Oncorhynchus masou ishikawae in Japan.

    PubMed

    Kawamura, K; Furukawa, M; Kubota, M; Harada, Y

    2012-07-01

    The expression of colour marks (parr marks, red and black spots) of the amago salmon Oncorhynchus masou ishikawae was compared with microsatellite information, to see the effects of stocking hatchery fish on the phenotype of indigenous populations, which face extinction through extensive stocking. A Bayesian-based assignment test suggested introgression of two exotic clusters into one indigenous cluster in the stocked area and its vicinity. The number of parr marks was significantly higher in one hatchery-origin population, which exclusively comprised one exotic cluster. An increased number of red spots in stocked hatchery fish was probably a consequence of hatchery feeding conditions. The number of black spots was correlated with body size in many populations, except for hatchery and heavily introgressed populations. Coefficients of correlation and regression of black spots with body size, which were largest in indigenous populations, decreased with an increase of introgression by hatchery fish. As indigenous populations have low genetic diversity with high relatedness, it was inferred that the height of correlation and regression coefficients in black spots is caused by high genetic homogeneity and fixation of alleles in loci related to the increase of black spots, both of which might have collapsed with introgression by hatchery fish. These results suggest the possibility that introgression by stocked fish causes a change of phenotype in indigenous populations.

  2. Oil spill impact on Pacific salmon (g. Oncorhynchus) of northwestern Sakhalin (Tengi River Basin as a pattern)

    NASA Astrophysics Data System (ADS)

    Ivanov, Alexander N.; Tarasov, Nikolay N.; Pusankov, Konstantin L.; Ivanova, Lubov V.; Pusankova, Ekaterina N.

    2001-01-01

    Northern Sakhalin is a region of the intensive oil and gas transportation by oil-pipe lines. In July 2, 1997, the oil spill has happened at the oil-pipe line 'Okha-Komsomolsk-on- Amur.' Oil pollution spread over the basin of Tengi Rive (Amur estuary). The Tengi River is a spawning area for endemic and important commercial fish. There is a reserve on the river. Genus Oncorhynchus (pink and chum salmon) prevail in ichthyofauna. A satellite data analysis (NOAA-12, NOAA-14) was a success to accurate the oil distribution over the Amur estuary. As a result of the accident, more than 120 t of oil have been spilled. 26.3 km of the river area, more than 60 km of the Amur estuary coast and about 850 km2 of its water area were polluted. In the basin of Tengi River about 58000 m2 of spawning area were lost. The main damage (89%) was caused to the fry feeding near the coast. The loss of fish production has constituted about 1800 t. By species the damage was as follows: 53% -- pink salmon, 29% -- chum salmon, 11% -- masu salmon and 7% -- coho salmon.

  3. Diet type dictates the gut microbiota and the immune response against Yersinia ruckeri in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Ingerslev, Hans-Christian; Strube, Mikael Lenz; Jørgensen, Louise von Gersdorff; Dalsgaard, Inger; Boye, Mette; Madsen, Lone

    2014-10-01

    This study investigated the influence of the rainbow trout (Oncorhynchus mykiss) commensal intestinal microbiota in connection to an experimental Yersina ruckeri infection, the causative agent of enteric redmouth disease. One marine and one plant diet was administered to two different groups of rainbow trout. The plant-based diet gave rise to an intestinal microbiota dominated by the genera Streptococcus, Leuconostoc and Weissella from phylum Firmicutes whereas phylum Proteobacteria/Bacteroidetes/Actinobacteria dominated the community in the marine fed fish. In connection to the Y. ruckeri bath challenge there was no effect of the diet type on the cumulative survival, but the number of Y. ruckeri positive fish as measured by plate count and the number of fish with a 'high' number of reads belonging to genus Yersinia as measured by 16S rRNA next-generation sequencing was higher for marine diet fed fish. Furthermore, the two experimental groups of fish showed a differential immune response, where Y. ruckeri challenged marine fed fish had a higher transcription of IL-1β and MBL-2 relative to challenged plant diet fed fish. The data suggest that the plant diet gave rise to a prebiotic effect favouring the presence of bacterial taxons proving protective in connection to bath challenge by Y. ruckeri.

  4. Physiological measures of neurotoxicity of diazinon and malathion to larval rainbow trout (Oncorhynchus mykiss) and their correlation with behavioral measures

    USGS Publications Warehouse

    Beauvais, S.L.; Jones, S.B.; Brewer, S.K.; Little, E.E.

    2000-01-01

    Relations between neurotoxicants and changes in physiological parameters and behavior were investigated in larval rainbow trout (RBT; Oncorhynchus mykiss) exposed to sublethal concentrations of two organophosphate pesticides (OPs). Fish were exposed to diazinon and malathion in static-renewal experiments. After exposures for 24, 96, or 96 h, followed by 48 h of recovery, individual RBT were videotaped to assess locomotory behaviors. Brain tissue from the same fish was assayed for the physiological endpoints, cholinesterase (ChE) activity, muscarinic cholinergic receptor (MChR) number (B(max)), and MChR affinity (K(D)). Cholinesterase activity decreased significantly with increasing concentrations of both diazinon and malathion and differed significantly among exposure durations, with 24- and 96-h means less than 48-h recovery means. Decreases in B(max) with OP concentration were not significant for either chemical, and K(D) was unaffected. Changes in swimming speed and distance were significantly correlated with changes in ChE activity for both chemicals; rate of turning was significantly correlated with ChE activity in malathion exposures. These results suggest that correlations between physiological and behavioral changes previously seen in mammals also occur in fish.

  5. Corticotropin-releasing factor and neuropeptide Y mRNA levels are modified by glucocorticoids in rainbow trout, Oncorhynchus mykiss.

    PubMed

    Doyon, Christian; Leclair, Jason; Trudeau, Vance L; Moon, Thomas W

    2006-04-01

    The primary stress response involves neuronal activation that ultimately leads to the release of glucocorticoids. Circulating glucocorticoids are thought to influence their own synthesis and release through a negative feedback mechanism that inhibits the activity of the hypothalamic and pituitary components of the stress axis. This study was designed to address the hypothesis that glucocorticoids modify corticotropin-releasing factor (CRF) and neuropeptide Y (NPY) mRNA levels in the rainbow trout (Oncorhynchus mykiss) brain. Cortisol implantation significantly reduced CRF1 and NPY mRNA levels in fish exposed to an isolation stress. In contrast, cortisol implantation did not prevent the stress-induced elevation of CRF1 and NPY mRNA levels during confinement. Treatment with the glucocorticoid receptor antagonist RU-486 reduced CRF1 mRNA levels in both isolated and confined fish, but had no effect on NPY mRNA. Although the cytochrome P450 inhibitor metyrapone reduced ACTH-induced cortisol secretion in vitro, plasma cortisol levels were elevated in isolated trout treated with metyrapone. Nevertheless, metyrapone implantation increased CRF1 and NPY mRNA levels in confined fish. Together, these results implicate cortisol as a modulator of CRF and NPY mRNA levels in the preoptic area of the trout brain, but that cortisol is only one such regulating mechanism.

  6. Genetic characterization of hybridization and introgression between anadromous rainbow trout (oncorhynchus mykiss irideus) and coastal cutthroat trout (o. clarki clarki)

    USGS Publications Warehouse

    Young, W.P.; Ostberg, C.O.; Keim, P.; Thorgaard, G.H.

    2001-01-01

    Interspecific hybridization represents a dynamic evolutionary phenomenon and major conservation problem in salmonid fishes. In this study we used amplified fragment length polymorphisms (AFLP) and mitochondrial DNA (mtDNA) markers to describe the extent and characterize the pattern of hybridization and introgression between coastal rainbow trout (Oncorhynchus mykiss irideus) and coastal cutthroat trout (O. clarki clarki). Hybrid individuals were initially identified using principle coordinate analysis of 133 polymorphic AFLP markers. Subsequent analysis using 23 diagnostic AFLP markers revealed the presence of F1, rainbow trout backcross, cutthroat trout backcross and later-generation hybrids. mtDNA analysis demonstrated equal numbers of F1 hybrids with rainbow and cutthroat trout mtDNA indicating reciprocal mating of the parental types. In contrast, rainbow and cutthroat trout backcross hybrids always exhibited the mtDNA from the recurrent parent, indicating a male hybrid mating with a pure female. This study illustrates the usefulness of the AFLP technique for generating large numbers of species diagnostic markers. The pattern of hybridization raises many questions concerning the existence and action of reproductive isolating mechanisms between these two species. Our findings are consistent with the hypothesis that introgression between anadromous populations of coastal rainbow and coastal cutthroat trout is limited by an environment-dependent reduction in hybrid fitness.

  7. Effects of surgically and gastrically implanted radio transmitters on swimming performance and predator avoidance of juvenile chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Adams, N.S.; Rondorf, D.W.; Evans, S.D.; Kelly, J.E.; Perry, R.W.

    1998-01-01

    Radiotelemetry data are often used to make inferences about an entire study population; therefore, the transmitter attachment method should be the one that least affects the study animal. Juvenile chinook salmon (Oncorhynchus tshawytscha) <120 mm in fork length (FL) with either gastrically or surgically implanted transmitters had significantly lower critical swimming speeds than control fish 1 and 19-23 days after tagging. For fish >120 mm FL, fish with gastric implants swam as well as controls 1 day but not 19-23 days after tagging. In contrast, fish with surgical implants swam as well as controls 19-23 days but not 1 day after tagging. During predation trials, fish with gastric or surgical implants were eaten by smallmouth bass (Micropterus dolomieu) in significantly greater numbers than controls. We do not recommend implanting transmitters (representing 4.6-10.4% of the fish's body weight) in fish <120 mm FL. Furthermore, surgical implants (representing 2.2-5.6% of the fish's body weight) may be the preferred method for biotelemetry studies of juvenile chinook salmon >120 mm FL.

  8. The Effects of Acute Waterborne Exposure to Sublethal Concentrations of Molybdenum on the Stress Response in Rainbow Trout, Oncorhynchus mykiss

    PubMed Central

    Ricketts, Chelsea D.; Bates, William R.; Reid, Scott D.

    2015-01-01

    To determine if molybdenum (Mo) is a chemical stressor, fingerling and juvenile rainbow trout (Oncorhynchus mykiss) were exposed to waterborne sodium molybdate (0, 2, 20, or 1,000 mg l-1 of Mo) and components of the physiological (plasma cortisol, blood glucose, and hematocrit) and cellular (heat shock protein [hsp] 72, hsp73, and hsp90 in the liver, gills, heart, and erythrocytes and metallothionein [MT] in the liver and gills) stress responses were measured prior to initiation of exposure and at 8, 24, and 96 h. During the acute exposure, plasma cortisol, blood glucose, and hematocrit levels remained unchanged in all treatments. Heat shock protein 72 was not induced as a result of exposure and there were no detectable changes in total hsp70 (72 and 73), hsp90, and MT levels in any of the tissues relative to controls. Both fingerling and juvenile fish responded with similar lack of apparent sensitivity to Mo exposure. These experiments demonstrate that exposure to waterborne Mo of up to 1,000 mg l-1 did not activate a physiological or cellular stress response in fish. Information from this study suggests that Mo water quality guidelines for the protection of aquatic life are highly protective of freshwater fish, namely rainbow trout. PMID:25629693

  9. Effects of oil-contaminated prey on the feeding, growth, and related energetics on pink salmon, Oncorhynchus gorbuscha Walbaum, fry

    SciTech Connect

    Schwartz, J.P.

    1984-01-01

    Pink salmon, Oncorhynchus gorbuscha Walbaum, fry were exposed to oil contaminated prey (OCP) in a series of experiments to determine the effect of oil exposure via the diet on the ability of pink fry to survive. Brine shrimp, Artemia salina, nauplii were contaminated with petroleum hydrocarbons by exposure to the water-soluble fraction (WSF) of Cook Inlet crude oil and fed to the fish. Feeding rates were measured for 10 days using OCP and for 5 days using uncontaminated prey (post-exposure period). In a separate experiment, fry growth was measured over a 50 day period. In another experiment, fry oxygen consumption, food absorption and utilization, and ammonia excretion was measured to determine the effects of OCP on fry metabolic activity. Results indicate that exposure to OCP can reduce fry growth primarily by reducing food intake, but additional nutrition is lost from the non-absorption of ingested food. Reductions in growth could decrease fry survival, and thereby reduce the number of returning adult pink salmon.

  10. The organochlorine o,p'-DDD disrupts the adrenal steroidogenic signaling pathway in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Lacroix, Martin; Hontela, Alice

    2003-08-01

    The mechanisms of action of o,p'-DDD on adrenal steroidogenesis were investigated in vitro in rainbow trout (Oncorhynchus mykiss). Acute exposures to o,p'-DDD inhibited ACTH-stimulated cortisol secretion while cell viability decreased significantly only at the highest concentration tested (200 microM o,p'-DDD). Stimulation of cortisol secretion with a cAMP analogue (dibutyryl-cAMP) was inhibited at a higher concentration than that needed to inhibit ACTH-stimulated cortisol synthesis in cells exposed to o,p'-DDD. Forskolin-stimulated cortisol secretion and cAMP production, and NaF-stimulated cAMP production were inhibited in a concentration-dependent manner by o,p'-DDD. In contrast, basal cortisol secretion was stimulated while basal cAMP production was unaffected by o,p'-DDD. Pregnenolone-stimulated cortisol secretion was enhanced by o,p'-DDD at a physiologically relevant pregnenolone concentration, while o,p'-DDD inhibited cortisol secretion when a pharmacological concentration of pregnenolone was used. Our results suggest that the cAMP generation step is a target in o,p'-DDD-mediated disruption of ACTH-stimulated adrenal steroidogenesis in rainbow trout but that other downstream targets such as steroidogenic enzymes responsible for cortisol synthesis might also be affected.

  11. An attenuated virus vaccine appears safe to the central nervous system of rainbow trout (Oncorhynchus mykiss) after intranasal delivery

    PubMed Central

    Larragoite, Erin T.; Tacchi, Luca; LaPatra, Scott E.

    2016-01-01

    Nasal vaccines are very effective but the olfactory organ provides direct access of antigens to the brain. Infectious hematopoietic necrosis virus (IHNV) is known to cause high mortalities in salmonids. The purpose of this study is to evaluate the safety of a live attenuated IHNV nasal (I.N) vaccine in rainbow trout (Oncorhynchus mykiss). In the olfactory organ, the vaccine was detected 1 and 4 days after primary I.N vaccination but not in the intramuscular (i.m) or control groups. In the brain, IHNV was detected by RT-qPCR 4 and 21 days after i.m primary vaccination. One i.m and one I.N vaccinated trout were positive at days 4 and 28 days post-boost, respectively. Presence of IHNV in the brain of i.m vaccinated fish correlated with moderate increases in IL-1β and TNF-α expression in this tissue. These results demonstrate that IHNV vaccine lasts for 4 days in the local nasal environment and that nasal vaccination appears to be safe to the CNS of rainbow trout. PMID:26772477

  12. Differences in Ichthyophonus prevalence and infection severity between upper Yukon River and Tanana River chinook salmon, Oncorhynchus tshawytscha (Walbaum), stocks

    USGS Publications Warehouse

    Kocan, R.; Hershberger, P.

    2006-01-01

    Two genetically distinct populations of chinook salmon, Oncorhynchus tshawytscha (Walbaum), were simultaneously sampled at the confluence of the Yukon and Tanana rivers in 2003. Upper Yukon-Canadian fish had significantly higher infection prevalence as well as more severe infections (higher parasite density in heart tissue) than the lower Yukon-Tanana River fish. Both populations had migrated the same distance from the mouth of the Yukon River at the time of sampling but had significantly different distances remaining to swim before reaching their respective spawning grounds. Multiple working hypotheses are proposed to explain the differences between the two stocks: (1) the two genetically distinct populations have different inherent resistance to infection, (2) genetically influenced differences in feeding behaviour resulted in temporal and/or spatial differences in exposure, (3) physiological differences resulting from different degrees of sexual maturity influenced the course of disease, and (4) the most severely infected Tanana River fish either died en route or fatigued and were unable to complete their migration to the Tanana River, thus leaving a population of apparently healthier fish. ?? 2006 Blackwell Publishing Ltd.

  13. Reduced growth of rainbow trout (Oncorhynchus mykiss) fed a live invertebrate diet pre-exposed to metal-contaminated sediments.

    PubMed

    Hansen, James A; Lipton, Joshua; Welsh, Paul G; Cacela, David; MacConnell, Beth

    2004-08-01

    Juvenile rainbow trout (Oncorhynchus mykiss) were fed live diets of Lumbriculus variegatus cultured in metal-contaminated sediments from the Clark Fork River Basin (MT, USA), an uncontaminated reference sediment, or an uncontaminated culture medium. Fish were tested in individual chambers; individual growth as well as the nutritional quality and caloric value of each trout's consumed diet were determined. Growth was measured following 14, 28, 42, 56, and 67 d of exposure. A subset of fish was sampled at 35 d for whole-body metals. Metals (whole body, digestive tract, and liver) and histology were measured at the end of the test. We observed significant growth inhibition in trout fed the contaminated diets; growth inhibition was associated with reductions in conversion of food energy to biomass rather than with reduced food intake. Growth inhibition was negatively correlated with As in trout tissue residues. Histological changes in contaminated treatments included hepatic necrosis and degenerative alterations in gallbladder. The present study provides evidence that metal-contaminated sediments can pose a hazard to trout health through a dietary exposure pathway. PMID:15352479

  14. Topographical Mapping of the Rainbow Trout (Oncorhynchus mykiss) Microbiome Reveals a Diverse Bacterial Community with Antifungal Properties in the Skin

    PubMed Central

    Lowrey, Liam; Woodhams, Douglas C.; Tacchi, Luca

    2015-01-01

    The mucosal surfaces of wild and farmed aquatic vertebrates face the threat of many aquatic pathogens, including fungi. These surfaces are colonized by diverse symbiotic bacterial communities that may contribute to fight infection. Whereas the gut microbiome of teleosts has been extensively studied using pyrosequencing, this tool has rarely been employed to study the compositions of the bacterial communities present on other teleost mucosal surfaces. Here we provide a topographical map of the mucosal microbiome of an aquatic vertebrate, the rainbow trout (Oncorhynchus mykiss). Using 16S rRNA pyrosequencing, we revealed novel bacterial diversity at each of the five body sites sampled and showed that body site is a strong predictor of community composition. The skin exhibited the highest diversity, followed by the olfactory organ, gills, and gut. Flectobacillus was highly represented within skin and gill communities. Principal coordinate analysis and plots revealed clustering of external sites apart from internal sites. A highly diverse community was present within the epithelium, as demonstrated by confocal microscopy and pyrosequencing. Using in vitro assays, we demonstrated that two Arthrobacter sp. skin isolates, a Psychrobacter sp. strain, and a combined skin aerobic bacterial sample inhibit the growth of Saprolegnia australis and Mucor hiemalis, two important aquatic fungal pathogens. These results underscore the importance of symbiotic bacterial communities of fish and their potential role for the control of aquatic fungal diseases. PMID:26209676

  15. Genetic variation in chinook, Oncorhynchus tshawytscha, and coho, O. Kisutch

    USGS Publications Warehouse

    Reisenbichler, R.R.; Phelps, S.R.

    1987-01-01

    We used starch-gel electrophoresis to genetically characterize the populations of chinook salmon, Oncorhynchus tshawytscha, and coho salmon, O. kisutch, in the major drainages of the north coast of Washington (the Quillayute, Uoh, Queets, and Quinault Rivers). Of 55 loci examined for electrophoretically detectable variation. 6 were polymorphic (frequency of the common allele was less than 0.95) in chinook salmon and 3 in coho salmon. Statistical tests of interdrainage and intradrainage variation for coho salmon were tenuous because most of the fish examined were from a single year class so that we could not account for variation among year classes. Nevertheless, these tests suggested that distinct stocks ofcoho salmon exist within drainages. and that variation was not significantly greater among drainages than within drainages. Interdrainage variation for wild chinook salmon was not significant. The data suggested that summer chinook salmon were electrophoretically different from fall chinook salmon, and the hatchery populations of chinook salmon were distinct from wild fish. A hatchery population developed primarily from north coast fish was electrophoretically more similar to wild chinook salmon than were the others.

  16. Detection and mapping of QTL for temperature tolerance and body size in Chinook salmon (Oncorhynchus tshawytscha) using genotyping by sequencing

    PubMed Central

    Everett, Meredith V; Seeb, James E

    2014-01-01

    Understanding how organisms interact with their environments is increasingly important for conservation efforts in many species, especially in light of highly anticipated climate changes. One method for understanding this relationship is to use genetic maps and QTL mapping to detect genomic regions linked to phenotypic traits of importance for adaptation. We used high-throughput genotyping by sequencing (GBS) to both detect and map thousands of SNPs in haploid Chinook salmon (Oncorhynchus tshawytscha). We next applied this map to detect QTL related to temperature tolerance and body size in families of diploid Chinook salmon. Using these techniques, we mapped 3534 SNPs in 34 linkage groups which is consistent with the haploid chromosome number for Chinook salmon. We successfully detected three QTL for temperature tolerance and one QTL for body size at the experiment-wide level, as well as additional QTL significant at the chromosome-wide level. The use of haploids coupled with GBS provides a robust pathway to rapidly develop genomic resources in nonmodel organisms; these QTL represent preliminary progress toward linking traits of conservation interest to regions in the Chinook salmon genome. PMID:24822082

  17. A microsatellite linkage map of rainbow trout (Oncorhynchus mykiss) characterized by large sex-specific differences in recombination rates.

    PubMed Central

    Sakamoto, T; Danzmann, R G; Gharbi, K; Howard, P; Ozaki, A; Khoo, S K; Woram, R A; Okamoto, N; Ferguson, M M; Holm, L E; Guyomard, R; Hoyheim, B

    2000-01-01

    We constructed a genetic linkage map for a tetraploid derivative species, the rainbow trout (Oncorhynchus mykiss), using 191 microsatellite, 3 RAPD, 7 ESMP, and 7 allozyme markers in three backcross families. The linkage map consists of 29 linkage groups with potential arm displacements in the female map due to male-specific pseudolinkage arrangements. Synteny of duplicated microsatellite markers was used to identify and confirm some previously reported pseudolinkage arrangements based upon allozyme markers. Fifteen centromeric regions (20 chromosome arms) were identified with a half-tetrad analysis using gynogenetic diploids. Female map length is approximately 10 M, but this is a large underestimate as many genotyped segments remain unassigned at a LOD threshold of 3.0. Extreme differences in female:male map distances were observed (ratio F:M, 3.25:1). Females had much lower recombination rates (0.14:1) in telomeric regions than males, while recombination rates were much higher in females within regions proximal to the centromere (F:M, 10:1). Quadrivalent formations that appear almost exclusively in males are postulated to account for the observed differences. PMID:10880492

  18. Effects of excretory/secretory products from Anisakis simplex (Nematoda) on immune gene expression in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Bahlool, Qusay Z M; Skovgaard, Alf; Kania, Per W; Buchmann, Kurt

    2013-09-01

    Excretory/secretory (ES) products are molecules produced by parasitic nematodes, including larval Anisakis simplex, a parasite occurring in numerous marine fish hosts. The effects of these substances on host physiology have not been fully described. The present work elucidates the influence of ES substances on the fish immune system by measuring immune gene expression in spleen and liver of rainbow trout (Oncorhynchus mykiss) injected intraperitoneally with ES products isolated from A. simplex third stage larvae. The overall gene expression profile of exposed fish showed a generalized down-regulation of the immune genes tested, suggesting a role of ES proteins in immunomodulation. We also tested the enzymatic activity of the ES proteins and found that lipase, esterase/lipase, valine and cysteine arylamidases, naphthol-AS-BI-phosphohydrolase and α-galactosidase activities were present in the ES solution. This type of hydrolytic enzyme activity may play a role in nematode penetration of host tissue. In addition, based on the notion that A. simplex ES products may have an immune-depressive effect (by minimizing immune gene expression) it could also be suggested that worm enzymes directly target host immune molecules which would add to a decreased host immune response and increased worm survival.

  19. The impact of small irrigation diversion dams on the recent migration rates of steelhead and redband trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Weigel, Dana E.; Connolly, Patrick J.; Powell, Madison S.

    2013-01-01

    Barriers to migration are numerous in stream environments and can occur from anthropogenic activities (such as dams and culverts) or natural processes (such as log jams or dams constructed by beaver (Castor canadensis)). Identification of barriers can be difficult when obstructions are temporary or incomplete providing passage periodically. We examine the effect of several small irrigation diversion dams on the recent migration rates of steelhead (Oncorhynchus mykiss) in three tributaries to the Methow River, Washington. The three basins had different recent migration patterns: Beaver Creek did not have any recent migration between sites, Libby Creek had two-way migration between sites and Gold Creek had downstream migration between sites. Sites with migration were significantly different from sites without migration in distance, number of obstructions, obstruction height to depth ratio and maximum stream gradient. When comparing the sites without migration in Beaver Creek to the sites with migration in Libby and Gold creeks, the number of obstructions was the only significant variable. Multinomial logistic regression identified obstruction height to depth ratio and maximum stream gradient as the best fitting model to predict the level of migration among sites. Small irrigation diversion dams were limiting population interactions in Beaver Creek and collectively blocking steelhead migration into the stream. Variables related to stream resistance (gradient, obstruction number and obstruction height to depth ratio) were better predictors of recent migration rates than distance, and can provide important insight into migration and population demographic processes in lotic species.

  20. Environmental enrichment in steelhead (Oncorhynchus mykiss) hatcheries: Field evaluation of aggression, foraging, and territoriality in natural and hatchery fry

    USGS Publications Warehouse

    Tatara, C.P.; Riley, S.C.; Scheurer, J.A.

    2008-01-01

    Reforms for salmonid hatcheries include production of hatchery fish with behavioral characteristics similar to wild conspecifics. Enrichment of the hatchery environment has been proposed to achieve this goal. Field experiments of steelhead (i.e., sea-run rainbow trout, Oncorhynchus mykiss) fry from a common stock reared under natural (i.e., stream), enriched hatchery, and conventional hatchery conditions indicated no significant differences in the rates of foraging or aggression between rearing treatments. However, the rates of foraging and aggression of natural fry were significantly affected by the type of hatchery fry stocked with them. Natural steelhead fry fed at lower rates and exhibited higher rates of aggression when stocked with steelhead fry raised in enriched hatchery environments. Territory sizes of steelhead fry ranged from 0.015 to 0.801 m2; were significantly, positively related to body length; and were not significantly different between rearing treatments. We conclude that hatchery steelhead fry released into streams establish territories that are proportional to their body length and similar in size to territories of natural steelhead fry. Our results indicate that both conventional and enriched hatchery environments produce natural social behaviors in steelhead released as fry and that fry from enriched hatchery environments may alter the foraging and aggressive behavior of natural, resident steelhead fry. ?? 2008 NRC.

  1. Differential virulence mechanisms of infectious hematopoietic necrosis virus in rainbow trout (Oncorhynchus mykiss) include host entry and virus replication kinetics

    USGS Publications Warehouse

    Penaranda, M.M.D.; Purcell, M.K.; Kurath, G.

    2009-01-01

    Host specificity is a phenomenon exhibited by all viruses. For the fish rhabdovirus infectious hematopoietic necrosis virus (IHNV), differential specificity of virus strains from the U and M genogroups has been established both in the field and in experimental challenges. In rainbow trout (Oncorhynchus mykiss), M IHNV strains are consistently more prevalent and more virulent than U IHNV. The basis of the differential ability of these two IHNV genogroups to cause disease in rainbow trout was investigated in live infection challenges with representative U and M IHNV strains. When IHNV was delivered by intraperitoneal injection, the mortality caused by U IHNV increased, indicating that the low virulence of U IHNV is partly due to inefficiency in entering the trout host. Analyses of in vivo replication showed that U IHNV consistently had lower prevalence and lower viral load than M IHNV during the course of infection. In analyses of the host immune response, M IHNV-infected fish consistently had higher and longer expression of innate immune-related genes such as Mx-1. This suggests that the higher virulence of M IHNV is not due to suppression of the immune response in rainbow trout. Taken together, the results support a kinetics hypothesis wherein faster replication enables M IHNV to rapidly achieve a threshold level of virus necessary to override the strong host innate immune response. ?? 2009 SGM.

  2. Distribution of temperature tolerance quantitative trait loci in Arctic charr (Salvelinus alpinus) and inferred homologies in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Somorjai, Ildiko M L; Danzmann, Roy G; Ferguson, Moira M

    2003-11-01

    We searched for quantitative trait loci (QTL) affecting upper temperature tolerance (UTT) in crosses between the Nauyuk Lake and Fraser River strains of Arctic charr (Salvelinus alpinus) using survival analysis. Two QTL were detected by using two microsatellite markers after correcting for experiment-wide error. A comparative mapping approach localized these two QTL to homologous linkage groups containing UTT QTL in rainbow trout (Oncorhynchus mykiss). Additional marginal associations were detected in several families in regions homologous to those with QTL in rainbow trout. Thus, the genes underlying UTT QTL may antedate the divergence of these two species, which occurred by approximately 16 MYA. The data also indicate that one pair of homeologs (ancestrally duplicated chromosomal segments) have contained QTL in Arctic charr since the evolution of salmonids from a tetraploid ancestor 25-100 MYA. This study represents one of the first examples of comparative QTL mapping in an animal polyploid group and illustrates the fate of QTL after genome duplication and reorganization. PMID:14668393

  3. Linkage arrangement of Na,K-ATPase genes in the tetraploid-derived genome of the rainbow trout (Oncorhynchus mykiss).

    PubMed

    Gharbi, K; Semple, J W; Ferguson, M M; Schulte, P M; Danzmann, R G

    2004-08-01

    As part of our efforts to characterize Na,K-ATPase isoforms in salmonid fish, we investigated the linkage arrangement of genes coding for the alpha and beta-subunits of the enzyme complex in the tetraploid-derived genome of the rainbow trout (Oncorhynchus mykiss). Genetic markers were developed from four of five previously characterized alpha-subunit isoforms (alpha1b, alpha1c, alpha2 and alpha3) and four expressed sequence tags derived from yet undescribed beta-subunit isoforms (beta1a, beta1b, beta3a and beta3b). Sex-specific linkage analysis of polymorphic loci in a reference meiotic panel revealed that Na,K-ATPase genes are generally dispersed throughout the rainbow trout genome. A notable exception was the colocalization of two alpha-subunit genes and one beta-subunit gene on linkage group RT-12, which may thus share a conserved orthologous segment with linkage group 1 in zebrafish (Danio rerio). Consistent with previously reported homeologous relationships among the chromosomes of the rainbow trout, primers designed from the alpha3-isoform detected a pair of duplicated genes on linkage groups RT-27 and RT-31. Similarly, the evolutionary conservation of homeologous regions on linkage groups RT-12 and RT-16 was further supported by the map localization of gene duplicates for the beta1b isoform. The detection of homeologs within each gene family also raises the possibility that novel isoforms may be discovered as functional duplicates. PMID:15265073

  4. Comparisons of spawning areas and times for two runs of chinook salmon (Oncorhynchus tshawytscha) in the Kenai River, Alaska

    USGS Publications Warehouse

    Burger, C.V.; Wilmot, R.L.; Wangaard, D.B.

    1985-01-01

    From 1979 to 1982,188 chinook salmon (Oncorhynchus tshawytscha) were tagged with radio transmitters to locate spawning areas in the glacial Kenai River, southcentral Alaska. Results confirmed that an early run entered the river in May and June and spawned in tributaries, and a late run entered the river from late June through August and spawned in the main stem. Spawning peaked during August in tributaries influenced by lakes, but during July in other tributaries. Lakes may have increased fall and winter temperatures of downstream waters, enabling successful reproduction for later spawning fish within these tributaries. This hypothesis assumes that hatching and emergence can be completed in a shorter time in lake-influenced waters. The time of upstream migration and spawning (mid- to late August) of the late run is unique among chinook stocks in Cook Inlet. This behavior may have developed only because two large lakes (Kenai and Skilak) directly influence the main-stem Kenai River. If run timing is genetically controlled, and if the various components of the two runs are isolated stocks that have adapted to predictable stream temperatures, there are implications for stock transplantation programs and for any activities of man that alter stream temperatures.

  5. Evaluation of strobe lights to reduce turbine entrainment of juvenile steelhead (Oncorhynchus mykiss) at Cowlitz Falls Dam, Washington

    USGS Publications Warehouse

    2009-01-01

    We conducted a radiotelemetry evaluation to determine if strobe lights could be used to decrease turbine entrainment of juvenile steelhead (Oncorhynchus mykiss) at Cowlitz Falls Dam, Washington. We found that radio-tagged juvenile steelhead approached and entered two spillbays (one lighted, one unlighted) in equal proportions. However, the presence of strobe lights was associated with decreased spillbay residence time of juvenile steelhead and increased passage through induction slots (secondary turbine intakes located upstream of the ogee on the spillway). Mean residence time of tagged fish inside the lighted spillbay was 14 min compared to 62 min inside the unlighted spillbay. Radio-tagged steelhead passed through induction slots at a higher proportion in the lighted spillbay (55%) than in the unlighted spillbay (26%). Recent studies have suggested that strobe lights can induce torpor in juvenile salmonids. We believe that strobe light exposure affected fish in our study at a location where they were susceptible to high flows thereby reducing mean residence time and increasing the proportion of tagged fish entering induction slots in the lighted spillbay. Our results suggest that factors such as deployment location, exposure, and flow are important variables that should be considered when evaluating strobe lights as a potential fish-deterring management tool.

  6. Short-term responses of selected endocrine parameters in juvenile rainbow trout (Oncorhynchus mykiss) exposed to 4-nonylphenol.

    PubMed

    Naderi, Mohammad; Zargham, Davood; Asadi, Asad; Bashti, Tayebeh; Kamayi, Kianoosh

    2015-12-01

    The synthetic organic compound 4-nonylphenol (4-NP) has been shown to have a wide range of adverse effects on the endocrine system of various animals including fish. The present study evaluated the potential effects of 4-NP on vitellogenin (VTG) synthesis, steroid, and thyroid hormone concentrations in both juvenile male and female rainbow trout (Oncorhynchus mykiss). Fish were exposed by intraperitoneal injection to different doses of 4-NP (1, 10, 50, and 100 μg g(-1)) or vehicle (coconut oil) over a period of 14 days. Blood samples were collected 7 and 14 days after initiation of treatment. Plasma VTG levels in 4-NP-treated fish were detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis as a high molecular weight protein band of 180 KDa. In addition, plasma VTG concentrations were quantified indirectly using plasma alkali-labile phosphate (ALP) and plasma calcium. Both ALP and calcium levels in plasma showed similar and parallel increase patterns after exposure to 4-NP that were significantly higher compared with controls. The analysis of plasma sex steroid levels revealed a significant increase in 17β-estradiol and testosterone in plasma of juvenile males and females, respectively. Furthermore, a significant increase was observed in plasma cortisol levels. On the other hand, 4-NP decreased both plasma triiodothyronine and thyroxine after 7 and 14 days of treatment. These results suggest that 4-NP can affect different parts of the endocrine system, which may lead to serious impairments in physiological homeostasis of juvenile rainbow trout. PMID:23771873

  7. Estimating Common Growth Patterns in Juvenile Chinook Salmon (Oncorhynchus tshawytscha) from Diverse Genetic Stocks and a Large Spatial Extent

    PubMed Central

    Scheuerell, Mark D.; Simenstad, Charles A.; Bottom, Daniel L.

    2016-01-01

    Life history variation in Pacific salmon (Oncorhynchus spp.) supports species resilience to natural disturbances and fishery exploitation. Within salmon species, life-history variation often manifests during freshwater and estuarine rearing, as variation in growth. To date, however, characterizing variability in growth patterns within and among individuals has been difficult via conventional sampling methods because of the inability to obtain repeated size measurements. In this study we related otolith microstructures to growth rates of individual juvenile Chinook salmon (O. tshawytscha) from the Columbia River estuary over a two-year period (2010–2012). We used dynamic factor analysis to determine whether there were common patterns in growth rates within juveniles based on their natal region, capture location habitat type, and whether they were wild or of hatchery origin. We identified up to five large-scale trends in juvenile growth rates depending on month and year of capture. We also found that hatchery fish had a narrower range of trend loadings for some capture groups, suggesting that hatchery fish do not express the same breadth of growth variability as wild fish. However, we were unable to resolve a relationship between specific growth patterns and habitat transitions. Our study exemplifies how a relatively new statistical analysis can be applied to dating or aging techniques to summarize individual variation, and characterize aspects of life history diversity. PMID:27695094

  8. Landscape-scale evaluation of genetic structure among barrier-isolated populations of coastal cutthroat trout, Oncorhynchus clarkii clarkii

    USGS Publications Warehouse

    Guy, T.J.; Gresswell, R.E.; Banks, M.A.

    2008-01-01

    Relationships among landscape structure, stochastic disturbance, and genetic diversity were assessed by examining interactions between watershed-scale environmental factors and genetic diversity of coastal cutthroat trout (Oncorhynchus clarkii clarkii) in 27 barrier-isolated watersheds from western Oregon, USA. Headwater populations of coastal cutthroat trout were genetically differentiated (mean FST = 0.33) using data from seven microsatellite loci (2232 individuals), but intrapopulation microsatellite genetic diversity (mean number of alleles per locus = 5, mean He = 0.60) was only moderate. Genetic diversity of coastal cutthroat trout was greater (P = 0.02) in the Coast Range ecoregion (mean alleles = 47) than in the Cascades ecoregion (mean alleles = 30), and differences coincided with indices of regional within-watershed complexity and connectivity. Furthermore, regional patterns of diversity evident from isolation-by-distance plots suggested that retention of within-population genetic diversity in the Coast Range ecoregion is higher than that in the Cascades, where genetic drift is the dominant factor influencing genetic patterns. Thus, it appears that physical landscape features have influenced genetic patterns in these populations isolated from short-term immigration. ?? 2008 NRC.

  9. Distribution of temperature tolerance quantitative trait loci in Arctic charr (Salvelinus alpinus) and inferred homologies in rainbow trout (Oncorhynchus mykiss).

    PubMed Central

    Somorjai, Ildiko M L; Danzmann, Roy G; Ferguson, Moira M

    2003-01-01

    We searched for quantitative trait loci (QTL) affecting upper temperature tolerance (UTT) in crosses between the Nauyuk Lake and Fraser River strains of Arctic charr (Salvelinus alpinus) using survival analysis. Two QTL were detected by using two microsatellite markers after correcting for experiment-wide error. A comparative mapping approach localized these two QTL to homologous linkage groups containing UTT QTL in rainbow trout (Oncorhynchus mykiss). Additional marginal associations were detected in several families in regions homologous to those with QTL in rainbow trout. Thus, the genes underlying UTT QTL may antedate the divergence of these two species, which occurred by approximately 16 MYA. The data also indicate that one pair of homeologs (ancestrally duplicated chromosomal segments) have contained QTL in Arctic charr since the evolution of salmonids from a tetraploid ancestor 25-100 MYA. This study represents one of the first examples of comparative QTL mapping in an animal polyploid group and illustrates the fate of QTL after genome duplication and reorganization. PMID:14668393

  10. Changing patterns in coastal cutthroat trout (Oncorhynchus clarki clarki) diet and prey in a gradient of deciduous canopies

    USGS Publications Warehouse

    Romero, N.; Gresswell, R.E.; Li, J.L.

    2005-01-01

    We examined the influence of riparian vegetation patterns on coastal cutthroat trout Oncorhynchus clarki clarki diet and prey from the summer of 2001 through the spring of 2002. Benthic and drifting invertebrates, allochthonous prey, and fish diet were collected from deciduous, conifer, and mixed sections of three Oregon coastal watersheds. The nine sites were best characterized as a continuum of deciduous cover, and shrub cover and proportion of deciduous canopy were positively correlated (r = 0.74). Most sources of prey (benthic invertebrate biomass, allochthonous invertebrate inputs, aquatic and total invertebrate drift) and aquatic prey ingested by coastal cutthroat trout were greater where shrub cover was more abundant. Only aquatic drift, total invertebrate drift, and allochthonous invertebrates were positively correlated with deciduous vegetation. Compared with coniferous sites, allochthonous invertebrates under deciduous and mixed canopies were almost 30% more abundant. Stream discharge likely influenced seasonal fluxes of aquatic invertebrate biomass in the benthos and drift. Aquatic insects dominated gut contents during this study; however, terrestrial prey were most common in the diet during the summer and fall. In the Pacific northwest, systematic removal of deciduous riparian vegetation to promote conifers may have unintended consequences on food resources of coastal cutthroat trout and aquatic food web interactions. ?? 2005 NRC.

  11. A latitudinal cline in the Chinook salmon (Oncorhynchus tshawytscha) Clock gene: evidence for selection on PolyQ length variants.

    PubMed

    O'Malley, Kathleen G; Banks, Michael A

    2008-12-22

    A critical seasonal event for anadromous Chinook salmon (Oncorhynchus tshawytscha) is the time at which adults migrate from the ocean to breed in freshwater. We investigated whether allelic variation at the circadian rhythm genes, OtsClock1a and OtsClock1b, underlies genetic control of migration timing among 42 populations in North America. We identified eight length variants of the functionally important polyglutamine repeat motif (PolyQ) of OtsClock1b while OtsClock1a PolyQ was highly conserved. We found evidence of a latitudinal cline in average allele length and frequency of the two most common OtsClock1b alleles. The shorter 335 bp allele increases in frequency with decreasing latitude while the longer 359 bp allele increases in frequency at higher latitudes. Comparison to 13 microsatellite loci showed that 335 and 359 bp deviate significantly from neutral expectations. Furthermore, a hierarchical gene diversity analysis based on OtsClock1b PolyQ variation revealed that run timing explains 40.9 per cent of the overall genetic variance among populations. By contrast, an analysis based on 13 microsatellite loci showed that run timing explains only 13.2 per cent of the overall genetic variance. Our findings suggest that length polymorphisms in OtsClock1b PolyQ may be maintained by selection and reflect an adaptation to ecological factors correlated with latitude, such as the seasonally changing day length.

  12. Effects of cadmium at sub-lethal concentration on growth and biochemical parameters in rainbow trout (Oncorhynchus mykiss)

    PubMed Central

    2013-01-01

    Cadmium (Cd), as one of heavy metals and an environmental stressor, may alter many physiological processes like growth and serum parameters in fish. The main objective of this study was to determine the effects of cadmium at sub-lethal concentrations (1 and 3 μg/l) on growth and serum biochemical parameters including enzymes, i.e. alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), glucose, triglyceride, cholesterol and total protein in rainbow trout (Oncorhynchus mykiss). Trout were exposed to cadmium, and, at intervals of 1, 15, and 30 days, selected parameters were evaluated. Condition Factor (K), Specific Growth Rate (SGR) and Body Weight Gain (BWG) consistently decreased, while Food Conversion Ratio (FCR) increased at the end of experiment. Glucose was elevated in trout exposed to both Cd concentrations at day 15 and then returned to levels comparable to control fish. Triglyceride and cholesterol decreased transiently at day 15 and then increased at day 30. Total protein, AST, ALT and ALP increased linearly by time and Cd concentration. This investigation suggests that growth and serum biochemical parameters could be used as important and sensitive biomarkers in ecotoxicological studies concerning the effects of metal contamination and fish health. PMID:23782857

  13. Predator avoidance ability of juvenile chinook salmon (Oncorhynchus tshawytscha) subjected to sublethal exposures of gas-supersaturated water

    USGS Publications Warehouse

    Mesa, M.G.; Warren, J.J.

    1997-01-01

    To assess the effects of gas bubble trauma (GBT) on the predator avoidance ability of juvenile chinook salmon (Oncorhynchus tshawytscha), we created groups of fish that differed in prevalence and severity of gas emboli in their lateral lines, fins, and gills by exposing them to 112% total dissolved gas (TDG) for 13 days, 120% TDG for 8 h, or 130% TDG for 3.5 h. We subjected exposed and unexposed control fish simultaneously to predation by northern squawfish (Ptychocheilus oregonensis) in water of normal gas saturation in 6, 18, and 10 tests using prey exposed to 112, 120, and 130% TDG, respectively. Only fish exposed to 130% TDG showed a significant increase in vulnerability to predation. The signs of GBT exhibited by fish sampled just prior to predator exposure were generally more severe in fish exposed to 130% TDG, which had the most extensive occlusion of the lateral line and gill filaments with gas emboli. Fish exposed to 112% TDG had the most severe signs of GBT in the fins. Our results suggest that fish showing GBT signs similar to those of our fish exposed to 130% TDG, regardless of their precise exposure history, may be more vulnerable to predation.

  14. Physiological and molecular ontogeny of branchial and extra-branchial urea excretion in posthatch rainbow trout (Oncorhynchus mykiss).

    PubMed

    Zimmer, Alex M; Wood, Chris M

    2016-02-01

    All teleost fish produce ammonia as a metabolic waste product. In embryos, ammonia excretion is limited by the chorion, and fish must detoxify ammonia by synthesizing urea via the ornithine urea cycle (OUC). Although urea is produced by embryos and larvae, urea excretion (J(urea)) is typically low until yolk sac absorption, increasing thereafter. The aim of this study was to determine the physiological and molecular characteristics of J(urea) by posthatch rainbow trout (Oncorhynchus mykiss). Following hatch, whole body urea concentration decreased over time, while J(urea) increased following yolk sac absorption. From 12 to 40 days posthatch (dph), extra-branchial routes of excretion accounted for the majority of J(urea), while the gills became the dominant site for J(urea) only after 55 dph. This represents the most delayed branchial ontogeny of any process studied to date. Urea transporter (UT) gene expression in the gills and skin increased over development, consistent with increases in branchial and extra-branchial J(urea). Following exposure to 25 mmol/l urea, the accumulation and subsequent elimination of exogenous urea was much greater at 55 dph than 12 dph, consistent with increased UT expression. Notably, UT gene expression in the gills of 55 dph larvae increased in response to high urea. In summary, there is a clear increase in urea transport capacity over posthatch development, despite a decrease in OUC activity.

  15. How much does inbreeding contribute to the reduced fitness of hatchery-born steelhead (Oncorhynchus mykiss) in the wild?

    PubMed

    Christie, Mark R; French, Rod A; Marine, Melanie L; Blouin, Michael S

    2014-01-01

    Many declining populations are supplemented with captive-born individuals that are released directly into the wild. Because captive-born individuals can have lower fitness in the wild than their wild-born counterparts, a comprehensive understanding of the mechanisms responsible for the reduced fitness of these individuals is required for appropriate conservation and management decisions. Inbreeding among captive-born individuals is one plausible mechanism because captive breeding programs frequently use small numbers of breeders to create large numbers of siblings that are subsequently released together into the wild. We tested this hypothesis in a supplementation program for steelhead (Oncorhynchus mykiss) from the Hood River, Oregon, for which first-generation hatchery fish were demonstrated to have lower fitness in the wild than their wild-born counterparts. To determine the contribution of inbreeding to this fitness decline, we first assigned 11 run-years of hatchery steelhead (3005 fish) back to their broodstock parents (462 fish) using 8 polymorphic microsatellite loci. By combining pedigree analyses with species-specific estimates of genetic load, we found that inbreeding could at most account for a 1-4% reduction in the fitness of hatchery fish relative to wild fish. Thus, inbreeding alone cannot adequately explain the 15% average fitness decline observed in first-generation hatchery fish from this population.

  16. Topographical Mapping of the Rainbow Trout (Oncorhynchus mykiss) Microbiome Reveals a Diverse Bacterial Community with Antifungal Properties in the Skin.

    PubMed

    Lowrey, Liam; Woodhams, Douglas C; Tacchi, Luca; Salinas, Irene

    2015-10-01

    The mucosal surfaces of wild and farmed aquatic vertebrates face the threat of many aquatic pathogens, including fungi. These surfaces are colonized by diverse symbiotic bacterial communities that may contribute to fight infection. Whereas the gut microbiome of teleosts has been extensively studied using pyrosequencing, this tool has rarely been employed to study the compositions of the bacterial communities present on other teleost mucosal surfaces. Here we provide a topographical map of the mucosal microbiome of an aquatic vertebrate, the rainbow trout (Oncorhynchus mykiss). Using 16S rRNA pyrosequencing, we revealed novel bacterial diversity at each of the five body sites sampled and showed that body site is a strong predictor of community composition. The skin exhibited the highest diversity, followed by the olfactory organ, gills, and gut. Flectobacillus was highly represented within skin and gill communities. Principal coordinate analysis and plots revealed clustering of external sites apart from internal sites. A highly diverse community was present within the epithelium, as demonstrated by confocal microscopy and pyrosequencing. Using in vitro assays, we demonstrated that two Arthrobacter sp. skin isolates, a Psychrobacter sp. strain, and a combined skin aerobic bacterial sample inhibit the growth of Saprolegnia australis and Mucor hiemalis, two important aquatic fungal pathogens. These results underscore the importance of symbiotic bacterial communities of fish and their potential role for the control of aquatic fungal diseases. PMID:26209676

  17. Short-term responses of selected endocrine parameters in juvenile rainbow trout (Oncorhynchus mykiss) exposed to 4-nonylphenol.

    PubMed

    Naderi, Mohammad; Zargham, Davood; Asadi, Asad; Bashti, Tayebeh; Kamayi, Kianoosh

    2015-12-01

    The synthetic organic compound 4-nonylphenol (4-NP) has been shown to have a wide range of adverse effects on the endocrine system of various animals including fish. The present study evaluated the potential effects of 4-NP on vitellogenin (VTG) synthesis, steroid, and thyroid hormone concentrations in both juvenile male and female rainbow trout (Oncorhynchus mykiss). Fish were exposed by intraperitoneal injection to different doses of 4-NP (1, 10, 50, and 100 μg g(-1)) or vehicle (coconut oil) over a period of 14 days. Blood samples were collected 7 and 14 days after initiation of treatment. Plasma VTG levels in 4-NP-treated fish were detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis as a high molecular weight protein band of 180 KDa. In addition, plasma VTG concentrations were quantified indirectly using plasma alkali-labile phosphate (ALP) and plasma calcium. Both ALP and calcium levels in plasma showed similar and parallel increase patterns after exposure to 4-NP that were significantly higher compared with controls. The analysis of plasma sex steroid levels revealed a significant increase in 17β-estradiol and testosterone in plasma of juvenile males and females, respectively. Furthermore, a significant increase was observed in plasma cortisol levels. On the other hand, 4-NP decreased both plasma triiodothyronine and thyroxine after 7 and 14 days of treatment. These results suggest that 4-NP can affect different parts of the endocrine system, which may lead to serious impairments in physiological homeostasis of juvenile rainbow trout.

  18. Rapid growth in the early marine period improves the marine survival of Chinook salmon (Oncorhynchus tshawytscha) in Puget Sound, Washington

    USGS Publications Warehouse

    Duffy, Elisabeth J.; Beauchamp, David A.

    2011-01-01

    We examined the effect of early marine entry timing and body size on the marine (smolt-to-adult) survival of Puget Sound Chinook salmon (Oncorhynchus tshawytscha). We used data from coded wire tag release groups of hatchery Chinook salmon to test whether hatchery release date, release size, and size in offshore waters in July and September influenced marine survival. Marine survival was most strongly related to the average body size in July, with larger sizes associated with higher survivals. This relationship was consistent over multiple years (1997–2002), suggesting that mortality after July is strongly size-dependent. Release size and date only slightly improved this relationship, whereas size in September showed little relationship to marine survival. Specifically, fish that experienced the highest marine survivals were released before 25 May and were larger than 17 g (or 120 mm fork length) by July. Our findings highlight the importance of local conditions in Puget Sound (Washington, USA) during the spring and summer, and suggest that declines in marine survival since the 1980s may have been caused by reductions in the quality of feeding and growing conditions during early marine life.

  19. Rapid growth in the early marine period improves the marine survival of Chinook salmon (Oncorhynchus tshawytscha) in Puget Sound, Washington

    USGS Publications Warehouse

    Duffy, E.J.; Beauchamp, D.A.

    2011-01-01

    We examined the effect of early marine entry timing and body size on the marine (smolt-to-adult) survival of Puget Sound Chinook salmon (Oncorhynchus tshawytscha). We used data from coded wire tag release groups of hatchery Chinook salmon to test whether hatchery release date, release size, and size in offshore waters in July and September influenced marine survival. Marine survival was most strongly related to the average body size in July, with larger sizes associated with higher survivals. This relationship was consistent over multiple years (1997-2002), suggesting that mortality after July is strongly size-dependent. Release size and date only slightly improved this relationship, whereas size in September showed little relationship to marine survival. Specifically, fish that experienced the highest marine survivals were released before 25 May and were larger than 17 g (or 120 mm fork length) by July. Our findings highlight the importance of local conditions in Puget Sound (Washington, USA) during the spring and summer, and suggest that declines in marine survival since the 1980s may have been caused by reductions in the quality of feeding and growing conditions during early marine life.

  20. Isolation and identification of viral hemorrhagic septicemia virus (VHSV) from farmed rainbow trout (Oncorhynchus mykiss) in Iran.

    PubMed

    Ahmadivand, Sohrab; Soltani, Mehdi; Mardani, Karim; Shokrpoor, Sara; Rahmati-Holasoo, Hooman; Mokhtari, Abbas; Hasanzadeh, Reza

    2016-04-01

    Viral hemorrhagic septicemia virus (VHSV) is a rhabdovirus that causes one of the most important fish diseases in rainbow trout (Oncorhynchus mykiss) production industry. During the present study from October 2014 to July 2015, the virus causing viral hemorrhagic septicemia (VHS) was isolated and identified in rainbow trout farms from five of sixteen farms experiencing mass mortalities in six provinces of Iran with major trout production. Cumulative mortalities at VHSV-positive farms ranged from 30 to 70%. Clinical signs of disease included exophthalmia, petechial hemorrhages in the mandible and around the eyes, a swollen abdomen and darkening of the integument, widespread petechiae of the musculature and pyloric regions, severe congestion of the kidney, and pale enlarged livers. In addition, histopathologic examinations of tissues showed severe lesions in muscle, kidney and liver, which were compatible with those already described for VHS. Furthermore, homogenates tissues of diseased fish induced cytopathic effects (CPE) in CHSE-214 cells, and confirmatory diagnosis of VHS was made by RT-PCR reactions. To our knowledge, this is the first report of isolation and identification of VHSV from farmed trout in Iran, which may have originated from Europe.