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Sample records for oncorhynchus mykiss absorption

  1. Dynamics of 17alpha-ethynylestradiol exposure in rainbow trout (Oncorhynchus mykiss): absorption, tissue distribution, and hepatic gene expression pattern.

    PubMed

    Skillman, Ann D; Nagler, James J; Hook, Sharon E; Small, Jack A; Schultz, Irvin R

    2006-11-01

    17alpha-Ethynylestradiol (EE2) is a synthetic estrogen identified in sewage effluents. To understand better the absorption kinetics of EE2 and the induction of vitellogenin (VTG) and estrogen receptor alpha (ERalpha) mRNA, we subjected male rainbow trout (Onchorynchus mykiss) to continuous water exposures of 125 ng/L of EE2 for up to 61 d. Trout were either repetitively sampled for blood plasma or serially killed at selected time intervals. Vitellogenin, ERalpha mRNA, and EE2 were measured using enzyme-linked immunosorbent assay and using quantitative polymerase chain reaction and gas chromatography-mass spectrometry, respectively. In separate experiments, trout were exposed to EE2 for 7 d, and hepatic gene expression was assessed using a low- and high-density cDNA microarray. The EE2 was rapidly absorbed by the trout, with an apparent equilibrium at 16 h in plasma and liver. The ERalpha mRNA levels also increased rapidly, reaching near-peak levels by 48 h. In contrast, plasma levels of VTG continuously increased for 19 d. After 61 d, tissues with the highest levels of VTG were the liver, kidney, and testes. Microarray-based gene expression studies provided unexpected results. In some cases, known estrogen-responsive genes (e.g., ERalpha) were unresponsive, whereas many of the genes that have no apparent link to estrogen function or EE2 toxicity were significantly altered in expression. Of the two microarray approaches tested in the present study, the high-density array appeared to be superior because of the improved quality of the hybridization signal and the robustness of the response in terms of the number of genes identified as being EE2 responsive.

  2. 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.

  3. 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...

  4. Ibuprofen metabolism in the liver and gill of rainbow trout, Oncorhynchus mykiss.

    PubMed

    Gomez, C F; Constantine, L; Moen, M; Vaz, A; Wang, W; Huggett, Duane B

    2011-03-01

    The presence of pharmaceuticals in the environment has become an important topic of discussion with respect to pharmaceutical absorption, metabolism and elimination in fish. This study investigates the metabolism of ibuprofen by rainbow trout (Oncorhynchus mykiss). In vitro metabolic loss of parent compound was measured in gill and liver S9 and microsomal fractions. Metabolite analysis found 2-hydroxy-ibuprofen as the major metabolite in uninduced S9 fractions. Supplementing S9 fractions with UDPGA did not significantly enhance metabolism. Additionally, assays involving the induction and inhibition of specific CYP isozymes support CYP1A2 as a possible metabolic pathway in fish.

  5. 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.

  6. Magnetic Discrimination Learning in Rainbow Trout (Oncorhynchus mykiss)

    NASA Astrophysics Data System (ADS)

    Haugh, Cordula V.; Walker, Michael M.

    Although conditioning techniques are the most powerful way to study behavioural responses by animals to external stimuli, the magnetic sense has proved surprisingly resistant to conditioning approaches. This study demonstrated learned discrimination of magnetic field intensity stimuli by a new species, the rainbow trout (Oncorhynchus mykiss). In a unitary conditioned discrimination technique, four juvenile rainbow trout were trained to strike a target at the end of a response bar in anticipation of food. In successive experiments, the trout failed to discriminate the presence and absence of a vibration stimulus, but subsequently learned to discriminate the presence and absence of a magnetic field intensity anomaly (peak intensity of 75 μTesla). The authors conclude that the necessary conditions for training animals to magnetic intensity are the use of spatially distinctive stimuli and of a conditioned response that requires movement.

  7. Hematological, biochemical, and behavioral responses of Oncorhynchus mykiss to dimethoate.

    PubMed

    Dogan, Demet; Can, Canan

    2011-12-01

    The effects of dimethoate on hematological, biochemical parameters, and behavior were investigated in Oncorhynchus mykiss exposed to sublethal concentrations of 0.0735, 0.3675, and 0.7350 mg/l for 5, 15, and 30 days. Significant decrease was determined in erythrocyte and leukocyte counts, hemoglobin, hematocrit, MCV, and MCH, which was pronounced after prolonged exposure indicating the appearance of microcytic hypochromic anemia. There were no prominent changes in thrombocyte and MCHC. The glucose concentration showed an ascending pattern that proved to be positively correlated with duration. The protein concentration declined in higher dimethoate concentrations following 15 and 30 days. Negative and significant correlation was detected between glucose and protein concentrations. The fish showed remarkable behavioral abnormality such as loss of balance, erratic swimming, and convulsion. Present findings revealed that dimethoate exerts its toxic action even in sublethal concentrations and hematological parameters and abnormal behavior may be sensitive indicators to evaluate pesticide intoxication.

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

    PubMed

    Evenhuis, Jason P; LaFrentz, Benjamin R

    2016-08-09

    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.

  9. 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.

  10. Differences in IgY gut absorption in gastric rainbow trout (Oncorhynchus mykiss) and agastric common carp (Cyprinus carpio) assessed in vivo and in vitro.

    PubMed

    Winkelbach, Anja; Günzel, Dorothee; Schulz, Carsten; Wuertz, Sven

    2015-01-01

    Oral IgY antibodies offer promising potential for passive immunization strategies. To evaluate barriers for successful IgY plasma recovery after oral application in vivo, gastric rainbow trout and agastric common carp were comparatively assessed. A positive control that received a low dose of unspecific IgY antibodies by intraperitoneal injection (0.0076 mg IgY g BW(-1) d(-1); BW=body mass) was compared with an oral administration of 75 and 150 fold in rainbow trout (corresponding to 0.57 and 1.14 mg g BW(-1)) and in carp (0.57 mg g BW(-1)). Dietary antibodies were delivered with the antacid sodium bicarbonate and three different putative uptake enhancers (Tween 20, vitamin E TPGS, sodium deoxycholate). IgY concentrations in the plasma were determined 1d (rainbow trout) or 5d after last feeding (both species). Irrespective of the enhancer used, ELISA revealed IgY absorption after feeding in carp, whereas IgY concentration in rainbow trout remained below the detection threshold. Intraperitoneal injections revealed IgY in plasma of both species. In vitro Ussing chamber experiments with posterior intestine tissue of carp and trout were carried out to determine whether species-specific differences in IgY translocation were due to acidic stomach passage or species-specific differences in transepithelial IgY passage. Significantly higher IgY translocation was measured in carp at high application dosage compared to all other groups, indicating that species-specific differences in IgY uptake after oral administration are not only related to peptic IgY degradation in the stomach, but also likely a result of differences in IgY transcytosis in the posterior intestine.

  11. 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...

  12. Growth enhancement of rainbow trout (Oncorhynchus mykiss) by passive immunisation against somatostatin-14

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile rainbow trout (Oncorhynchus mykiss) were passively immunised against somatostatin-14 (SS-14) using an antibody originating from egg laying chicken (Gallus domesticus). Fish were immunised weekly (0, 7, 14, 21, 28, 35 d) with chicken egg yolk derived immunoglobulin (IgY) against SS-14 (1:25 ...

  13. Fatty acid partitioning varies across fillet regions during sexual maturation in female rainbow trout (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rainbow trout (Oncorhynchus mykiss) are commonly reared as diploids (2N, two sets of chromosomes) or triploids (3N, three sets of chromosomes). Sexual maturation in 2N has negative effects on production efficiency, nutrient retention, and fillet quality. On the other hand, 3N female rainbow trout ...

  14. 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...

  15. 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...

  16. 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...

  17. 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

  18. Diagnostic single nucleotide polymorphisms for identifying westslope cutthroat trout (Oncorhynchus clarki lewisi), Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) and rainbow trout (Oncorhynchus mykiss).

    PubMed

    Kalinowski, S T; Novak, B J; Drinan, D P; Jennings, R deM; Vu, N V

    2011-03-01

    We describe 12 diagnostic single nucleotide polymorphism (SNP) assays for use in species identification among rainbow and cutthroat trout: five of these loci have alleles unique to rainbow trout (Oncorhynchus mykiss), three unique to westslope cutthroat trout (O. clarkii lewisi) and four unique to Yellowstone cutthroat trout (O. clarkii bouvieri). These diagnostic assays were identified using a total of 489 individuals from 26 populations and five fish hatchery strains.

  19. 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.

  20. Using scale characteristics and water temperature to reconstruct growth rates of juvenile steelhead Oncorhynchus mykiss.

    PubMed

    Beakes, M P; Sharron, S; Charish, R; Moore, J W; Satterthwaite, W H; Sturm, E; Wells, B K; Sogard, S M; Mangel, M

    2014-01-01

    Juvenile steelhead Oncorhynchus mykiss from a northern California Central Valley population were reared in a controlled laboratory experiment. Significantly different rates of growth were observed among fish reared under two ration treatments and three temperature treatments (8, 14 and 20°C). Wider circulus spacing and faster deposition was associated with faster growth. For the same growth rate, however, circulus spacing was two-fold wider and deposited 36% less frequently in the cold compared to the hot temperature treatment. In a multiple linear regression, median circulus spacing and water temperature accounted for 68% of the variation in observed O. mykiss growth. These results corroborate previous research on scale characteristics and growth, while providing novel evidence that highlights the importance of water temperature in these relationships. Thus, this study establishes the utility of using scale analysis as a relatively non-invasive method for inferring growth in salmonids.

  1. Functional characterization of a BCL10 isoform in the rainbow trout Oncorhynchus mykiss

    PubMed Central

    Mazzone, Pellegrino; Scudiero, Ivan; Coccia, Elena; Ferravante, Angela; Paolucci, Marina; D’Andrea, Egildo Luca; Varricchio, Ettore; Pizzulo, Maddalena; Reale, Carla; Zotti, Tiziana; Vito, Pasquale; Stilo, Romania

    2015-01-01

    The complexes formed by BCL10, MALT1 and members of the family of CARMA proteins have recently been the focus of much attention because they represent a key mechanism for regulating activation of the transcription factor NF-κB. Here, we report the functional characterization of a novel isoform of BCL10 in the trout Oncorhynchus mykiss, which we named tBCL10. tBCL10 dimerizes, binds to components of the CBM complex and forms cytoplasmic filaments. Functionally, tBCL10 activates NF-κB transcription factor and is inhibited by the deubiquitinating enzyme A20. Finally, depletion experiments indicate that tBCL10 can functionally replace the human protein. This work demonstrates the evolutionary conservation of the mechanism of NF-κB activation through the CBM complex, and indicates that the rainbow trout O.mykiss can serve as a model organism to study this pathway. PMID:25834783

  2. Functional characterization of a BCL10 isoform in the rainbow trout Oncorhynchus mykiss.

    PubMed

    Mazzone, Pellegrino; Scudiero, Ivan; Coccia, Elena; Ferravante, Angela; Paolucci, Marina; D'Andrea, Egildo Luca; Varricchio, Ettore; Pizzulo, Maddalena; Reale, Carla; Zotti, Tiziana; Vito, Pasquale; Stilo, Romania

    2015-01-01

    The complexes formed by BCL10, MALT1 and members of the family of CARMA proteins have recently been the focus of much attention because they represent a key mechanism for regulating activation of the transcription factor NF-κB. Here, we report the functional characterization of a novel isoform of BCL10 in the trout Oncorhynchus mykiss, which we named tBCL10. tBCL10 dimerizes, binds to components of the CBM complex and forms cytoplasmic filaments. Functionally, tBCL10 activates NF-κB transcription factor and is inhibited by the deubiquitinating enzyme A20. Finally, depletion experiments indicate that tBCL10 can functionally replace the human protein. This work demonstrates the evolutionary conservation of the mechanism of NF-κB activation through the CBM complex, and indicates that the rainbow trout O . mykiss can serve as a model organism to study this pathway.

  3. Histopathological findings in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with 3 different Aeromonas species.

    PubMed

    Zepeda-Velázquez, Andrea Paloma; Vega-Sánchez, Vicente; Salgado-Miranda, Celene; Soriano-Vargas, Edgardo

    2015-07-01

    This study describes the macroscopic and microscopic lesions in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with genetically identified Aeromonas salmonicida, A. hydrophila, and A. veronii species. The genus Aeromonas includes bacteria that naturally inhabit both waterways and organisms. At least 27 Aeromonas species have been identified to date, some of which can cause significant economic losses in aquaculture. As up to 68.8% of Aeromonas isolates may be misidentified in routine biochemical and phenotypic tests, however, reported cases of Aeromonas infection in fish may be wrongly identified. Our findings confirmed that the 3 Aeromonas species studied are associated with septicemia and dermal lesions in rainbow trout.

  4. Histopathological findings in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with 3 different Aeromonas species

    PubMed Central

    Zepeda-Velázquez, Andrea Paloma; Vega-Sánchez, Vicente; Salgado-Miranda, Celene; Soriano-Vargas, Edgardo

    2015-01-01

    This study describes the macroscopic and microscopic lesions in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with genetically identified Aeromonas salmonicida, A. hydrophila, and A. veronii species. The genus Aeromonas includes bacteria that naturally inhabit both waterways and organisms. At least 27 Aeromonas species have been identified to date, some of which can cause significant economic losses in aquaculture. As up to 68.8% of Aeromonas isolates may be misidentified in routine biochemical and phenotypic tests, however, reported cases of Aeromonas infection in fish may be wrongly identified. Our findings confirmed that the 3 Aeromonas species studied are associated with septicemia and dermal lesions in rainbow trout. PMID:26130859

  5. 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.

  6. Enhancing highly unsaturated omega-3 fatty acids in phase-fed rainbow trout (Oncorhynchus mykiss) using Alaskan fish oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to investigate differences in the kinetics of fatty acids (FA) deposition in fillets of market-sized (approximately 450g) rainbow trout (Oncorhynchus mykiss) fed diets containing commercial Alaskan fish oils versus menhaden oil. Comparisons were made with FA leve...

  7. 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...

  8. 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...

  9. 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 ...

  10. Effects of triploidy on growth and protein degradation during the recovery from feed deprivation in rainbow trout (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identifying physiological differences between diploid and triploid rainbow trout will help define how ploidy affects mechanisms that impact growth and nutrient utilization. In this study juvenile diploid and triploid female rainbow trout (Oncorhynchus mykiss) were either continually fed or fasted f...

  11. 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...

  12. 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...

  13. 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...

  14. 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 ...

  15. 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...

  16. 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.

  17. Effects of elevated dietary iron on the gastrointestinal expression of Nramp genes and iron homeostasis in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Kwong, Raymond W M; Hamilton, Charmain D; Niyogi, Som

    2013-04-01

    Diet is the primary source of iron (Fe) for freshwater fish, and the absorption of Fe is believed to occur via the Nramp family of divalent metal transporters (also called DMT1). Presently, the homeostatic regulation of dietary Fe absorption in fish is poorly understood. This study examined the gastrointestinal mRNA expression of two Nramp isoforms, Nramp-β and Nramp-γ, in the freshwater rainbow trout (Oncorhynchus mykiss), following exposure to elevated dietary Fe [1,256 mg Fe/kg food vs. 136 mg Fe/kg food (control)] for 14 days. The physiological performance, plasma Fe status and tissue-specific accumulation of Fe were also evaluated. In general, the mRNA expression level of Nramp was higher in the intestine relative to the stomach. Interestingly, fish fed on a high-Fe diet exhibited a significant induction in Nramp expression after 7 days, followed by a decrease to the level observed in control fish on day 14. The increase in Nramp expression correlated with the elevated gastrointestinal and plasma Fe concentrations. However, the hepatic Fe concentration remained unchanged during the entire exposure period, indicating strong homeostatic regulation of hepatic Fe level in fish. Fish appeared to handle increased systemic Fe level by elevating the plasma transferrin level, thereby enhancing the Fe-binding capacity in the plasma. Overall, our study provides new interesting insights into the homeostatic regulation of dietary Fe uptake and handling in freshwater fish.

  18. Physiological and molecular ontogeny of branchial and extra-branchial urea excretion in posthatch rainbow trout (Oncorhynchus mykiss)

    PubMed Central

    Wood, Chris M.

    2015-01-01

    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 (Jurea) is typically low until yolk sac absorption, increasing thereafter. The aim of this study was to determine the physiological and molecular characteristics of Jurea by posthatch rainbow trout (Oncorhynchus mykiss). Following hatch, whole body urea concentration decreased over time, while Jurea increased following yolk sac absorption. From 12 to 40 days posthatch (dph), extra-branchial routes of excretion accounted for the majority of Jurea, while the gills became the dominant site for Jurea 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 Jurea. 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. PMID:26608657

  19. 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.

  20. 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.

  1. 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.

  2. Avoidance response of rainbow trout Oncorhynchus mykiss to hexavalent chromium solutions.

    PubMed

    Svecevicius, Gintaras

    2007-12-01

    Laboratory tests were conducted on one-year-old rainbow trout Oncorhynchus mykiss to evaluate their ability to detect and avoid hexavalent chromium (Cr(6+)). Test fish were given a choice to discriminate between clean water and Cr(6+) solutions of six sublethal concentrations ranging from 0.0015 to 0.3 mg Cr/L in a counter-current flow, steep gradient chamber. The intensity of avoidance response reached a significant level at test concentrations of 0.003 mg Cr/L and higher, and was directly proportional to the Cr(6+) concentration logarithm. Avoidance threshold was estimated through regression analysis and to be 0.0017 mg Cr/L. This result is approximately sixfold lower than maximum-permitted concentration of 0.01 mg Cr/L accepted as the Lithuanian water-quality guideline for the protection of aquatic life.

  3. Use of behavioral responses of rainbow trout Oncorhynchus mykiss in identifying sublethal exposure to hexavalent chromium.

    PubMed

    Svecevicius, Gintaras

    2009-05-01

    Laboratory tests were conducted in a flow-through apparatus on 1-year-old rainbow trout Oncorhynchus mykiss to evaluate the sensitivity of a number of their behavioral responses to hexavalent chromium (Cr(6+)). Test fish were exposed to Cr(6+) concentrations corresponding to 0.001-1 parts of the rainbow trout 96-h LC50 (0.029-28.5 mg Cr/L, respectively) in short-term (15 min) tests. Sensitivity parameter responses could be arranged into the following sequence: latent period of detection response = locomotor activity > gill ventilation frequency > coughing rate. All the rainbow trout responses were sensitive behavioral indicators of sublethal exposure. Behavioral responses meet the criteria as rapid tools for bioassay testing and could be easily standardized using Cr(6+) as a reference toxicant.

  4. Avoidance of copper and zinc by rainbow trout Oncorhynchus mykiss pre-exposed to copper.

    PubMed

    Svecevičius, Gintaras

    2012-01-01

    Laboratory tests were conducted on 1-year-old rainbow trout Oncorhynchus mykiss in a counter-current flow, steep-gradient chamber to evaluate their ability to detect and avoid copper and zinc at concentrations of 0.1 mg Cu/L and 1 mg Zn/L, respectively, after 10-day pre-exposure to five copper sublethal concentrations ranging from 0.1 to 0.5 mg Cu/L and after 10-day re-acclimation period in clean water. Avoidance response intensity in affected fish significantly decreased with increase in pre-exposure Cu concentration. The strength of avoidance response to Cu and Zn test solutions in pre-exposed fish after re-acclimation gradually increased in a concentration-dependent order.

  5. Fast genomic biomarker responses of retene and pyrene in liver of juvenile rainbow trout, Oncorhynchus mykiss.

    PubMed

    Räsänen, Kati; Arsiola, Tiina; Oikari, Aimo

    2012-10-01

    We studied the transcriptive effects of two PAHs, retene (RET) and pyrene (PYR), in three equimolar sublethal concentrations (0.9-10 μg/L) in the liver of juvenile rainbow trout, Oncorhynchus mykiss. After 24 h of in vivo exposure, expressions of selected genes (CYP1A, Hsp30, Hsp70, Grp78, Sep15, GP1) were analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). These PAHs changed the studied gene transcriptions differently, but not significantly, except for CYP1A, which was induced only by RET. RET induced CYP1A gene expression even at low, environmentally realistic concentrations in the liver of juvenile rainbow trout.

  6. 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.

  7. 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.

  8. Effects of some pesticides on the vital organs of juvenile rainbow trout (Oncorhynchus mykiss).

    PubMed

    Capkin, Erol; Terzi, Ertugrul; Boran, Halis; Yandi, Ilhan; Altinok, Ilhan

    2010-12-01

    Gill, trunk kidney, spleen, and liver of rainbow trout (Oncorhynchus mykiss) were examined after exposure to different sublethal concentrations of carbosulfan (25, 50 and 200 μgL(-1)), propineb (3, 6 and 24 mgL(-1)), and benomyl (2, 5 and 20 mgL(-1)) for 14 days. Lesions were observed in gill, trunk kidney, spleen, and liver of rainbow trout exposed to either concentration of pesticides. The most important lesions were determined in the highest concentrations of pesticides. Lamellar fusion, lamellar hyperplasia, epithelial lifting, vacuolization of epithelial tissue, epithelial necrosis, hypertrophy and sloughing of epithelium were observed on fish exposed to carbosulfan, propineb and benomyl. Fish had cell necrosis, degeneration and oedemas in liver, trunk kidney and spleen. None of these lesions were seen in control fish.

  9. 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.

  10. Detection of viruses in farmed rainbow trout (Oncorhynchus mykiss) in Korea by RT-LAMP assay.

    PubMed

    Suebsing, Rungkarn; Kim, Jeong-Ho; Kim, Seok Ryel; Park, Myung-Ae; Oh, Myung-Joo

    2011-10-01

    The viral diseases have been the serious problem in salmonid farming, and rainbow trout is not an exception. In this study, routine surveys were conducted for detecting of viruses in farmed rainbow trout (Oncorhynchus mykiss) in Korea during 2009-2010. Head kidneys from individual fish were employed for virus detection by using a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay. Infectious pancreatic necrosis virus (IPNV), infectious hematopoietic necrosis virus (IHNV), and viral hemorrhagic septicemia virus (VHSV) were the target viruses in this study. 53.5% (46/86) were found to be IPNV-positive, while IHNV and VHSV showed RT-LAMP negative during examination for 2 years. Ten IPNV-positive samples were randomly selected for viral isolation and the cells showing CPEs were subjected to RT-LAMP, RT-PCR, and direct sequencing. Phylogenetic analysis showed that the rainbow trout isolate has high similarity homologies with the VR-299 strain, as previously described.

  11. Rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) 7-day survival and growth test method.

    PubMed

    Lazorchak, James M; Smith, Mark E

    2007-10-01

    A short-term method was developed in this study for conducting subchronic survival and growth renewal toxicity tests with rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis). Previously published early life-stage methods for various salmonid species involve test durations of 30 to 90 days. This trout method, however, follows a previously published 7-day fathead minnow (Pimephales promelas) growth method. The tests performed in this study measured subchronic growth and survival effects using standard reference toxicants (ammonium chloride, potassium chloride, phenol, and zinc sulfate), receiving water, and effluent samples. The test results were compared with performance criteria and results for 7-day survival and growth tests with P. promelas to determine the level of comparability between the two species. The results from tests with both salmonid species indicated that this 7-day survival and growth test method using O. mykiss and S. fontinalis provides reproducible results with various reference toxicant materials and can be used successfully to detect potential toxicity in environmental samples.

  12. 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.

  13. 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

  14. [Sex identification of the rainbow trout Oncorhynchus mykiss by polymerase chain reaction].

    PubMed

    Rud, Yu P; Maistrenko, M I; Buchatskii, L P

    2015-01-01

    A polymerase chain reaction-based test for rapid sex identification of the rainbow trout Oncorhynchus mykiss has been elaborated. Using the data deposited with the NCBI genome bank, nucleotide sequences of the specific sex-linked locus of salmonid species have been analyzed and the oligonucleotide primers have been selected. The length of the amplification products is 800 nucleotide pairs. Amplification specificity has been tested by nucleotide analysis of the amplicon sequences. All PCR products match the Y chromosome region housing the corresponding specific locus. A comparative analysis of the nucleotide sequences of the fragments carrying the rainbow trout (and other salmonid species) sex-linked marker demonstrates a high degree of identity, amounting to 95-99%. The maximal identity between the sequences (99%) is observed when analyzing representatives of the same genus, for example, Oncorhynchus. Thus, the sex is detectable by a simple PCR test, thereby allowing the male revertants emerging via hormonal sex reversion to be identified. This test is a rapid diagnostic method, since it requires only 1 day for testing and informing the fish farm on its results. Results of abdomen opening of rainbow trout revertants and examination of their hormonal status are also described.

  15. Sympathetic, parasympathetic and enteric regulation of the gastrointestinal vasculature in rainbow trout (Oncorhynchus mykiss) under normal and postprandial conditions.

    PubMed

    Seth, Henrik; Axelsson, Michael

    2010-09-15

    The control of the gastrointestinal hyperemia that occurs after feeding in most animals is of fundamental importance for the subsequent absorption, metabolism and redistribution of nutrients. Yet, in fish, it has received little attention and the nature of it is far from clear. We sought to investigate the importance of extrinsic and intrinsic innervation of the gastrointestinal tract in the regulation of gastrointestinal blood flow in rainbow trout (Oncorhynchus mykiss). The contribution of the extrinsic innervation, i.e. by the sympathetic and the parasympathetic nervous system, was examined by comparing the response to the injection of a predigested nutrient diet into the proximal intestine of untreated fish with the response in fish in which the splanchnic and vagal innervation of the gut had been removed. We also injected the predigested nutrient diet into anaesthetized fish treated with tetrodotoxin that would block the intrinsic innervation of the gut (i.e. enteric nervous system). Our results confirm the notion that the sympathetic portion of the extrinsic innervation maintains the basal vascular tone, but neither the splanchnic nor the vagal innervation is fundamental to the postprandial hyperemia. However, the tetrodotoxin treatment completely abolished the postprandial hyperemia, indicating the importance of the enteric nervous system. In conclusion, it seems as though the enteric nervous system is essential to the regulation of the postprandial hyperemia, and that the extrinsic innervation is involved mainly in the regulation of gastrointestinal blood flow under normal conditions and in response to central coordination with other organs.

  16. Sperm metabolism of the telost fishes Chalcalburnus chalcoides and Oncorhynchus mykiss and its relation to motility and viability.

    PubMed

    Lahnsteiner, F; Berger, B; Weismann, T

    1999-09-01

    In the teleost fish Chalcalburnus chalcoides (Cyprinidae) the influence of metabolic inhibitors, substrates, coenzymes, and oxygen concentrations on spermatozoal parameters during motility and during immotile incubation was studied, the respiration rate was characterized, representative metabolite levels were measured, and the results were compared with Oncorhynchus mykiss (Salmonidae). In Chalcalburnus chalcoides the sperm motility rate, the average path swimming velocity, the motility duration, and the viability of immotile semen were significantly reduced in the presence of inhibitors of respiration (potassium cyanide, 2.4-dinitrophenol, atractyloside). Anaerobic conditions (<1 mg O(2)/liter) and inhibition of the tricarboxylic acid cycle by malonate and >7.5 mmol/liter succinate had similar effects on the sperm motility parameters and on the viability of immotile spermatozoa. Pyruvate and coenzyme A (an acyl-group carrier during oxidative carboxylation of pyruvate) prolonged the duration of sperm motility and the viability of immotile incubated spermatozoa, and also increased the spermatozoal respiration rate. Glucose levels significantly decreased during motility and during immotile storage and, under anaerobic conditions, the levels of lactate increased indicating that pyruvate derived from glycolysis. The respiration rate and the glycolytic rate significantly increased during motility. Therefore oxidative phosphorylation, tricarboxylic acid cycle, and aerobic glycolysis are central energy-supplying pathways for spermatozoa of Chalcalburnus chalcoides. The stimulatory effect of pyruvate and coenzyme A indicated that glycolysis is a rate-controlling pathway. Similar results were obtained for Oncorhynchus mykiss with the only exception that the stimulatory effect of coenzyme A was more significant than the stimulatory effect of pyruvate. When the sperm motility-activating saline solutions were optimized in aspects of energy supply, ionic composition, and

  17. Molecular characterization of a novel orthomyxovirus from rainbow and steelhead trout (Oncorhynchus mykiss).

    PubMed

    Batts, William N; LaPatra, Scott E; Katona, Ryan; Leis, Eric; Ng, Terry Fei Fan; Brieuc, Marine S O; Breyta, Rachel B; Purcell, Maureen K; Conway, Carla M; Waltzek, Thomas B; Delwart, Eric; Winton, James R

    2017-02-15

    A novel virus, rainbow trout orthomyxovirus (RbtOV), was isolated in 1997 and again in 2000 from commercially-reared rainbow trout (Oncorhynchus mykiss) in Idaho, USA. The virus grew optimally in the CHSE-214 cell line at 15°C producing a diffuse cytopathic effect; however, juvenile rainbow trout exposed to cell culture-grown virus showed no mortality or gross pathology. Electron microscopy of preparations from infected cell cultures revealed the presence of typical orthomyxovirus particles. The complete genome of RbtOV is comprised of eight linear segments of single-stranded, negative-sense RNA having highly conserved 5' and 3'-terminal nucleotide sequences. Another virus isolated in 2014 from steelhead trout (also O. mykiss) in Wisconsin, USA, and designated SttOV was found to have eight genome segments with high amino acid sequence identities (89-99%) to the corresponding genes of RbtOV, suggesting these new viruses are isolates of the same virus species and may be more widespread than currently realized. The new isolates had the same genome segment order and the closest pairwise amino acid sequence identities of 16-42% with Infectious salmon anemia virus (ISAV), the type species and currently only member of the genus Isavirus in the family Orthomyxoviridae. However, pairwise comparisons of the predicted amino acid sequences of the 10 RbtOV and SttOV proteins with orthologs from representatives of the established orthomyxoviral genera and a phylogenetic analysis using the PB1 protein showed that while RbtOV and SttOV clustered most closely with ISAV, they diverged sufficiently to merit consideration as representatives of a novel genus. A set of PCR primers was designed using conserved regions of the PB1 gene to produce amplicons that may be sequenced for identification of similar fish orthomyxoviruses in the future.

  18. Molecular characterization of a novel orthomyxovirus from rainbow and steelhead trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Batts, William N.; LaPatra, Scott E; Katona, Ryan; Leis, Eric; Fei Fan Ng, Terry; Bruieuc, Marine S O; Breyta, Rachel; Purcell, Maureen; Waltzek, Thomas B; Delwart, Eric; Winton, James

    2017-01-01

    A novel virus, rainbow trout orthomyxovirus (RbtOV), was isolated in 1997 and again in 2000 from commercially-reared rainbow trout (Oncorhynchus mykiss) in Idaho, USA. The virus grew optimally in the CHSE-214 cell line at 15°C producing a diffuse cytopathic effect; however, juvenile rainbow trout exposed to cell culture-grown virus showed no mortality or gross pathology. Electron microscopy of preparations from infected cell cultures revealed the presence of typical orthomyxovirus particles. The complete genome of RbtOV is comprised of eight linear segments of single-stranded, negative-sense RNA having highly conserved 5′ and 3′-terminal nucleotide sequences. Another virus isolated in 2014 from steelhead trout (also O. mykiss) in Wisconsin, USA, and designated SttOV was found to have eight genome segments with high amino acid sequence identities (89–99%) to the corresponding genes of RbtOV, suggesting these new viruses are isolates of the same virus species and may be more widespread than currently realized. The new isolates had the same genome segment order and the closest pairwise amino acid sequence identities of 16–42% with Infectious salmon anemia virus (ISAV), the type species and currently only member of the genus Isavirus in the family Orthomyxoviridae. However, pairwise comparisons of the predicted amino acid sequences of the 10 RbtOV and SttOV proteins with orthologs from representatives of the established orthomyxoviral genera and a phylogenetic analysis using the PB1 protein showed that while RbtOV and SttOV clustered most closely with ISAV, they diverged sufficiently to merit consideration as representatives of a novel genus. A set of PCR primers was designed using conserved regions of the PB1 gene to produce amplicons that may be sequenced for identification of similar fish orthomyxoviruses in the future.

  19. Acute and chronic effects of erythromycin exposure on oxidative stress and genotoxicity parameters of Oncorhynchus mykiss.

    PubMed

    Rodrigues, S; Antunes, S C; Correia, A T; Nunes, B

    2016-03-01

    Erythromycin (ERY) is a macrolide antibiotic used in human and veterinary medicine, and has been detected in various aquatic compartments. Recent studies have indicated that this compound can exert biological activity on non-target organisms environmentally exposed. The present study aimed to assess the toxic effects of ERY in Oncorhynchus mykiss after acute and chronic exposures. The here adopted strategy involved exposure to three levels of ERY, the first being similar to concentrations reported to occur in the wild, thus ecologically relevant. Catalase (CAT), total glutathione peroxidase (GPx), glutathione reductase (GRed) activities and lipid peroxidation (TBARS levels) were quantified as oxidative stress biomarkers in gills and liver. Genotoxic endpoints, reflecting different types of genetic damage in blood cells, were also determined, by performing analysis of genetic damage (determination of the genetic damage index, GDI, measured by comet assay) and of erythrocytic nuclear abnormalities (ENAs). The results suggest the occurrence of a mild, but significant, oxidative stress scenario in gills. For acutely exposed organisms, significant alterations were observed in CAT and GRed activities, and also in TBARS levels, which however are modifications with uncertain biological interpretation, despite indicating involvement of an oxidative effect and response. After chronic exposure, a significant decrease of CAT activity, increase of GPx activity and TBARS levels in gills was noticed. In liver, significant decrease in TBARS levels were observed in both exposures. Comet and ENAs assays indicated significant increases on genotoxic damage of O. mykiss, after erythromycin exposures. This set of data (acute and chronic) suggests that erythromycin has the potential to induce DNA strand breaks in blood cells, and demonstrate the induction of chromosome breakage and/or segregational abnormalities. Overall results indicate that both DNA damaging effects induced by

  20. 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

  1. Cytotoxicity of atorvastatin and simvastatin on primary rainbow trout (Oncorhynchus mykiss) hepatocytes.

    PubMed

    Ellesat, Kathrin Sabine; Tollefsen, Knut-Erik; Asberg, Anders; Thomas, Kevin V; Hylland, Ketil

    2010-09-01

    Statins are cholesterol-lowering pharmaceuticals and commonly prescribed drugs in European countries. Their discharge into the aquatic environment has increased in the last few years and they are present at detectable levels in most sewage effluents. The aim of the present study was to quantify the cytotoxic effects of acid and lactone forms of two statins, atorvastatin and simvastatin, as well as selected metabolites (ortho- and para-hydroxy atorvastatin acid, ortho-hydroxy atorvastatin lactone, simvastatin hydroxyl carboxylic acid, and 3''hydroxy simvastatin lactone) to hepatocytes from rainbow trout (Oncorhynchus mykiss). Hepatocytes were exposed for 24, 48, and 72 h to different concentrations of each test substance (0.4-400 microM). Cytotoxicity was measured as metabolic inhibition and loss of membrane integrity with the fluorescent probes alamar blue (AB) and 5-carboxyfluorescein diacetate, acetoxymethyl ester (CFDA-AM), respectively. Atorvastatin, simvastatin, and ortho-hydroxy atorvastatin lactone had dose-dependent cytotoxic effects on hepatocytes. Simvastatin was more toxic than atorvastatin and the lactone form more toxic than the acid form. Exposure time affected atorvastatin and ortho-hydroxy atorvastatin lactone but not simvastatin toxicity.

  2. 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.

  3. 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.

  4. 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.

  5. Histopathological changes in rainbow trout (Oncorhynchus mykiss) after exposure to sublethal composite nitrogen fertilizers.

    PubMed

    Capkin, Erol; Birincioglu, Serap; Altinok, Ilhan

    2009-10-01

    Subchronic toxicity of composite inorganic fertilizers such as ammonium sulfate [fertilizer A; (NH(4))(2)SO(4); 21% NH(4)-N)], composite fertilizer 15-15-15 (fertilizer B; commercial formulation: 15% NH(4)-N, 15% phosphorus, and 15% potassium oxide), and composite fertilizer 25-5-10 (fertilizer C; commercial formulation: 25% NH(4)-N, 5% phosphorus, and 10% potassium oxide) on the skin, liver, kidney, pancreas, and gills of the juvenile rainbow trout (Oncorhynchus mykiss) was studied in two-week toxicity tests under static-renewal test conditions. Fish exposed to sublethal concentrations of fertilizers did not show any behavioral abnormality compared to control groups. Histological lesions were observed in skin, gills, liver, pancreas, and trunk kidney of the fish. In the epidermis, degenerated/vacuolated epithelial cells, microcystic dilatations, and intracellular edema of mucus cell were observed. Liver had swollen and degenerated hepatocytes without losing adenoid structure. Hematopoietic tissues had necrosis and vacuolar degeneration on proximal tubules of the kidney. In order, the most affected organs were skin, liver, and kidney.

  6. 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.

  7. 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.

  8. 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).

  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.

  10. Biogenic Amines and Predictive Models of Quality of Rainbow Trout ( Oncorhynchus mykiss ) Fillets during Storage.

    PubMed

    Li, Qingzheng; Lv, Jian; Zhang, Longteng; Dong, Zehong; Feng, Ligeng; Luo, Yongkang

    2017-02-01

    To estimate biogenic amines and changes in quality of rainbow trout ( Oncorhynchus mykiss ) fillets at different temperatures, we determined the sensory attributes, total volatile basic nitrogen (TVB-N), total viable counts (TVC), and biogenic amines (BAs) of samples that were untreated (CK) or dry cured with 1.8% salt (T). There was no significant difference between CK and T samples in terms of TVB-N, TVC, and BAs. TVB-N and TVC increased significantly (P < 0.05) with storage time at 3, 9, and 15°C. Putrescine (PUT) and cadaverine (CAD) increased significantly (P < 0.05) at -3, 3, 9, and 15°C during storage. Histamine formed more easily when storage temperatures were higher. The kinetic models of sensory scores for TVB-N, TVC, PUT, CAD, and the sum of PUT and CAD (PUT+CAD) in T samples versus storage time and temperature were developed based on the Arrhenius equation. High regression coefficients (R(2) > 0.9) indicated the acceptability of the kinetic model for predicting changes in the quality of the rainbow trout fillets. Relative errors between predicted and experimental values of TVB-N, TVC, and PUT+CAD were all within 10% except for TVB-N on day 6. The prediction model based on TVB-N, TVC, and PUT+CAD can be applied to evaluate changes in quality of rainbow trout fillets from -3 to 15°C (270 to 288 K).

  11. 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.

  12. Staphylococcus warneri, a resident skin commensal of rainbow trout (Oncorhynchus mykiss) with pathobiont characteristics.

    PubMed

    Musharrafieh, Rami; Tacchi, Luca; Trujeque, Joshua; LaPatra, Scott; Salinas, Irene

    2014-02-21

    Commensal microorganisms live in association with the mucosal surfaces of all vertebrates. The skin of teleost fish is known to harbor commensals. In this study we report for the first time the presence of an intracellular Gram positive bacteria, Staphylococcus warneri that resides in the skin epidermis of rainbow trout (Oncorhynchus mykiss). S. warneri was isolated from healthy hatchery trout skin epithelial cells. In situ hybridization confirmed the intracellular nature of the bacterium. Skin explants exposed in vitro to S. warneri or the extracellular pathogen Vibrio anguillarum show that S. warneri is able to induce an anti-inflammatory cytokine status via TGF-β1b compared to the pro-inflammatory responses (IL-1β, IL-6 and TNF-∝) elicited by V. anguillarum. In vivo experiments showed that S. warneri is not pathogenic to rainbow trout when injected intraperitoneally at high concentrations. However, S. warneri is able to stimulate V. anguillarum growth and biofilm formation on rainbow trout scales. Our results demonstrate that rainbow trout skin commensals such as S. warneri have the potential to become indirect pathobionts by enhancing growth and biofilm formation of pathogens such as V. anguillarum. These results show that fish farming practices (i.e. handling and other manipulations) can alter the skin microbiota and compromise the skin health of rainbow trout.

  13. Rainbow trout (Oncorhynchus mykiss) detection, avoidance, and chemosensory effects of oil sands process-affected water.

    PubMed

    Lari, Ebrahim; Pyle, Greg G

    2017-03-24

    Oil sands process-affected water (OSPW) - a byproduct of the oil sands industry in Northern Alberta, Canada - is currently stored in on-site tailings ponds. The goal of the present study was to investigate the interaction of OSPW with the olfactory system and olfactory-mediated behaviours of fish upon the first encounter with OSPW. The response of rainbow trout (Oncorhynchus mykiss) to different concentrations (0.1, 1, and 10%) of OSPW was studied using a choice maze and electro-olfactography (EOG), respectively. The results of the present study showed that rainbow trout are capable of detecting and avoiding OSPW at a concentration as low as 0.1%. Exposure to 1% OSPW impaired (i.e. reduced sensitivity) the olfactory response of rainbow trout to alarm and food cues within 5 min or less. The results of the present study demonstrated that fish could detect and avoid minute concentrations of OSPW. However, if fish were exposed to OSPW-contaminated water and unable to escape, their olfaction would be impaired.

  14. 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.

  15. 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.

  16. Subunit vaccine candidates against Aeromonas salmonicida in rainbow trout Oncorhynchus mykiss

    PubMed Central

    Jørgensen, Louise von Gersdorff; Skov, Jakob; Chettri, Jiwan Kumar; Holm Mattsson, Andreas; Dalsgaard, Inger; Kania, Per Walter; Buchmann, Kurt

    2017-01-01

    Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis and a major fish health problem in salmonid aquaculture worldwide. Injection vaccination with commercial mineral oil-adjuvanted bacterin vaccines has been partly successful in preventing the disease but in Danish rainbow trout (Oncorhynchus mykiss, Walbaum) aquaculture furunculosis outbreaks still occur. In this study we tested the efficacy of experimental subunit vaccines against A. salmonicida infection in rainbow trout. We utilized in silico screening of the proteome of A. salmonicida subsp. salmonicida strain A449 and identified potential protective protein antigens that were tested by in vivo challenge trial. A total of 14 proteins were recombinantly expressed in Escherichia coli and prepared in 3 different subunit vaccine combinations to immunize 3 groups of rainbow trout by intraperitoneal (i.p.) injection. The fish were exposed to virulent A. salmonicida 7 weeks after immunization. To assess the efficacy of the subunit vaccines we evaluated the immune response in fish after immunization and challenge infection by measuring the antibody levels and monitoring the survival of fish in different groups. The survival of fish at 3 weeks after challenge infection showed that all 3 groups of fish immunized with 3 different protein combinations exhibited significantly lower mortalities (17–30%) compared to the control groups (48% and 56%). The ELISA results revealed significantly elevated antibody levels in fish against several protein antigens, which in some cases were positively correlated to the survival. PMID:28182704

  17. Identification of a novel cathelicidin gene in the rainbow trout, Oncorhynchus mykiss.

    PubMed

    Chang, Chin-I; Pleguezuelos, Olga; Zhang, Yong-An; Zou, Jun; Secombes, Christopher J

    2005-08-01

    We report the cloning of a novel antimicrobial peptide gene, termed rtCATH_1, found in the rainbow trout, Oncorhynchus mykiss. The predicted 216-residue rtCATH_1 prepropeptide consists of three domains: a 22-residue signal peptide, a 128-residue cathelin-like region containing two identifiable cathelicidin family signatures, and a predicted 66-residue C-terminal cationic antimicrobial peptide. This predicted mature peptide was unique in possessing features of different known (mammalian) cathelicidin subgroups, such as the cysteine-bridged family and the specific amino-acid-rich family. The rtCATH_1 gene comprises four exons, as seen in all known mammalian cathelicidin genes, and several transcription factor binding sites known to be of relevance to host defenses were identified in the 5' flanking region. By Northern blot analysis, the expression of rtCATH_1 was detected in gill, head kidney, and spleen of bacterially challenged fish. Primary cultures of head kidney leukocytes from rainbow trout stimulated with lipopolysaccharide or poly(I x C) also expressed rtCATH_1. A 36-residue peptide corresponding to the core part of the fish cathelicidin was chemically synthesized and shown to exhibit potent antimicrobial activity and a low hemolytic effect. Thus, rtCATH_1 represents a novel antimicrobial peptide gene belonging to the cathelicidin family and may play an important role in the innate immunity of rainbow trout.

  18. Relative sensitivity of bull trout (Salvelinus confluentus) and rainbow trout (Oncorhynchus mykiss) to acute copper toxicity.

    PubMed

    Hansen, James A; Lipton, Josh; Welsh, Paul G

    2002-03-01

    Bull trout (Salvelinus confluentus) were recently listed as threatened in the United States under the federal Endangered Species Act. Past and present habitat for this species includes waterways contaminated with heavy metals released from mining activities. Because the sensitivity of this species to copper was previously unknown, we conducted acute copper toxicity tests with bull and rainbow trout (Oncorhynchus mykiss) in side-by-side comparison tests. Bioassays were conducted using water at two temperatures (8 degrees C and 16 degrees C) and two hardness levels (100 and 220 mg/L as CaCO3). At a water hardness of 100 mg/L, both species were less sensitive to copper when tested at 16 degrees C compared to 8 degrees C. The two species had similar sensitivity to copper in 100-mg/ L hardness water, but bull trout were 2.5 to 4 times less sensitive than rainbow trout in 220-mg/L hardness water. However, when our results were viewed in the context of the broader literature on rainbow trout sensitivity to copper, the sensitivities of the two species appeared similar. This suggests that adoption of toxicity thresholds that are protective of rainbow trout would be protective of bull trout; however, an additional safety factor may be warranted because of the additional level of protection necessary for this federally threatened species.

  19. Genetic variation of resistance to mercury poisoning in steelhead (Oncorhynchus mykiss) alevins.

    PubMed

    Blanc, J M; McIntyre, J D; Simon, R C

    2003-09-01

    Newly hatched steelhead alevins were obtained from the factorial breeding of 24 male and 10 female steelhead trout, Oncorhynchus mykiss. Each set of offspring were in a separate cell. They were tested for resistance to intoxication by methylmercuric chloride (CH3HgCl) in water at a nearly constant mercury concentration of 8 microg l(-1). High mortality (81% of the tested alevins) occurred within 2 weeks. Resistance to intoxication, as measured by the time to death, as well as by the survival rate, shared high paternal and maternal variation with negligible interaction. Heritability of time to death was 0.59 +/- 0.17; heritability of survival (all-or-none trait) was lower (0.26 +/- 0.09). Mercury in dead alevins increased with time to death, exhibiting a large environmental variation and (comparatively) negligible genetic influence. At the end of the bioassay, the mercury content in survivors varied widely (3-21 microg g(-1) wet weight). The content was greater than, but correlated with that of dead alevins from the same cells, and it showed little relation with survival rate. Thus, it seems that resistance to poisoning implies a tolerance to high levels of mercury rather than a limitation of its accumulation.

  20. Embryotoxicity of extracts from Lake Ontario rainbow trout (Oncorhynchus mykiss) to Japanese medaka (Oryzias latipes)

    SciTech Connect

    Harris, G.E.; Metcalfe, T.L.; Metcalfe, C.D. . Environmental and Resources Studies Program); Huestis, S.Y. )

    1994-09-01

    Various preparative techniques were used to extract nonpolar organic compounds from the muscle tissue of Lake Ontario rainbow trout (Oncorhynchus mykiss). In this extract, PCBs and organochlorine compounds were detected in nanogram-per-milliliter quantities, and polychlorinated dibenzo-p-dioxins and dibenzofurans were detected in picogram-per-milliliter quantities. The extract and various subfractions of the extract were tested for embryotoxicity in a bioassay with embryos of Japanese medaka (Oryzias latipes). The whole extract was embryotoxic to medaka, as were an extract fraction containing PCBs (fraction A) and extract fractions containing nonpolar organochlorine compounds (fractions B and C). When subfractions prepared from fraction A were tested for embryotoxicity, a subfraction containing non-ortho-substituted PCB congeners was embryo-toxic, whereas subfractions containing mono-ortho- and di-ortho-substituted PCB congeners were relatively nontoxic. Pathological lesions characteristic of exposure to planar halogenated aromatic hydrocarbons were observed only in embryos exposed to the non-ortho-PCB subfraction. The non-ortho-PCB subfraction of fraction A was more toxic than the original fraction A, which indicates that nontoxic PCBs reduce the toxicity of the non-ortho-PCBs through some unknown mechanism. This study indicates that organochlorine compounds and non-ortho-substituted PCBs have the potential to be embryotoxic to early life stages of Great lakes fish, but nontoxic contaminants can modify this toxic response. These data are relevant to the interpretation of correlations between embryo mortalities and concentrations of persistent organic contaminants in Great Lakes salmonids.

  1. Signatures of natural selection among lineages and habitats in Oncorhynchus mykiss.

    PubMed

    Limborg, Morten T; Blankenship, Scott M; Young, Sewall F; Utter, Fred M; Seeb, Lisa W; Hansen, Mette H H; Seeb, James E

    2012-01-01

    Recent advances in molecular interrogation techniques now allow unprecedented genomic inference about the role of adaptive genetic divergence in wild populations. We used high-throughput genotyping to screen a genome-wide panel of 276 single nucleotide polymorphisms (SNPs) for the economically and culturally important salmonid Oncorhynchus mykiss. Samples included 805 individuals from 11 anadromous and resident populations from the northwestern United States and British Columbia, and represented two major lineages including paired populations of each life history within single drainages of each lineage. Overall patterns of variation affirmed clear distinctions between lineages and in most instances, isolation by distance within them. Evidence for divergent selection at eight candidate loci included significant landscape correlations, particularly with temperature. High diversity of two nonsynonymous mutations within the peptide-binding region of the major histocompatibility complex (MHC) class II (DAB) gene provided signatures of balancing selection. Weak signals for potential selection between sympatric resident and anadromous populations were revealed from genome scans and allele frequency comparisons. Our results suggest an important adaptive role for immune-related functions and present a large genomic resource for future studies.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. Effect of nanosilver on cortisol release and morphometrics in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Murray, Laura; Rennie, Michael D; Enders, Eva C; Pleskach, Kerri; Martin, Jonathan D

    2016-11-17

    Nanosilver (nAg) is a nanoparticle commonly incorporated into consumer products for its antimicrobial properties that has been detected in aquatic environments. Toxic effects of nAg on fish have been observed, and nAg may induce a stress response in fish in the form of increased blood plasma cortisol. Effects of nAg exposure on rainbow trout (Oncorhynchus mykiss) were investigated over a 28-d period using blood plasma cortisol concentrations as an indicator of stress. Several morphometric measures (growth, Fulton's condition factor, and hepatosomatic index [HSI]) were also taken during the experiment to investigate potential whole-body effects of exposure, and concentrations of nAg in fish muscle tissue were measured. Fish were exposed to environmentally relevant (average 0.28 μg/L) and higher (average 47.60 μg/L) exposure concentrations of nAg. The results showed a significant increase in blood plasma cortisol for both exposure treatments. A significant effect on HSI by treatment dependent on exposure time was also observed, although no obvious trend was detected, whereas other morphometric measures were not affected by nAg exposure. In addition, Ag was detected in fish muscle tissue. The results indicate that although nAg did engage the stress response in fish, it did not affect growth or condition under the experimental conditions and time frame investigated. Environ Toxicol Chem 2017;9999:1-8. © 2016 SETAC.

  9. Ceramides are involved in the regulation of food intake in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Velasco, Cristina; Librán-Pérez, Marta; Otero-Rodiño, Cristina; López-Patiño, Marcos A; Míguez, Jesús M; Soengas, José L

    2016-10-01

    We hypothesize that ceramides are involved in the regulation of food intake in fish. Therefore, we assessed in rainbow trout (Oncorhynchus mykiss) the effects of intracerebroventricular treatment with C6:0 ceramide on food intake. In a second experiment, we assessed the effects in brain areas of ceramide treatment on neuropeptide expression, fatty acid-sensing systems, and cellular signaling pathways. Ceramide treatment induced a decrease in food intake, a response opposed to the orexigenic effect described in mammals, which can be related to enhanced mRNA abundance of cocaine and amphetamine-related transcript and proopiomelanocortin and decreased mRNA abundance of Agouti-related protein and neuropeptide Y. Fatty acid-sensing systems appear to be inactivated by ceramide treatment. The mRNA abundance of integrative sensors AMPK and sirtuin 1, and the phosphorylation status of cellular signaling pathways dependent on protein kinase B, AMPK, mammalian target of rapamycin (mTOR), and forkhead box protein O1 (FoxO1) are generally activated by ceramide treatment. However, there are differences between hypothalamus and hindbrain in the phosphorylation status of AMPK (decreased in hypothalamus and increased in hindbrain), mTOR (decreased in hypothalamus and increased in hindbrain), and FoxO1 (increased in hypothalamus and decreased in hindbrain) to ceramide treatment. The results suggest that ceramides are involved in the regulation of food intake in rainbow trout through mechanisms comparable to those characterized previously in mammals in some cases.

  10. Effects of Haematococcus pluvialis supplementation on antioxidant system and metabolism in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Sheikhzadeh, Najmeh; Tayefi-Nasrabadi, Hossein; Oushani, Ali Khani; Enferadi, Mohammad Hamed Najafi

    2012-04-01

    Effects of commercial source for astaxanthin (Haematococcus pluvialis) (H.p) on antioxidant power, specific marker enzymes, and some metabolites were examined in rainbow trout (Oncorhynchus mykiss). Fish were fed on diets containing 1, 3, and 10 g microalga kg(-1) feed for 30 days. Serum total antioxidant activity and lipid peroxidation product, indicated by malondialdehyde (MDA), significantly enhanced with different doses of administration, indicating the elevated antioxidant status in all treatment groups. In group fed with high dose of alga, significantly elevated aspartate aminotransferase activity (AST) was noted, indicating damage of normal liver function in this group. Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were not affected in all groups. Although serum total protein remained unaffected, serum glucose level was decreased significantly in lower doses of administration. Furthermore, triglyceride and cholesterol levels showed significant decrease in 3 g kg(-1) microalga group by modulation of lipid metabolism in this group. On the other hand, in highest dose, significant increase in lipids was observed, indicating the slight dysfunction in lipid metabolism in this treatment group. The present study suggests that Haematococcus pluvialis especially in dose of 3 g kg(-1) feed administration may effectively enhance the antioxidant system and some biochemical parameters in rainbow trout.

  11. Rainbow Trout (Oncorhynchus mykiss) and Ultra-Low Dose Cancer Studies*

    PubMed Central

    Williams, David E.; Orner, Gayle; Willard, Kristin D.; Tilton, Susan; Hendricks, Jerry D.; Pereira, Clifford; Benninghoff, Abby D.; Bailey, George S.

    2010-01-01

    Cancer risk assessment utilizing rodents requires extrapolation across five orders of magnitude to estimate the Virtually Safe Dose (VSD). Regulatory agencies rely upon the Linear Extrapolated Dose (LED) except when sufficient information on mechanism of action justifies alternative models. Rainbow trout (Oncorhynchus mykiss) has been utilized at Oregon State University as a model for human cancer for forty years. Low cost and high capacity, made possible by our unique facility, along with low spontaneous background and high sensitivity, allow design and conduct of statistically challenging studies not possible in rodents. Utilization of custom microarrays demonstrates similarities in gene expression in trout and human hepatocellular carcinoma (HCC). We have completed one study employing over 42,000 trout with dibenzo[a,l]pyrene (DBP) and determined the dose resulting in 1 additional cancer in 5,000 animals, a 50-fold enhancement over the mouse ED01 study. Liver tumor incidence at low dose deviated significantly from linearity (concave down), whereas, DBP-DNA adductions deviated slightly (convex up). A second study is underway with aflatoxin B1 (AFB1). Results to date indicate AFB1 at low dose, in contrast to DBP, elicits a linear dose-response function on the log-log scale which falls below the LED with a slope slightly greater than 1.0. Such studies demonstrate the statistical power of the trout cancer model and strengthen the case for incorporation of these data-sets into risk assessment for these environmental human carcinogens. PMID:19135172

  12. Rainbow trout (Oncorhynchus mykiss) and ultra-low dose cancer studies.

    PubMed

    Williams, David E; Orner, Gayle; Willard, Kristin D; Tilton, Susan; Hendricks, Jerry D; Pereira, Clifford; Benninghoff, Abby D; Bailey, George S

    2009-03-01

    Cancer risk assessment utilizing rodents requires extrapolation across five orders of magnitude to estimate the Virtually Safe Dose (VSD). Regulatory agencies rely upon the Linear Extrapolated Dose (LED) except when sufficient information on mechanism of action justifies alternative models. Rainbow trout (Oncorhynchus mykiss) has been utilized at Oregon State University as a model for human cancer for forty years. Low cost and high capacity, made possible by our unique facility, along with low spontaneous background and high sensitivity, allow design and conduct of statistically challenging studies not possible in rodents. Utilization of custom microarrays demonstrates similarities in gene expression in trout and human hepatocellular carcinoma (HCC). We have completed one study employing over 42,000 trout with dibenzo[a,l]pyrene (DBP) and determined the dose resulting in 1 additional cancer in 5000 animals, a 50-fold enhancement over the mouse ED(01) study. Liver tumor incidence at low dose deviated significantly from linearity (concave down), whereas, DBP-DNA adductions deviated slightly (convex up). A second study is underway with aflatoxin B(1) (AFB(1)). Results to date indicate AFB(1) at low dose, in contrast to DBP, elicits a linear dose-response function on the log-log scale which falls below the LED with a slope slightly greater than 1.0. Such studies demonstrate the statistical power of the trout cancer model and strengthen the case for incorporation of these data-sets into risk assessment for these environmental human carcinogens.

  13. Cytokine expression in leucocytes and gut cells of rainbow trout, Oncorhynchus mykiss Walbaum, induced by probiotics.

    PubMed

    Kim, Do-Hyung; Austin, Brian

    2006-12-15

    Understanding how the various host cells respond to probiotic bacteria in vitro may provide important insight into elaborate immune responses triggered by beneficial bacteria. The aim of this study was to investigate the detailed pattern of the mRNA expression of cytokines (IL-1beta, IL-8, TNF-alpha and TGF-beta) in head kidney (HK) leucocytes and gut cells isolated from rainbow trout (Oncorhynchus mykiss Walbaum) after co-culturing with live probiotics. HK leucocytes and gut cells adjusted to 5 x 10(6) and 2 x 10(6) ml(-1), respectively, in L-15 medium containing 25% decomplemented FCS and 300 mg l(-1) L-glutamine were co-cultured with Carnobacterium maltaromaticum B26 and C. divergens B33 at an multiplicity of infection of 25 for 6 and 12 h. Quantitative real-time reverse transcriptase polymerase chain reaction using SYBR Green I was employed to determine the mRNA expression of studied genes. Although neither probiotic strains significantly induced mRNA of the cytokines in gut cells, expression ratios of IL-1beta and TNF-alpha of HK cells were significantly higher, suggesting that these bacteria can stimulate innate immunity in rainbow trout.

  14. Two novel muramidases from skin mucosa of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Fernandes, J M O; Kemp, G D; Smith, V J

    2004-05-01

    Two novel antibacterial muramidases were purified to homogeneity from skin exudates of rainbow trout (Oncorhynchus mykiss). Unusually, one has an acidic isoelectric point and it is the first anionic muramidase to be reported for fish. Its molecular mass is 14,268 Da, as determined by mass spectrometry. The other muramidase is cationic with a mass of 14,252 Da. Partial N-terminal amino acid sequencing and peptide mapping strongly point to it being a c-type lysozyme, the first to be purified and characterised from skin of a salmonid. Its optimum pH ranges from 4.5 to 5.5 and its optimum temperature, at pH 5.0, is 33-49 degrees C, although it still exhibits activity at 5 degrees C. It is strongly bactericidal to the Gram-(+) bacterium Planococcus citreus, with a minimum bactericidal concentration of 100 U ml(-1), but is neither chitinolytic nor haemolytic. These two muramidases probably contribute to epithelial defence of the fish against microbes, either alone or in synergism with antibacterial peptides.

  15. Accumulation and disposition of hexabromocyclododecane (HBCD) in juvenile rainbow trout (Oncorhynchus mykiss).

    PubMed

    Haukås, Marianne; Mariussen, Espen; Ruus, Anders; Tollefsen, Knut Erik

    2009-11-08

    The brominated flame retardant hexabromocyclododecane (HBCD) has been reported in environmental samples worldwide. The three diastereomers, alpha-, beta- and gamma-HBCD, behave differently in aquatic food webs; likely depending on different factors influencing assimilation efficiency and metabolism. In the present study, two oral exposure experiments with rainbow trout were performed to assess the role of selective uptake on diastereomer-specific accumulation and disposition of HBCD to liver, brain and muscle. In both experiments, juvenile rainbow trout (Oncorhynchus mykiss) were administrated a technical HBCD-mixture in commercial feed (10mgkg(-1)), followed by up to 21 days of food deprivation. Already 6h after exposure, the HBCD accumulation was significant, and the concentrations peaked 4-8 days after the exposure. The relative change in HBCD pattern during the accumulation process (0-8 days), suggested that there was a diastereomer-selective uptake of alpha- and beta-HBCD in the rainbow trout. During the initial 48h, considerable amounts of all three diastereomers were distributed to liver, brain and muscle. A 70% reduction in SigmaHBCD levels after 21 days, indicated elimination of HBCD from brain and liver, but no clear elimination from the muscle was observed. Differences in HBCD pattern between organs at the end of the experiment support a proposal of an organ-specific diastereomer accumulation.

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

    PubMed

    Salaberria, Iurgi; Hansen, Bjørn Henrik; Asensio, Vega; Olsvik, Pål A; Andersen, Rolf A; Jenssen, Bjørn 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 microg 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.

  17. Dimethoate-induced oxidative stress and DNA damage in Oncorhynchus mykiss.

    PubMed

    Dogan, Demet; Can, Canan; Kocyigit, Abdurrahim; Dikilitas, Murat; Taskin, Abdullah; Bilinc, Hasan

    2011-06-01

    The present study was conducted in order to investigate pro-oxidant activity of dimethoate in liver and brain tissues following sublethal pesticide exposure for 5, 15 and 30 d by using SOD, GPx, CAT enzyme activities and lipid peroxidation as biomarkers as well as DNA damaging potential via detecting% Tail DNA, Tail moment and Olive tail moment as endpoints in erythrocytes of Oncorhynchus mykiss in an in vitro experiment. Antioxidant enzyme activities were found to elicit two staged response which was an initial induction followed by a sharp inhibition in liver tissue while a sustained increase in GPx activity and slight stimulation in SOD activity were detected in brain tissue. Lipid peroxidation showed an ascending pattern throughout the exposure period in both tissues and a decreasing trend was determined in tissue protein levels which was proved to be positively correlated with duration. Similar findings were obtained from outcomes preferred to quantify DNA damage and TM was decided to reflect the extent of damage more sensitively because of determined positive correlation with concentrations applied. Considering these results, it can be concluded that oxidative stress condition evoked by dimethoate could not be responded effectively and genotoxic nature of pesticide was proven by determined clastogenic effect possibly via being an alkylation agent or stimulating the production of reactive species.

  18. Staphylococcus warneri, a resident skin commensal of rainbow trout (Oncorhynchus mykiss) with pathobiont characteristics

    PubMed Central

    Rami, Musharrafieh; Luca, Tacchi; Joshua, Trujeque; Scott, LaPatra; Irene, Salinas

    2014-01-01

    Commensal microorganisms live in association with the mucosal surfaces of all vertebrates. The skin of teleost fish is known to harbor commensals. In this study we report for the first time the presence of an intracellular Gram positive bacteria, Staphylococcus warneri that resides in the skin epidermis of rainbow trout (Oncorhynchus mykiss). S. warneri was isolated from healthy hatchery trout skin epithelial cells. In situ hybridization confirmed the intracellular nature of the bacterium. Skin explants exposed in vitro to S. warneri or the extracellular pathogen Vibrio anguillarum show that S. warneri is able to induce an anti-inflammatory cytokine status via TGF-β 1b compared to the pro-inflammatory responses (IL-1β , IL-6 and TNF-α) elicited by V. anguillarum. In vivo experiments showed that S. warneri is not pathogenic to rainbow trout when injected intraperitoneally at high concentrations. However, S. warneri is able to stimulate V. anguillarum growth and biofilm formation on rainbow trout scales. Our results demonstrate that rainbow trout skin commensals such as S. warneri have the potential to become indirect pathobionts by enhancing growth and biofilm formation of pathogens such as V. anguillarum. These results show that fish farming practices (i.e. handling and other manipulations) can alter the skin microbiota and compromise the skin health of rainbow trout. PMID:24438987

  19. Hypothermic storage of isolated spermatogonia and oogonia from rainbow trout (Oncorhynchus mykiss).

    PubMed

    Falahatkar, Bahram; Poursaeid, Samaneh; Kitada, Ryota; Yoshizaki, Goro

    2017-03-14

    A growing number of fish species are endangered due to human activities. A short- or long-time preservation of gametes could conserve genetic resources of threatened fish species. The aim of this study was to evaluate a hypothermic condition for short-term preservation of spermatogonia and oogonia cells isolated from immature transgenic rainbow trout, Oncorhynchus mykiss, and to determine the maximum time point for further transplantation. Viability rate of germ cells was investigated after isolation and during storage at 4 °C up to 24 h. Dulbecco's modification of Eagle's medium supplemented with Hepes fetal bovine serum and l-glutamine was used as hypothermic storage media. The results showed that while viability decreased following 24 h storage, the remaining viable cells did not vary morphologically as well as GFP intensity retained similar to those observed in freshly isolated cells. The hypothermal storage study indicated that culture medium is suitable for preserving germ cells in the short periods of time. Simplicity, easily available culture media and low cost provide new insight into hypothermic conditions for preserving and transporting of germ cells for next applied and basic studies.

  20. Cellular components of probiotics control Yersinia ruckeri infection in rainbow trout, Oncorhynchus mykiss (Walbaum).

    PubMed

    Abbass, A; Sharifuzzaman, S M; Austin, B

    2010-01-01

    Subcellular components of the probiotics Aeromonas sobria GC2 and Bacillus subtilis JB-1, when administered to rainbow trout, Oncorhynchus mykiss, conferred protection against a new biogroup of Yersinia ruckeri. Thus, intraperitoneal or intramuscular injection of rainbow trout with cell wall proteins (CWPs), outer membrane proteins (OMPs), lipopolysaccharides (LPS), whole cell proteins (WCPs) and live cells followed by challenge on day 8 with Y. ruckeri led to 80-100% survival compared with 10% survival in the controls. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) profiles of WCPs and OMPs from GC2 had 10 and 5 variable protein bands in comparison to 11 and 5 bands in the WCPs and CWPs from JB-1. Proteomic analyses were employed following SDS-PAGE to categorize one dominant protein of 104.7 kDa from the CWPs of JB-1 and equated it with 'Bacillus spp. endoglucanase' with a Mascot score >69. These results point to the potential of using cellular components of probiotics for protection of fish against bacterial diseases.

  1. 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.

  2. Evaluation of Optimum Dietary Threonine Requirement by Plasma Free Threonine and Ammonia Concentrations in Surgically Modified Rainbow Trout, Oncorhynchus mykiss

    PubMed Central

    Yun, Hyeonho; Park, Gunjun; Ok, Imho; Katya, Kumar; Heung, Silas; Bai, Sungchul C.

    2015-01-01

    This study was carried out to evaluate the dietary threonine requirement by measuring the plasma free threonine and ammonia concentrations in rainbow trout, Oncorhynchus mykiss after dorsal aorta cannulation. A total of 70 fish (average initial weight 506±8.2 g) were randomly distributed into each of the 14 net cages (5 fish/cage). After 48 hours (h) of feed deprivation, each group was intubated at 1% body weight with one of the seven L-amino acid based diets containing graded levels of threonine (0.42%, 0.72%, 0.92%, 1.12%, 1.32%, 1.52%, or 1.82% of diet, dry matter basis). Blood samples were taken at 0, 5, and 24 h after intubation. Post-prandial plasma free threonine concentrations (PPthr) of fish 5 h after intubation with diets containing 1.32% or more threonine were significantly higher than those of fish intubated with diets containing 1.12% or less threonine (p<0.05). Post-absorptive free threonine concentrations (PAthr) after 24 h of intubation of the fish with diets containing 0.92% or more threonine were significantly higher than those of fish intubated with diets containing 0.72% or less threonine. Post-prandial plasma ammonia concentrations (PPA, 5 h after intubation) were not significantly different among fish intubated with diets containing 1.12% or less threonine, except the PPA of fish intubated with diet containing 0.42% threonine. Broken-line model analyses of PPthr, PAthr, and PPA indicated that the dietary threonine requirement of rainbow trout should be between 0.95% (2.71) and 1.07% (3.06) of diet (% of dietary protein on a dry matter basis). PMID:25656187

  3. 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.

  4. 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

  5. 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.

  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. 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.

  9. Purification and characterization of calpain and calpastatin from rainbow trout, Oncorhynchus mykiss.

    PubMed

    Saito, Masataka; Li, Hongqi; Thompson, Valery F; Kunisaki, Naomichi; Goll, Darrel E

    2007-04-01

    Although the calpain system has been studied extensively in mammalian animals, much less is known about the properties of mu-calpain, m-calpain, and calpastatin in lower vertebrates such as fish. These three proteins were isolated and partly characterized from rainbow trout, Oncorhynchus mykiss, muscle. Trout m-calpain contains an 80-kDa large subunit, but the approximately 26-kDa small subunit from trout m-calpain is smaller than the 28-kDa small subunit from mammalian calpains. Trout mu-calpain and calpastatin were only partly purified; identity of trout mu-calpain was confirmed by labeling with antibodies to bovine skeletal muscle mu-calpain, and identity of trout calpastatin was confirmed by specific inhibition of bovine skeletal muscle mu- and m-calpain. Trout mu-calpain requires 4.4+/-2.8 microM and trout m-calpain requires 585+/-51 microM Ca(2+) for half-maximal activity, similar to the Ca(2+) requirements of mu- and m-calpain from mammalian tissues. Sequencing tryptic peptides indicated that the amino acid sequence of trout calpastatin shares little homology with the amino acid sequences of mammalian calpastatins. Screening a rainbow trout cDNA library identified three cDNAs encoding for the large subunit of a putative m-calpain. The amino acid sequence predicted by trout m-calpain cDNA was 65% identical to the human 80-kDa m-calpain sequence. Gene duplication and polyploidy occur in fish, and the amino acid sequence of the trout m-calpain 80-kDa subunit identified in this study was 83% identical to the sequence of a trout m-calpain 80-kDa subunit described earlier. This is the first report of two isoforms of m-calpain in a single species.

  10. Localization of rem2 in the central nervous system of the adult rainbow trout (Oncorhynchus mykiss).

    PubMed

    Downs, Anna G; Scholles, Katie R; Hollis, David M

    2016-12-01

    Rem2 is member of the RGK (Rem, Rad, and Gem/Kir) subfamily of the Ras superfamily of GTP binding proteins known to influence Ca(2+) entry into the cell. In addition, Rem2, which is found at high levels in the vertebrate brain, is also implicated in cell proliferation and synapse formation. Though the specific, regional localization of Rem2 in the adult mammalian central nervous system has been well-described, such information is lacking in other vertebrates. Rem2 is involved in neuronal processes where the capacities between adults of different vertebrate classes vary. Thus, we sought to localize the rem2 gene in the central nervous system of an adult anamniotic vertebrate, the rainbow trout (Oncorhynchus mykiss). In situ hybridization using a digoxigenin (DIG)-labeled RNA probe was used to identify the regional distribution of rem2 expression throughout the trout central nervous system, while real-time polymerase chain reaction (rtPCR) further supported these findings. Based on in situ hybridization, the regional distribution of rem2 occurred within each major subdivision of the brain and included large populations of rem2 expressing cells in the dorsal telencephalon of the cerebrum, the internal cellular layer of the olfactory bulb, and the optic tectum of the midbrain. In contrast, no rem2 expressing cells were resolved within the cerebellum. These results were corroborated by rtPCR, where differential rem2 expression occurred between the major subdivisions assayed with the highest levels being found in the cerebrum, while it was nearly absent in the cerebellum. These data indicate that rem2 gene expression is broadly distributed and likely influences diverse functions in the adult fish central nervous system.

  11. 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

  12. 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

  13. 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. 

  14. 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.

  15. 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.

  16. Effects of intracerebroventricular administered fluoxetine on cardio-ventilatory functions in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Kermorgant, Marc; Lancien, Frédéric; Mimassi, Nagi; Tyler, Charles R; Le Mével, Jean-Claude

    2014-09-01

    Fluoxetine (FLX) is a selective serotonin (5-HT) reuptake inhibitor present in the aquatic environment which is known to bioconcentrate in the brains of exposed fish. FLX acts as a disruptor of various neuroendocrine functions in the brain, but nothing is known about the possible consequence of FLX exposure on the cardio-ventilatory system in fish. Here we undertook to investigate the central actions of FLX on ventilatory and cardiovascular function in unanesthetized rainbow trout (Oncorhynchus mykiss). Intracerebroventricular (ICV) injection of FLX (dosed between 5 and 25 μg) resulted in a significantly elevated total ventilation (VTOT), with a maximum hyperventilation of +176% (at a dose of 25μg) compared with vehicle injected controls. This increase was due to an increase in ventilatory amplitude (VAMP: +126%) with minor effects on ventilatory frequency. The highest dose of FLX (25 μg) produced a significant increase in mean dorsal aortic blood pressure (PDA: +20%) without effects on heart rate (ƒH). In comparison, intra-arterial injections of FLX (500-2,500 μg) had no effect on ventilation but the highest doses increased both PDA and ƒH. The ICV and IA cardio-ventilatory effects of FLX were very similar to those previously observed following injections of 5-HT, indicating that FLX probably acts via stimulating endogenous 5-HT activity through inhibition of 5-HT transporter(s). Our results demonstrate for the first time in fish that FLX administered within the brain exerts potent stimulatory effects on ventilation and blood pressure increase. The doses of FLX given to fish in our study are higher than the brain concentrations of FLX in fish that result from acute exposure to FLX through the water. Nonetheless, our results indicate possible disrupting action of long term exposure to FLX discharged into the environment on central target sites sensitive to 5-HT involved in cardio-ventilatory control.

  17. 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

  18. 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.

  19. 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.

  20. Intersex Occurrence in Rainbow Trout (Oncorhynchus mykiss) Male Fry Chronically Exposed to Ethynylestradiol

    PubMed Central

    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

  1. Endocrine and orexigenic actions of growth hormone secretagogues in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Shepherd, Brian S; Johnson, Jaime K; Silverstein, Jeffrey T; Parhar, Ishwar S; Vijayan, Mathilakath M; McGuire, Alison; Weber, Gregory M

    2007-03-01

    The effects of growth hormone secretagogues (GHSs) on the teleost somatotropic axis are poorly understood, particularly with respect to insulin-like growth factor-I (IGF-I) and the IGF-binding proteins (IGFBPs). To assess the endocrine and orexigenic responses of rainbow trout (Oncorhynchus mykiss) to GHS treatment, animals were injected with human GHRH(1-29)-amide, KP-102 or rat ghrelin at 0, 1 or 10 pmol/g body mass. Feed intake was tested at 2 and 5 h post-injection and plasma levels of growth hormone (GH), IGF-I and the IGFBPs were determined at 3, 6 and 12 h post-injection. Feed intake was significantly elevated by all of the GHSs tested at both post-injection time points. All GHSs elevated plasma GH levels in a time-dependent manner. Plasma IGF-I levels were elevated by all GHSs at 3 h post-injection, whereas those animals treated with KP-102 and ghrelin exhibited depressions at 6 h. Four IGFBPs were identified in the plasma by western blotting. Levels of the 20 kDa IGFBP decreased over the sampling time. Levels of the 32 kDa IGFBP were significantly depressed by all GHSs tested. Levels of the 42 kDa IGFBP were significantly elevated by all GHSs tested. Plasma levels of the 50 kDa IGFBP was decreased in some treatment groups at 3 h, but elevated by 6 h in the ghrelin-treated groups and elevated in all treatment groups by 12 h post-injection. The endocrine and orexigenic responses demonstrate that GHSs influence the teleost neuroendocrine system beyond short-term actions (<3 h post-injection) on GH release and the responses of the IGFBPs to GHS treatment support this notion and clarify their identification as functional homologues to mammalian IGFBPs.

  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. Genetic variation underlying resistance to infectious hematopoietic necrosis virus in a steelhead trout (Oncorhynchus mykiss) population.

    PubMed

    Brieuc, Marine S O; Purcell, Maureen K; Palmer, Alexander D; Naish, Kerry A

    2015-11-17

    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.

  4. The orexinergic system in rainbow trout Oncorhynchus mykiss and its regulation by dietary lipids.

    PubMed

    Varricchio, Ettore; Russo, Finizia; Coccia, Elena; Turchini, Giovanni Mario; Francis, David Scott; Paolucci, Marina

    2015-08-01

    In this study, we report the distribution of orexin A (OXA), orexin B (OXB), and orexin receptor (OX2R) immunoreactive (ir) cells in the hypothalamus and gastrointestinal tract of Oncorhynchus mykiss fed diets with different dietary fatty acid compositions. Trout were fed five iso-energetic experimental diets containing fish oil, or one of four different vegetable oils (olive, sunflower, linseed, and palm oils) as the added dietary lipid source for 12 weeks. OXA, OXB, and OX2R immunoreactive neurons and nervous fibers were identified in the lateral and ventro-medial hypothalamus. OXA, OXB, and OX2R ir cells were found in the mucosa and glands of the stomach and in the mucosa of both the pyloric cecae and intestine. OX2R ir cells were localized in the mucosa layer of both the pyloric cecae and intestine. These immunohistochemical (IHC) results were confirmed via Western blotting. Antibodies against preproorexin (PPO) crossreacted with a band of ∼16 kDa in the hypothalamus, stomach, pyloric cecae, and intestine. Antibodies against OX2R crossreacted with a band of ∼38 kDa in the hypothalamus, pyloric cecae, and intestine. The presence and distribution of OXA, OXB, and OX2R ir cells in the hypothalamus and gastrointestinal tract did not appear to be affected by dietary oils. The presence of orexin system immunoreactive cells in the stomach, pyloric cecae, and intestine of rainbow trout, but not in the enteric nervous system, could suggest a possible role of these peptides as signaling of gastric emptying or endocrine modulation, implying a main local action played by orexins.

  5. Intramuscular challenge of rainbow trout (Oncorhynchus mykiss) with two Norwegian field strains of Flavobacterium psychrophilum.

    PubMed

    Fredriksen, Børge N; Furevik, Anette; Gauthier, David; Egenberg, Marie; Paulsen, Erik D; Brudeseth, Bjørn

    2013-08-01

    In recent years there has been an increasing occurrence of Flavobacterium psychrophilum infections in farmed salmonids in Norway. The current study describes two field isolates of F. psychrophilum collected from farmed rainbow trout (Oncorhynchus mykiss) fingerlings and post smolts in Norway. Virulence of the two isolates was tested in vivo by intramuscular (IM) and/or intraperitoneal (IP) challenge of disease free, un-vaccinated rainbow trout. The isolates were concluded to be highly virulent compared to a reference isolate as they yielded high mortality after IM challenge even at low challenge doses. The more virulent of the two isolates was further used to establish a challenge model to evaluate the efficacy of vaccines against infections with F. psychrophilum. Three groups were included in the vaccination-challenge study; a vaccinated group given a 6 antigen (Ag) component vaccine containing F. psychrophilum antigens (6 Ag/F.psy(+)), a control vaccinated group administered a similar 5 antigen component vaccine without F. psychrophilum antigens (5 Ag/F.psy(-)), and a non-injected negative control group. Results from the IM challenge demonstrated that 1) our challenge model is able to discriminate between protected and unprotected experimental groups and 2) that the vaccine induced protection is specific against F. psychrophilum as mortality in the 5 Ag/F.psy(-) group was equally high as in the negative control, while the 6 Ag/F.psy(+) induced a high level of protection (RPS60 = 86.7%). The present study is one of the first to describe protection against F. psychrophilum infections induced by a multicomponent injection vaccine.

  6. Flavobacterium oncorhynchi sp. nov., a new species isolated from rainbow trout (Oncorhynchus mykiss).

    PubMed

    Zamora, L; Fernández-Garayzábal, J F; Svensson-Stadler, L A; Palacios, M A; Domínguez, L; Moore, E R B; Vela, A I

    2012-03-01

    Eighteen isolates of a Gram-negative, catalase and oxidase-positive, rod-shaped bacterium, recovered from diseased rainbow trout (Oncorhynchus mykiss), were characterized, using a polyphasic taxonomic approach. Studies based on comparative 16S rRNA gene sequence analysis showed that that the eighteen new isolates shared 99.2-100% sequence similarities. Phylogenetic analysis revealed that isolates from trout belonged to the genus Flavobacterium, showing the highest sequence similarities to F. chungangense (98.6%), F. frigidimaris (98.1%), F. hercynium (97.9%) and F. aquidurense (97.8%). DNA-DNA reassociation values between the trout isolates (exemplified by strain 631-08(T)) and five type strains of the most closely related Flavobacterium species exhibited less than 27% similarity. The G+C content of the genomic DNA was 33.0 mol%. The major respiratory quinone was observed to be menaquinone 6 (MK-6) and iso-C(15:0), C(15:0) and C(16:1) ω7c the predominant fatty acids. The polar lipid profile of strain 631-08(T) consisted of phosphatidylethanolamine, unknown aminolipids AL1 and AL3, lipids L1, L2, L3 and L4 and phospholipid PL1. The novel isolates were differentiated from related Flavobacterium species by physiological and biochemical tests. On the basis of the evidence from this polyphasic study, it is proposed that the isolates from rainbow trout be classified as a new species of the genus Flavobacterium, Flavobacterium oncorhynchi sp. nov. The type strain is 631-08(T) (= CECT 7678(T) = CCUG 59446(T)).

  7. Potential effects of changes in temperature and food resources on life history trajectories of juvenile Oncorhynchus mykiss

    USGS Publications Warehouse

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

    2013-01-01

    Increasing temperatures and changes in food resources owing to climate change may alter the growth and migratory behavior of organisms. This is particularly important for salmonid species like Oncorhynchus mykiss, where some individuals remain in freshwater to mature (nonanadromous Rainbow Trout) and others migrate to sea (anadromous Steelhead). Whether one strategy is adopted over the other may depend on the individual's growth and size. In this study, we explored (1) how water temperature in Beaver Creek, a tributary to the Methow River, Washington, may increase under four climate scenarios, (2) how these thermal changes may alter the life history trajectory followed by O. mykiss (i.e., when and if to smolt), and (3) how changes in food quality or quantity might interact with increasing temperatures. We combined bioenergetic and state-dependent life history models parameterized for O. mykiss in Beaver Creek to mimic baseline life history trajectories. Based on our simulations, when mean water temperature was increased by 0.6°C there was a reduction in life history diversity and a 57% increase in the number of individuals becoming smolts. When mean temperature was increased by 2.7°C, it resulted in 87% fewer smolts than in the baseline and fewer life history trajectories expressed. A reduction in food resources led to slower growth, more life history trajectories, and a greater proportion of smolts. In contrast, when food resources were increased, fish grew faster, which reduced the proportion of smolts and life history diversity. Our modeling suggests that warmer water temperatures associated with climate change could decrease the life history diversity of O. mykiss in the central portion of their range and thereby reduce resiliency to other disturbances. In addition, changes in food resources could mediate or exacerbate the effect of water temperature on the life history trajectories of O. mykiss.

  8. 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...

  9. The effects of ozone and water exchange rates on water quality and rainbow trout Oncorhynchus mykiss performance in replicated water recirculating systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rainbow trout Oncorhynchus mykiss performance and water quality were evaluated and compared within six replicated 9.5 cubic meter water recirculating aquaculture systems (WRAS) operated with and without ozone at various water exchange rates. Three separate studies were conducted: 1) low water exchan...

  10. Evaluation of supplemental fish bone meal made from Alaska seafood processing byproducts and dicalcium phosphate in plant-protein based diets for rainbow trout (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report performance of rainbow trout (Oncorhynchus mykiss) fed a balanced dietary mix of plant-proteins supplemented with either fish bone meal (FBM) derived from Alaskan seafood processing byproducts or dicalcium phosphate. Seven experimental diets were formulated to contain two levels of dicalci...

  11. Dataset of proinflammatory cytokine and cytokine receptor gene expression in rainbow trout (Oncorhynchus mykiss) measured using a novel GeXP multiplex, RT-PCR assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A GeXP multiplex, RT-PCR assay was developed and optimized that simultaneously measures expression of a suite of immune-relevant genes in rainbow trout (Oncorhynchus mykiss), concentrating on tumor necrosis factor and interleukin-1 ligand/receptor systems and acute phase response genes. The dataset ...

  12. 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...

  13. Comparing the effects of high vs. low nitrate on the health, performance, and welfare of juvenile rainbow trout Oncorhynchus mykiss within water recirculating aquaculture systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research indicates that rainbow trout (Oncorhynchus mykiss) begin to exhibit health and welfare problems when cultured within water recirculating aquaculture systems (WRAS) operated at low exchange (6.7 days hydraulic retention time) and a mean feed loading rate of 4.1 kg feed/m3 daily make...

  14. 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.

  15. 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.

  16. Renal responses to acute lead waterborne exposure in the freshwater rainbow trout (Oncorhynchus mykiss).

    PubMed

    Patel, Monika; Rogers, Joseph T; Pane, Eric F; Wood, Chris M

    2006-12-30

    The possible nephrotoxic effects of waterborne lead exposure (as Pb(NO3)2) were investigated in the freshwater rainbow trout (Oncorhynchus mykiss). Kidney lead accumulation was time-dependent, increasing upon exposure to 0.57+/-0.01 mg dissolved Pb L(-1) for up to 96 h with a significantly higher burden occurring in the posterior kidney compared to the anterior segment. Urine analyses in trout exposed to 1.20+/-0.09 mg dissolved Pb L(-1) revealed a significant increase in urinary lead excretion rate throughout 96 h of exposure. Urine flow rate and glomerular filtration rate (GFR) were not impacted with the exception of a significant decrease in GFR from 84 to 96 h in lead-exposed trout. Urine pH decreased significantly over time in lead-exposed fish. Correspondingly, urine ammonia excretion rate showed a marked increase from 48 h onwards. In experimental fish, urine glucose excretion was significantly greater by 96 h while urine lactate, urea and protein excretion were not significantly altered by lead exposure. The urine excretion rate of Ca2+ increased significantly by approximately 43% after only 24 h of lead exposure, and was maintained at a higher rate than controls for up to 96 h. Magnesium excretion increased in a time-dependent fashion, reaching a two- to three-fold rise by 96 h. In contrast, rates of Na+ and Cl- excretion were decreased in experimental fish by approximately 30% by 48 h, this trend continuing for the duration of lead-exposure. There were no changes in any of these parameters in similarly treated control fish. Clearance ratio analyses indicated progressive decreases in the net reabsorption efficiencies of the renal system for Ca2+, Mg2+, Pb, and glucose, suggesting that the active tubular transport mechanisms for these substances were inhibited by lead exposure, while Na+, K+, Cl-, lactate, and protein reabsorptions were unaffected. Net ammonia secretion increased. We conclude that changes in renal function both reflect and help to minimize

  17. 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

  18. Toxicogenomic responses in rainbow trout (Oncorhynchus mykiss) hepatocytes exposed to model chemicals and a synthetic mixture.

    PubMed

    Finne, E F; Cooper, G A; Koop, B F; Hylland, K; Tollefsen, K E

    2007-03-10

    As more salmon gene expression data has become available, the cDNA microarray platform has emerged as an appealing alternative in ecotoxicological screening of single chemicals and environmental samples relevant to the aquatic environment. This study was performed to validate biomarker gene responses of in vitro cultured rainbow trout (Oncorhynchus mykiss) hepatocytes exposed to model chemicals, and to investigate effects of mixture toxicity in a synthetic mixture. Chemicals used for 24h single chemical- and mixture exposures were 10 nM 17alpha-ethinylestradiol (EE2), 0.75 nM 2,3,7,8-tetrachloro-di-benzodioxin (TCDD), 100 microM paraquat (PQ) and 0.75 microM 4-nitroquinoline-1-oxide (NQO). RNA was isolated from exposed cells, DNAse treated and quality controlled before cDNA synthesis, fluorescent labelling and hybridisation to a 16k salmonid microarray. The salmonid 16k cDNA array identified differential gene expression predictive of exposure, which could be verified by quantitative real time PCR. More precisely, the responses of biomarker genes such as cytochrome p4501A and UDP-glucuronosyl transferase to TCDD exposure, glutathione reductase and gammaglutamyl cysteine synthetase to paraquat exposure, as well as vitellogenin and vitelline envelope protein to EE2 exposure validated the use of microarray applied to RNA extracted from in vitro exposed hepatocytes. The mutagenic compound NQO did not result in any change in gene expression. Results from exposure to a synthetic mixture of the same four chemicals, using identical concentrations as for single chemical exposures, revealed combined effects that were not predicted by results for individual chemicals alone. In general, the response of exposure to this mixture led to an average loss of approximately 60% of the transcriptomic signature found for single chemical exposure. The present findings show that microarray analyses may contribute to our mechanistic understanding of single contaminant mode of action as well

  19. Functionalization impacts the effects of carbon nanotubes on the immune system of rainbow trout, Oncorhynchus mykiss.

    PubMed

    Klaper, Rebecca; Arndt, Devrah; Setyowati, Kristin; Chen, Jian; Goetz, Frederick

    2010-10-15

    Recent studies have demonstrated the potential for manufactured nanomaterials to reach the aquatic environment. There is a need to determine if these materials will have an impact on aquatic species and at what level of exposure. In addition there is a need to develop models to test the potential effects of the multitude of particle types in production on aquatic vertebrates. The purpose of this research was to determine the impact of manufactured nanomaterials on the immune system of an aquatic vertebrate model, the rainbow trout (Oncorhynchus mykiss). We investigated how structure and type of functionalization of manufactured nanomaterials could affect immunotoxicity. To assess immunotoxicity, we used a well-studied trout macrophage primary cell culture system in conjunction with the expression of IL-1β and IFNα for proinflammatory and antiviral gene expression. There was a significant difference among the different carbon nanotube-based nanomaterials in their level of stimulation of IL-1β in macrophage cells and the dose at which they became stimulatory. At concentrations that were sublethal to cells, almost all nanomaterials were stimulatory at some concentration. Single-walled nanotubes and multi-walled nanotubes that were differentially functionalized to be water-soluble, varied in their effects; specifically the concentrations at which they were stimulatory and they were more stimulatory to IL-1β expression compared with unfunctionalized nanotubes. Each functionalized nanotube type caused a dose-dependent response with the lowest exposures (0.05-1.0 μg/ml) having no stimulatory response and at the highest concentrations (5 μg/ml and 10 μg/ml) stimulating a response similar to the positive LPS positive control. Anionic functionalized multi-walled nanotubes and zwitterionic single-walled nanotubes were stimulatory at the lowest dose (0.5 μg/ml). Sodium deoxycholate, often used to suspend nanomaterials, was also tested and was as stimulatory to the

  20. 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

  1. Gene expression patterns in rainbow trout, Oncorhynchus mykiss, exposed to a suite of model toxicants.

    PubMed

    Hook, Sharon E; Skillman, Ann D; Small, Jack A; Schultz, Irvin R

    2006-05-25

    The increased availability and use of DNA microarrays has allowed the characterization of gene expression patterns associated with exposure to different toxicants. An important question is whether toxicant induced changes in gene expression in fish are sufficiently diverse to allow for identification of specific modes of action and/or specific contaminants. In theory, each class of toxicant may generate a gene expression profile unique to its mode of toxic action. In this study, isogenic (cloned) rainbow trout Oncorhynchus mykiss were exposed to sublethal levels of a series of model toxicants with varying modes of action, including ethynylestradiol (xeno-estrogen), 2,2,4,4'-tetrabromodiphenyl ether (BDE-47, thyroid active), diquat (oxidant stressor), chromium VI, and benzo[a]pyrene (BaP) for a period of 1-3 weeks. An additional experiment measured trenbolone (anabolic steroid; model androgen) induced gene expression changes in sexually mature female trout. Following exposure, fish were euthanized, livers removed and RNA extracted. Fluorescently labeled cDNA were generated and hybridized against a commercially available Atlantic Salmon/Trout array (GRASP project, University of Victoria) spotted with 16,000 cDNA's. The slides were scanned to measure abundance of a given transcript in each sample relative to controls. Data were analyzed via Genespring (Silicon Genetics) to identify a list of up- and downregulated genes, as well as to determine gene clustering patterns that can be used as "expression signatures". The results indicate each toxicant exposure caused between 64 and 222 genes to be significantly altered in expression. Most genes exhibiting altered expression responded to only one of the toxicants and relatively few were co-expressed in multiple treatments. For example, BaP and Diquat, both of which exert toxicity via oxidative stress, upregulated 28 of the same genes, of over 100 genes altered by either treatment. Other genes associated with steroidogenesis

  2. 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.

  3. 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

  4. 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

  5. Growth hormone receptors in ovary and liver during gametogenesis in female rainbow trout (Oncorhynchus mykiss).

    PubMed

    Gomez, J M; Mourot, B; Fostier, A; Le Gac, F

    1999-03-01

    Changes of growth hormone receptivity in the ovary during the reproductive cycle were studied in rainbow trout (Oncorhynchus mykiss). A method for characterizing growth hormone receptors in crude ovary homogenate was required for this. Binding of radiolabelled recombinant rainbow trout growth hormone (125I-labelled rtGH) to crude ovary preparation was dependent on ovarian tissue concentration. The sites were specific to growth hormone, with no affinity for prolactins and gonadotrophins. Similar high affinities for 125I-labelled rtGH were obtained with crude ovary (4.2 x 10(9) +/- 0.3 mol l-1) and crude liver preparations (4.9 x 10(9) +/- 0.1 mol l-1) at all stages of ovogenesis, and with ovarian membrane preparations (8.2 x 10(9) mol l-1) tested at the beginning of vitellogenesis. Ovarian growth hormone receptor concentration was highest during the early phases of follicular development (endogenous vitellogenesis: 315-310 fmol g-1 ovary) and decreased regularly during oocyte and follicular growth (exogenous vitellogenesis) to reach a minimal value at oocyte maturation (42 fmol g-1 ovary). In postovulated fish, binding was at a similar level (297 fmol g-1 ovary) to that found in endogenous vitellogenesis. Conversely, the absolute binding capacity of the whole ovary was low from immaturity to early exogenous vitellogenesis (0.1-0.6 pmol per pair of gonads), increased slowly during vitellogenesis and more markedly during rapid oocyte growth and at the time of final maturation (10.8 pmol per pair of gonads). In postovulated fish, the absolute binding capacity decreased partially (4.4 pmol per pair of gonads). Mean hepatic growth hormone receptor concentration did not vary with the reproductive stage for most of the cycle (3.0-4.5 pmol g-1 liver) except in endogenous vitellogenesis where significantly higher concentrations were observed (6.7 pmol g-1 liver). Individual ovarian growth hormone receptor concentrations were correlated with hepatic growth hormone receptor

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Behavioral response of young rainbow trout (Oncorhynchus mykiss) to forest fire-retardant chemicals in the laboratory.

    PubMed

    Wells, Jason B; Little, Edward E; Calfee, Robin D

    2004-03-01

    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.

  12. Severe, chronic proliferative kidney disease (PKD) induced in rainbow trout Oncorhynchus mykiss held at a constant 18 degrees C.

    PubMed

    Morris, D J; Ferguson, H W; Adams, A

    2005-09-23

    Proliferative kidney disease (PKD), caused by the myxozoan parasite Tetracapsuloides bryosalmonae, is well documented as a seasonal disease of rainbow trout Oncorhynchus mykiss. Water temperatures influence the course of the infection both within the fish and the invertebrate host, the recovery of fish from the disease being accelerated with decreasing water temperatures. During this study, groups of rainbow trout were held at a constant temperature (18 degrees C) for a sustained period of time following initial exposure to T. bryosalmonae. While the majority of these fish had recovered from the clinical disease after 9 mo, 10% remained infected, showing clinical signs of disease. A histological study revealed that the majority exhibited very high parasite loads and unusually severe symptoms of PKD. This demonstrates that while most rainbow trout can recover from PKD independent of water temperature, there exists a sub-population that cannot.

  13. 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

  14. 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.

  15. Behavioural type in newly emerged steelhead Oncorhynchus mykiss does not predict growth rate in a conventional hatchery rearing environment.

    PubMed

    Conrad, J L; Sih, A

    2009-10-01

    Behavioural assays were conducted on newly emerged steelhead Oncorhynchus mykiss to investigate the presence of behavioural syndromes and to determine whether behavioural type in young fish predicts growth rate in a conventional hatchery rearing environment. Individual fry were consistent in their position choice and activity behaviours across safe and unsafe contexts, as well as among assays conducted on different days. Position choice and activity behaviours, however, were not necessarily correlated to each other. Both behaviours predicted feeding rates during behavioural assays, but there was no relationship between fry behaviour and subsequent growth rate or survival during the first 3 months of hatchery rearing. These results support the hypothesis that selection in captivity may be relaxed with respect to behavioural type rather than directional, allowing for increased behavioural variance in domesticated populations. Modest magnitudes of correlations among fry behaviours, however, suggest that behavioural type may be unstable at the onset of the juvenile feeding stage.

  16. A new species of myxozoan (Myxosporea) from the brain and spinal cord of rainbow trout (Oncorhynchus mykiss) from Idaho.

    PubMed

    Hogge, Carla I; Campbell, Matthew R; Johnson, Keith A

    2008-02-01

    A new species of Myxosporea, Myxobolus neurotropus n. sp., is described from the brain and spinal cord of rainbow trout (Oncorhynchus mykiss) from Duncan Creek, Owyhee County, Idaho. Spores are oval, have 2 pyriform polar capsules, and possess a thick spore wall (sutural rim) with a short intracapsular offshoot. The mean spore dimensions are length 11.8 microm, width 10.8 microm, and thickness 8.8 microm. This myxozoan is compared to other described Myxobolus species found in cranial tissues of salmonids in terms of spore morphology and phylogenetic analysis. Because it is found in brain and spinal cord, it is encountered while performing screening tests for Myxobolus cerebralis, the causative agent of salmonid whirling disease. Where chronic inflammation and granulomatous lesions are associated with M. cerebralis, histological examination shows no host response to M. neurotropus n. sp. A diagnostic polymerase chain reaction (PCR) test is included as an aid in properly identifying the species.

  17. 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.

  18. A loop mediated isothermal amplification (LAMP) method for detection of infectious hematopoietic necrosis virus (IHNV) in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Gunimaladevi, I; Kono, T; Lapatra, S E; Sakai, M

    2005-05-01

    A reverse transcription loop-mediated isothermal amplification (RT-LAMP) protocol was developed for detection of infectious hematopoietic necrosis virus (IHNV) RNA in rainbow trout (Oncorhynchus mykiss). A set of four primers, two outer and two inner primers for the RT-LAMP and the LAMP assay, were designed based on the sequence of G-protein of IHNV. Time and temperature conditions were optimized for 60 min at 63 degrees C for both RT-LAMP and LAMP protocols. The detection limit was found to be similar for both RT-LAMP and LAMP. When the sensitivity of RT-LAMP and LAMP were compared with conventional nested PCR, a10-fold higher sensitivity was seen for the LAMP protocols.

  19. 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.

  20. Effect of acetaminophen exposure in Oncorhynchus mykiss gills and liver: detoxification mechanisms, oxidative defence system and peroxidative damage.

    PubMed

    Ramos, A S; Correia, A T; Antunes, S C; Gonçalves, F; Nunes, B

    2014-05-01

    The increasing presence of pharmaceutical drugs in nature is cause of concern due to the occurrence of oxidative stress in non-target species. Acetaminophen is widely used in human medicine as an analgesic and antipyretic drug, and it is one of the most sold non-prescription drugs. The present study aimed to assess the toxic effects of acetaminophen (APAP) in Oncorhynchus mykiss following acute and chronic exposures in realistic levels. In order to evaluate the APAP effects in the rainbow trout, gills and liver were analyzed with biochemical biomarkers, such as catalase (CAT), total and selenium-dependent glutathione peroxidase (GPx), glutathione reductase (GRed) and glutathione-S-transferases (GSTs) activity and also lipid peroxidation levels (TBARS). The results obtained in all tests indicate that a significant response of oxidative stress was established, along with the increase of APAP concentrations. The establishment of an oxidative stress scenario occurred with the involvement of all tested biomarkers, sustaining a generalized set of pro-oxidative effects elicited by APAP. Additionally, the occurrence of oxidative damage strongly suggests the impairment of the antioxidant defense mechanism of O. mykiss. It is important to note that the occurrence of oxidative deleterious effects and peroxidative damages occurred for concentrations similar to those already reported for several freshwater ecosystems. The importance of these assumptions is further discussed under the scope of ecological relevance of the assessment of effects caused by pharmaceuticals in non-target organisms.

  1. 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.

  2. Ecological interactions between hatchery summer steelhead and wild Oncorhynchus mykiss in the Willamette River basin, 2014

    SciTech Connect

    Harnish, Ryan A.; Green, Ethan D.; Vernon, Christopher R.; Mcmichael, Geoffrey A.

    2014-12-01

    The purpose of this study was to determine the extent to which juvenile hatchery summer steelhead and wild winter steelhead overlap in space and time, to evaluate the extent of residualism among hatchery summer steelhead in the South Santiam River, and to evaluate the potential for negative ecological interactions among hatchery summer steelhead and wild winter steelhead. Because it is not possible to visually discern juvenile winter steelhead from resident rainbow trout, we treated all adipose-intact juvenile O. mykiss as one group that represented juvenile wild winter steelhead. The 2014 study objectives were to 1) estimate the proportion of hatchery summer steelhead that residualized in the South Santiam River in 2014, 2) determine the extent to which hatchery and naturally produced O. mykiss overlapped in space and time in the South Santiam River, and 3) characterize the behavioral interactions between hatchery-origin juvenile summer steelhead and naturally produced O. mykiss. We used a combination of radio telemetry and direct observations (i.e., snorkeling) to determine the potential for negative interactions between hatchery summer and wild winter steelhead juveniles in the South Santiam River. Data collected from these two independent methods indicated that a significant portion of the hatchery summer steelhead released as smolts did not rapidly emigrate from the South Santiam River in 2014. Of the 164 radio-tagged steelhead that volitionally left the hatchery, only 66 (40.2%) were detected outside of the South Santiam River. Forty-four (26.8% of 164) of the radio-tagged hatchery summer steelhead successfully emigrated to Willamette Falls. Thus, the last known location of the majority of the tagged fish (98 of 164 = 59.8%) was in the South Santiam River. Thirty-three of the tagged hatchery steelhead were detected in the South Santiam River during mobile-tracking surveys. Of those, 21 were found to be alive in the South Santiam River over three months after

  3. A bioinformatics-based update on microRNAs and their targets in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Yang, Liandong; He, Shunping

    2014-01-01

    MicroRNAs (miRNAs) participate in various vitally biological processes via controlling target genes activity and thousands of miRNAs have been identified in many species to date, including 18,698 known animal miRNA in miRBase. However, there are only limited studies reported in rainbow trout (Oncorhynchus mykiss) especially via the computational-based approaches. In present study, we systematically investigated the miRNAs in rainbow trout using a well-developed comparative genome-based homologue search. A total of 196 potential miRNAs, belonging to 124 miRNA families, were identified, most of which were firstly reported in rainbow trout. The length of miRNAs ranged from 17 to 24 nt with an average of 20 nt while the length of their precursors varied from 47 to 152 nt with an average of 85 nt. The identified miRNAs were not evenly distributed in each miRNA family, with only one member per family for a majority, and multiple members were also identified for several families. Nucleotide U was dominant in the pre-miRNAs with a percentage of 30.04%. The rainbow trout pre-miRNAs had relatively high negative minimal folding free energy (MFE) and adjusted MFE (AMFE). Not only the mature miRNAs but their precursor sequences are conserved among the living organisms. About 2466 O. mykiss genes were predicted as potential targets for 189 miRNAs. Gene Ontology (GO) analysis showed that nearly 2093, 2107, and 2081 target genes are involved in cellular component, molecular function, and biological processes respectively. KEGG pathway enrichment analysis illuminated that these miRNAs targets might regulate 105 metabolic pathways, including those of purine metabolism, nitrogen metabolism, and oxidative phosphorylation. This study has provided an update on rainbow trout miRNAs and their targets, which represents a foundation for future studies.

  4. Growth of juvenile steelhead Oncorhynchus mykiss under size-selective pressure limited by seasonal bioenergetic and environmental constraints

    USGS Publications Warehouse

    Thompson, Jamie N.; Beauchamp, David A.

    2016-01-01

    Increased freshwater growth of juvenile steelhead Oncorhynchus mykiss improved survival to smolt and adult stages, thus prompting an examination of factors affecting growth during critical periods that influenced survival through subsequent life stages. For three tributaries with contrasting thermal regimes, a bioenergetics model was used to evaluate how feeding rate and energy density of prey influenced seasonal growth and stage-specific survival of juvenile O. mykiss. Sensitivity analysis examined target levels for feeding rate and energy density of prey during the growing season that improved survival to the smolt and adult stages in each tributary. Simulated daily growth was greatest during warmer months (1 July to 30 September), whereas substantial body mass was lost during cooler months (1 December to 31 March). Incremental increases in annual feeding rate or energy density of prey during summer broadened the temperature range at which faster growth occurred and increased the growth of the average juvenile to match those that survived to smolt and adult stages. Survival to later life stages could be improved by increasing feeding rate or energy density of the diet during summer months, when warmer water temperatures accommodated increased growth potential. Higher growth during the summer period in each tributary could improve resiliency during subsequent colder periods that lead to metabolic stress and weight loss. As growth and corresponding survival rates in fresh water are altered by shifting abiotic regimes, it will be increasingly important for fisheries managers to better understand the mechanisms affecting growth limitations in rearing habitats and what measures might maintain or improve growth conditions and survival.

  5. Mitochondrial DNA variation in rainbow trout (Oncorhynchus mykiss) across its native range: testing biogeographical hypotheses and their relevance to conservation.

    PubMed

    McCusker, M R; Parkinson, E; Taylor, E B

    2000-12-01

    North-western North America has been repeatedly glaciated over most of the past two million years, with the most recent glaciation occurring between 60 000 and 10 000 years ago. Intraspecific genetic variation in many species has been shaped by where they survived glaciation and what postglacial recolonization routes were used. In this study, molecular techniques were used to investigate biogeographical, taxonomic and conservation issues in rainbow trout, Oncorhynchus mykiss. Mitochondrial DNA (mtDNA) variation was assessed using a restriction fragment length polymorphism (RFLP) analysis, focusing mainly on the previously understudied northern extent of the species' range. Two phylogenetically distinct mitochondrial lineages were found that differed from each other by up to 1.8% in sequence. Although the geographical distributions of the two clades overlap extensively, diversity and distributional analyses strongly suggest that trout survived glaciation in both coastal and inland refugia followed by postglacial gene flow and secondary contact. Postglacial dispersal into British Columbia most likely occurred from the Queen Charlotte Islands and the Columbia River. Although trout most likely also survived glaciation along the coast of Washington, Oregon and California, as well as near the Bering Strait, evidence suggests that dispersal into British Columbia from these areas was limited. Sequence analysis of mitochondrial haplotypes revealed higher diversity in California than in the northern part of the species' range, indicating an ancient presence of the species in the south. Phylogeographic divergence probably predates adaptive variation in the species as suggested by evidence for parallel evolution of life history types across the range of O. mykiss.

  6. 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.

  7. 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.

  8. Evaluation of strobe lights to reduce turbine entrainment of juvenile steelhead (Oncorhynchus mykiss) at Cowlitz Falls Dam, Washington

    USGS Publications Warehouse

    Kock, Tobias J.; Evans, Scott D.; Liedtke, Theresa L.; Rondorf, Dennis W.; Kohn, Mike

    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.

  9. Central effects of native urotensin II on motor activity, ventilatory movements, and heart rate in the trout Oncorhynchus mykiss.

    PubMed

    Lancien, Frédéric; Leprince, Jérôme; Mimassi, Nagi; Mabin, Dominique; Vaudry, Hubert; Le Mével, Jean-Claude

    2004-10-15

    Urotensin II (UII) has been originally isolated from fish urophysis. However, in fish as in mammals, UII is also produced in brain neurons. Although UII binding sites are widely distributed in the fish central nervous system (CNS), little is known regarding its central activities. In the present study, we have investigated the effects of intracerebroventricular (ICV) administration of synthetic trout UII on the duration of motor activity (ACT; evidenced by bursts of activity on the trace of the ventilatory signal), ventilatory frequency (VF), ventilatory amplitude (VA), and heart rate (HR) in unanesthesized trout, Oncorhynchus mykiss. ICV injection of very low doses of UII (1 and 5 pmol) produced a dose-dependent increase of ACT without affecting VF, VA, or HR. At a higher dose (50 pmol), UII stimulated ACT as well as VF, VA, and HR. ICV injection of trout angiotensin II (5 pmol) did not affect ACT, VF, and VA, but provoked a robust increase in HR. These data provide the first evidence that central administration of UII stimulates motor activity in a nonmammalian vertebrate.

  10. 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.

  11. 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.

  12. 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.

  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. 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.

  15. Intestinal nematodes affect selenium bioaccumulation, oxidative stress biomarkers, and health parameters in juvenile rainbow trout (Oncorhynchus mykiss).

    PubMed

    Hursky, Olesya; Pietrock, Michael

    2015-02-17

    In environmental studies, parasites are often seen as a product of enhanced host susceptibility due to exposure to one or several stressors, whereas potential consequences of infections on host responses are often overlooked. Therefore, the present study focused on effects of parasitism on bioaccumulation of selenium (Se) in rainbow trout (Oncorhynchus mykiss). Joint effects of biological (parasite) and chemical (Se) stressors on biomarkers of oxidative stress (glutathione-S-transferase (GST), superoxide dismutase (SOD)), and fish health (condition factor (K), hepatosomatic index (HSI), gross energy) were also examined. Fish of the control group received uncontaminated food, while test fish, either experimentally infected with the nematode Raphidascaris acus or not, were exposed to dietary selenomethionine (Se-Met) at an environmentally relevant dose over 7 weeks. Selenium bioaccumulation by the parasite was low relative to its host, and parasitized trout showed slowed Se accumulation in the muscle as compared to uninfected fish. Furthermore, GST and SOD activities of trout exposed to both Se-Met and parasites were generally significantly lower than in fish exposed to Se-Met alone. Gross energy concentrations, but not K or HSI, were reduced in fish exposed to both Se-Met and R. acus. Together the experiment strongly calls for consideration of parasites when interpreting effects of pollutants on aquatic organisms in field investigations.

  16. Effects of sodium chloride on chronic silver toxicity to early life stages of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Dethloff, Gail M; Naddy, Rami B; Gorsuch, Joseph W

    2007-08-01

    The chronic (early life stage) toxicity of silver to rainbow trout (Oncorhynchus mykiss) was determined in flow-through exposures. Rainbow trout embryos were exposed to silver (as AgNO3) from 48 h or less postfertilization to 30 d postswimup in soft water in the presence and absence of 49 mg/L of NaCl (30 mg/L of Cl). The studies determined effect levels for rainbow trout exposed throughout an extended development period and assessed possible protective effects of sodium chloride. Lowest-observed-effect concentrations were greater than 1.25 microg/L of dissolved silver for survival, mean day to hatch, mean day to swimup, and whole-body sodium content in both studies. Whole-body silver concentrations increased significantly at 0.13 microg/L of dissolved silver in unmodified water and at 1.09 microg/L of dissolved silver in amended water. The maximum-acceptable toxicant concentration for growth was greater than 1.25 microg/L of dissolved silver in unmodified water and 0.32 microg/L of dissolved silver in amended water. Whole-body silver concentrations were more sensitive than survival and growth end points in unmodified water. Interpretation of sodium chloride effects on chronic silver toxicity to rainbow trout was complicated by differences in measured effect levels that were potentially the result of strain differences between test organisms in the two studies.

  17. 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

  18. Comparative embryotoxicity of pulp mill extracts in rainbow trout (Oncorhynchus mykiss), American flagfish (Jordanella floridae) and Japanese medaka (Oryzias latipes).

    PubMed

    Orrego, Rodrigo; Guchardi, John; Beyger, Lindsay; Krause, Rachelle; Holdway, Douglas

    2011-08-01

    This study evaluated the effects of Chilean pulp mill effluent extracts (untreated, primary and secondary treated pulp mill effluents), along with steroid standards (testosterone and 17β-estradiol) and a wood extractive standard (beta-sitosterol) on developing post-fertilized fish embryos. Our study included a cold freshwater species, rainbow trout (Oncorhynchus mykiss), and two warm freshwater species American flagfish (Jordanella floridae) and Japanese medaka (Oryzias latipes). Embryotoxicity results included delay in time to hatch and decreased hatchability but no significant egg and larvae mortality was observed in the pulp mill extract exposed embryos. By contrast, significant early hatching and increased hatchability were observed in beta-sitosterol exposed embryos, along with high mortality of testosterone exposed embryos across species. Teratogenic responses were observed in medaka embryos in all treatments. Abnormalities were detected starting at development stages 19-20 (2-4 somite stages) and included optical deformities (micro-opthalmia, 1 or 2 eyes) and lack of development of brains and hearts. Additionally, phenotypic sex identification of surviving offspring found female-biased sex-ratios in all treatments except testosterone across species. Overall, our study indicated that Chilean pulp and paper mill extractives caused embryotoxicity (post-fertilized embryos) across species and irrespective of the effluent treatment. The effects were mainly associated with delayed time to hatch, decreased hatchability, and species-specific teratogenesis.

  19. Effect of linear alkylbenzene sulphonate (LAS) on non-specific defence mechanisms in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Bakirel, Tülay; Keleş, Oya; Karataş, Süheyla; Ozcan, Mukaddes; Türkmen, Gülhan; Candan, Akin

    2005-01-26

    Linear alkylbenzene sulphonate (LAS) is among the most widely disseminated xenobiotics to enter waste streams and the aquatic environment. In the present investigation, we present a novel approach to evaluate in toxicity of LAS. The effects of sublethal levels (0.2 and 0.4 mg/l) of LAS on non-specific immune system, phagocytosis, respiratory burst and lyzosyme activity, and specific growth rate in the rainbow trout, Oncorhynchus mykiss, during a 54-day exposure were examined by a static bioassay test procedure. The phagocytic activity of leukocytes from fish exposed to 0.4 mg/l LAS statistically decreased compared with the control fish values. No significant reductions were observed in the extra-intracellular respiratory burst and lysozyme activities after exposure to LAS at any of the concentrations tested. The final body weight in fish groups exposed to the LAS were found to be significantly lower than in the control. The specific growth rate results also supported the result above. The results of this study showed sublethal doses (0.2-0.4 mg/l) of LAS caused to statistically insignificant suppression of non-specific immune system mechanisms excluding phagocytosis in fish at laboratory conditions. These doses of LAS may produce potential synergism on immune system when presented with other environmental pollutants.

  20. 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.

  1. 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

  2. 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

  3. The role of beaver in shaping steelhead trout (Oncorhynchus mykiss) habitat complexity and thermal refugia in a central Oregon stream

    NASA Astrophysics Data System (ADS)

    Consolati, F.; Wheaton, J. M.; Neilson, B. T.; Bouwes, N.; Pollock, M. M.

    2012-12-01

    The incised and degraded habitat of Bridge Creek, tributary to the John Day River in central Oregon, is thought to be limiting the local population of ESA-listed steelhead trout (Oncorhynchus mykiss). Restoration efforts for this watershed are aimed to improve their habitat through reconnecting the channel with portions of its former floodplain (now terraces) to increase stream habitat complexity and the extent of riparian vegetation. This is being done via the installation of over a hundred beaver dam support (BDS) structures that are designed to either mimic beaver dams or support existing beaver dams. The overall objective of this study is to determine if the BDS structures have had an effect on stream channel habitat complexity and thermal refugia in selected sections of Bridge Creek. Analysis of stream temperature data in restoration treatment and control areas will show the effects of beaver dams on stream temperature. Analysis of aerial imagery and high resolution topographic data will exhibit how the number and types of geomorphic units have changed after the construction of beaver dams. Combined, the results of this research are aimed to increase our understanding of how beaver dams impact fish habitat and stream temperature.

  4. Genetic characterization of hybridization and introgression between anadromous rainbow trout (Oncorhynchus mykiss irideus) and coastal cutthroat trout (O. clarki clarki).

    PubMed

    Young, W P; Ostberg, C O; Keim, P; Thorgaard, G H

    2001-04-01

    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.

  5. Effects of Using Tricaine Methanesulfonate and Metomidate before Euthanasia on the Contractile Properties of Rainbow Trout (Oncorhynchus mykiss) Myocardium

    PubMed Central

    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

  6. 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.

  7. Spatial Distribution of Gyrodactylus salmonis (Monogenea) on the Body of Captive Fingerling Oncorhynchus mykiss, Including Attachment Within the Olfactory Chamber.

    PubMed

    Lari, Ebrahim; Cone, David K; Goater, Cameron P; Pyle, Greg G

    2016-04-01

    Gyrodactylus salmonis is a common ectoparasite on the fins and body of North American salmonids in fresh water. In this study, the spatial distribution of G. salmonis on 60 captive hatchery-reared rainbow trout, Oncorhynchus mykiss , is reported. The highest parasite densities occurred on 5 × 5-mm(2) sections of the dorsal fin followed by the trunk, other fins, and the olfactory chamber, with the lowest densities on the head. The finding of infections within the olfactory chamber of 93% of the fish was unexpected. One possibility is that such infections represented spillover from high-density infrapopulations that occur on the skin and fins. However, this possibility is unlikely, because worm densities at various sites along the body surface of infected fish did not correlate with densities within the olfactory chamber. The parasite conceivably enters the chamber either via water incurrent or by crawling in from the head and subsequently remaining at this site to feed and reproduce. Results from scanning electron microscopy are consistent with physical modification to the olfactory epithelium associated with the attachment/reattachment of the opisthaptor and epithelial grazing.

  8. The first report of Gyrodactylus salaris Malmberg, 1957 (Platyhelminthes, Monogenea) on Italian cultured stocks of rainbow trout (Oncorhynchus mykiss Walbaum).

    PubMed

    Paladini, Giuseppe; Gustinelli, Andrea; Fioravanti, Maria L; Hansen, Haakon; Shinn, Andrew P

    2009-11-12

    The monogenean Gyrodactylus salaris Malmberg, 1957 is considered one of the most important parasites of wild salmonids in the European Community due to the heavy ecological and economical damage it has inflicted on Atlantic salmon (Salmo salar) parr populations. Rainbow trout (Oncorhynchus mykiss) is susceptible to G. salaris and can act as a suitable carrier host and, consequently, its trade in EU territory is restricted in relation to the status of "recognized free" zones. Despite the economic importance of rainbow trout farming in Italy, information on the Italian gyrodactylid fauna is lacking and prior to this study, G. salaris had not been officially reported. During a routine health examination of farmed rainbow trout stock throughout Central and Northern Italy in 2004-2005, five fish farms were found to be infected with G. salaris alongside three other gyrodactylids. Morphological and molecular characterisation confirmed the presence of G. salaris, Gyrodactylus teuchis Lautraite, Blanc, Thiery, Daniel et Vigneulle, 1999 and Gyrodactylus derjavinoides Malmberg, Collins, Cunningham et Jalali, 2007, while Gyrodactylus truttae Gläser, 1974 was identified by morphological analysis only. The findings from this study extend the distribution of G. salaris within Europe and highlight the importance of the rainbow trout trade in its dissemination.

  9. 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.

  10. Identification by in situ hybridization of segmented filamentous bacteria in the intestine of diarrheic rainbow trout (Oncorhynchus mykiss).

    PubMed

    Urdaci, M C; Regnault, B; Grimont, P A

    2001-01-01

    Nonculturable segmented filamentous bacteria (SFB) have been described in the gut of rats, mice and chickens, and 16S rRNA sequences for these organisms are available. These organisms, peripherically related to Clostridium phylogenetic group I, have been provisionally named 'Candidatus Arthromitus'. This work reports the observation of similar bacteria in the intestinal content of the distal intestine, preferentially, in the adult rainbow trout (Oncorhynchus mykiss) that exhibited episodic acute diarrhea, usually during the summer. Abdominal distension, intestinal fluid-mucus content and epithelium detachment were observed in trout. The demonstration that the observed microorganisms are bacteria and belong in the 'Candidatus Arthromitus' group was achieved by in situ hybridization with, respectively, a eubacterial probe and an oligonucleotide probe designed to react specifically with SFB 16S rRNA (encoded by the rrs gene) sequences. The sequenced rrs gene was compared with published sequences and found to be closely related to (although distinct from) other SFB sequences. Implication of these bacteria in trout diarrheic illness remains hypothetical.

  11. Modulation of innate immune response, mucosal parameters and disease resistance in rainbow trout (Oncorhynchus mykiss) upon synbiotic feeding.

    PubMed

    Hoseinifar, Seyed Hossein; Mirvaghefi, Alireza; Amoozegar, Mohammad Ali; Sharifian, Maryam; Esteban, M Ángeles

    2015-07-01

    The present study investigates the effects of dietary supplements of galactooligosaccharides (GOS), Pediococcus acidilactici and P. acidilactici + GOS on innate immune response, skin mucus as well as disease resistance of rainbow trout (Oncorhynchus mykiss) fingerlings (15.04 ± 0.52 g). After 8 weeks of feeding, several innate immune (lysozyme, alternative complement and respiratory burst activities) and skin mucus parameters (bactericidal activity against Streptococcus faecium, Streptococcus iniae, Serratia marcescens, Staphylococcus aureus and Escherichia coli and mucus protein content) were studied. The results indicated that the three supplemented diet significantly increased innate immune response and skin mucus parameters in rainbow trout. The highest innate immune response, skin mucus activity as well as protein level was observed in synbiotic fed fish. Furthermore, at the end of the feeding experiment, some fish were intraperitoneally injected with Streptococcus iniae to determine the disease resistance. The mortality of fingerlings fed supplemented diet was significantly lower than fish from control group being the lowest mortality recorded in synbiotic fed fish group.

  12. A putative serine protease, SpSsp1, from Saprolegnia parasitica is recognised by sera of rainbow trout, Oncorhynchus mykiss

    PubMed Central

    Minor, Kirsty L.; Anderson, Victoria L.; Davis, Katie S.; Van Den Berg, Albert H.; Christie, James S.; Löbach, Lars; Faruk, Ali Reza; Wawra, Stephan; Secombes, Chris J.; Van West, Pieter

    2014-01-01

    Saprolegniosis, the disease caused by Saprolegnia sp., results in considerable economic losses in aquaculture. Current control methods are inadequate, as they are either largely ineffective or present environmental and fish health concerns. Vaccination of fish presents an attractive alternative to these control methods. Therefore we set out to identify suitable antigens that could help generate a fish vaccine against Saprolegnia parasitica. Unexpectedly, antibodies against S. parasitica were found in serum from healthy rainbow trout, Oncorhynchus mykiss. The antibodies detected a single band in secreted proteins that were run on a one-dimensional SDS-polyacrylamide gel, which corresponded to two protein spots on a two-dimensional gel. The proteins were analysed by liquid chromatography tandem mass spectrometry. Mascot and bioinformatic analysis resulted in the identification of a single secreted protein, SpSsp1, of 481 amino acid residues, containing a subtilisin domain. Expression analysis demonstrated that SpSsp1 is highly expressed in all tested mycelial stages of S. parasitica. Investigation of other non-infected trout from several fish farms in the United Kingdom showed similar activity in their sera towards SpSsp1. Several fish that had no visible saprolegniosis showed an antibody response towards SpSsp1 suggesting that SpSsp1 might be a useful candidate for future vaccination trial experiments. PMID:25088077

  13. A putative serine protease, SpSsp1, from Saprolegnia parasitica is recognised by sera of rainbow trout, Oncorhynchus mykiss.

    PubMed

    Minor, Kirsty L; Anderson, Victoria L; Davis, Katie S; Van Den Berg, Albert H; Christie, James S; Löbach, Lars; Faruk, Ali Reza; Wawra, Stephan; Secombes, Chris J; Van West, Pieter

    2014-07-01

    Saprolegniosis, the disease caused by Saprolegnia sp., results in considerable economic losses in aquaculture. Current control methods are inadequate, as they are either largely ineffective or present environmental and fish health concerns. Vaccination of fish presents an attractive alternative to these control methods. Therefore we set out to identify suitable antigens that could help generate a fish vaccine against Saprolegnia parasitica. Unexpectedly, antibodies against S. parasitica were found in serum from healthy rainbow trout, Oncorhynchus mykiss. The antibodies detected a single band in secreted proteins that were run on a one-dimensional SDS-polyacrylamide gel, which corresponded to two protein spots on a two-dimensional gel. The proteins were analysed by liquid chromatography tandem mass spectrometry. Mascot and bioinformatic analysis resulted in the identification of a single secreted protein, SpSsp1, of 481 amino acid residues, containing a subtilisin domain. Expression analysis demonstrated that SpSsp1 is highly expressed in all tested mycelial stages of S. parasitica. Investigation of other non-infected trout from several fish farms in the United Kingdom showed similar activity in their sera towards SpSsp1. Several fish that had no visible saprolegniosis showed an antibody response towards SpSsp1 suggesting that SpSsp1 might be a useful candidate for future vaccination trial experiments.

  14. 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

  15. 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

  16. Organically bound tritium (OBT) formation in rainbow trout (Oncorhynchus mykiss): HTO and OBT-spiked food exposure experiments.

    PubMed

    Kim, S B; Shultz, C; Stuart, M; McNamara, E; Festarini, A; Bureau, D P

    2013-02-01

    In order to determine the rate of organically bound tritium (OBT) formation, rainbow trout (Oncorhynchus mykiss) were exposed to tritiated water (HTO) or OBT-spiked food. The HTO (in water) exposure study was conducted using a tritium activity concentration of approximately 7000 Bq/L and the OBT (in food) exposure study was conducted using a tritium activity concentration of approximately 30,000 Bq/L. Fish in both studies were expected to be exposed to similar tritium levels assuming 25% incorporation of the tritiated amino acids found in the food. Four different sampling campaigns of HTO exposure (Day 10, 30, 70, 140) and five different sampling campaigns of OBT-spiked food exposure (Day 9, 30, 70, 100, 140) were conducted to measure HTO and OBT activity concentrations in fish tissues. OBT depuration was also evaluated over a period of 30 days following the 140 d exposure studies. The results suggested that the OBT formation rate was slower when the fish were exposed to HTO compared to when the fish were ingesting OBT. In addition, the results indicated that OBT can bioaccumulate in fish tissues following OBT-spiked food exposure.

  17. Effects of didecyldimethylammonium chloride on the biochemistry, swimming performance, gill histology and disease resistance of juvenile rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Johnston, B.D.; Wood, A.W.; Farrell, A.P.; Kennedy, C.J.

    1995-12-31

    The acute lethal and sublethal toxicity of the antisapstain didecyldimethylammonium chloride (DDAC) to juvenile rainbow trout (Oncorhynchus mykiss) was investigated. The 96-h LC{sub 50} value in a flow-through exposure system was 0.4 mg-1{sup {minus}1}. Plasma cortisol, glucose and lactate levels were significantly elevated after an acute 24-h exposure to 0.4 mg-1{sup {minus}1}. Values for hepato-somatic index (HSI), haematocit, leucocrit, plasma haemoglobin, and liver glycogen remained unchanged. Swimming performance decreased significantly after exposure to 0.2 mg-1{sup {minus}1} for exposure durations of 12-h and 24-h and to 0.4 mg{sup {minus}1} for exposure durations of 12-h, 24-h, and 48-h. Scanning electron microscopic analysis revealed no gross lesions in gill epithelia as a result of toxicant exposure. In disease challenge experiments, exposure to sublethal concentrations of DDAC for 24-h did not effect the susceptibility of rainbow trout to the pathogen Vibrio anguilarum. Of a suite of toxicity tests, specific biochemical markers were unsatisfactory in revealing sublethal toxic effects. These were best revealed by an integrative measure of performance, namely swimming performance, but not disease resistance.

  18. In vitro and in vivo effects of phytoestrogens on protein turnover in rainbow trout (Oncorhynchus mykiss) white muscle.

    PubMed

    Cleveland, Beth M

    2014-09-01

    Soybeans and other legumes investigated as fishmeal replacements in aquafeeds contain phytoestrogens capable of binding to and activating estrogen receptors. Estradiol has catabolic effects in salmonid white muscle, partially through increases in protein turnover. The current study determines whether phytoestrogens promote similar effects. In rainbow trout (Oncorhynchus mykiss) primary myocyte cultures, the phytoestrogens genistein, daidzein, glycitein, and R- and S-equol reduced rates of protein synthesis and genistein, the phytoestrogen of greatest abundance in soy, also increased rates of protein degradation. Increased expression of the ubiquitin ligase fbxo32 and autophagy-related genes was observed with high concentrations of genistein (100 μM), and R- and S-equol (100 μM) also up-regulated autophagy-related genes. In contrast, low genistein concentrations in vitro (0.01-0.10 μM) and in vivo (5 μg/g body mass) decreased fbxo32 expression, suggesting a potential metabolic benefit for low levels of genistein exposure. Phytoestrogens reduced cell proliferation, indicating that effects of phytoestrogens extend from metabolic to mitogenic processes. Co-incubation of genistein with the estrogen receptor (ER) antagonist, ICI 182,780, ameliorated effects of genistein on protein degradation, but not protein synthesis or cell proliferation, indicating that effects of genistein are mediated through ER-dependent and ER-independent mechanisms. Collectively, these data warrant additional studies to determine the extent to which dietary phytoestrogens, especially genistein, affect physiological processes that impact growth and nutrient retention.

  19. Elemental signatures in otoliths of hatchery rainbow trout (Oncorhynchus mykiss): Distinctiveness and utility fo detecting origins and movement

    USGS Publications Warehouse

    Gibson-Reinemer, D. K.; Johnson, B.M.; Martinez, P.J.; Winkelman, D.L.; Koenig, A.E.; Woodhead, J.D.

    2009-01-01

    Otolith chemistry in freshwater has considerable potential to reveal patterns of origin and movement, which would benefit traditional fisheries management and provide a valuable tool to curb the spread of invasive and illicitly stocked species. We evaluated the relationship between otolith and water chemistry for five markers (Ba/Ca, Mn/Ca, Sr/ Ca, Zn/Ca, and 87Sr/86Sr) in rainbow trout (Oncorhynchus mykiss) using the existing hatchery system in Colorado and Wyoming, USA, to provide controlled, seminatural conditions. Otolith Ba/Ca, Sr/Ca, and 87Sr/86Sr reflected ambient levels, whereas Mn/Ca and Zn/Ca did not. Using only the markers correlated with water chemistry, we classified fish to their hatchery of origin with up to 96% accuracy when element and isotope data were used together. Large changes in 87Sr/Sr were evident in otolith transects, although subtler changes in Sr/Ca were also detectable. Our results suggest the relatively few otolith markers that reflect ambient chemistry can discriminate among locations and track movements well enough to provide valuable insight in a variety of applied contexts.

  20. Identification of estrogen-responsive vitelline envelope protein fragments from rainbow trout (Oncorhynchus mykiss) plasma using mass spectrometry.

    PubMed

    Salinas, K; Hemmer, M J; Serrano, J; Higgins, L; Anderson, L B; Benninghoff, A D; Williams, D E; Walker, C

    2010-11-01

    Plasma peptides previously associated with exposure of juvenile male rainbow trout (Oncorhynchus mykiss) to the hormone 17β-estradiol (E2) were identified using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Specifically, plasma peptides of interest were fractionated and subsequently identified via spectra obtained by MALDI QqTOF MS/MS and LC-MALDI TOFTOF MS/MS analysis, de novo sequencing and database matching. The two peptide masses were identified as significant matches for fragments of the C-terminal propeptides from rainbow trout vitelline envelope protein (VEP)α and VEPγ isoforms. Our findings document the presence of the C-terminal propeptides from rainbow trout VEPα and VEPγ proteins in the bloodstream of juvenile male rainbow trout exposed to E2 via MALDI-TOF-MS detection. We provide three possible explanations for the presence of C-terminal propeptides in the bloodstream, as well as compare previously obtained hepatic transcriptomic results with the plasma proteomic results obtained in the present study.

  1. Effects of temperature on disease progression and swimming stamina in Ichthyophonus-infected rainbow trout, Oncorhynchus mykiss (Walbaum)

    USGS Publications Warehouse

    Kocan, R.; Hershberger, P.; Sanders, G.; Winton, J.

    2009-01-01

    Rainbow trout, Oncorhynchus mykiss, were infected with Ichthyophonus sp. and held at 10 ??C, 15 ??C and 20 ??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 ??C for 16 weeks then subjected to forced swimming at 10 ??C, 15 ??C and 20 ??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 ??C (P = 0.02) and highly significant at 20 ??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. ?? 2009 Blackwell Publishing Ltd.

  2. Impacts of chloramine-T treatment on antioxidant enzyme activities and genotoxicity in rainbow trout, Oncorhynchus mykiss (Walbaum).

    PubMed

    Boran, H; Altinok, I

    2014-05-01

    Juvenile rainbow trout Oncorhynchus mykiss (Walbaum) were exposed to therapeutic, and higher concentrations of chloramine-T (Cl-T) to assess the effects of this chemical on the antioxidant enzyme system and genetic structure. Red blood cells acetylcholinesterase, ∆-aminolevulinic acid dehydratase, paraoxonase and liver glutathione S-transferase activity were increased at 10 and 20 mg L(-1) Cl-T-exposed fish, while they were decreased at 30 mg L(-1) Cl-T-exposed fish. On the other hand, liver catalase activity and liver protein levels increased at 10 mg L(-1) and decreased at 20 and 30 mg L(-1) concentrations of Cl-T. Liver super-oxide dismutase activity decreased at 10 mg L(-1) and 20 mg L(-1) Cl-T and increased at 30 mg L(-1) of Cl-T. Compared to control, comet assay indicated that Cl-T did not cause significant DNA damage to red blood cells of the fish. Results indicate that 10 or 20 mg L(-1) Cl-T can be safely used to prevent or treat external parasitic and bacterial infection of rainbow trout.

  3. 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.

  4. 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.

  5. Differential virulence mechanisms of infectious hematopoietic necrosis virus in rainbow trout (Oncorhynchus mykiss) include host entry and virus replication kinetics.

    PubMed

    Peñaranda, Ma Michelle D; Purcell, Maureen K; Kurath, Gael

    2009-09-01

    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.

  6. A soluble nonglycosylated recombinant infectious hematopoietic necrosis virus (IHNV) G-protein induces IFNs in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Verjan, Noel; Ooi, Ei Lin; Nochi, Tomonori; Kondo, Hidehiro; Hirono, Ikuo; Aoki, Takashi; Kiyono, Hiroshi; Yuki, Yoshikazu

    2008-07-01

    Viral glycoproteins interact with cell-surface receptors to mediate virus entry and innate immune system activation. We found that a soluble recombinant infectious hematopoietic necrosis virus G-protein (rIHNV-G) stimulated an early innate immune response mediated by proinflammatory cytokines, IFN1 and IFN-gamma in rainbow trout (Oncorhynchus mykiss) fry. Expression of both IFN1 and IFN-gamma mRNA transcripts was an early event and was rIHNV-G dose-dependent. In addition, preliminary evidence revealed that the innate immune response induced by rIHNV-G protein could protect rainbow trout fry from a subsequent IHNV virus challenge. Finally, the binding and distribution of FITC-rIHNV-G protein on rainbow trout spleen and head kidney leukocytes resemble morphological changes which occur on the cell membrane during antigen-receptor interaction including membrane reorganization, patching, polarization and capping. Thus a soluble nonglycosylated rIHNV-G protein could mediate the activation of rainbow trout leukocytes, with concomitant production of proinflammatory cytokines and IFNs.

  7. Dual DNA vaccination of rainbow trout (Oncorhynchus mykiss) against two different rhabdoviruses, VHSV and IHNV, induces specific divalent protection.

    PubMed

    Einer-Jensen, Katja; Delgado, Lourdes; Lorenzen, Ellen; Bovo, Giuseppe; Evensen, Øystein; Lapatra, Scott; Lorenzen, Niels

    2009-02-18

    DNA vaccines encoding the glycoprotein genes of the salmonid rhabdoviruses VHSV and IHNV are very efficient in eliciting protective immune responses against their respective diseases in rainbow trout (Oncorhynchus mykiss). The early anti-viral response (EAVR) provides protection by 4 days post vaccination and is non-specific and transient while the specific anti-viral response (SAVR) is long lasting and highly specific. Since both VHSV and IHNV are endemic in rainbow trout in several geographical regions of Europe and Atlantic salmon (Salmo salar) on the Pacific coast of North America, co-vaccination against the two diseases would be a preferable option. In the present study we demonstrated that a single injection of mixed DNA vaccines induced long-lasting protection against both individual and a simultaneous virus challenge 80 days post vaccination. Transfected muscle cells at the injection site expressed both G proteins. This study confirms the applied potential of using a combined DNA vaccination for protection of fish against two different rhabdoviral diseases.

  8. Differential Expression of Genes that Control Respiration Contribute to Thermal Adaptation in Redband Trout (Oncorhynchus mykiss gairdneri).

    PubMed

    Garvin, Michael R; Thorgaard, Gary H; Narum, Shawn R

    2015-05-04

    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.

  9. New subtype of salmonid alphavirus (SAV), Togaviridae, from Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss in Norway.

    PubMed

    Hodneland, K; Bratland, A; Christie, K E; Endresen, C; Nylund, A

    2005-09-05

    In Europe, 2 closely related alphaviruses (Togaviridae) are regarded as the causative agents of sleeping disease (SD) and salmon pancreas disease (SPD): SD virus (SDV) has been isolated from rainbow trout Oncorhynchus mykiss in France and the UK, while SPD virus (SPDV) has been isolated from salmon Salmo salar in Ireland and the UK. Farmed salmonids in western Norway also suffer from a disease called pancreas disease (PD), and this disease is also believed to be caused by an alphavirus. However, this virus has not yet been characterised at the molecular level. We have cultured a Norwegian salmonid alphavirus from moribund fishes diagnosed with cardiac myopathy syndrome (CMS) and fishes diagnosed with PD. The virus has also been found in salmon suffering from haemorrhagic smolt syndrome in the fresh water phase. The genomic organisation of the Norwegian salmonid alphavirus is identical to that in SPDV and SDV, and the nucleotide sequence similarity to the other 2 alphaviruses is 91.6 and 92.9%, respectively. Based on the pathological changes, host species and the nucleotide sequence, we suggest naming this virus Norwegian salmonid alphavirus (NSAV). Together with SPDV and SDV it constitutes a third subtype of salmonid alphavirus (SAV) species within the genus Alphavirus, family Togaviridae.

  10. Enhancement of the immune response and protection induced by probiotic lactic acid bacteria against furunculosis in rainbow trout (Oncorhynchus mykiss).

    PubMed

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

    2007-10-01

    We analysed the effect of probiotic strains on the cellular and humoral immune responses of rainbow trout (Oncorhynchus mykiss), and their capacity to prevent furunculosis during a challenge trial. Probiotic strains (Lactococcus lactis ssp. lactis CLFP 100, Leuconostoc mesenteroides CLFP 196, and Lactobacillus sakei CLFP 202) were administered orally to fish for 2 weeks at 10(6) CFU g(-1) of feed. In comparison to untreated control fish, the phagocytic activity of head kidney leukocytes and the alternative complement activity in serum were significantly greater in all probiotic groups at the end of the second week. With the exception of the group fed with Lactobacillus sakei, superoxide anion production was also significantly increased in the probiotic groups. Analysis of lysozyme activity did not exhibit any significant difference in the probiotic and control groups. Fifteen days after the start of the probiotic feeding, fish were challenged with Aeromonas salmonicida ssp. salmonicida. The fish supplemented with probiotics exhibited survival rates ranging from 97.8% to 100%, whereas survival was 65.6% in fish not treated with the probiotics. These results demonstrate that probiotic supplementation to fish can reduce the severity of furunculosis, and suggest that this reduction may be associated with enhanced humoral and cellular immune response.

  11. Fish in hot water: hypoxaemia does not trigger catecholamine mobilization during heat shock in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Currie, S; Ahmady, E; Watters, M A; Perry, S F; Gilmour, K M

    2013-06-01

    Rainbow trout (Oncorhynchus mykiss) exposed to an acute heat shock (1 h at 25 °C after raising water temperature from 13 °C to 25 °C over 4 h) mount a significant catecholamine response. The present study investigated the proximate mechanisms underlying catecholamine mobilization. Trout exposed to heat shock in vivo exhibited a significant reduction in arterial O(2) tension, but arterial O(2) concentration was not affected by heat shock, nor was catecholamine release during heat shock prevented by prior and concomitant exposure to hyperoxia (to prevent the fall in arterial O(2) tension). Thus, catecholamine mobilization probably was not triggered by impaired blood O(2) transport. Heat-shocked trout also exhibited an elevation of arterial CO(2) tension coupled with a fall in arterial pH, but these factors are not expected to trigger catecholamine release. The changes in blood O(2) and CO(2) tension occurred despite a significant hyperventilatory response to heat shock. Future studies should investigate whether catecholamine mobilization during heat shock in rainbow trout is triggered by a specific effect of high temperature activating the sympathetic nervous system via a thermosensitive transient receptor potential channel.

  12. A comparison of genetic ariation between an anadromous steelhead, Oncorhynchus mykiss, population and seven derived populations sequestered in freshwater for 70 years

    USGS Publications Warehouse

    Thrower, Frank; Guthrie, Charles; Nielsen, Jennifer; Joyce, John

    2004-01-01

    In 1926 cannery workers from the Wakefield Fisheries Plant at Little Port Walter in Southeast Alaska captured small trout, Oncorhynchus mykiss, from a portion of Sashin Creek populated with a wild steelhead (anadromous O. mykiss) run. They planted them into Sashin Lake which had been fishless to that time and separated from the lower stream by two large waterfalls that prevented upstream migration of any fish. In 1996 we sampled adult steelhead from the lower creek and juvenile O. mykiss from an intermediate portion of the creek, Sashin Lake, and five lakes that had been stocked with fish from Sashin Lake in 1938. Tissue samples from these eight populations were compared for variation in: microsatellite DNA at 10 loci; D-loop sequences in mitochondrial DNA; and allozymes at 73 loci known to be variable in steelhead. Genetic variability was consistently less in the Sashin Lake population and all derived populations than in the source anadromous population. The cause of this reduction is unknown but it is likely that very few fish survived to reproduce from the initial transplant in 1926. Stockings of 50–85 fish into five other fishless lakes in 1938 from Sashin Lake did not result in a similar dramatic reduction in variability. We discuss potential explanations for the observed patterns of genetic diversity in relation to the maintenance of endangered anadromous O. mykiss populations in freshwater refugia.

  13. Influence of water quality on silver toxicity to rainbow trout (Oncorhynchus mykiss), fathead minnows (Pimephales promelas), and water fleas (Daphnia magna)

    SciTech Connect

    Karen, D.J.; Ownby, D.R.; Forsythe, B.L.; Bills, T.P.; La Point, T.W.; Cobb, G.B.; Klaine, S.J.

    1999-01-01

    Toxicity bioassays were conducted to quantify water quality conditions under which silver, as silver nitrate, is toxic to Oncorhynchus mykiss. Pimephales promelas, and Daphnia magna. Bioassays for P. promelas and D. magna were conducted as static replacement tests, whereas a flow-through bioassay system was modified and used for O. mykiss. Results from 96-h toxicity bioassays for O. mykiss indicated that chloride, hardness, and dissolved organic carbon (DOC) protected against silver toxicosis, with DOC affording the highest protective effects. For P. promelas and D. magna, little protection was provided by increased CaCo+O{sub 3} alone, whereas DOC had a major ameliorating influence on measured silver toxicity. Lower concentrations of chloride had little effect on reducing silver nitrate toxicity. Dissolved organic carbon was more important than hardness for predicting the toxicity of ionic silver in natural waters to O. mykiss, P. promelas, and D. magna. Similarly, DOC significantly reduced silver nitrate toxicity to trout, whereas Cl{sup {minus}} and hardness had only a minor protective effect. However, Cl{sup {minus}}/DOC mixtures showed a greater-than-additive protective effect. Thus, the authors suggest that incorporating an organic carbon coefficient into the silver criterion equation will enhance the criterion values for site specificity.

  14. Use of lupin, Lupinus perennis, mango, Mangifera indica, and stinging nettle, Urtica dioica, as feed additives to prevent Aeromonas hydrophila infection in rainbow trout, Oncorhynchus mykiss (Walbaum).

    PubMed

    Awad, E; Austin, B

    2010-05-01

    Feeding rainbow trout, Oncorhynchus mykiss (Walbaum), with 1% lupin, Lupinus perennis, mango, Mangifera indica, or stinging nettle, Urtica dioica, for 14 days led to reductions in mortality after challenge with Aeromonas hydrophila. In addition, there was significant enhancement in serum bactericidal activity, respiratory burst and lysozyme activity in the treatment groups compared to the controls. Use of lupin and mango led to the highest number of red blood and white blood cells in recipient fish, with use of stinging nettle leading to the highest haematocrit and haemoglobin values; the highest value of mean corpuscular volume and haemoglobin was in the control groups and those fed with stinging nettle.

  15. Gastro-intestinal transport of calcium and cadmium in fresh water and seawater acclimated trout (Oncorhynchus mykiss).

    PubMed

    Klinck, Joel S; Wood, Chris M

    2013-03-01

    Transport of calcium (Ca) and cadmium (Cd) was examined along the gastro-intestinal tract (GIT) of freshwater and seawater Oncorhynchus mykiss irideus (FWT and SWTies respectively) using in vitro and in vivo experiments. Based on known physiological differences between FWT and SWT which aid in regulating ion levels and osmolarity, we hypothesized that SWT would have lower rates of Ca uptake. Also, we predicted that Cd rates would also be lower because Cd is known to share a common transport mechanism with Ca. Kinetics of Ca and Cd transport were determined using mucosal salines of varying concentrations [1, 10, 30, 60, and 100 (mmolL(-1) for Ca, μmolL(-1) for Cd)]. Linear and saturating relationships were found for Ca for FWT and SWT, but overall SWT had lower rates. Linear and/or saturating relationships were also found for Cd uptake, but rates varied little between fish types. Elevated Ca had no inhibitory effect on Cd transport, and Ca channel blockers nifedipine and verapamil had little effect on Ca or Cd uptake. However, lanthanum reduced Ca transport into some compartments. A 21 day in vivo feeding experiment was also performed where FWT and SWT were exposed to control diets or Cd-spiked diets (552 μg Cd g(-1) food). Whole body Cd uptake between fish types was similar, but the majority of Cd in SWT remained in the posterior intestine tissue, while FWT transported more Cd through their gut wall. Overall it appears that large differences in Ca and Cd uptake between FWT and SWT exist, with SWT generally having lower rates.

  16. Isolation and Functional Characterisation of a fads2 in Rainbow Trout (Oncorhynchus mykiss) with Δ5 Desaturase Activity

    PubMed Central

    Abdul Hamid, Noor Khalidah; Carmona-Antoñanzas, Greta; Monroig, Óscar; Tocher, Douglas R.; Turchini, Giovanni M.; Donald, John A.

    2016-01-01

    Rainbow trout, Oncorhynchus mykiss, are intensively cultured globally. Understanding their requirement for long-chain polyunsaturated fatty acids (LC-PUFA) and the biochemistry of the enzymes and biosynthetic pathways required for fatty acid synthesis is important and highly relevant in current aquaculture. Most gnathostome vertebrates have two fatty acid desaturase (fads) genes with known functions in LC-PUFA biosynthesis and termed fads1 and fads2. However, teleost fish have exclusively fads2 genes. In rainbow trout, a fads2 cDNA had been previously cloned and found to encode an enzyme with Δ6 desaturase activity. In the present study, a second fads2 cDNA was cloned from the liver of rainbow trout and termed fads2b. The full-length mRNA contained 1578 nucleotides with an open reading frame of 1365 nucleotides that encoded a 454 amino acid protein with a predicted molecular weight of 52.48 kDa. The predicted Fads2b protein had the characteristic traits of the microsomal Fads family, including an N-terminal cytochrome b5 domain containing the heme-binding motif (HPPG), histidine boxes (HDXGH, HFQHH and QIEHH) and three transmembrane regions. The fads2b was expressed predominantly in the brain, liver, intestine and pyloric caeca. Expression of the fasd2b in yeast generated a protein that was found to specifically convert eicosatetraenoic acid (20:4n-3) to eicosapentaenoic acid (20:5n-3), and therefore functioned as a Δ5 desaturase. Therefore, rainbow trout have two fads2 genes that encode proteins with Δ5 and Δ6 desaturase activities, respectively, which enable this species to perform all the desaturation steps required for the biosynthesis of LC-PUFA from C18 precursors. PMID:26943160

  17. Effects of water hardness and temperature on the acute toxicity of mercuric chloride on rainbow trout (Oncorhynchus mykiss).

    PubMed

    Terzi, Ertugrul; Verep, Bulent

    2012-07-01

    In this study, the toxicity of mercuric chloride (HgCl(2)), an important pollutant threatening water resources for many years, and the effects of water temperature and hardness on the toxicity in cultured rainbow trout Oncorhynchus mykiss (4.79 ± 0.16 g; 7.38 ± 0.24 cm; mean ± SD) were investigated at different temperatures (12 and 17°C) and hardness concentrations (35, 70 and 120 mg l(-1) as calcium carbonate, CaCO(3)). For this purpose, the acute toxicity tests were performed by 96-h static tests in different water temperatures and water hardness concentrations. For acute toxicity tests, solutions ranging from 0.4 to 1.2 mg l(-1) were used at 12°C and solutions ranging from 0.4 to 1.0 mg l(-1) at 17°C. The LC(50) values of HgCl(2) that killed 50% of rainbow trout within 96 h in the hardness concentrations of 35, 70 and 120 mg l(-1) CaCO(3) were calculated using probit analysis, and were found to be 0.725, 0.788, 0.855 mg l(-1) at 12°C and 0.670, 0.741, 0.787 mg l(-1) at 17°C, respectively. Consequently, the toxicity of HgCl(2) on rainbow trout decreased when the temperature decreased from 17 to 12°C. Toxicity increased when the hardness decreased from 120 to 35 mg l(-1) CaCO(3). In contrast to temperature, water hardness presents a negative effect on the toxicity of HgCl(2).

  18. Short-term exposure to 17alpha-ethynylestradiol decreases the fertility of sexually maturing male rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Schultz, Irv R.; Skillman, Ann D.; Nicolas, Jean-Marc; Cyr, Daniel G.; Nagler, James J.

    2003-06-01

    The synthetic estrogen 17alpha-ethynylestradiol (EE2) is a commonly used oral contraceptive that has been increasingly detected in sewage effluents. This study determined whether EE2 exposure adversely affected reproduction in sexually maturing male rainbow trout (Oncorhynchus mykiss). We exposed male trout to graded water concentrations of EE2 (10, 100, and 1,000 ng/ L) for 62 d leading up to the time of spawning. Semen and blood plasma samples were removed from each fish. Semen was used to fertilize groups of eggs from one nonexposed female. As a measure of fertility, eggs were incubated for 28 d after fertilization to determine the proportion that attained the eyed stage of embryonic development. Additional endpoints also measured included sperm motility, spermatocrit, gonadosomatic and hepatosomatic indices, testis histology, and circulating plasma levels of the sex steroids 17alpha, 20beta-dihydroxyprogesterone (17,20-DHP) and 11-ketotestosterone (11-KT). Exposure to 1,000 ng/L of EE2 caused complete mortality of the treatment group by day 57. Exposure to lower EE2 water concentrations (10 and 100 ng/L) caused an increase in sperm density, while a significant reduction in testis mass was observed only in the 100-ng/L exposure group. Most significantly, semen harvested from fish exposed to 10 and 100 ng/L EE2 caused an approximately 50% reduction in the number of eggs attaining the eyed stage of embryonic development. Plasma levels of 17,20-DHP in exposed fish were roughly twice the level of the controls, while levels of 11-KT were significantly reduced in fish exposed to 100 ng/L EE2. These results suggest that sexually maturing male rainbow trout are susceptible to detrimental reproductive effects of short-term exposures to environmentally relevant levels of EE2.

  19. Fate of Tetracapsuloides bryosalmonae (Myxozoa) after infection of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss.

    PubMed

    Kumar, Gokhlesh; Abd-Elfattah, Ahmed; Saleh, Mona; El-Matbouli, Mansour

    2013-11-25

    Tetracapsuloides bryosalmonae (Myxozoa) is the causative agent of proliferative kidney disease in salmonids. We assessed differences in intensity of T. bryosalmonae infection between brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss from the clinical phase of infection onwards. Specific pathogen-free fish were exposed to T. bryosalmonae spores under controlled laboratory conditions and sampled at 6, 8, 10, 12, 14, and 17 wk post exposure (wpe), and the transmission of T. bryosalmonae from infected fish to the bryozoan Fredericella sultana was observed. Parasite load was determined in fish kidneys by quantitative real-time PCR (qRT-PCR), and parasite stages were detected in kidney, liver, and spleen tissues at different time points by immunohistochemistry. T. bryosalmonae was successfully transmitted from infected brown trout to F. sultana colonies but not from infected rainbow trout. Body length and weight of infected brown trout did not differ significantly from control brown trout during all time points, while length and weight of infected rainbow trout differed significantly compared to controls from 10 to 17 wpe. qRT-PCR revealed that parasite load was significantly higher in kidneys of brown trout compared with rainbow trout. Immunohistochemistry showed high numbers of intra-luminal stages (sporogonic stages) in kidneys of brown trout with low numbers of pre-sporogonic stages. Sporogonic stages were not seen in kidneys of rainbow trout; only high numbers of pre-sporogonic stages were detected. Numbers of pre-sporogonic stages were low in the spleen and liver of brown trout but high in rainbow trout. These data confirmed that there are differences in the development and infection progress of T. bryosalmonae between brown trout and rainbow trout.

  20. Comparative analysis of innate immune responses to Streptococcus phocae strains in Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss).

    PubMed

    Salazar, Soraya; Oliver, Cristian; Yáñez, Alejandro J; Avendaño-Herrera, Ruben

    2016-04-01

    Streptococcus phocae subsp. salmonis is a Gram-positive bacterium that causes mortality only in Atlantic salmon (Salmo salar) farmed in Chile, even when this species is co-cultured with rainbow trout (Oncorhynchus mykiss). This susceptibility could be determined by innate immune response components and their responses to bacterial infection. This fish pathogen shares subspecies status with Streptococcus phocae subsp. phocae isolated from seals. The present study compared innate immune system mechanisms in Atlantic salmon and rainbow trout when challenged with different S. phocae, including two isolates from Atlantic salmon (LM-08-Sp and LM-13-Sp) and two from seal (ATCC 51973(T) and P23). Streptococcus phocae growth was evaluated in the mucus and serum of both species, with rainbow trout samples evidencing inhibitory effects. Lysozyme activity supported this observation, with significantly higher (p < 0.01) expression in rainbow trout serum and mucus as compared to Atlantic salmon. No differences were found in phagocytic capacity between fish species when stimulated with ATCC 51973(T) and P23. Against all S. phocae strains, rainbow trout and Atlantic salmon showed up to two-fold increased bactericidal activity, and rainbow trout demonstrated up to three-fold greater reactive oxygen species production in macrophages. In conclusion, the non-specific humoral and cellular barriers of Atlantic salmon were immunologically insufficient against S. phocae subsp. salmonis, thereby facilitating streptococcosis. Moreover, the more robust response of rainbow trout to S. phocae could not be attributed to any specific component of the innate immune system, but was rather the consequence of a combined response by the evaluated components.

  1. Effects of in vitro nickel exposure on the macrophage-mediated immune functions of rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Bowser, D.H.; Frenkel, K.; Zelikoff, J.T. )

    1994-03-01

    Nickel is occurs naturally in the geophysical environment. It has become a common byproduct of industrialization. Nickel is released into the atmosphere and coal-burning power plants and trash incinerators, and is also discharged into waste water by industries which convert scrap or new nickel into alloys. The effluent that spreads to streams, rivers, and lakes may disrupt the integrity of the aquatic environment. Excess nickel contamination is hazardous to aquatic ecosystems due to its existence and bioaccumulation. While the adverse health effects associated with nickel exposure have been extensively examined in mammalian systems, very little is known concerning nickel's effects on aquatic organisms. Although trace amounts of nickel are necessary for maintaining the metabolic homeostasis of some vertebrate species, larger amounts of nickel have been shown to be toxic. In addition to being both genotoxic and carcinogenic, nickel modulates immunological functions in a variety of mammalian species. The toxic effects of nickel on the numbers, activity, and ultrastructure of macrophages (M[o]) have been well-studied. A number of other toxic metals such as copper, manganese, and cadmium modulate the immune responses of fish. To appraise the immunomodulating potential of nickel on fish, and to begin to establish baseline parameters of altered immune function as potential biomarkers of in vivo nickel exposure, elicited peritoneal macrophages from rainbow trout (Oncorhynchus mykiss) were treated in vitro with increasing concentrations of nickel sulfate (NiSO[sub 4]). Following exposure, M[o] activities important for maintaining host immunocompetence were evaluated and these include; mobility (random and stimulus-directed), production of reactive oxygen intermediates (ROI), acid phosphatase activity, and phagocytosis. 20 refs., 3 figs.

  2. Relative sensitivity of bull trout (Salvelinus confluentus) and rainbow trout (Oncorhynchus mykiss) to acute exposures of cadmium and zinc.

    PubMed

    Hansen, James A; Welsh, Paul G; Lipton, Josh; Cacela, Dave; Dailey, Anne D

    2002-01-01

    Bull trout (Salvelinus confluentus) were recently listed as threatened in the United States under the federal Endangered Species Act. Present and historical habitat of this species includes waterways that have been impacted by metals released from mining and mineral processing activities. We conducted paired bioassays with bull trout and rainbow trout (Oncorhynchus mykiss) to examine the relative sensitivity of each species to Cd and Zn independently and as a mixture. A total of 15 pairs of acute toxicity bioassays were completed to evaluate the effects of different water hardness (30 or 90 mg/L as CaCO3), pH (6.5 or 7.5), and temperature (8 or 12 degrees C) on Cd and Zn toxicity. For both species, the acute toxicity of both Cd and Zn was greater than previously observed in laboratory studies. Bull trout were about twice as tolerant of Cd and about 50% more tolerant of Zn than were rainbow trout. Higher hardness and lower pH water produced lower toxicity and slower rates of toxicity in both species. Elevated temperature significantly increased the sensitivity of bull trout to Zn but decreased the sensitivity (not significantly) of rainbow trout to Zn. At a hardness of 30 mg/L, the toxicity values (i.e., median lethal concentration; 120-h LC50) for both species were lower than the current U.S. national water quality criteria for protection of aquatic life, indicating that current national criteria may not be protective of sensitive salmonids--including the threatened bull trout--in low calcium waters.

  3. An ecological risk assessment of the acute and chronic effects of the herbicide clopyralid to rainbow trout (Oncorhynchus mykiss).

    PubMed

    Fairchild, J F; Allert, A L; Feltz, K P; Nelson, K J; Valle, J A

    2009-11-01

    Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) is a pyridine herbicide frequently used to control invasive, noxious weeds in the northwestern United States. Clopyralid exhibits low acute toxicity to fish, including the rainbow trout (Oncorhynchus mykiss) and the threatened bull trout (Salvelinus confluentus). However, there are no published chronic toxicity data for clopyralid and fish that can be used in ecological risk assessments. We conducted 30-day chronic toxicity studies with juvenile rainbow trout exposed to the acid form of clopyralid. The 30-day maximum acceptable toxicant concentration (MATC) for growth, calculated as the geometric mean of the no observable effect concentration (68 mg/L) and the lowest observable effect concentration (136 mg/L), was 96 mg/L. No mortality was measured at the highest chronic concentration tested (273 mg/L). The acute:chronic ratio, calculated by dividing the previously published 96-h acutely lethal concentration (96-h ALC(50); 700 mg/L) by the MATC was 7.3. Toxicity values were compared to a four-tiered exposure assessment profile assuming an application rate of 1.12 kg/ha. The Tier 1 exposure estimation, based on direct overspray of a 2-m deep pond, was 0.055 mg/L. The Tier 2 maximum exposure estimate, based on the Generic Exposure Estimate Concentration model (GEENEC), was 0.057 mg/L. The Tier 3 maximum exposure estimate, based on previously published results of the Groundwater Loading Effects of Agricultural Management Systems model (GLEAMS), was 0.073 mg/L. The Tier 4 exposure estimate, based on published edge-of-field monitoring data, was estimated at 0.008 mg/L. Comparison of toxicity data to estimated environmental concentrations of clopyralid indicates that the safety factor for rainbow trout exposed to clopyralid at labeled use rates exceeds 1000. Therefore, the herbicide presents little to no risk to rainbow trout or other salmonids such as the threatened bull trout.

  4. The effect of hatchery release strategy on marine migratory behaviour and apparent survival of Seymour River steelhead smolts (Oncorhynchus mykiss).

    PubMed

    Balfry, Shannon; Welch, David W; Atkinson, Jody; Lill, Al; Vincent, Stephen

    2011-03-29

    Early marine migratory behaviour and apparent survival of hatchery-reared Seymour River steelhead (Oncorhynchus mykiss) smolts was examined over a four year period (2006-2009) to assess the impact of various management strategies on improving early marine survival. Acoustically tagged smolts were released to measure their survival using estuary and coastal marine receivers forming components of the Pacific Ocean Shelf Tracking (POST) array. Early marine survival was statistically indistinguishable between releases of summer run and winter run steelhead races, night and day releases, and groups released 10 days apart. In 2009, the survival of summer run steelhead released into the river was again trialed against groups released directly into the ocean at a distance from the river mouth. Apparent survival was improved significantly for the ocean released groups. The health and physiological status of the various release groups were monitored in years 2007-2009, and results indicate that the fish were in good health, with no clinical signs of disease at the time of release. The possibility of a disease event contributing to early marine mortality was further examined in 2009 by vaccinating half of the released fish against common fish diseases (vibriosis, furunculosis). The results suggest that marine survival may be enhanced using this approach, although not to the extent observed when the smolts were transported away from the river mouth before release. In summary, direct experimental testing of different release strategies using the POST array to measure ocean survival accelerated the scientific process by allowing rapid collection of data which enabled the rejection of several existing theories and allowed tentative identification of several new alternative approaches that might improve early marine survival of Seymour River steelhead.

  5. Time course of hepatic gene expression and plasma vitellogenin protein concentrations in estrone-exposed juvenile rainbow trout (Oncorhynchus mykiss).

    PubMed

    Osachoff, Heather L; Brown, Lorraine L Y; Tirrul, Leena; van Aggelen, Graham C; Brinkman, Fiona S L; Kennedy, Christopher J

    2016-09-01

    Estrone (E1), a natural estrogen hormone found in sewage effluents and surface waters, has known endocrine disrupting effects in fish, thus, it is a contaminant of emerging concern. Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to an environmentally-relevant concentration of E1 (24ng/L E1 [0.1nM]) for 7d and then placed in clean water for a 9d recovery period. RNA sequencing showed transcripts from numerous affected biological processes (e.g. immune, metabolic, apoptosis, clotting, and endocrine) were altered by E1 after 4d of treatment. The time course of E1-inducible responses relating to vitellogenesis was examined daily during the two phases of exposure. Hepatic gene expression alterations evaluated by quantitative polymerase chain reaction (QPCR) were found during the treatment period for vitellogenin (VTG), vitelline envelope proteins (VEPs) α, β and γ, and estrogen receptor α1 (ERα1) transcripts. ERα1 was the only transcript induced each day during the treatment phase, thus it was a good indicator of E1 exposure. Gradual increases occurred in VEPβ and VEPγ transcripts, peaking at d7. VTG transcript was only elevated at d4, making it less sensitive than VEPs to this low-level E1 treatment. Inductions of ERα1, VEPα, VEPβ and VEPγ transcripts ceased 1d into the recovery phase. Plasma VTG protein concentrations were not immediately elevated but peaked 7d into the recovery phase. Thus, elevated vitellogenesis-related gene expression and protein production occurred slowly but steadily at this concentration of E1, confirming the sequence of events for transcripts and VTG protein responses to xenoestrogen exposure.

  6. Proteome changes in rainbow trout (Oncorhynchus mykiss) fertilized eggs as an effect of triploidization heat-shock treatment.

    PubMed

    Babaheydari, Samad Bahrami; Keyvanshokooh, Saeed; Dorafshan, Salar; Johari, Seyed Ali

    2016-03-01

    The aim of the present study was to explore proteome changes in rainbow trout (Oncorhynchus mykiss) fertilized eggs as an effect of triploidization heat-shock treatment. Eggs and milt were taken from eight females and six males. The gametes were pooled to minimize the individual differences. 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 and were incubated at 10-11°C under the same environmental conditions in hatchery troughs until the fry stage. Triplicate samples of 30 eggs (10 eggs per trough) from each group were randomly selected 1.5h post-fertilization for proteome extraction. Egg proteins were analyzed using two-dimensional electrophoresis (2-DE) and MALDI-TOF/TOF mass spectrometry. Based on the results from the statistical analyses, 15 protein spots were found to decrease significantly in abundance in heat-shock treated group and were selected for identification. Out of 15 protein spots showing altered abundance, 14 spots were successfully identified. All of the egg proteins identified in our study were related to vitellogenin (vtg). Decreased abundance of vitellogenin in heat-shock treated eggs in our study may either be explained by (i) higher utilization of vtg as an effect of increased cell size in triploids or (ii) changed metabolism in response to heat-shock stress and (iii) diffusion of vtg through chorion due to incidence of egg shell damage. Decreased abundance of vitellogenin in heat-shock treated eggs was associated with reduced early survival rates and lowered growth performance of triploid fish.

  7. Effects of polychlorinated biphenyls on whole animal energy mobilization and hepatic cellular respiration in rainbow trout, Oncorhynchus mykiss.

    PubMed

    Nault, Rance; Al-Hameedi, Samar; Moon, Thomas W

    2012-05-01

    The production of polychlorinated biphenyls (PCBs) was banned in 1977 but these chemicals persist in the environment and threaten aquatic organisms. PCB exposure often results in activation of the aryl hydrocarbon receptor (AhR) and increases in hepatic detoxification mechanisms. Activation of these detoxification mechanisms is believed to be associated with energetic demands that may come at the expense of other physiological processes such as growth, activity and reproduction. We tested the hypothesis that exposure to sub-lethal levels of PCBs results in increased energy demand and energy mobilization using both an in vivo and in vitro approach. Rainbow trout (Oncorhynchus mykiss) received a single intraperitoneal sub-lethal dose (50μgkg(-1)) of 3,3',4,4',5-pentachlorobiphenyl (PCB 126) and left for 10d after which standard oxygen consumption and plasma and liver metabolites were assessed. PCB 126 exposed trout did not alter standard oxygen consumption but did increase plasma glucose concentration implying the mobilization of glucose to cope with this exposure regime. Cellular respiration was assessed in trout hepatocytes exposed to PCB 126 or PCB 77 (3,3'4,4'-tetrachlorobiphenyl) two AhR activators but with different potencies (PCB 126≫PCB 77). Mitochondrial respiration was assessed by stimulating complex II with succinate and although no increases in respiration were associated with PCB exposure in non-stimulated cells, PCB 77 impaired mitochondrial respiration by preventing stimulation of complex II respiration and potentially masking any actual energetic costs of PCB exposure. These studies suggest that energy is mobilized upon exposure to PCBs, however, actual increases in energy demand may be overshadowed by impaired mitochondrial respiration.

  8. Cell proliferation and apoptosis in optic nerve and brain integration centers of adult trout Oncorhynchus mykiss after optic nerve injury.

    PubMed

    Pushchina, Evgeniya V; Shukla, Sachin; Varaksin, Anatoly A; Obukhov, Dmitry K

    2016-04-01

    Fishes have remarkable ability to effectively rebuild the structure of nerve cells and nerve fibers after central nervous system injury. However, the underlying mechanism is poorly understood. In order to address this issue, we investigated the proliferation and apoptosis of cells in contralateral and ipsilateral optic nerves, after stab wound injury to the eye of an adult trout Oncorhynchus mykiss. Heterogenous population of proliferating cells was investigated at 1 week after injury. TUNEL labeling gave a qualitative and quantitative assessment of apoptosis in the cells of optic nerve of trout 2 days after injury. After optic nerve injury, apoptotic response was investigated, and mass patterns of cell migration were found. The maximal concentration of apoptotic bodies was detected in the areas of mass clumps of cells. It is probably indicative of massive cell death in the area of high phagocytic activity of macrophages/microglia. At 1 week after optic nerve injury, we observed nerve cell proliferation in the trout brain integration centers: the cerebellum and the optic tectum. In the optic tectum, proliferating cell nuclear antigen (PCNA)-immunopositive radial glia-like cells were identified. Proliferative activity of nerve cells was detected in the dorsal proliferative (matrix) area of the cerebellum and in parenchymal cells of the molecular and granular layers whereas local clusters of undifferentiated cells which formed neurogenic niches were observed in both the optic tectum and cerebellum after optic nerve injury. In vitro analysis of brain cells of trout showed that suspension cells compared with monolayer cells retain higher proliferative activity, as evidenced by PCNA immunolabeling. Phase contrast observation showed mitosis in individual cells and the formation of neurospheres which gradually increased during 1-4 days of culture. The present findings suggest that trout can be used as a novel model for studying neuronal regeneration.

  9. Host-derived probiotics Enterococcus casseliflavus improves resistance against Streptococcus iniae infection in rainbow trout (Oncorhynchus mykiss) via immunomodulation.

    PubMed

    Safari, Reza; Adel, Milad; Lazado, Carlo C; Caipang, Christopher Marlowe A; Dadar, Maryam

    2016-05-01

    The present study evaluated the benefits of dietary administration of host-derived candidate probiotics Enterococcus casseliflavus in juvenile rainbow trout Oncorhynchus mykiss. Experimental diets were prepared by incorporating the microorganisms in the basal feed at 3 inclusion levels (i.e. 10(7) CFU g(-1) of feed [T1], 10(8) CFU g(-1) of feed [T2], 10(9) CFU g(-1) of feed [T3]). The probiotic feeds were administered for 8 weeks, with a group fed with the basal diet serving as control. The effects on growth performance, gut health, innate immunity and disease resistance were evaluated. Results showed that growth performance parameters were significantly improved in T2 and T3 groups. Activities of digestive enzymes such as trypsin and lipase were significantly higher in these two groups as well. Gut micro-ecology was influenced by probiotic feeding as shown by the significant increase in intestinal lactic acid bacteria and total viable aerobic counts in T2 and T3. Humoral immunity was impacted by dietary probiotics as total serum protein and albumin were significantly elevated in T3. The levels of serum IgM significantly increased in all probiotic fed groups at week 8; with the T3 group registering the highest increment. Respiratory burst activity of blood leukocytes were significantly improved in T2 and T3. Hematological profiling further revealed that neutrophil counts significantly increased in all probiotic fed groups. Challenge test showed that probiotic feeding significantly improved host resistance to Streptococcus iniae infection, specifically in T2 and T3 where a considerable modulation of immune responses was observed. Taken together, this study demonstrated E. casseliflavus as a potential probiotics for rainbow trout with the capability of improving growth performance and enhancing disease resistance by immunomodulation.

  10. Effects of carbon dioxide exposure on intensively cultured rainbow trout Oncorhynchus mykiss: Physiological responses and fillet attributes

    USGS Publications Warehouse

    Danley, M.L.; Kenney, P.B.; Mazik, P.M.; Kiser, R.; Hankins, J.A.

    2005-01-01

    Rainbow trout Oncorhynchus mykiss (261.6 ?? 24.7 g initial weight, mean ?? SEM) at 13.1 ?? 0.2 C were exposed for 94 d to one of three CO2 treatments: control (22.1 ?? 2.8 mg/L), medium (34.5 ?? 3.8 mg/L), or high (48.7 ?? 4.4 mg/L). Trout were checked daily for survival, and fish were sampled at 0, 28, 56, and 84 d for physiological responses, growth, and fillet quality assessments. Trout were also challenged to a 15-min crowding stress at 93 d to assess their ability to initiate a stress response during hypercapnia. Chronically exposed trout showed nearly 100% survival through 84 d exposure (1 of 1,500 fish died). Growth and physiological results showed that increasing elevated CO2 concentrations result in corresponding decreased growth rates and CO2-specific physiological parameters: The medium and high CO2 treatments had significantly slower growth and subsequently smaller fish by 84 d. Exposed trout also showed significantly (P < 0.05) decreased plasma chloride for medium and high CO2 treatments compared to the control from 28 through 84 d. Decreased growth and smaller fish in the medium and high CO2 treatments resulted in correspondingly smaller fresh and smoked fillet weights. Chronic CO2 exposure did not result in notable changes in ultimate muscle pH. Exposure to 15-min crowding stress at 93 d resulted in significant changes in hematocrit, plasma cortisol, glucose, and chloride for all treatment groups. CO2-specific changes were detected in hematocrit, plasma cortisol, and plasma chloride responses following the 15-min crowding stress. ?? Copyright by the World Aquaculture Society 2005.

  11. The sub-lethal effects and tissue concentration of the human pharmaceutical atenolol in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Steinbach, Christoph; Burkina, Viktoriia; Fedorova, Ganna; Grabicova, Katerina; Stara, Alzbeta; Velisek, Josef; Zlabek, Vladimir; Schmidt-Posthaus, Heike; Grabic, Roman; Kocour Kroupova, Hana

    2014-11-01

    Atenolol is a highly prescribed anti-hypertensive pharmaceutical and a member of the group of β-blockers. It has been detected at concentrations ranging from ng L(-1) to low μg L(-1) in waste and surface waters. The present study aimed to assess the sub-lethal effects of atenolol on rainbow trout (Oncorhynchus mykiss) and to determine its tissue-specific bioconcentration. Juvenile rainbow trout were exposed for 21 and 42 days to three concentration levels of atenolol (1 μg L(-1) - environmentally relevant concentration, 10 μg L(-1), and 1000 μg L(-1)). The fish exposed to 1 μg L(-1) atenolol exhibited a higher lactate content in the blood plasma and a reduced haemoglobin content compared with the control. The results show that exposure to atenolol at concentrations greater than or equal to 10 μg L(-1) significantly reduces both the haematocrit value and the glucose concentration in the blood plasma. The activities of the studied antioxidant enzymes (catalase and superoxide dismutase) were not significantly affected by atenolol exposure, and only the highest tested concentration of atenolol significantly reduced the activity of glutathione reductase. The activities of selected CYP450 enzymes were not affected by atenolol exposure. The histological changes indicate that atenolol has an effect on the vascular system, as evidenced by the observed liver congestion and changes in the pericardium and myocardium. Atenolol was found to have a very low bioconcentration factor (the highest value found was 0.27). The bioconcentration levels followed the order liver>kidney>muscle. The concentration of atenolol in the blood plasma was below the limit of quantification (2.0 ng g(-1)). The bioconcentration factors and the activities of selected CYP450 enzymes suggest that atenolol is not metabolised in the liver and may be excreted unchanged.

  12. Effects of the anti-androgen cyproterone acetate (CPA) on oocyte meiotic maturation in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Rime, Hélène; Nguyen, Thaovi; Ombredane, Kevin; Fostier, Alexis; Bobe, Julien

    2015-07-01

    In the present study, we aimed at characterizing the effect of cyproterone acetate (CPA), an anti-androgenic compound, on oocyte meiotic maturation in a freshwater teleost fish species, the rainbow trout (Oncorhynchus mykiss). Fully-grown post-vitellogenic ovarian follicles were incubated in vitro with CPA, luteinizing hormone (Lh) or a combination of CPA and Lh. Incubations were also performed using a combination of Lh and testosterone (T). The occurrence of oocyte maturation (i.e., resumption of the meiotic process) was assessed by monitoring germinal vesicle breakdown (GVBD) after a 72h in vitro incubation. The effect of CPA on the production of 17,20β-dihydroxy-4-pregnen-3-one (17,20βP), the natural maturation-inducing steroid (MIS), was quantified by radioimmunoassay. Our results show that CPA dramatically inhibits Lh-induced oocyte maturation and MIS synthesis. We also observed a synergistic effect of Lh and T on oocyte maturation in highly competent oocytes (i.e., able to resume meiosis after stimulation by low doses of Lh). Our results also show that a combination of CPA and Lh inhibits phosphorylation of extracellular signal-regulated kinase (Erk), kinases that are associated with oocyte maturation in many species. As a whole, our results indicate that CPA has a potential to alter meiotic maturation in rainbow trout. Further analyses are, however, needed to determine the mechanisms by which this anti-androgen interferes with the meiotic process. Furthermore, the present study provides a framework for better understanding of the ecological consequences of exposure to anti-androgens and resulting meiotic maturation abnormalities observed in trout.

  13. Effects of copper, hypoxia and acute temperature shifts on mitochondrial oxidation in rainbow trout (Oncorhynchus mykiss) acclimated to warm temperature.

    PubMed

    Sappal, Ravinder; Fast, Mark; Stevens, Don; Kibenge, Fred; Siah, Ahmed; Kamunde, Collins

    2015-12-01

    Temperature fluctuations, hypoxia and metals pollution frequently occur simultaneously or sequentially in aquatic systems and their interactions may confound interpretation of their biological impacts. With a focus on energy homeostasis, the present study examined how warm acclimation influences the responses and interactions of acute temperature shift, hypoxia and copper (Cu) exposure in fish. Rainbow trout (Oncorhynchus mykiss) were acclimated to cold (11°C; control) and warm (20°C) temperature for 3 weeks followed by exposure to environmentally realistic levels of Cu and hypoxia for 24h. Subsequently, mitochondrial electron transport system (ETS) respiratory activity supported by complexes I-IV (CI-IV), plasma metabolites and condition indices were measured. Warm acclimation reduced fish condition, induced aerobic metabolism and altered the responses of fish to acute temperature shift, hypoxia and Cu. Whereas warm acclimation decelerated the ETS and increased the sensitivity of maximal oxidation rates of the proximal (CI and II) complexes to acute temperature shift, it reduced the thermal sensitivity of state 4 (proton leak). Effects of Cu with and without hypoxia were variable depending on the acclimation status and functional index. Notably, Cu stimulated respiratory activity in the proximal ETS segments, while hypoxia was mostly inhibitory and minimized the stimulatory effect of Cu. The effects of Cu and hypoxia were modified by temperature and showed reciprocal antagonistic interaction on the ETS and plasma metabolites, with modest additive actions limited to CII and IV state 4. Overall, our results indicate that warm acclimation came at a cost of reduced ETS efficiency and increased sensitivity to added stressors.

  14. Cell proliferation and apoptosis in optic nerve and brain integration centers of adult trout Oncorhynchus mykiss after optic nerve injury

    PubMed Central

    Pushchina, Evgeniya V.; Shukla, Sachin; Varaksin, Anatoly A.; Obukhov, Dmitry K.

    2016-01-01

    Fishes have remarkable ability to effectively rebuild the structure of nerve cells and nerve fibers after central nervous system injury. However, the underlying mechanism is poorly understood. In order to address this issue, we investigated the proliferation and apoptosis of cells in contralateral and ipsilateral optic nerves, after stab wound injury to the eye of an adult trout Oncorhynchus mykiss. Heterogenous population of proliferating cells was investigated at 1 week after injury. TUNEL labeling gave a qualitative and quantitative assessment of apoptosis in the cells of optic nerve of trout 2 days after injury. After optic nerve injury, apoptotic response was investigated, and mass patterns of cell migration were found. The maximal concentration of apoptotic bodies was detected in the areas of mass clumps of cells. It is probably indicative of massive cell death in the area of high phagocytic activity of macrophages/microglia. At 1 week after optic nerve injury, we observed nerve cell proliferation in the trout brain integration centers: the cerebellum and the optic tectum. In the optic tectum, proliferating cell nuclear antigen (PCNA)-immunopositive radial glia-like cells were identified. Proliferative activity of nerve cells was detected in the dorsal proliferative (matrix) area of the cerebellum and in parenchymal cells of the molecular and granular layers whereas local clusters of undifferentiated cells which formed neurogenic niches were observed in both the optic tectum and cerebellum after optic nerve injury. In vitro analysis of brain cells of trout showed that suspension cells compared with monolayer cells retain higher proliferative activity, as evidenced by PCNA immunolabeling. Phase contrast observation showed mitosis in individual cells and the formation of neurospheres which gradually increased during 1–4 days of culture. The present findings suggest that trout can be used as a novel model for studying neuronal regeneration. PMID:27212918

  15. Proliferative kidney disease in rainbow trout (Oncorhynchus mykiss) under intensive breeding conditions: Pathogenesis and haematological and immune parameters.

    PubMed

    Palikova, Miroslava; Papezikova, Ivana; Markova, Zdenka; Navratil, Stanislav; Mares, Jan; Mares, Lukas; Vojtek, Libor; Hyrsl, Pavel; Jelinkova, Eva; Schmidt-Posthaus, Heike

    2017-03-06

    Proliferative kidney disease (PKD) is an endoparasitic disease of salmonid fish caused by Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea). This study presents a comprehensive view on PKD development in rainbow trout (Oncorhynchus mykiss) reared at an intensive fish breeding facility, with focus on mortality, pathology/histopathology, haematological findings and immune functions. Diseased and reference fish were sampled monthly and time course of natural infection was followed up from the onset of clinical signs (September 2014) to full recovery (January 2015). PKD- associated cumulative mortality was 30% with a peak value in October, while immunohistochemical testing indicated a continuous significant decrease in T. bryosalmonae numbers from September to December; with no parasites detected in January. During peak clinical infection, a significant decrease in red blood cell counts, haematocrit values, haemoglobin concentration, along with a reduction in lymphocytes and a significant phagocyte elevation corresponding with an increase in phagocyte oxidative burst were measured in comparison to control animals. Complement activity and total immunoglobulin plasma concentrations were also elevated, though only during the initial monitoring period (September). Individuals surviving PKD, recovered and were able to fully regenerate both renal structure and haematopoietic parameters to normal levels. Changes in the red blood cell parameters indicate anaemia and a decreased oxygen transportation capacity during the clinical disease phase. Together with an increased oxygen demand at higher temperatures and decreased oxygen solubility this could lead to decompensation and elevated mortality. The stimulation of immune parameters, and especially oxidative phagocytic burst, is likely to have had a strong effect on both, regeneration and elimination of the pathogenic agent.

  16. Characterization of Pediococcus acidilactici strains isolated from rainbow trout (Oncorhynchus mykiss) feed and larvae: safety, DNA fingerprinting, and bacteriocinogenicity.

    PubMed

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

    2016-05-03

    The use of lactic acid bacteria (LAB) as probiotics constitutes an alternative or complementary strategy to chemotherapy and vaccination for disease control in aquaculture. The objectives of this work were (1) the in vitro safety assessment of 8 Pediococcus acidilactici strains isolated from rainbow trout (Oncorhynchus mykiss, Walbaum) feed and larvae; (2) the evaluation of their genetic relatedness; (3) the study of their antimicrobial/bacteriocin activity against fish pathogens; and (4) the biochemical and genetic characterization of the bacteriocin produced by the strain displaying the greatest antimicrobial activity. Concerning the safety assessment, none of the pediococci showed antibiotic resistance nor produced hemolysin or gelatinase, degraded gastric mucin, or deconjugated bile salts. Four strains (50%) produced tyramine or putrescine, but the corresponding genes were not amplified by PCR. Enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) fingerprinting allowed clustering of the pediococci into 2 well-defined groups (68% similarity). From the 8 pediococci displaying direct antimicrobial activity against at least 3 out of 9 fish pathogens, 6 strains (75%) were identified as bacteriocin producers. The bacteriocin produced by P. acidilactici L-14 was purified, and mass spectrometry and DNA sequencing revealed its identity to pediocin PA-1 (PedPA-1). Altogether, our results allowed the identification of 4 (50%) putatively safe pediococci, including 2 bacteriocinogenic strains. ERIC-PCR fingerprinting was a valuable tool for genetic profiling of P. acidilactici strains. This work reports for the first time the characterization of a PedPA-1-producing P. acidilactici strain isolated from an aquatic environment (rainbow trout larvae), which shows interesting properties related to its potential use as a probiotic in aquaculture.

  17. The physiological consequences of exposure to chronic, sublethal waterborne nickel in rainbow trout (Oncorhynchus mykiss): exercise vs resting physiology.

    PubMed

    Pane, Eric F; Haque, Aziz; Goss, Greg G; Wood, Chris M

    2004-03-01

    In rainbow trout (Oncorhynchus mykiss), following chronic (42 day) exposure to both 384 microg Ni l(-1) and 2034 microg Ni l(-1), Ni accumulation was greatest in the gill, kidney and plasma, with the plasma as the main sink for Ni. Indeed, trapped plasma analysis revealed that extensive loading of Ni in the plasma accounted for substantial percentages of accumulated Ni in several tissues including the liver and heart. Accumulated Ni in the gill and kidney was less dependent on plasma Ni concentration, suggesting a more intracellular accumulation of Ni in these tissues. We present evidence for a clear, persistent cost of acclimation to chronic, sublethal Ni exposure. Chronic (40-99 day) exposure to sublethal waterborne Ni (243-394 microg Ni l(-1); approximately 1% of the 96 h LC(50)) impaired the exercise physiology, but not the resting physiology, of rainbow trout. Ni acted as a limiting stressor, decreasing maximal rates of oxygen consumption (MO2,max) during strenuous exercise in trout exposed for 34 days to sublethal Ni. This drop in high-performance gas exchange was attributed mainly to a reduction in relative branchial diffusing capacity (D(rel)) caused by thickening of secondary lamellae. Morphometric analysis of the gills of chronically exposed fish revealed overall swelling of secondary lamellae, as well as hypertrophic respiratory epithelia within secondary lamellae. Additionally, contraction of the lamellar blood pillar system and narrowing of interlamellar water channels occurred, possibly contributing to decreased high-performance gas exchange. Decreased aerobic capacity persisted in fish previously exposed to nickel despite a clean-water exposure period of 38 days and an almost complete depuration of gill Ni, suggesting that extrabranchial mechanisms of chronic Ni toxicity may also be important. Chronic impairment of such a dynamically active and critical organ as the gill may depress the overall fitness of a fish by impairing predator avoidance, prey

  18. Experiences from a biomarker study on farmed rainbow trout (Oncorhynchus mykiss) used for environmental monitoring in a Swedish river.

    PubMed

    Hanson, Niklas; Larsson, Ake

    2009-07-01

    Biomarkers in fish may serve as a useful tool for evaluating the pollution load in the environment and for early warning signals about new environmental threats. By employing a strategy with fish that are caged or reared in tanks, problems linked to migration and feeding status can be reduced or eliminated. Such a strategy, however, also may introduce other confounding factors linked to, for example, hierarchical behavior or disease outbreaks. In the present study, rainbow trout (Oncorhynchus mykiss) were reared in plastic tanks at four sites in the Göta älv river system (plus one external reference) in western Sweden during 2006 and 2007. Because of low population density and high water turnover in the area, pollution levels are expected to be low. Therefore, this should be a good test for the sensitivity of the methodology. Several significant differences were found between sites as well as between years, such as ethoxyresorufin-O-deethylase (EROD) activity, polycyclic aromatic hydrocarbon (PAH) metabolites in bile, and concentration of inorganic ions in blood plasma, but it also was seen that factors other than pollution could be contributing to these differences. The condition factor (CF) varied between sites, possibly because of differences in feeding resulting from variations in water turbidity. Furthermore, even the small differences in CF that were found within sites correlated significantly to several of the biomarkers. It was shown that PAHs likely are the most important EROD inducers in Göta älv and that variation over time is greater than variation between sites. Because CF differed between sites despite a standardized feeding ration, starving of the fish during the exposure period should be considered for future studies.

  19. Sex biased survival and differences in migration of wild steelhead (Oncorhynchus mykiss) smolts from two coastal Oregon rivers

    USGS Publications Warehouse

    Thompson, Neil F.; Leblanc, Camille A.; Romer, Jeremy D.; Schreck, Carl B.; Blouin, Michael S.; Noakes, David L. G.

    2016-01-01

    In salmonids with partial migration, females are more likely than males to undergo smoltification and migrate to the ocean (vs. maturing in freshwater). However, it is not known whether sex affects survivorship during smolt migration (from fresh water to entry into the ocean). We captured wild steelhead (Oncorhynchus mykiss) smolts in two coastal Oregon rivers (USA) and collected fin tissue samples for genetic sex determination (2009; N = 70 in the Alsea and N = 69 in the Nehalem, 2010; N = 25 in the Alsea). We implanted acoustic tags and monitored downstream migration and survival until entry in to the Pacific Ocean. Survival was defined as detection at an estuary/ocean transition array. We found no effect of sex on smolt survivorship in the Nehalem River in 2009, or in the Alsea River in 2010. However, males exhibited significantly lower survival than females in the Alsea River during 2009. Residency did not influence this result as an equal proportion of males and females did not reach the estuary entrance (11% of males, 9% of females). The sexes did not differ in timing or duration of migration, so those variables seem unlikely to explain sex-biased survivorship. Larger males had higher odds of survival than smaller males in 2009, but the body size of females did not affect survivorship. The difference in survivorship between years in the Alsea River could be due to flow conditions, which were higher in 2010 than in 2009. Our findings suggest that sex may affect steelhead smolt survival during migration, but that the difference in survivorship may be weak and not a strong factor influencing adult sex ratios.

  20. Intestinal ammonia transport in freshwater and seawater acclimated rainbow trout (Oncorhynchus mykiss): evidence for a Na+ coupled uptake mechanism.

    PubMed

    Rubino, Julian G; Zimmer, Alex M; Wood, Chris M

    2015-05-01

    In vitro gut sac experiments were performed on freshwater and 60% seawater acclimated trout (Oncorhynchus mykiss) under treatments designed to discern possible mechanisms of intestinal ammonia transport. Seawater acclimation increased ammonia flux rate into the serosal saline (Jsamm) in the anterior intestine, however it did not alter Jsamm in the mid- or posterior intestine suggesting similar mechanisms of ammonia handling in freshwater and seawater fish. Both fluid transport rate (FTR) and Jsamm were inhibited in response to basolateral ouabain treatment, suggesting a linkage of ammonia uptake to active transport, possibly coupled to fluid transport processes via solvent drag. Furthermore, decreases in FTR and Jsamm caused by low Na(+) treatment indicated a Na(+) linked transport mechanism. Mucosal bumetanide (10(-4) M) had no impact on FTR, yet decreased Jsamm in the anterior and mid-intestine, suggesting NH4(+) substitution for K(+) on an apical NKCC, and at least a partial uncoupling of ammonia transport from fluid transport. Additional treatments (amiloride, 5-(N-ethyl-N-isopropyl)amiloride (EIPA), phenamil, bafilomycin, 4',6-diamidino-2-phenylindole (DAPI), high sodium) intended to disrupt alternative routes of Na(+) uptake yielded no change in FTR or Jsamm, suggesting the absence of direct competition between Na(+) and ammonia for transport. Finally, [(14)C]methylamine permeability (PMA) measurements indicated the likely presence of an intestinal Rh-mediated ammonia transport system, as increasing NH4Cl (0, 1, 5 mmol l(-1)) concentrations reduced PMA, suggesting competition for transport through Rh proteins. Overall, the data presented in this paper provide some of the first insights into mechanisms of teleost intestinal ammonia transport.

  1. Acute exposure to waterborne copper inhibits both the excretion and uptake of ammonia in freshwater rainbow trout (Oncorhynchus mykiss).

    PubMed

    Lim, Michael Yu-Ting; Zimmer, Alex M; Wood, Chris M

    2015-02-01

    In freshwater fish, exposure to sub-lethal concentrations of waterborne copper (Cu) results in inhibitions of ammonia excretion (Jamm) and Na(+) uptake (J(Na)in), yet the mechanisms by which these occur are not fully understood. In the present study, rainbow trout (Oncorhynchus mykiss) fry exposed to 50μg/l Cu for 24h displayed a sustained 40% decrease in Jamm and a transient 60% decrease in J(Na)in. Previously, these effects have been attributed to inhibitions of gill Na(+)/K(+)-ATPase and/or carbonic anhydrase (CA) activities by Cu. Trout fry did not display significant reductions in the branchial activities of these enzymes or H(+)-ATPase over 24h Cu exposure. Recently, Rhesus (Rh) glycoproteins, bi-directional NH3 gas channels, have been implicated in the mechanism of Cu toxicity. Juvenile trout were exposed to nominal 0, 50, and 200μg/l Cu for 3-6h under control conditions (ammonia-free water) followed by 6h exposure to high environmental ammonia (HEA; 1.5mmol/l NH4HCO3). HEA led to significant ammonia uptake in control fish (0μg/l Cu), and exposure to 50 and 200μg/l Cu resulted in significant reductions of ammonia uptake during HEA exposure. This is the first evidence that Cu inhibits both the excretion and uptake of ammonia, implicating bi-directional Rh glycoproteins as a target for Cu toxicity. We propose a model whereby Rh blockade by Cu causes the sustained inhibition of Jamm and transient inhibition of J(Na)in, with H(+)-ATPase potentially aiding in J(Na)in recovery. More work is needed to elucidate the role of Rh proteins in sub-lethal Cu toxicity.

  2. Nutrient-induced gastrointestinal hyperemia and specific dynamic action in rainbow trout (Oncorhynchus mykiss)--importance of proteins and lipids.

    PubMed

    Seth, Henrik; Sandblom, Erik; Axelsson, Michael

    2009-02-01

    Mechanical gastric distension induces a dorsal aortic pressor response in rainbow trout (Oncorhynchus mykiss) with no change in gastrointestinal blood flow. To elucidate what role chemical stimuli from the digested food has on the postprandial cardiovascular response, a new method was developed to investigate the contribution of individual nutrient components. Three predigested experimental diets were injected directly into the proximal intestine of rainbow trout and cardiac output (CO), gut blood flow (Qcma), heart rate (HR), and stroke volume (SV) were recorded. Specific dynamic action (SDA) was estimated by measuring oxygen consumption. When a balanced diet (50% protein, 25% fat, 15% carbohydrate) was injected, Qcma and CO increased within 1 h by 45 and 27%, respectively. The response to a high-protein diet (70% protein, 5% fat, 15% carbohydrate) was quantitatively similar but delayed, with a maximal blood flow response after 2 h. With a high-lipid diet (60% fat, 15% protein, 15% carbohydrate), the peak increase in Qcma by 22% occurred after 30 min and thereafter declined rapidly. The SDA response (19%) to the balanced diet was temporally matched with the hyperemia. With a high-protein diet, the response is delayed and enlarged (34%) compared with the balanced diet. The high-lipid diet gave no significant SDA response. We conclude that the chemical composition of the food influences the postprandial hyperemia and the SDA, such that the components appear to work in a synergistic fashion. The present results also demonstrate that both redistribution of blood flow and an overall increase in CO contribute to the postprandial increase in gut blood flow in this species.

  3. Cholecystokinin as a regulator of cardiac function and postprandial gastrointestinal blood flow in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Seth, Henrik; Gräns, Albin; Axelsson, Michael

    2010-05-01

    We have studied the potential role of CCK as a regulator/modulator of the postprandial increase in gastrointestinal blood flow. Rainbow trout (Oncorhynchus mykiss) were instrumented with pulsed Doppler flow probes to measure the effects of CCK on cardiac output and gastrointestinal blood flow. Furthermore, vascular preparations were used to study the direct effects of CCK on the vessels. In addition, we used in situ perfused hearts to further study the effects of CCK on the cardiovascular system. When the sulfated form of CCK-8 was injected at a physiological concentration (0.19 pmol/kg) in vivo, there was a significant increase in the gastrointestinal blood flow (18 +/- 4%). This increase in gastrointestinal blood flow was followed by a subsequent increase in cardiac output (30 +/- 6%). When the dose was increased to 0.76 pmol/kg, there was only a 14 +/- 6% increase in gastrointestinal blood flow; possibly due to a dose-dependent increase in the gill vascular resistance as previously reported or a direct effect on the heart. Nevertheless, CCK did not affect the isolated vessel preparations, and thus, it seems unlikely that CCK has a direct effect on the blood vessels of the second or third order. CCK did, however, have profound effects on the dynamics of the heart, and without a change in cardiac output, there was a significant increase in the amplitude (59 +/- 4%) and rate (dQ/dt: 55 +/- 4%; -dQ/dt: 208 +/- 49%) of the phasic flow profile. If and how this might be coupled to a postprandial gastrointestinal hyperemia remains to be determined. We conclude that CCK has the potential as a regulator of the postprandial gastrointestinal blood flow in fish and most likely has its effect by inducing a gastrointestinal hyperemia. The mechanism by which CCK acts is at present unknown.

  4. Trace elements in farmed fish (Cyprinus carpio, Ctenopharyngodon idella and Oncorhynchus mykiss) from Beijing: implication from feed.

    PubMed

    Jiang, Haifeng; Qin, Dongli; Mou, Zhenbo; Zhao, Jiwei; Tang, Shizhan; Wu, Song; Gao, Lei

    2016-06-01

    Concentrations of 30 trace elements, Li, V, Cr, Mn, Fe, Ni, Cu, Mo, Zn, Se, Sr, Co, Al, Ti, As, Cs, Sc, Te, Ba, Ga, Pb, Sn, Cd, Sb, Ag, Tm, TI, Be, Hg and U in major cultured freshwater fish species (common carp-Cyprinus carpio, grass carp-Ctenopharyngodon idella and rainbow trout-Oncorhynchus mykiss) with the corresponding feed from 23 fish farms in Beijing, China, were investigated. The results revealed that Fe, Zn, Cu, Mn, Sr, Se were the major accumulated essential elements and Al, Ti were the major accumulated non-essential elements, while Mo, Co, Ga, Sn, Cd, Sb, Ag, Tm, U, TI, Be, Te, Pb and Hg were hardly detectable. Contents of investigated trace elements were close to or much lower than those in fish from other areas in China. Correlation analysis suggested that the elemental concentrations in those fish species were relatively constant and did not vary much with the fish feed. In comparison with the limits for aquafeeds and fish established by Chinese legislation, Cd in 37.5% of rainbow trout feeds and As in 20% of rainbow trout samples exceeded the maximum limit, assuming that inorganic As accounts for 10% of total As. Further health risk assessment showed that fish consumption would not pose risks to consumers as far as non-essential element contaminants are concerned. However, the carcinogenic risk of As in rainbow trout for the inhabitants in Beijing exceeded the acceptable level of 10(-)(4), to which more attention should be paid.

  5. New insights into the nutritional regulation of gluconeogenesis in carnivorous rainbow trout (Oncorhynchus mykiss): a gene duplication trail.

    PubMed

    Marandel, Lucie; Seiliez, Iban; Véron, Vincent; Skiba-Cassy, Sandrine; Panserat, Stéphane

    2015-07-01

    The rainbow trout (Oncorhynchus mykiss) is considered to be a strictly carnivorous fish species that is metabolically adapted for high catabolism of proteins and low utilization of dietary carbohydrates. This species consequently has a "glucose-intolerant" phenotype manifested by persistent hyperglycemia when fed a high-carbohydrate diet. Gluconeogenesis in adult fish is also poorly, if ever, regulated by carbohydrates, suggesting that this metabolic pathway is involved in this specific phenotype. In this study, we hypothesized that the fate of duplicated genes after the salmonid-specific 4th whole genome duplication (Ss4R) may have led to adaptive innovation and that their study might provide new elements to enhance our understanding of gluconeogenesis and poor dietary carbohydrate use in this species. Our evolutionary analysis of gluconeogenic genes revealed that pck1, pck2, fbp1a, and g6pca were retained as singletons after Ss4r, while g6pcb1, g6pcb2, and fbp1b ohnolog pairs were maintained. For all genes, duplication may have led to sub- or neofunctionalization. Expression profiles suggest that the gluconeogenesis pathway remained active in trout fed a no-carbohydrate diet. When trout were fed a high-carbohydrate diet (30%), most of the gluconeogenic genes were non- or downregulated, except for g6pbc2 ohnologs, whose RNA levels were surprisingly increased. This study demonstrates that Ss4R in trout involved adaptive innovation via gene duplication and via the outcome of the resulting ohnologs. Indeed, maintenance of ohnologous g6pcb2 pair may contribute in a significant way to the glucose-intolerant phenotype of trout and may partially explain its poor use of dietary carbohydrates.

  6. Expression of immune-related genes in rainbow trout (Oncorhynchus mykiss) induced by probiotic bacteria during Lactococcus garvieae infection.

    PubMed

    Pérez-Sánchez, Tania; Balcázar, José Luis; Merrifield, Daniel L; Carnevali, Oliana; Gioacchini, Giorgia; de Blas, Ignacio; Ruiz-Zarzuela, Imanol

    2011-08-01

    The aim of the present study was to investigate the effect of lactic acid bacteria (LAB) on the control of lactococcosis as well as to assess the impact of probiotics on the expression of immune-related genes in the head kidney and intestine of rainbow trout (Oncorhynchus mykiss). Lactobacillus plantarum, Lactococcus lactis and Leuconostoc mesenteroides, were administered orally at 10⁶ CFU g⁻¹ feed to fish for 36 days. Twenty-one days after the start of the feeding period, fish were challenged with Lactococcus garvieae. Only the fish fed the diet containing Lb. plantarum showed significantly (P < 0.05) improved protection against L. garvieae compared to the control. Subsequently, real-time PCR was employed to determine the mRNA levels of IL-1β, IL-8, IL-10 and TNF-α in the head kidney, and IL-8, Tlr5 and IgT in the intestine of the control and Lb. plantarum groups. IL-1β, IL-10 and TNF-α gene expression were significantly up-regulated by Lb. plantarum. Moreover, the mRNA levels of IL-10, IL-8 and IgT were significantly higher in the Lb. plantarum group after L. garvieae infection, suggesting that Lb. plantarum can stimulate the immune response of rainbow trout. PCR-DGGE revealed no detectable levels of the probiotics or the pathogen present on the distal intestinal mucosa. These findings demonstrate that direct probiotic-host interactions with the intestine are not always necessary to induce host stimulatory responses which ultimately enhance disease resistance. Furthermore, as L. garvieae did not colonise the intestinal tract, and therefore likely did not infect via this route, the antagonistic properties of the probiotic candidate towards L. garvieae were likely of little influence in mediating the improved disease resistance which could be attributed to the elevated immunological response.

  7. Sex hormone-binding globulins characterization and gonadal gene expression during sex differentiation in the rainbow trout, Oncorhynchus mykiss.

    PubMed

    Marivin, Elisa; Yano, Ayaka; Guérin, Adèle; Nguyen, Thao-Vi; Fostier, Alexis; Bobe, Julien; Guiguen, Yann

    2014-08-01

    Sex hormone-binding globulin (SHBG) binds androgens and estrogens in the blood of many vertebrates, including teleost fish. In mammals, SHBG is synthetized in the liver and secreted into the blood. In fish, shbga also exhibits a hepatic expression. In salmonids, in which the gene has been duplicated, the recently discovered shbgb gene exhibits a predominantly ovarian expression. The present work aimed at gaining new insight into shbgb gene structure and expression during gonadal sex differentiation, a steroid-sensitive process, and Shbgb protein structure and binding characteristics; specifically, rainbow trout (Oncorhynchus mykiss) shbgb was analyzed. shbgb structure was analyzed in silico while expression was characterized during gonadal sex differentiation using all-male and all-female populations. We observed that shbgb gene and cognate-protein structures are similar to homologs previously described in zebrafish and mammals. The shbgb gene is predominantly expressed in differentiating female gonads, with increased expression around the end of ovarian differentiation. In the ovary, shbgb mRNA was detected in a subset of somatic cells surrounding the ovarian lamellae. Furthermore, Shbgb binds steroids with a higher selectivity than Shbga, exhibiting a higher affinity for estradiol compared to Shbga. In conclusion, Shbgb binding characteristics are clearly different from those of Shbga. Shbgb is expressed in the differentiating ovary during a period when the synthesis and action of testosterone and estradiol must be tightly regulated. This strongly suggests that Shbgb participates in the regulation of steroid metabolism and/or mediation, that is, needed during early gonadal development in rainbow trout.

  8. Consecutive emamectin benzoate and deltamethrin treatments affect the expressions and activities of detoxification enzymes in the rainbow trout (Oncorhynchus mykiss).

    PubMed

    Cárcamo, Juan Guillermo; Aguilar, Marcelo N; Carreño, Constanza F; Vera, Tamara; Arias-Darraz, Luis; Figueroa, Jaime E; Romero, Alex P; Alvarez, Marco; Yañez, Alejandro J

    2017-01-01

    Rainbow trout (Oncorhynchus mykiss) subjected to three consecutive, alternating treatments with emamectin benzoate (EMB) and deltamethrin (DM) during outbreaks of Caligus rogercresseyi in a farm located in southern Chile (Hornopiren, Chiloé), were studied to determine the effects of these treatments on the protein and enzymatic activity levels of cytochrome P450 1A (CYP1A), flavin-containing monooxygenase (FMO) and glutathione S-transferase (GST) in different tissues. Consecutive and alternating EMB/DM treatments resulted in a 10-fold increase and 3-fold decrease of CYP1A protein levels in the intestine and gills, respectively. Notably, CYP1A activity levels decreased in most of the analyzed tissues. FMO protein and activity levels markedly increased in the kidney and the intestine. GST was up-regulated in all tissues, either as protein or enzyme activity. When comparing consecutive EMB/DM treatments against previous studies of EMB treatment alone, CYP1A activity levels were similarly diminished, except in muscle. Likewise, FMO activity levels were increased in most of the analyzed tissues, particularly in the muscle, kidney, and intestine. The increases observed for GST were essentially unchanged between consecutive EMB/DM and EMB only treatments. These results indicate that consecutive EMB/DM treatments in rainbow trout induce the expression and activity of FMO and GST enzymes and decrease CYP1A activity. These altered activities of detoxification enzymes could generate imbalances in metabolic processes, synthesis, degradation of hormones and complications associated with drug interactions. It is especially important when analyzing possible effects of consecutive antiparasitic treatments on withholding periods and salmon farming yields.

  9. Broodstock History Strongly Influences Natural Spawning Success in Hatchery Steelhead (Oncorhynchus mykiss).

    PubMed

    Ford, Michael J; Murdoch, Andrew R; Hughes, Michael S; Seamons, Todd R; LaHood, Eric S

    2016-01-01

    We used genetic parentage analysis of 6200 potential parents and 5497 juvenile offspring to evaluate the relative reproductive success of hatchery and natural steelhead (Onchorhynchus mykiss) when spawning in the wild between 2008 and 2011 in the Wenatchee River, Washington. Hatchery fish originating from two prior generation hatchery parents had <20% of the reproductive success of natural origin spawners. In contrast, hatchery females originating from a cross between two natural origin parents of the prior generation had equivalent or better reproductive success than natural origin females. Males originating from such a cross had reproductive success of 26-93% that of natural males. The reproductive success of hatchery females and males from crosses consisting of one natural origin fish and one hatchery origin fish was 24-54% that of natural fish. The strong influence of hatchery broodstock origin on reproductive success confirms similar results from a previous study of a different population of the same species and suggests a genetic basis for the low reproductive success of hatchery steelhead, although environmental factors cannot be entirely ruled out. In addition to broodstock origin, fish size, return time, age, and spawning location were significant predictors of reproductive success. Our results indicate that incorporating natural fish into hatchery broodstock is clearly beneficial for improving subsequent natural spawning success, even in a population that has a decades-long history of hatchery releases, as is the case in the Wenatchee River.

  10. Broodstock History Strongly Influences Natural Spawning Success in Hatchery Steelhead (Oncorhynchus mykiss)

    PubMed Central

    Murdoch, Andrew R.; Hughes, Michael S.; Seamons, Todd R.; LaHood, Eric S.

    2016-01-01

    We used genetic parentage analysis of 6200 potential parents and 5497 juvenile offspring to evaluate the relative reproductive success of hatchery and natural steelhead (Onchorhynchus mykiss) when spawning in the wild between 2008 and 2011 in the Wenatchee River, Washington. Hatchery fish originating from two prior generation hatchery parents had <20% of the reproductive success of natural origin spawners. In contrast, hatchery females originating from a cross between two natural origin parents of the prior generation had equivalent or better reproductive success than natural origin females. Males originating from such a cross had reproductive success of 26–93% that of natural males. The reproductive success of hatchery females and males from crosses consisting of one natural origin fish and one hatchery origin fish was 24–54% that of natural fish. The strong influence of hatchery broodstock origin on reproductive success confirms similar results from a previous study of a different population of the same species and suggests a genetic basis for the low reproductive success of hatchery steelhead, although environmental factors cannot be entirely ruled out. In addition to broodstock origin, fish size, return time, age, and spawning location were significant predictors of reproductive success. Our results indicate that incorporating natural fish into hatchery broodstock is clearly beneficial for improving subsequent natural spawning success, even in a population that has a decades-long history of hatchery releases, as is the case in the Wenatchee River. PMID:27737000

  11. Response of rainbow trout (Oncorhynchus mykiss) D-11 cell line to 3-methylcholanthrene (3MC) exposure.

    PubMed

    Ferraris, M; Flora, A; Fornasari, D; Radice, S; Marabini, L; Frigerio, S; Chiesara, E

    2002-08-01

    The rainbow trout cytochrome P4501A gene subfamily consists of two members, CYP1A1 and CYP1A3, which are induced by polycyclic aromatic hydrocarbons (PAHs). In this study, we investigated the induction of cytochrome P4501A3 in the rainbow trout (Onchorhynchus mykiss) D-11 cell line after 3-methylcholanthrene (3MC) exposure by generating chimeric constructs in which a 2.3 kb fragment or portion of the 5'-flanking region of the trout cytochrome CYP1A3 gene was fused to the firefly luciferase (Luc) gene. The constructs were then transiently transfected into the trout D-11 cells and their transcriptional activity measured by luciferase assay after treatment with different 3MC concentrations. Maximal induction following exposure to 2 microM 3MC was 2.2-fold after 72 h. Deletion of the region specifying the 5' untranslated region (5'UTR) of the mRNA encoding the CYP1A3 gene increased unstimulated luciferase activity but also led to a loss of response to 3MC treatment. This finding suggests that the region specifying the 5'UTR contains a negative element that is also involved in the transcriptional response to 3MC.

  12. Dataset of proinflammatory cytokine and cytokine receptor gene expression in rainbow trout (Oncorhynchus mykiss) measured using a novel GeXP multiplex, RT-PCR assay.

    PubMed

    Kutyrev, Ivan; Cleveland, Beth; Leeds, Timothy; Wiens, Gregory D

    2017-04-01

    A GeXP multiplex, RT-PCR assay was developed and optimized that simultaneously measures expression of a suite of immune-relevant genes in rainbow trout (Oncorhynchus mykiss), concentrating on tumor necrosis factor and interleukin-1 ligand/receptor systems and acute phase response genes. The dataset includes expression values for drpt, il11a, il1b1, il1b2, il1b3, il1r-like-1(e3-5), il1r-like-1(e9-11), il1r1-like-a, il1r1-like-b, il1r2, saa, tnfa1, tnfa2, tnfa3, tnfrsf1a, tnfrsf1a-like-a, tnfrsf1a-like-b, tnfrsf5, and tnfrsf9. Gene expression was measured at four time-points post-challenge in both a resistant line (ARS-Fp-R) and a susceptible line (ARS-Fp-S) of rainbow trout. In addition, fish body weight, spleen index and the Flavobacterium psychrophilum load are reported. These data are an extension of information presented and discussed in "Proinflammatory cytokine and cytokine receptor gene expression kinetics following challenge with Flavobacterium psychrophilum in resistant and susceptible lines of rainbow trout (Oncorhynchus mykiss)" (Kutyrev et al., 2016) [1].

  13. Comparing the effects of feeding a grain- or a fish meal-based diet on water quality, waste production, and rainbow trout Oncorhynchus mykiss performance within low exchange water recirculating aquaculture systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Feeding a fish meal-free grain-based diet (GB) was compared to feeding a fish meal-based diet (FM) relative to water quality criteria, waste production, water treatment process performance, and rainbow trout Oncorhynchus mykiss performance within six replicated water recirculating aquaculture system...

  14. Fatty-acid profiles of white muscle and liver in stream-maturing steelhead trout Oncorhynchus mykiss from early migration to kelt emigration

    USGS Publications Warehouse

    Penney, Zachary L.; Moffitt, Christine M.

    2015-01-01

    The profiles of specific fatty acids (FA) in white muscle and liver of fasting steelhead troutOncorhynchus mykiss were evaluated at three periods during their prespawning migration and at kelt emigration in the Snake–Columbia River of Washington, Oregon and Idaho, to improve the understanding of energy change. Twenty-seven FAs were identified; depletion of 10 of these was positively correlated in liver and white muscle of prespawning O. mykiss. To observe relative changes in FA content more accurately over sampling intervals, the lipid fraction of tissues was used to normalize the quantity of individual FA to an equivalent tissue wet mass. Saturated and monounsaturated FAs were depleted between upstream migration in September and kelt emigration in June, whereas polyunsaturated FAs were more conserved. Liver was depleted of FAs more rapidly than muscle. Three FAs were detected across all sampling intervals: 16:0, 18:1 and 22:6n3, which are probably structurally important to membranes. When structurally important FAs of O. mykiss are depleted to provide energy, physiological performance and survival may be affected.

  15. Differences in the induction of cyp1A and related genes in cultured rainbow trout Oncorhynchus mykiss. Additional considerations for the use of EROD activity as a biomarker.

    PubMed

    Valdehita, A; Fernández-Cruz, M L; Torrent, F; Sericano, J L; Navas, J M

    2012-07-01

    Two rainbow trout Oncorhynchus mykiss fish farms were repeatedly sampled in order to observe the variability of ethoxyresorufin-O-deethylase (EROD) activity and of related genes in the liver. Fish coming from fish farm A exhibited EROD levels that could be considered as basal according to the scientific literature, however, EROD activity in fish coming from fish farm B was significantly increased. This was accompanied by augmented aryl hydrocarbon receptor (ahr) and cytochrome P4501A (cyp1A) messenger RNA expression and reduced oestrogen receptor (er) and vitellogenin (vtg) transcription. Only sediment extracts from the entry channel of fish farm B induced EROD activity in O. mykiss cultured cells, however, this induction could not be explained by the levels of polyaromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) measured in the sediments. The results of this study point out that O. mykiss cultured in fish farms could be used as sentinels for indication of pollution. In this particular work, however, no conclusive evidence has been found for a relationship between the presence of PAHs and PCBs and the observed EROD induction.

  16. Effects of heat stress on respiratory burst, oxidative damage and SERPINH1 (HSP47) mRNA expression in rainbow trout Oncorhynchus mykiss.

    PubMed

    Wang, Yanni; Liu, Zhe; Li, Zhen; Shi, Haina; Kang, Yujun; Wang, Jianfu; Huang, Jinqiang; Jiang, Li

    2016-04-01

    For rainbow trout Oncorhynchus mykiss, high temperature is a major abiotic stress that limits its growth and productivity. In this study, spleen macrophage respiratory burst (RB), serum superoxide dismutase (SOD), serum malondialdehyde (MDA) and mRNA expression of the SERPINH1 (HSP47) gene in different tissues (liver, spleen, head kidney and heart) were measured in unstressed (18 °C) and heat-stressed (25 °C) fish. Spleen macrophage RB activity, serum SOD activity and MDA content all increased significantly (P < 0.05) during heat shock, and peaked at 8, 12 and 4 h, respectively. SERPINH1 mRNA expression responded in a time- and tissue-specific manner to heat stress, which was mainly reflected in the significant up-regulation in all tissues (P < 0.05) and greater expression in the liver than the other tissues (P < 0.05). During the heat-shock recovery period, the MDA content returned to the unstressed level. These results indicate that heat shock causes cell injury, induces oxidative damage and promotes SERPINH1 mRNA expression, which plays an important protective function during heat stress in O. mykiss. In practice, close attention should be given to temperature changes in O. mykiss production to reduce the effects of high temperature.

  17. Gene expression patterns in Rainbow Trout, Oncorhynchus mykiss, exposed to a suite of model toxicants

    SciTech Connect

    Hook, Sharon E.; Skillman, Ann D.; Small, Jonathan A.; Schultz, Irv R.

    2006-05-25

    The increased availability and use of DNA microarrays has allowed the characterization of gene expression patterns associated with different toxicants. An important question is whether toxicant induced changes in gene expression in fish are sufficiently diverse to allow for identification of specific modes of action and/or specific contaminants. In theory, each class of toxicant may generate a gene expression profile unique to its mode of toxic action. We exposed isogenic (cloned) rainbow trout Oncorhyncus mykiss, to sublethal levels of a series of model toxicants with varying modes of action, including ethynylestradiol (xeno-estrogen), trenbolone (anabolic steroid; model androgen), 2,2,4,4´tetrabromodiphenyl ether (BDE-47, thyroid active), diquat (oxidant stressor), chromium VI, and benzo[a]pyrene (BaP) for a period of 1-3 weeks. Following exposure, fish were euthanized, livers harvested and RNA extracted. Fluorescently labeled cDNA were generated and hybridized against a commercially available Atlantic Salmon / Trout array (GRASP project, University of Victoria) spotted with 16,000 cDNA’s. The slides were scanned to measure abundance of a given transcript in each sample relative to controls. Data were analyzed via Genespring (Silicon Genetics) to identify a list of up and down regulated genes, as well as to determine gene clustering patterns that can be used as “expression signatures”. Our analysis indicates each toxicant generated specific gene expression profiles. Most genes exhibiting altered expression responded to only one of the toxicants. Relatively few genes are co-expressed in multiple treatments. For example, BaP and Diquat, both of which exert toxicity via oxidative stress, up-regulated 28 of the same genes, of over 100 genes altered by ether treatment. Other genes associated with steroidogenesis, p450 and estrogen responsive genes appear to be useful for selectively identifying toxicant mode of in fish, suggesting a link between gene expression

  18. Transcription of immune genes upon challenge with viral hemorrhagic septicemia virus (VHSV) in DNA vaccinated rainbow trout (Oncorhynchus mykiss).

    PubMed

    Cuesta, A; Tafalla, C

    2009-01-07

    Even though DNA vaccination has proven as one of the most effective methods in controlling fish rhabdoviruses, the immune mechanisms responsible for protection are still unknown. Many studies have focused on studying which cytokines and immune genes are triggered in response to the vaccine at different times post-vaccination. However, to elucidate the mechanism(s) responsible for protection, to our understanding it is also of great relevance to study the immune response to the virus in fish that have been previously vaccinated and compare it to the effects that the virus might have on non-vaccinated fish. This type of study has never been performed to date in fish. Thus, in the current work, we vaccinated rainbow trout (Oncorhynchus mykiss) with a DNA vaccine against viral hemorrhagic septicemia virus (VHSV), and 30 days post-vaccination we challenged the fish with a virulent VHSV. It was then, that we studied the immune response to the virus at very early times post-infection in fish, in order to compare the effects of VHSV on vaccinated or non-vaccinated trout. We studied the levels of expression of interleukin 1beta (IL-1beta), major histocompatibility complex (MHC) class Ialpha and IIalpha genes, immunoglobulin M (IgM), CD8alpha, type I interferon (IFN), Mx, IFN-gamma and natural killer enhancing factor (NKEF) in head kidney, spleen and blood. When we compared the effect that VHSV had on vaccinated fish to the effect that the virus produced in fish vaccinated with the empty plasmid, the genes that were significantly up-regulated were IL-1beta and MHC IIalpha in the spleen at day 1 post-infection, MHC Ialpha in all organs at day 1 post-infection, and IFN and Mx in the spleen and blood at days 1 and 3 post-infection, respectively. Genes that correlate with an increased specific immune response were not significantly increased in response to VHSV in these vaccinated animals. The results suggest that DNA vaccination induces a memory state in fish that, on the

  19. Divergent spatial regulation of duplicated fatty acid-binding protein (fabp) genes in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Bayır, Mehtap; Bayır, Abdulkadir; Wright, Jonathan M

    2015-06-01

    The increased use of plant oil as a dietary supplement with the resultant high dietary lipid loads challenges the lipid transport, metabolism and storage mechanisms in economically important aquaculture species, such as rainbow trout. Fatty acid-binding proteins (Fabp), ubiquitous in tissues highly active in fatty acid metabolism, participate in lipid uptake and transport, and overall lipid homeostasis. In the present study, searches of nucleotide sequence databases identified mRNA transcripts coded by 14 different fatty acid-binding protein (fabp) genes in rainbow trout (Oncorhynchus mykiss), which include the complete minimal suite of seven distinct fabp genes (fabp1, 2, 3, 6, 7, 10 and 11) discovered thus far in teleost fishes. Phylogenetic analyses suggest that many of these extant fabp genes in rainbow trout exist as duplicates, which putatively arose owing to the teleost-specific whole genome duplication (WGD); three pairs of duplicated fabp genes (fabp2a.1/fabp2a.2, fabp7b.1/fabp7b.2 and fabp10a.1/fabp10a.2) most likely were generated by the salmonid-specific WGD subsequent to the teleost-specific WGD; and fabp3 and fabp6 exist as single copy genes in the rainbow trout genome. Assay of the steady-state levels of fabp gene transcripts by RT-qPCR revealed: (1) steady-state transcript levels differ substantially between fabp genes and, in some instances, by as much as 30×10(4)-fold; (2) some fabp transcripts are widely distributed in many tissues, whereas others are restricted to one or a few tissues; and (3) divergence of regulatory mechanisms that control spatial transcription of duplicated fabp genes in rainbow trout appears related to length of time since their duplication. The suite of fabp genes described here provides the foundation to investigate the role(s) of fatty acid-binding proteins in the uptake, mobilization and storage of fatty acids in cultured fish fed diets differing in lipid content, especially the use of plant oil as a dietary supplement

  20. Effect of Cryptobia salmositica-induced anorexia on feeding behavior and immune response in juvenile rainbow trout Oncorhynchus mykiss.

    PubMed

    Chin, Adrian; Guo, Fu Ci; Bernier, Nicholas J; Woo, Patrick T K

    2004-01-28

    At 10 degrees C, rainbow trout Oncorhynchus mykiss (n = 13 per group) infected with Cryptobia salmositica Katz, 1951 became anorexic at 3 wk post-infection (w.p.i.), with feed-intake decreasing significantly from 1.33 to 0.94% body weight (b.w.). Anorexia was most severe at 4 w.p.i. (0.80% b.w.), coinciding with peak parasitemia (9.2 x 10(6) parasites ml blood(-1)) and anemia. At 8 w.p.i., fish had recovered their appetite although they still had contained detectable parasites (6.8 x 10(5) parasites ml(-1)) and were anemic (pack cell volume, PCV, of 24.4%). However at 5 degrees C, anorexia occurred at 5 w.p.i. (0.81% b.w.), and was most severe at 7 w.p.i. (0.40% b.w.). At 8 w.p.i. (0.43% b.w.), fish displayed high parasitemia (4.6 x 10(6) parasites ml(-1)) and low PCV (10.8%). Fish at 5 degrees C had lower gastric evacuation (GE) rates (GE48h) than 10 degrees C fish, however there were no differences between infected and naive fish at both temperatures. Before anorexia, there was no significant correlation between mean share of meal (MSM, a measure of how food was partitioned within a group) and coefficient of variation in feeding but this became significant during anorexia (p = 0.02 and p = 0.0002 at 10 and 5 degrees C respectively). Significant correlations were detected between b.w. and MSM before onset of anorexia at 10 degrees C (p = 0.005) and 5 degrees C (p = 0.02); this was maintained at 10 degrees C (p = 0.001) but not at 5 degrees C (p = 0.98). Fish on an anorexic diet (0.93% b.w.) responded well at 10 degrees C to a live C. salmositica vaccine; this could partly be due to constant antigenic stimulation by the live vaccine.

  1. Viability and DNA fragmentation of rainbow trout embryos (Oncorhynchus mykiss) obtained from eggs stored at 4 °C.

    PubMed

    Ubilla, A; Valdebenito, I; Árias, M E; Risopatrón, J

    2016-05-01

    In vitro storage of salmonid eggs leads to aging of the cells causing a decline in quality and reducing their capacity to develop and produce embryos. The quality of salmonid embryos is assessed by morphologic analyses; however, data on the application of biomarkers to determine the cell viability and DNA integrity of embryos in these species are limited. The aim of this study was to evaluate the effect on embryo development, viability and DNA fragmentation in the embryonic cells of in vitro storage time at 4 °C of rainbow trout (Oncorhynchus mykiss) eggs. The embryos were obtained by IVF from eggs stored for 0 (control), 48, and 96 hours at 4 °C. At 72 hours after fertilization, dechorionated embryos were examined to determine percentages of developed embryos (embryos with normal cell division morphology), viability (LIVE/DEAD sperm viability kit), and DNA integrity (terminal deoxynucleotidyl transferase [TdT] dUTP nick-end labeling assay). The percentage of developing embryos decreased (P < 0.05) with storage time of the eggs (95.10 ± 2.55; 88.14 ± 4.50; 79.99 ± 6.60 for 0, 48, and 96 hours, respectively). Similarly, cell viability decreased (P < 0.05; 96.07 ± 7.15; 80.42 ± 8.55; 77.47 ± 7.88 for 0, 48, and 96 hours, respectively), and an increase (P < 0.05) in DNA fragmentation in the embryos was observed at 96-hour storage. A positive correlation was found between cell DNA fragmentation and storage time (r = 0.8173; P < 0.0001). The results revealed that terminal deoxynucleotidyl transferase [TdT] dUTP nick-end labeling assay technique is reliable mean to assess the state of the DNA in salmonid embryos and that in vitro eggs storage for 96h reduces embryo development and cell DNA integrity. DNA integrity evaluation constitutes a biomarker of the quality of the ova and resulting embryos so as to predict their capacity to produce good-quality embryos in salmonids, particularly under culture conditions.

  2. An ecological risk assessment of the acute and chronic effects of the herbicide clopyralid to rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Fairchild, J.F.; Allert, A.L.; Feltz, K.P.; Nelson, K.J.; Valle, J.A.

    2009-01-01

    Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) is a pyridine herbicide frequently used to control invasive, noxious weeds in the northwestern United States. Clopyralid exhibits low acute toxicity to fish, including the rainbow trout (Oncorhynchus mykiss) and the threatened bull trout (Salvelinus confluentus). However, there are no published chronic toxicity data for clopyralid and fish that can be used in ecological risk assessments. We conducted 30-day chronic toxicity studies with juvenile rainbow trout exposed to the acid form of clopyralid. The 30-day maximum acceptable toxicant concentration (MATC) for growth, calculated as the geometric mean of the no observable effect concentration (68 mg/L) and the lowest observable effect concentration (136 mg/L), was 96 mg/L. No mortality was measured at the highest chronic concentration tested (273 mg/L). The acute:chronic ratio, calculated by dividing the previously published 96-h acutely lethal concentration (96-h ALC50; 700 mg/L) by the MATC was 7.3. Toxicity values were compared to a four-tiered exposure assessment profile assuming an application rate of 1.12 kg/ha. The Tier 1 exposure estimation, based on direct overspray of a 2-m deep pond, was 0.055 mg/L. The Tier 2 maximum exposure estimate, based on the Generic Exposure Estimate Concentration model (GEENEC), was 0.057 mg/L. The Tier 3 maximum exposure estimate, based on previously published results of the Groundwater Loading Effects of Agricultural Management Systems model (GLEAMS), was 0.073 mg/L. The Tier 4 exposure estimate, based on published edge-of-field monitoring data, was estimated at 0.008 mg/L. Comparison of toxicity data to estimated environmental concentrations of clopyralid indicates that the safety factor for rainbow trout exposed to clopyralid at labeled use rates exceeds 1000. Therefore, the herbicide presents little to no risk to rainbow trout or other salmonids such as the threatened bull trout. ?? 2009 US Government.

  3. Evaluation of Enterococcus spp. from rainbow trout (Oncorhynchus mykiss, Walbaum), feed, and rearing environment against fish pathogens.

    PubMed

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

    2015-04-01

    The use of lactic acid bacteria of aquatic origin as probiotics constitutes an alternative strategy to the antibiotic treatment for disease control in aquaculture. Enterococci are currently used as probiotics in human and animal health. In this study, we evaluated the safety of 64 enterococci isolated from rainbow trout (Oncorhynchus mykiss, Walbaum), feed and rearing environment, and their antimicrobial activity against 9 fish pathogens. The 64 enterococcal isolates were identified to the species level by polymerase chain reaction (PCR), using specific primers for the different enterococcal species, and confirmed by superoxide dismutase gene sequencing. Enterococcus faecium and E. hirae were the most common species (42.2 and 35.9%, respectively). A total of 48 isolates (75%) showed phenotypic resistance to at least 1 antibiotic determined by a disk-diffusion method, and 25 isolates (39.1%) harbored at least 1 antibiotic resistance gene [erm(B), tet(M), tet(S), tet(K), tet(L), tet(T), vanC2, and aad(E)], detected by PCR. One (1.6%) isolate produced gelatinase and none produced hemolysin, using a plate assay. The virulence genes gelE (46.9%), efaAfs (17.2%), agg (1.6%), and hyl (1.6%) were detected by PCR. A total of 48 isolates (75%) exerted antimicrobial activity against 1 or more of the tested fish pathogens, using a stab-on-agar test. From these isolates, 21 (43.8%) harbored at least 1 bacteriocin-encoding gene (entP, entL50A and entL50B, hirJM79, entSE-K4, entQ and entA), detected by PCR. None of the enterococci showed bile deconjugation and mucin degradation abilities. A total of 17 enterococcal isolates (26.6%) that did not harbor any antibiotic resistance or virulence factor were considered safe for application as probiotics, including 6 isolates (35.3%) that showed antimicrobial activity against at least 1 fish pathogen and harbored at least 1 bacteriocin-encoding gene. Rainbow trout, feed, and rearing environment constitute an appropriate source for the

  4. Effects of Pb plus Cd mixtures on toxicity, and internal electrolyte and osmotic balance in the rainbow trout (Oncorhynchus mykiss).

    PubMed

    Clemow, Yvonne H; Wilkie, Michael P

    2015-04-01

    The physiological and toxicological effects of Cd and Pb have been thoroughly studied, but relatively little work has been done to determine how mixtures of these metals affect fishes in soft (<100 μmol L(-1)Ca(2+)) slightly acidic (pH ∼6) waters typical of many lakes in the Canadian Shield and other regions. Recently, it has been suggested that acute exposure to Cd plus Pb mixtures (3h) had greater than additive effects on both Ca(2+) and Na(+) influx, which could potentially exacerbate disturbances to ion balance and result in greater toxicity in rainbow trout (Oncorhynchus mykiss). The goal of the present study was to test this hypothesis by assessing the physiological and toxicological effects of Cd plus Pb mixtures over longer time periods (3-5 days), but at relatively low, more environmentally relevant concentrations of these metals. Accordingly, toxicity and measurements of blood acid-base regulation (PaO2, pHa), hematology (Ht, Hb, MCHC, and Protein), ionic composition (body ions and plasma Ca(2+), Na(+), Cl(-), osmolality), unidirectional Na(+) fluxes and branchial Na(+)/K(+)-ATPase activity were measured in rainbow trout exposed to Cd plus Pb mixtures. Experiments on rainbow trout, implanted with dorsal aortic catheters for repetitive blood sampling, demonstrated that exposure to Pb alone (26 nmol PbL(-1)) was less toxic than Cd alone (6 nmol CdL(-1)), which was much less toxic to the fish than a Cd plus Pb mixture (7 nmol CdL(-1) plus 45 nmol PbL(-1)), which led to greater than additive 80% mortality by 5d. Both Cd and Pb inhibited Na(+) influx over 3d exposure to the metals, which was partially offset by decreases in the diffusive efflux (outflux) of Na(+) across the gill. Despite an absence of detectable effects of Pb alone on plasma ion balance, Cd plus Pb mixtures exacerbated Cd-induced reductions in plasma Ca(2+) concentration, and resulted in pronounced reductions in plasma Na(+), Cl(-), and osmolality. No effects on Na(+)/K(+)-ATPase activity

  5. Effects of varying densities on serum reproductive parameters in pen-reared juvenile female rainbow trout Oncorhynchus mykiss farms

    NASA Astrophysics Data System (ADS)

    Hou, Zhishuai; Wen, Haishen; Li, Jifang; He, Feng; Liu, Qun; Wang, Jinhuan; Guan, Biao; Wang, Qinglong

    2017-01-01

    The primary goal of this study was to assess the effect of varying densities on serum reproductive parameters of immature rainbow trout Oncorhynchus mykiss. Experimental trout were maintained in intensive, pen-reared farms for 300 days in fresh water reservoirs. Initial densities were 4.6, 6.6, and 8.6 kg/m3 (40, 60, 80 ind./m3), indicated as SD1, SD2, SD3, and final densities were 31.1, 40.6, 49.3 kg/m3, respectively. A summary of the ovarian stages were observed by histological examination. Serum E2 (estradiol), T (testosterone) were evaluated by radioimmunoassay and FSH (follicle-stimulating-hormone), LH (luteinizing-hormone), vitellogenin, 17α,20β-P (17α,20βdihydroxy4-pregnen-3-one) were measured by enzyme-linked immunosorbent assay. Our findings demonstrated that ovarian development were retarded (from stage III to stage IV) at highest rearing density (SD3) after 180 days of intensive culture (over 40.6 kg/m3). In addition, we observed an inverse relationship between serum reproductive parameters and rearing density. Furthermore, compared to serum reproductive parameters of SD1, E2, T, FSH, vitellogenin, 17α,20β-P, GSI and LH of two higher density groups decreased firstly and significantly at 60 (over 15.9 kg/m 3 ), 180 (over 31.7 kg/m 3 ), 180 (over 40.6 kg/m3), 240 (over 36 kg/m3), 240 (over 36 kg/m3), 240 (over 45 kg/m3) and 300 (over 49.3 kg/m3) days, respectively. Comparing serum reproductive parameters within the same ovarian development stage of rainbow trout from varying densities revealed that higher population density also led to significantly lower overall serum reproductive parameters. Overall, this study presents the reproductive, endocrinological parameters of juvenile female rainbow trout at high rearing densities and indicates the need for rainbow trout (114.44±5.21 g, 19.69±0.31 cm) that are initially stocked at 6.6 or 8.6 kg/m3 should be classified and subdivided into lower density after 180 days of farming (not over 31.7 kg/m3).

  6. The effects of aquaculture production noise on the growth, condition factor, feed conversion, and survival of rainbow trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    Davidson, J.; Bebak, J.; Mazik, P.

    2009-01-01

    Intensive aquaculture systems, particularly recirculating systems, utilize equipment such as aerators, air and water pumps, blowers, and filtration systems that inadvertently increase noise levels in fish culture tanks. Sound levels and frequencies measured within intensive aquaculture systems are within the range of fish hearing, but species-specific effects of aquaculture production noise are not well defined. Field and laboratory studies have shown that fish behavior and physiology can be negatively impacted by intense sound. Therefore, chronic exposure to aquaculture production noise could cause increased stress, reduced growth rates and feed conversion efficiency, and decreased survival. The objective of this study was to provide an in-depth evaluation of the long term effects of aquaculture production noise on the growth, condition factor, feed conversion efficiency, and survival of cultured rainbow trout, Oncorhynchus mykiss. Rainbow trout were cultured in replicated tanks using two sound treatments: 117??dB re 1????Pa RMS which represented sound levels lower than those recorded in an intensive recycle system and 149??dB re 1????Pa RMS, representing sound levels near the upper limits known to occur in recycle systems. To begin the study mean fish weights in the 117 and 149??dB tanks were 40 and 39??g, respectively. After five months of exposure no significant differences were identified between treatments for mean weight, length, specific growth rates, condition factor, feed conversion, or survival (n = 4). Mean final weights for the 117 and 149??dB treatments were 641 ?? 3 and 631 ?? 10??g, respectively. Overall specific growth rates were equal, i.e. 1.84 ?? 0.00 and 1.84 ?? 0.01%/day. Analysis of growth rates of individually tagged rainbow trout indicated that fish from the 149??dB tanks grew slower during the first month of noise exposure (p < 0.05); however, fish acclimated to the noise thereafter. This study further suggests that rainbow trout growth

  7. Effects of organic acids on growth and phosphorus utilization in rainbow trout, Oncorhynchus mykiss. .

    PubMed

    Pandey, Abhed; Satoh, Shuichi

    2014-11-01

    The present study aimed to investigate the effect of phosphorus and various organic acids supplementation on growth, nutrient retention and loading in rainbow trout fed on low fishmeal based diets. Five experimental diets were formulated, Diet D1 (0.5P) was positive control with 0.5% inorganic phosphorus addition and D2 (0P, negative control) without addition of inorganic phosphorus. D3, D4 and D5 were supplemented with 1% fumaric (FuA), formic (FoA) and acetic (AA) acids, respectively. All the diets were fed until satiation to duplicate groups of 25 fish for 12 weeks. Feed conversion ratio (FCR) was recorded best with FoA diet and absorption of phosphorus was significantly higher (P < 0.05) in all the diets supplemented with organic acids and was similar to positive control. The phosphorus and nitrogen retention with FoA diet was significantly high (P < 0.05) as compared to 0P diet, in turn reducing their excretion. Hence, the present study demonstrated that, without additional phosphorus in the low fish meal-based diets, FoA supplement improved growth performance, absorption and retention of phosphorus and nitrogen and reducing excretion; thus it can be better incorporated to develop environment-friendly feed for rainbow trout.

  8. Long-term trends in naturalized rainbow trout (Oncorhynchus mykiss) populations in the upper Esopus Creek, Ulster County, New York, 2009–15

    USGS Publications Warehouse

    George, Scott D.; Baldigo, Barry P.

    2016-05-13

    The U.S. Geological Survey, in cooperation with Cornell Cooperative Extension of Ulster County, New York State Energy Research and Development Authority, the New York State Department of Environmental Conservation, and the New York City Department of Environmental Protection, surveyed fish communities annually on the main stem and tributaries of the upper Esopus Creek, Ulster County, New York, from 2009 to 2015. This report summarizes the density, biomass, and size structure of rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) populations from the 2015 surveys along with data from the preceding 6 years. The mean density of rainbow trout populations in 2015 was 98 fish per 0.1 hectare, which was the highest value observed since 2010, and the mean biomass of rainbow trout populations in 2015 was 864 grams per 0.1 hectare, which was the highest value observed since 2012.

  9. Determination of the exposure parameters that maximise the concentrations of the anaesthetic/sedative eugenol in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue.

    PubMed

    Meinertz, J R; Porcher, S T; Smerud, J R; Gaikowski, M P

    2014-01-01

    Studies were conducted to determine the anaesthetic/sedative concentrations and durations that would maximise anaesthetic/sedative residue concentrations in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue. Rainbow trout (167-404 g) were exposed to 50 mg l(-1) AQUI-S(®) 20E (10% active ingredient, eugenol) in 17°C freshwater for durations up to 1440 min, 100 and 250 mg l(-1) AQUI-S(®) 20E for durations up to 240 min, and 500 and 1000 mg l(-1) AQUI-S(®) 20E for durations up to 90 min. Fish exposed to 100 mg l(-1) AQUI-S(®) 20E for durations of 30, 60, 120 and 240 min had the greatest eugenol concentrations in the fillet tissue, 50, 58, 54 and 62 µg g(-1), respectively. All other exposure concentrations and durations resulted in significantly lower eugenol concentrations, i.e. all < 39 µg g(-1).

  10. Determination of the exposure parameters that maximise the concentrations of the anaesthetic/sedative eugenol in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue

    USGS Publications Warehouse

    Meinertz, Jeffery R.; Porcher, Scott T.; Smerud, Justin R.

    2014-01-01

    Studies were conducted to determine the anaesthetic/sedative concentrations and durations that would maximize anaesthetic/sedative residue concentrations in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue. Rainbow trout (167–404 g) were exposed to 50 mg l−1 AQUI-S® 20E (10% active ingredient, eugenol) in 17°C freshwater for durations up to 1440 min, 100 and 250 mg l−1 AQUI-S® 20E for durations up to 240 min, and 500 and 1000 mg l−1 AQUI-S® 20E for durations up to 90 min. Fish exposed to 100 mg l−1 AQUI-S® 20E for durations of 30, 60, 120 and 240 min had the greatest eugenol concentrations in the fillet tissue, 50, 58, 54 and 62 µg g−1, respectively. All other exposure concentrations and durations resulted in significantly lower eugenol concentrations, i.e. all −1.

  11. The in vitro effect of bovine lactoferrin on the activity of organ leukocytes in rainbow trout (Oncorhynchus mykiss), European eel (Anguilla anguilla) and wels catfish (Silurus glanis).

    PubMed

    Małaczewska, J; Wójcik, M; Wójcik, R; Siwicki, A K

    2010-01-01

    Lactoferrin (LF) is a glycoprotein found in milk, neutrophil granules, secretions and selected organs of mammals. Lactoferrin exhibits antibacterial, antiviral, fungicidal, immunoregulatory and other functions. Although fish are devoid of this protein and its cell receptors, LF effect on the immune mechanisms of fish has been demonstrated. The objective of this study was to investigate the effect of bovine lactoferrin, applied in vitro, on the activity of head kidney and spleen leukocytes in three freshwater fish species: rainbow trout (Oncorhynchus mykiss), European eel (Anguilla anguilla) and wels catfish (Silurus glanis). The obtained results validate LF beneficial effect on the respiratory burst of phagocytes in rainbow trout and wels catfish despite the fact that the potential killing activity against Aeromonas hydrophila was not stimulated in any of the studied species. Bovine lactoferrin enhanced the proliferation of T-lymphocytes in rainbow trout and European eel, as well as of B-lymphocytes in rainbow trout.

  12. Pros and cons of fish skin cells in culture: long-term full skin and short-term scale cell culture from rainbow trout, Oncorhynchus mykiss.

    PubMed

    Rakers, Sebastian; Klinger, Matthias; Kruse, Charli; Gebert, Marina

    2011-12-01

    Here, we report the establishment of a permanent skin cell culture from rainbow trout (Oncorhynchus mykiss). The cells of the fish skin cell culture could be propagated over 60 passages so far. Furthermore, we show for the first time that it is possible to integrate freshly harvested rainbow trout scales into this new fish skin cell culture. We further demonstrated that epithelial cells derived from the scales survived in the artificial micro-environment of surrounding fibroblast-like cells. Also, antibody staining indicated that both cell types proliferated and started to build connections with the other cell type. It seems that it is possible to generate an 'artificial skin' with two different cell types. This could lead to the development of a three-dimensional test system, which might be a better in vitro representative of fish skin in vivo than individual skin cell lines.

  13. Antimicrobial peptide CAP18 and its effect on Yersinia ruckeri infections in rainbow trout Oncorhynchus mykiss (Walbaum): comparing administration by injection and oral routes.

    PubMed

    Chettri, J K; Mehrdana, F; Hansen, E B; Ebbensgaard, A; Overgaard, M T; Lauritsen, A H; Dalsgaard, I; Buchmann, K

    2017-01-01

    The antimicrobial peptide CAP18 has been demonstrated to have a strong in vitro bactericidal effect on Yersinia ruckeri, but its activity in vivo has not been described. In this work, we investigated whether CAP18 protects rainbow trout Oncorhynchus mykiss (Walbaum) against enteric red mouth disease caused by this pathogen either following i.p. injection or by oral administration (in feed). It was found that injection of CAP18 into juvenile rainbow trout before exposure to Y. ruckeri was associated with lowered mortality compared to non-medicated fish although it was less effective than the conventional antibiotic oxolinic acid. Oral administration of CAP18 to trout did not prevent infection. The proteolytic effect of secretions on the peptide CAP18 in the fish gastrointestinal tract is suggested to account for the inferior effect of oral administration.

  14. Effect of dietary macronutrient proportion on intermediate metabolism and oxidative status in sturgeon (Acipenser naccarii) and trout (Oncorhynchus mykiss): comparative study.

    PubMed

    Furné, M; García-Gallego, M; Hidalgo, M C; Sanz, A

    2016-08-01

    Three isoenergetic diets varying the proportion of dietary energy supplied by each of the macronutrients (carbohydrate, lipid, or protein) were delivered, to farmed sturgeon (Acipenser naccarii) and trout (Oncorhynchus mykiss), to test the possible effects on the intermediate metabolism and oxidative status in liver, white muscle, and heart. In trout, there is an adaptive metabolic response to an increase in lipids and carbohydrates in the diet. However, this does not happen in the sturgeon. These differences may be due to different dietary habits of both species. In terms of oxidative status, only the liver displayed oxidative stress in both species, showing an increase in the lipid peroxidation and antioxidant enzyme activities after feeding with the high-lipid and high-protein diet.

  15. Depletion of isoeugenol residues from the fillet tissue of AQUI-S™ exposed rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Meinertz, Jeffery R.; Schreier, Theresa M.

    2009-01-01

    There is a critical need in U.S. public aquaculture and fishery management for an approved sedative that allows for the immediate release of fish after sedation. AQUI-STM is a fish anesthetic/sedative approved for use in several countries and until recently was being developed in the U.S. as a sedative for immediate release of fish after sedation. The U.S. National Toxicology Program reported that isoeugenol (the active ingredient in AQUI-STM) exposed male mice showed clear evidence of carcinogenicity, therefore efforts within the U.S. Department of Interior to develop AQUI-STM as a sedative that allows for immediate release ceased. Despite the ruling, AQUI-STM still has the potential to be approved as an anesthetic with a short withdrawal time. Among the data required to gain approval for use in the U.S. are data describing the composition and depletion of all AQUI-STM residues from fish fillet tissue. A total residue depletion study for AQUI-STM was conducted by exposing market-sized rainbow trout, Oncorhynchus mykiss (mean weight, 502.7 ± 54 g; s.d.) to 8.9 mg/L of 14C-[URL]-isoeugenol for 60 min in 17 °C water. The 14C-[URL]-isoeugenol was mixed with a surfactant resulting in a mixture that mimicked AQUI-STM. Groups of fish (n = 6) were sampled immediately after the exposure (0-h sample group) and at 0.5, 1, 2, and 4 h thereafter. Total isoeugenol-equivalent residue concentrations in the fillet tissue were determined by oxidizing triplicate subsamples of homogenized skin-on fillet tissue from each fish to 14CO2 and enumerating the radioactivity by static liquid scintillation counting. Isoeugenol concentrations in fillet tissue were determined by extracting homogenized fillet tissue with solvents and determining the isoeugenol concentrations in the extracts with high performance liquid chromatography techniques. The mean total isoeugenol-equivalent residue concentrations in the 0, 0.5, 1, 2, and 4-h sample groups were 55.4, 32.0, 19.8, 11

  16. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2005-2006 Annual Report.

    SciTech Connect

    Branstetter, Ryan; Whiteaker, John; Hatch, Douglas R.

    2006-12-01

    Iteroparity, the ability to repeat spawn, is a natural life history strategy that is expressed by some species from the family Salmonidae. Estimated rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the current expression of repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations, and could help reestablish this naturally occurring life history trait. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia River Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, wild emigrating steelhead kelts were placed into one of four study groups (in river release, direct capture and transport, short-term reconditioning, or long-term reconditioning). Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 7 March to 8 June 2006. In total, 348 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 17.0% (348 of 2,002) of the entire 2005-2006 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. Steelhead kelts were reconditioned in 20-foot circular tanks, and fed freeze-dried krill initially (first 2

  17. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2002 Annual Report.

    SciTech Connect

    Hatch, Douglas R.; Branstetter, Ryan; Blodgett, Joe

    2003-07-01

    Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing means could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and again develop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, we captured wild emigrating steelhead kelts from the Yakima River and evaluated reconditioning (short and long-term) success and diet formulations at Prosser Hatchery on the Yakima River. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Evaluation Facility (CJEF, located at Yakima River kilometer 48) from March 12 to June 13, 2002. In total, 899 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 19.8% (899 of 4,525) of the entire 2001-2002 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. Kelts were reconditioned in circular tanks and were fed freeze-dried krill, Moore-Clark pellets, altered Moore-Clark pellets (soaked in krill extract and dyed), or a combination of the altered Moore

  18. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2000 Annual Report.

    SciTech Connect

    Evans, Allen F.; Beaty, Roy E.; Hatch, Douglas R.

    2001-12-01

    Repeat spawning is a life history strategy that is expressed by some species from the family salmonidae. Natural rates of repeat spawning for Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. Increasing this repeat spawning rate using fish culture techniques could assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to grow and develop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for local populations. The primary purpose of this project in 2000 was to test the general feasibility of collecting, feeding, and treating steelhead kelts in a captive environment. Steelhead kelts were collected from the Yakima River at the Chandler Juvenile Evaluation Facility (Rkm 48) from 12 March to 13 June 2000. Kelts were reconditioned at adjacent Prosser Hatchery in both rectangular and circular tanks and fed a mixed diet of starter paste, adult sized trout pellets, and freeze-dried krill. Formalin was used to control outbreaks of fungus, and we tested the use of ivermectin to control internal parasites (e.g., Salmincola spp.). Some the kelts that died during the reconditioning process were analyzed via pathology and gonad histology to ascertain the possible cause of death and to describe their reproductive development at the time of death. All surviving specimens were released for natural spawning on 12 December 2000. Overall success of the reconditioning process was based on the proportion of fish that survived captivity, gained weight, and on the number of fish that successfully underwent gonadal recrudescence. Many of the reconditioned kelts were radio tagged to assess their spawning migration behavior and

  19. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2003 Annual Report.

    SciTech Connect

    Hatch, Douglas R.; Branstetter, Ryan; Blodgett, Joe

    2004-03-01

    Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, we captured wild emigrating steelhead kelts from the Yakima River and evaluated reconditioning (short and long-term) success and diet formulations at Prosser Hatchery on the Yakima River. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 12 March to 28 May 2003. In total, 690 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 30.8% (690 of 2,235) of the entire 2002-2003 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. All steelhead kelts were reconditioned in circular tanks, fed freeze-dried krill and received hw-wiegandt multi vit dietary supplement; long-term steelhead kelts also received Moore-Clark pellets

  20. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2005 Annual Report.

    SciTech Connect

    Branstetter, Ryan; Whiteaker, John; Hatch, Douglas R.

    2006-01-01

    Iteroparity, the ability to repeat spawn, is a natural life history strategy that is expressed by some species from the family Salmonidae. Estimated rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the current expression of repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations, and could help reestablish this naturally occurring life history trait. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia River Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, wild emigrating steelhead kelts were placed into one of four study groups (in river release, direct capture and transport, short-term reconditioning, or long-term reconditioning). Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 11 March to 23 June 2005. In total, 519 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 15.0% (519 of 3,451) of the entire 2004-2005 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. Steelhead kelts were reconditioned in 20-foot circular tanks, and fed freeze-dried krill initially (first 2

  1. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2001 Annual Report.

    SciTech Connect

    Hatch, Douglas R.; Anders, Paul J., Evans, Allen F.

    2002-12-01

    Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead (Oncorhynchus mykiss) populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are artificially and in some cases severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing means could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and again develop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon (Salmo salar) and sea-trout (S. trutta). The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To address recovery, we captured wild emigrating steelhead kelts from the Yakima River and tested reconditioning and the effects of several diet formulations on its success at Prosser Hatchery on the Yakama Reservation. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Evaluation Facility (CJEF, located at Yakima River kilometer 48) from 12 March to 5 July 2001. Kelts were reconditioned in circular tanks and fed a mixed diet of starter paste, adult sized trout pellets, and freeze-dried krill. Formalin was used to control outbreaks of fungus and we tested the use of Ivermectin{trademark}to control internal parasites (e.g., Salmincola spp.). Surviving specimens were released for natural spawning in two groups on 15 November 2001 and 18 January 2002. Overall success of the reconditioning process was based on

  2. 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.

  3. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2004 Annual Report.

    SciTech Connect

    Hatch, Douglas R.; Branstetter, Ryan; Whiteaker, John

    2004-11-01

    Iteroparity, the ability to repeat spawn, is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the expression of historical repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations, and could help reestablish this naturally occurring life history trait. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia River Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, wild emigrating steelhead kelts were placed into one of three study groups (direct capture and transport, short-term reconditioning, or long-term reconditioning). Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 15 March to 21 June 2004. In total, 842 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 30.5% (842 of 2,755) of the entire 2003-2004 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. All steelhead kelts were reconditioned in 20-foot circular tanks, and fed freeze-dried krill initially or for the duration of the

  4. Spatial partitioning and asymmetric hybridization among sympatric coastal steelhead trout (Oncorhynchus mykiss irideus), coastal cutthroat trout (O. clarki clarki) and interspecific hybrids

    USGS Publications Warehouse

    Ostberg, C.O.; Slatton, S.L.; Rodriguez, R.J.

    2004-01-01

    Hybridization between sympatric species provides unique opportunities to examine the contrast between mechanisms that promote hybridization and maintain species integrity. We surveyed hybridization between sympatric coastal steelhead (Oncorhynchus mykiss irideus) and coastal cutthroat trout (O. clarki clarki) from two streams in Washington State, Olsen Creek (256 individuals sampled) and Jansen Creek (431 individuals sampled), over a 3-year period. We applied 11 O. mykiss-specific nuclear markers, 11 O. c. clarki-specific nuclear markers and a mitochondrial DNA marker to assess spatial partitioning among species and hybrids and determine the directionality of hybridization. F1 and post-F1 hybrids, respectively, composed an average of 1.2% and 33.6% of the population sampled in Jansen Creek, and 5.9% and 30.4% of the population sampled in Olsen Creek. A modest level of habitat partitioning among species and hybrids was detected. Mitochondrial DNA analysis indicated that all F 1 hybrids (15 from Olsen Creek and five from Jansen Creek) arose from matings between steelhead females and cutthroat males implicating a sneak spawning behaviour by cutthroat males. First-generation cutthroat backcrosses contained O. c. clarki mtDNA more often than expected suggesting natural selection against F1 hybrids. More hybrids were backcrossed toward cutthroat than steelhead and our results indicate recurrent hybridization within these creeks. Age analysis demonstrated that hybrids were between 1 and 4 years old. These results suggest that within sympatric salmonid hybrid zones, exogenous processes (environmentally dependent factors) help to maintain the distinction between parental types through reduced fitness of hybrids within parental environments while divergent natural selection promotes parental types through distinct adaptive advantages of parental phenotypes.

  5. Investigations of Bull Trout (Salvelinus Confluentus), Steelhead Trout (Oncorhynchus Mykiss), and Spring Chinook Salmon (O. Tshawytscha) Interactions in Southeast Washington Streams. Final Report 1992.

    SciTech Connect

    Underwood, Keith D.

    1995-01-01

    The goal of this two year study was to determine if supplementation with hatchery reared steelhead trout (Oncorhynchus mykiss) and spring chinook salmon (O. tshawytscha) negatively impacted wild native bull trout (Salvelinus confluentus) through competitive interactions. Four streams with varying levels of fish supplementation activity were sampled in Southeast Washington. Tasks performed during this study were population density, relative abundance, microhabitat utilization, habitat availability, diet analysis, bull trout spawning ground surveys, radio telemetry of adult bull trout, and growth analysis. Results indicate that bull trout overlapped geographically with the supplemented species in each of the study streams suggesting competition among species was possible. Within a stream, bull trout and the supplemented species utilized dissimilar microhabitats and microhabitat utilization by each species was the same among streams suggesting that there was no shifts in microhabitat utilization among streams. The diet of bull trout and O. mykiss significantly overlapped in each of the study streams. The stream most intensely supplemented contained bull trout with the slowest growth and the non-supplemented stream contained bull trout with the fastest growth. Conversely, the stream most intensely supplemented contain steelhead with the fastest growth and the non-supplemented stream contained steelhead with the slowest growth. Growth indicated that bull trout may have been negatively impacted from supplementation, although other factors may have contributed. At current population levels, and current habitat quantity and quality, no impacts to bull trout as a result of supplementation with hatchery reared steelhead trout and spring chinook salmon were detected. Project limitations and future research recommendations are discussed.

  6. Spatial partitioning and asymmetric hybridization among sympatric coastal steelhead trout (Oncorhynchus mykiss irideus), coastal cutthroat trout (O. clarki clarki) and interspecific hybrids.

    PubMed

    Ostberg, Carl O; Slatton, Stacey L; Rodriguez, Russell J

    2004-09-01

    Hybridization between sympatric species provides unique opportunities to examine the contrast between mechanisms that promote hybridization and maintain species integrity. We surveyed hybridization between sympatric coastal steelhead (Oncorhynchus mykiss irideus) and coastal cutthroat trout (O. clarki clarki) from two streams in Washington State, Olsen Creek (256 individuals sampled) and Jansen Creek (431 individuals sampled), over a 3-year period. We applied 11 O. mykiss-specific nuclear markers, 11 O. c. clarki-specific nuclear markers and a mitochondrial DNA marker to assess spatial partitioning among species and hybrids and determine the directionality of hybridization. F1 and post-F1 hybrids, respectively, composed an average of 1.2% and 33.6% of the population sampled in Jansen Creek, and 5.9% and 30.4% of the population sampled in Olsen Creek. A modest level of habitat partitioning among species and hybrids was detected. Mitochondrial DNA analysis indicated that all F1 hybrids (15 from Olsen Creek and five from Jansen Creek) arose from matings between steelhead females and cutthroat males implicating a sneak spawning behaviour by cutthroat males. First-generation cutthroat backcrosses contained O. c. clarki mtDNA more often than expected suggesting natural selection against F1 hybrids. More hybrids were backcrossed toward cutthroat than steelhead and our results indicate recurrent hybridization within these creeks. Age analysis demonstrated that hybrids were between 1 and 4 years old. These results suggest that within sympatric salmonid hybrid zones, exogenous processes (environmentally dependent factors) help to maintain the distinction between parental types through reduced fitness of hybrids within parental environments while divergent natural selection promotes parental types through distinct adaptive advantages of parental phenotypes.

  7. Steelhead trout Oncorhynchus mykiss metabolic rate is affected by dietary Aloe vera inclusion but not by mounting an immune response against formalin-killed Aeromonas salmonicida.

    PubMed

    Zanuzzo, F S; Urbinati, E C; Nash, G W; Gamperl, A K

    2015-07-01

    The oxygen consumption (MO2) of two groups of 10° C acclimated steelhead trout Oncorhynchus mykiss was measured for 72 h after they were given a 100 µl kg(-1) intraperitoneal injection of formalin-killed Aeromonas salmonicida (ASAL) or phosphate-buffered saline (PBS). In addition, plasma cortisol levels were measured in fish from both groups prior to, and 1 and 3 h after, they were given a 30 s net stress. The first group was fed an unaltered commercial diet for 4 weeks, whereas the second group was fed the same diet but with 0·5% (5 g kg(-1) ) Aloe vera powder added; A. vera has potential as an immunostimulant for use in aquaculture, but its effects on basal and acute phase response (APR)-related metabolic expenditures and stress physiology, are unknown. Injection of ASAL v. PBS had no measurable effect on the MO2 of O. mykiss indicating that the APR in this species is not associated with any net increase in energy expenditure. In contrast, incorporating 0·5% A. vera powder into the feed decreased routine metabolic rate by c. 8% in both injection groups and standard metabolic rate in the ASAL-injected group (by c. 4 mg O2 kg(-1) h(-1) ; 5%). Aloe vera fed fish had resting cortisol levels that were approximately half of those in fish on the commercial diet (c. 2·5 v. 5·0 ng ml(-1) ), but neither this difference nor those post-stress reached statistical significance (P > 0·05).

  8. Relationship between effective population size, inbreeding and adult fitness-related traits in a steelhead (Oncorhynchus mykiss) population released in the wild.

    PubMed

    Naish, K A; Seamons, T R; Dauer, M B; Hauser, L; Quinn, T P

    2013-03-01

    Inbreeding is of concern in supportive breeding programmes in Pacific salmonids, Oncorhynchus spp, where the number of breeding adults is limited by rearing space or poor survival to adulthood, and large numbers are released to supplement wild stocks and fisheries. We reconstructed the pedigree of 6602 migratory hatchery steelhead (Oncorhynchus mykiss) over four generations, to determine the incidence and fitness consequences of inbreeding in a northwest USA programme. The hatchery maintained an effective population size, Ñ(e) = 107.9 from F(0) to F(2), despite an increasing census size (N), which resulted in a decreasing N(e)/N ratio (0.35 in F(0) to 0.08 in F(2)). The reduced ratio was attributed to a small broodstock size, nonrandom transfers and high variance in reproductive success (particularly in males). We observed accumulation of inbreeding from the founder generation (in F(4), percentage individuals with inbreeding coefficients Δf > 0 = 15.7%). Generalized linear mixed models showed that body length and weight decreased significantly with increasing Δf, and inbred fish returned later to spawn in a model that included father identity. However, there was no significant correlation between Δf and age at return, female fecundity or gonad weight. Similarly, there was no relationship between Δf and reproductive success of F(2) and F(3) individuals, which might be explained by the fact that reproductive success is partially controlled by hatchery mating protocols. This study is one of the first to show that small changes in inbreeding coefficient can affect some fitness-related traits in a monitored population propagated and released to the wild.

  9. Modes of transmission of Glugea plecoglossi (Microspora) via the skin and digestive tract in an experimental infection model using rainbow trout, Oncorhynchus mykiss (Walbaum).

    PubMed

    Lee, S-J; Yokoyama, H; Ogawa, K

    2004-08-01

    Glugea plecoglossi (Microspora) is a significant cause of economic loss in cultured ayu, Plecoglossus altivelis, in Japan, due to the unsightly appearance of infected fish harbouring xenomas in the body cavity. Modes of transmission of G. plecoglossi via the skin and digestive tract were studied in an experimental infection model using rainbow trout, Oncorhynchus mykiss. Combined with Uvitex 2B and in situ hybridization (ISH) assays, the early development of G. plecoglossi was successfully traced. Following a bath exposure of fish Uvitex 2B-labelled G. plecoglossi spores were observed to attach to microscopic injuries (trypan blue-positive sites) of fish skin, after which ISH-positive sporoplasms were found to invade the epidermis as early as 5 min post-infection (PI), migrating rapidly to the subdermis. It was also shown that G. plecoglossi entering via the skin does not spread into the internal organs but develops into subdermal xenomas. After rainbow trout were exposed to G. plecoglossi spores by oral intubation, spores germinated in the intestinal lumen, followed by penetration of sporoplasms into the gut mucosal epithelium 5 min PI. In vitro trials determining stimulation factors (fish mucus, changes in pH, digestive enzymes) for the extrusion of the polar tube were inconclusive. The present study indicates that skin wounds and the gut epithelium can be portals of entry of G. plecoglossi and that natural infection in fish seems to occur perorally rather than via the skin.

  10. A physiological approach to quantifying thermal habitat quality for redband rainbow trout (Oncorhynchus mykiss gairdneri) in the south Fork John Day River, Oregon

    USGS Publications Warehouse

    Feldhaus, J.W.; Heppell, S.A.; Li, H.; Mesa, M.G.

    2010-01-01

    We examined tissue-specific levels of heat shock protein 70 (hsp70) and whole body lipid levels in juvenile redband trout (Oncorhynchus mykiss gairdneri) from the South Fork of the John Day River (SFJD), Oregon, with the goal of determining if these measures could be used as physiological indicators of thermal habitat quality for juvenile redband trout. Our objectives were to determine the hsp70 induction temperature in liver, fin, and white muscle tissue and characterize the relation between whole body lipids and hsp70 for fish in the SFJD. We found significant increases in hsp70 levels between 19 and 22??C in fin, liver, and white muscle tissue. Maximum hsp70 levels in liver, fin, and white muscle tissue occurred when mean weekly maximum temperatures (MWMT) exceeded 20-22??C. In general, the estimated hsp70 induction temperature for fin and white muscle tissue was higher than liver tissue. Whole body lipid levels began to decrease when MWMT exceeded 20. 4??C. There was a significant interaction between temperature and hsp70 in fin and white muscle tissue, but not liver tissue. Collectively, these results suggest that increased hsp70 levels in juvenile redband trout are symptomatic of thermal stress, and that energy storage capacity decreases with this stress. The possible decrease in growth potential and fitness for thermally stressed individuals emphasizes the physiological justification for thermal management criteria in salmon-bearing streams. ?? Springer Science+Business Media B.V. 2010.

  11. High-fat diet reduces local myostatin-1 paralog expression and alters skeletal muscle lipid content in rainbow trout, Oncorhynchus mykiss.

    PubMed

    Galt, Nicholas J; Froehlich, Jacob Michael; Meyer, Ben M; Barrows, Frederic T; Biga, Peggy R

    2014-06-01

    Muscle growth is an energetically demanding process that is reliant on intramuscular fatty acid depots in most fishes. The complex mechanisms regulating this growth and lipid metabolism are of great interest for human health and aquaculture applications. It is well established that the skeletal muscle chalone, myostatin, plays a role in lipid metabolism and adipogenesis in mammals; however, this function has not been fully assessed in fishes. We therefore examined the interaction between dietary lipid levels and myostatin expression in rainbow trout (Oncorhynchus mykiss). Five weeks of high-fat diet (HFD; 25 % lipid) intake increased white muscle lipid content and decreased circulating glucose levels and hepatosomatic index when compared to low-fat diet (LFD; 10 % lipid) intake. In addition, HFD intake reduced myostatin-1a and myostatin-1b expression in white muscle and myostatin-1b expression in brain tissue. Characterization of the myostatin-1a, myostatin-1b, and myostatin-2a promoters revealed putative binding sites for a subset of transcription factors associated with lipid metabolism. Taken together, these data suggest that HFD may regulate myostatin expression through cis-regulatory elements sensitive to increased lipid intake. Further, these findings provide a framework for future investigations of mechanisms describing the relationships between myostatin and lipid metabolism in fish.

  12. High-fat diet reduces local myostatin-1 paralog expression and alters skeletal muscle lipid content in rainbow trout, Oncorhynchus mykiss

    PubMed Central

    Galt, Nicholas J.; Froehlich, Jacob Michael; Meyer, Ben M.; Barrows, Frederic T.; Biga, Peggy R.

    2014-01-01

    Muscle growth is an energetically demanding process that is reliant on intramuscular fatty acid depots in most fishes. The complex mechanisms regulating this growth and lipid metabolism are of great interest for human health and aquaculture applications. It is well established that the skeletal muscle chalone, myostatin, plays a role in lipid metabolism and adipogenesis in mammals; however, this function has not been fully assessed in fishes. We therefore examined the interaction between dietary lipid levels and myostatin expression in rainbow trout (Oncorhynchus mykiss). Five-weeks of high-fat (HFD; 25% lipid) dietary intake increased white muscle lipid content, and decreased circulating glucose levels and hepatosomatic index when compared to low-fat diet (LFD; 10% lipid) intake. In addition HFD intake reduced myostatin-1a and -1b expression in white muscle and myostatin-1b expression in brain tissue. Characterization of the myostatin-1a, -1b, and -2a promoters revealed putative binding sites for a subset of transcription factors associated with lipid metabolism. Taken together, these data suggest that HFD may regulate myostatin expression through cis-regulatory elements sensitive to increased lipid intake. Further, these findings provide a framework for future investigations of mechanisms describing the relationships between myostatin and lipid metabolism in fish. PMID:24264425

  13. Effect of short-term decrease in water temperature on body temperature and involvement of testosterone in steelhead and rainbow trout, Oncorhynchus mykiss.

    PubMed

    Miura, Go; Munakata, Arimune; Yada, Takashi; Schreck, Carl B; Noakes, David L G; Matsuda, Hiroyuki

    2013-09-01

    The Pacific salmonid species Oncorhynchus mykiss is separated into a migratory form (steelhead trout) and a non-migratory form (rainbow trout). A decrease in water temperature is likely a cue triggering downstream behavior in the migratory form, and testosterone inhibits onset of this behavior. To elucidate differences in sensitivity to water temperature decreases between the migratory and non-migratory forms and effect of testosterone on the sensitivity, we examined two experiments. In experiment 1, we compared changes in body temperature during a short-term decrease in water temperature between both live and dead steelhead and rainbow trout. In experiment 2, we investigated effects of testosterone on body temperature decrease in steelhead trout. Water temperature was decreased by 3°C in 30min. The body temperature of the steelhead decreased faster than that of the rainbow trout. In contrast, there was no significant difference in the decrease in body temperature between dead steelhead and rainbow trout specimens. The body temperature of the testosterone-treated steelhead trout decreased more slowly than that of control fish. Our results suggest that the migratory form is more sensitive to decreases in water temperature than the non-migratory form. Moreover, testosterone might play an inhibitory role in sensitivity to such decreases.

  14. Comparison of plasma and tissue disposition of enrofloxacin in rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio) after a single oral administration.

    PubMed

    Kyuchukova, Ralica; Milanova, Aneliya; Pavlov, Alexander; Lashev, Lubomir

    2015-01-01

    The aim of the study was to investigate the serum and tissue disposition of enrofloxacin and its active metabolite ciprofloxacin in rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio) after a single oral administration at a dose of 10 mg kg(-1). Concentrations of enrofloxacin in the serum of rainbow trout showed high variability with two peaks at the third and 24th hour after administration. The highest concentrations were found in the liver. The curves of liver levels showed similar changes to the respective serum samples. In the muscles, enrofloxacin concentrations were also higher compared with the respective serum samples. Ciprofloxacin concentrations were lower and showed smaller variations in all investigated tissues. The serum and tissue concentrations of enrofloxacin and ciprofloxacin in common carp showed two peaks, with the first Cmax at the third hour after drug administration as in rainbow trout. Concentrations of both investigated substances were higher in the liver than in the serum. The differences in common carp were less pronounced in comparison with rainbow trout. Relatively high levels of both substances were found in the muscles. Seven days after treatment enrofloxacin concentrations in the serum and tissues were within the therapeutic levels for most of the sensitive microorganisms in trout. Lower concentrations of its metabolite ciprofloxacin were found in the investigated tissues at the last sampling point. Lower levels of both substances were found in carp.

  15. Early ocean survival and marine movements of hatchery and wild steelhead trout ( Oncorhynchus mykiss) determined by an acoustic array: Queen Charlotte Strait, British Columbia

    NASA Astrophysics Data System (ADS)

    Welch, David W.; Ward, Bruce R.; Batten, Sonia D.

    2004-03-01

    Early ocean movements, residency, and survival of steelhead (Oncorhynchus mykiss) were examined in Queen Charlotte Strait, a large (20×100 km2) marine area separating Vancouver Island from the mainland. The results provide the first detailed data on the ocean biology of hatchery and wild steelhead smolts. Initial ocean movements were not strongly directed, with most smolts swimming in the range of 0.2-0.5 body length (BL) s-1. The majority (78%) vacated Queen Charlotte Strait within 1 week of release in freshwater. Relative marine survival of hatchery smolts surgically implanted 1 month prior to release was identical to that of wild smolts implanted on the day of release; survival of hatchery smolts transported to the study site, implanted, and released all on the same day was significantly lower. The results suggest that the early marine survival of hatchery and wild smolts may be fundamentally similar, but that the cumulative stress of transportation and surgery may reduce post-surgery survival. Hatchery smolts moved at higher average swimming speeds than wild smolts, but the difference was not statistically significant. Early marine survival within the study region appears to be relatively high (⩾55%), contradicting assumptions that the early marine phase is the critical period for determining salmon recruitment.

  16. Serum disposition of bovine lactoferrin after oral and anal administration and its proteolytic cleavage by gastric transit in rainbow trout (Oncorhynchus mykiss W.).

    PubMed

    Cecchini, Stefano; Caputo, Anna R

    2009-01-01

    Several studies have shown an immunomodulatory effect of orally administered bovine lactoferrin (LF) in fish, but the process of digestion was not characterized. In the present study, we investigated the fate of bovine LF after oral and anal administration, and studied the appearance of intact LF in the bloodstream and its proteolytic attack during the gastric transit in rainbow trout (Oncorhynchus mykiss) held at 9 degrees C and 18 degrees C. Data obtained showed the presence of intact bovine LF in the bloodstream only after anal administration in fish held at 18 degrees C and the presence of several peptides derived from bovine LF in the gastric content. Immunoblotting analysis showed that only a part of bovine LF-derived peptides reacted with the applied anti-bovine LF antibody. The concentration of intact bovine LF, after 30 min of administration, in the gastric content of fish reared at 18 degrees C, being extremely low, if any, led us to suspect that the immunoregulatory effect of dietary bovine LF shown in fish by several authors is not due to the intact form but to bioactive fragments, originated by the proteolytic attack during the gastric transit, as demonstrated in higher vertebrates.

  17. Negligible risk associated with the movement of processed rainbow trout, Oncorhynchus mykiss (Walbaum), from an infectious haematopoietic necrosis virus (IHNV) endemic area

    USGS Publications Warehouse

    LaPatra, S.E.; Batts, W.N.; Overturf, K.; Jones, G.N.; Shewmaker, W.D.; Winton, J.R.

    2001-01-01

    To assess the risk of transmission of infectious haematopoietic necrosis virus (IHNV) associated with the movement of processed rainbow trout, Oncorhynchus mykiss, from an area where the virus is endemic, 240 freshly eviscerated fish (225-500 g) exhibiting spinal curvature or spinal compression types of deformities were tested for IHNV by virus isolation and polymerase chain reaction (PCR) techniques. Commercially produced rainbow trout, approximately 1-year-old, that exhibited spinal deformities were considered to have had a high likelihood of having survived an outbreak of IHN. Serological analysis of fish exhibiting spinal curvature or spinal compression types of deformities for anti-IHNV antibodies resulted, in 71 and 50% of the serum samples, respectively, with detectable neutralization activity suggesting previous infection with IHNV. A portion of the skin and muscle in the area of the deformity was collected, as well as brain tissue from each commercially processed fish. Tissue homogenates were tested for IHNV using the epithelioma papulosum cyprini (EPC) cell line pretreated with polyethylene glycol and the chinook salmon embryo (CHSE-214) cell line using standard methods. Nested, reverse transcriptase (RT)-PCR for the detection of IHNV used the central 1231 bp portion of the glycoprotein (G) challenge studies and is suggested as a mechanism responsible for virus clearance. These results provide scientific information that can be used to assess the risk associated with the movement of processed rainbow trout from an IHNV endemic area.

  18. Characterisation of aroma-active and off-odour compounds in German rainbow trout (Oncorhynchus mykiss). Part I: Case of aquaculture water from earthen-ponds farming.

    PubMed

    Mahmoud, Mohamed Ahmed Abbas; Buettner, Andrea

    2016-11-01

    Comprehensive analyses were accomplished to explore the odorous molecules responsible for off-odour development in earthen-ponds rainbow trout (Oncorhynchus mykiss) aquaculture farming in Germany. In this part of the study, water odorants were extracted using solvent-assisted flavour evaporation (SAFE); then, extracts were analysed by one- and two- dimensional high resolution gas chromatography coupled with olfactometry and mass spectrometry using two columns with different polarity (DB-FFAP and DB-5). Aroma extract dilution analysis (AEDA) of the solvent extract samples revealed 54 odorants, and 47 of them were identified. In this study, a series of compounds is described for the first time in German earthen-ponds rainbow trout aquaculture water including, amongst others, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol), vanillin, (E)-4,5-epoxy-(E)-2-decenal, 4-ethyloctanoic acid, 3-methylindole (skatole), 5α-androst-16-en-3-one (androstenone), and 2-(2-butoxyethoxy) ethanol. Moreover, the sensory experiment indicated that (E)-4,5-epoxy-(E)-2-decenal, (E,E)-2,4-octadienal, and 1-octen-3-one are the main contributors to the metallic, cucumber, and mushroom notes of the samples.

  19. Hemato - Immunological and biochemical parameters, skin antibacterial activity, and survival in rainbow trout (Oncorhynchus mykiss) following the diet supplemented with Mentha piperita against Yersinia ruckeri.

    PubMed

    Adel, Milad; Pourgholam, Reza; Zorriehzahra, Jalil; Ghiasi, Maryam

    2016-08-01

    This study was aimed to assess the potential effects of Mentha piperita on the hemato - immunological and biochemical parameters, skin antibacterial activity and protection against Yersinia ruckeri infection in rainbow trout Oncorhynchus mykiss. Fish were divided into 4 groups before being fed diets supplemented with 0, 1, 2 and 3% of Mentha piperita (MP) plant extract for 8 weeks. Dose-dependent increases immune (both in skin mucus and blood serum) and hematological parameters (number of red and white cells, hematocrit and hemoglobin contents), as well as in respiratory burst activity, total protein, albumin, and neutrophil levels in fish fed supplemented diets compared to the control fish. Furthermore, dietary MP plant extract supplements have no significant effect on blood biochemical parameters and enzymatic activities of liver determined in serum of rainbow trout. After 8 weeks the cessation of feeding with MP plant extract, survival rates of 54.4%, 63.6% and 75.2% were recorded in groups which received 1, 2 and 3% of MP plant extract of feed, respectively, compared to 34.6% survivals in the control. This study underlying several positive effects of dietary administration of MP plant extract to farmed fish.

  20. Exploring Early Micronutrient Deficiencies in Rainbow Trout (Oncorhynchus mykiss) by Next-Generation Sequencing Technology – From Black Box to Functional Genomics

    PubMed Central

    Olsvik, Pål A.; Hemre, Gro-Ingunn; Waagbø, Rune

    2013-01-01

    This work studies final nutritional status and transcriptional responses of rainbow trout (Oncorhynchus mykiss Walbaum 1792) (28 g) after a 10 week feeding experiment designed to elucidate the effect of adding a vitamin and mineral premix on growth, health, and nutritional endpoints. Juvenile fish were fed a either a diet supplemented with a vitamin and mineral premix (Diet S) or the same diet without premix supplementation (Diet U). The analyzed micronutrient composition of diets differed accordingly. Pooled livers from 15 fish from each dietary group were used to create suppression subtractive hybridization (SSH) cDNA libraries that were sequenced with 454 FLX GS Titanium Technology. In total 552 812 reads were sequenced from the two cDNA libraries. Ingenuity pathway analysis (IPA) was then used to characterize the hepatic transcriptome of the two dietary groups of rainbow trout. In the present communication we discuss how selected micronutrients may affect the transcriptome at suboptimal status by directly impacting the cellular metabolism, functions, and structures, and by introducing respective compensatory mechanisms. Processes related to lipid metabolism, peptide hydrolysis, oxygen transportation, and growth development were mostly affected. Considering the transcriptomics data relative to changes in nutritional status from the feeding study and the background phenotypic outcome of growth performance and gill histopathology, the outcome of the transcriptional profiling are suggested to be mainly related to suboptimal pantothenic acid and vitamin C nutrition. PMID:23894486

  1. Effects of pulp and paper mill discharges on caged rainbow trout (Oncorhynchus mykiss): biomarker responses along a pollution gradient in the Biobio River, Chile.

    PubMed

    Orrego, Rodrigo; Burgos, Abed; Moraga-Cid, Gustavo; Inzunza, Barbara; Gonzalez, Margarita; Valenzuela, Ariel; Barra, Ricardo; Gavilán, Juan F

    2006-09-01

    Caging experiments were conducted using hatchery-reared, immature, female rainbow trout (Oncorhynchus mykiss) in three previously defined areas of the Biobio River (south central Chile) representing a pollution gradient from the pulp and paper mill discharges area: a pre-impact area (upstream area, reference location), an impact area (area directly influenced), and a postimpact area (downstream area, less influenced). No significant changes were observed in the physiological index as represented by condition factor (K) and liver somatic index during different sampling times (after 11, 21, and 30 d of exposure). Ethoxyresorufin-O-deethylase activities were significantly higher in trout caged at the impact and postimpact discharges areas (two- to fourfold) compared with the reference (pre-impact) area, and a strong inhibition of acetylcholinesterase activity, reaching 50%, was observed mainly in fish caged at the impact area. A significant endocrine-disrupting effect (reproductive level) was evidenced by significant increments in gonad somatic index and plasma vitellogenin levels combined with an induction of gonad maturation (presence of vitellogenic oocytes) in trout caged at the impact and postimpact areas. These results, generated by an in situ approach, confirmed our group's findings for trout exposed to sediment in the laboratory: discharges of pulp mill effluent in the Biobio River are associated with the effects evaluated at different biological levels.

  2. Micro-computed tomography (μCT) as a novel method in ecotoxicology--determination of morphometric and somatic data in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Brinkmann, Markus; Rizzo, Larissa Y; Lammers, Twan; Gremse, Felix; Schiwy, Sabrina; Kiessling, Fabian; Hollert, Henner

    2016-02-01

    Fish are important sentinel organisms for the assessment of water quality and play a central role in ecotoxicological research. Of particular importance to the assessment of health and fitness of fish stocks in response to environmental conditions or pollution are morphometric (e.g. Fulton's condition index) and somatic indices (e.g. hepatosomatic, and gonadosomatic index). Standard measurements of somatic indices are invasive and require, by definition, the sacrifice of examined animals, thus prohibiting longitudinal studies and relocation of animals captured in the field. As a potential solution, in the present study, we propose the use of micro-computed tomography (μCT) as imaging modality to non-invasively tomographically image rainbow trout (Oncorhynchus mykiss) exposed to different sediment suspensions. We here demonstrate that μCT can be used as a tool to reliably measure the volumes of different organs, which could then be applied as a substitute of their weights in calculation of somatic indices. To the best of our knowledge, this study is the first to report the results of μCT analyses in the context of ecotoxicological research in rainbow trout. It has the potential to greatly increase the information value of experiments conducted with fish and also to potentially reduce the number of animals required for studying temporal effects through facilitating longitudinal studies within the same individuals.

  3. [Reparative Neurogenesis in the Brain and Changes in the Optic Nerve of Adult Trout Oncorhynchus mykiss after Mechanical Damage of the Eye].

    PubMed

    Puschina, E V; Varaksin, A A; Obukhov, D K

    2016-01-01

    Reparative proliferation and neurogenesis in the brain integrative centers after mechanical eye injury in an adult trout Oncorhynchus mykiss have been studied. We have found that proliferation and neurogenesis in proliferative brain regions, the cerebellum, and the optic tectum were significantly enhanced after the eye injury. The cerebellum showed a significant increase in the proliferative activity of the cells of the dorsal proliferative zone and parenchymal cells of the molecular and granular layers. One week after the injury, PCNA-positive radial glia cells have been identified in the tectum. We have found for the first time that the eye trauma resulted in the development of local clusters of undifferentiated cells forming so called neurogenic niches in the tectum and cerebellum. The differentiation of neuronal cells detected by labeling cells with antibodies against the protein HuC/D occurred in the proliferative zones of the telencephalon, the optic tectum, cerebellum, and medulla of a trout within 2 days after the injury. We have shown that the HuC/D expression is higher in the proliferative brain regions than in the definitive neurons of a trout. In addition, we have examined cell proliferation, migration, and apoptosis caused by the eye injury in the contra- and ipsilateral optic nerves and adjacent muscle fibers 2 days after the trauma. The qualitative and quantitative assessment of proliferation and apoptosis in the cells of the optic nerve of a trout has been made using antibodies against PCNA and the TUNEL method.

  4. Effects of dietary supplementation of synbiotic on growth performance, serum biochemical parameters and carcass composition in rainbow trout (Oncorhynchus mykiss) fingerlings.

    PubMed

    Mehrabi, Z; Firouzbakhsh, F; Jafarpour, A

    2012-06-01

    The aim of this study was to evaluate the influence of a synbiotic (Biomin IMBO) on serum parameters and feeding efficiency in rainbow trout (Oncorhynchus mykiss) fingerlings. The fish with initial average weight of 4.59 ± 0.2 g were randomly assigned to four dietary treatments for two months. The dietary treatment (0.5, 1 and 1.5 g/kg of diet) was supplemented with basal diet and non-supplemented basal diet was used as control. After two months, all treatments supplemented with synbiotic showed significant (p < 0.05) increase in final mean weight, weight gain percentage, specific growth rate, condition factor, food conversion efficiency and survival rate, compared to the control group. Among all supplemented treatments, the best result in terms of growth factors and survival was observed in the treatment supplemented with 1 g synbiotic per kilogram of diet. Furthermore, supplementation with symbiotic, specifically 1 and 1.5 g/kg, significantly (p < 0.05) increased the total serum protein, but there was no significant (p > 0.05) difference in globulin content, albumin/globulin ratio, and triglyceride content among experimental treatments. In terms of body composition, carcass protein content of fish fed with synbiotic significantly (p < 0.05) increased compared to the control. These results revealed that a feeding regime with synbiotic for two months led to a significant increase in growth performance, survival rate and feeding efficiency in rainbow trout fingerlings.

  5. Cardiovascular actions of the stress-related neurohormonal peptides, corticotropin-releasing factor and urotensin-I in the trout Oncorhynchus mykiss.

    PubMed

    Le Mével, Jean-Claude; Mimassi, Nagi; Lancien, Frédéric; Mabin, Dominique; Conlon, J Michael

    2006-03-01

    In this review, we summarize the most significant data concerning the cardiovascular effects of centrally and peripherally administered synthetic trout corticotropin-releasing factor (CRF) and urotensin-I (U-I) in our animal model, the unanesthetized trout Oncorhynchus mykiss. Although there is more than 60% sequence identity between these two stress-related neurohormonal peptides, CRF and U-I-induced differential actions upon the mean dorsal aortic blood pressure (Pda) and the heart rate (HR) in trout maintained under similar experimental situations. After intracerebroventricular injections, only U-I induced an increase in Pda while in non-cannulated trout, CRF only decreased the HR and elevated the heart rate variability by a presumed activation of the parasympathetic nervous system activity to the heart. The CRF antagonist, the alpha-helical CRF(9-41) blocked these central actions of CRF. After intra-arterial (IA) injections, U-I induced a direct hypotensive action and an elevation in HR. This hypotensive phase was reversed to hypertension by the release of catecholamines. IA injection of CRF caused no change in Pda or HR. These cardiovascular effects are compared with the much better established actions of CRF and the orthologous urocortins in mammals.

  6. Microencapsulation of a putative probiotic Enterobacter species, C6-6, to protect rainbow trout, Oncorhynchus mykiss (Walbaum), against bacterial coldwater disease.

    PubMed

    Ghosh, B; Cain, K D; Nowak, B F; Bridle, A R

    2016-01-01

    Flavobacterium psychrophilum is the causative agent of bacterial coldwater disease (BCWD), which has a major impact on salmonid aquaculture globally. An Enterobacter species, C6-6, isolated from the gut of rainbow trout, Oncorhynchus mykiss (Walbaum), has been identified as a potential probiotic species providing protection against BCWD. This study examined the effects of alginate microencapsulation on the protective efficacy of C6-6 against BCWD in vivo when administered to rainbow trout fry orally or by intraperitoneal (IP) injection. Viable C6-6 bacteria were microencapsulated successfully, and this process (microencapsulation) did not significantly deteriorate its protective properties as compared to the administration of non-microencapsulated C6-6 bacteria. Both oral and IP delivery of C6-6 achieved significantly better protection than control treatments that did not contain C6-6 bacteria. The highest relative percent survival (RPS) resulted from IP delivery (71.4%) and was significantly greater than the highest oral RPS (38.6%). Successful intestinal colonization was not critical to protective effects of C6-6. The study showed that C6-6 administration, with or without encapsulation, was a viable choice for protecting fry from BCWD especially when administered intraperitoneally.

  7. Establishment of a comprehensive reference transcriptome for vertebral bone tissue to study the impacts of nutritional phosphorus deficiency in rainbow trout (Oncorhynchus mykiss, Walbaum).

    PubMed

    Le Luyer, J; Deschamps, M-H; Proulx, E; Poirier Stewart, N; Joly Beauparlant, C; Droit, A; Robert, C; Vandenberg, G W

    2014-10-31

    Reducing dietary phosphorus (P) is a common approach to reduce effluent P outputs. The potential resulting P-deficiency is known to negatively impact fish bone condition and might result in vertebral deformities. To date, no large-scale study involving deep sequencing of the bone transcriptome has been conducted in salmonids and vertebral molecular changes remain poorly described. This study aims to provide the first comprehensive vertebral transcriptome for rainbow trout (Oncorhynchus mykiss) to allow functional and quantitative expression studies. Fish weighing 60.8±1.6g, were fed for 27weeks using two practical diets having 0.29% (deficient) and 0.45% (sufficient) available phosphorus (P), respectively. Deep sequencing was conducted using HiSeq2000 Illumina 100 paired-end technology from pooled P-deficient and P-sufficient fish and individuals displaying vertebral deformities. Over 140 million trimmed paired-end reads were assembled de novo with Trinity and resulted in 679,869 transcripts with a mean length of 542.5bp. From these sequences, 340,747 matched with referenced ESTs from rainbow trout. Furthermore, 141,909 and 117,564 sequences were functionally annotated against Nr and Uniprot databases, respectively. Interestingly, we observed putative homologue sequences for most of the key components involved in bone formation and turnover in mammals.

  8. Presence of UV filters in surface water and the effects of phenylbenzimidazole sulfonic acid on rainbow trout (Oncorhynchus mykiss) following a chronic toxicity test.

    PubMed

    Grabicova, Katerina; Fedorova, Ganna; Burkina, Viktoriia; Steinbach, Christoph; Schmidt-Posthaus, Heike; Zlabek, Vladimir; Kocour Kroupova, Hana; Grabic, Roman; Randak, Tomas

    2013-10-01

    UV filters belong to a group of compounds that are used by humans and are present in municipal waste-waters, effluents from sewage treatment plants and surface waters. Current information regarding UV filters and their effects on fish is limited. In this study, the occurrence of three commonly used UV filters - 2-phenylbenzimidazole-5-sulfonic acid (PBSA), 2-hydroxy-4-methoxybenzophenone (benzophenone-3, BP-3) and 5-benzoyl-4-hydroxy-2-methoxy-benzenesulfonic acid (benzophenone-4, BP-4) - in South Bohemia (Czech Republic) surface waters is presented. PBSA concentrations (up to 13μgL(-1)) were significantly greater than BP-3 or BP-4 concentrations (up to 620 and 390ngL(-1), respectively). On the basis of these results, PBSA was selected for use in a toxicity test utilizing the common model organism rainbow trout (Oncorhynchus mykiss). Fish were exposed to three concentrations of PBSA (1, 10 and 1000µgL(-1)) for 21 and 42 days. The PBSA concentrations in the fish plasma, liver and kidneys were elevated after 21 and 42 days of exposure. PBSA increased activity of certain P450 cytochromes. Exposure to PBSA also changed various biochemical parameters and enzyme activities in the fish plasma. However, no pathological changes were obvious in the liver or gonads.

  9. Effects of somatostatin on the growth hormone-insulin-like growth factor axis and seawater adaptation of rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Poppinga, J.; Kittilson, J.; McCormick, S.D.; Sheridan, M.A.

    2007-01-01

    Growth hormone (GH) has been shown to contribute to the seawater (SW) adaptability of euryhaline fish both directly and indirectly through insulin-like growth factor-1 (IGF-1). This study examined the role of somatostatin-14 (SS-14), a potent inhibitor of GH, on the GH-IGF-1 axis and seawater adaptation. Juvenile rainbow trout (Oncorhynchus mykiss) were injected intraperitoneally with SS-14 or saline and transferred to 20??ppt seawater. A slight elevation in plasma chloride levels was accompanied by significantly reduced gill Na+, K+-ATPase activity in SS-14-treated fish compared to control fish 12??h after SW transfer. Seawater increased hepatic mRNA levels of GH receptor 1 (GHR 1; 239%), GHR 2 (48%), and IGF-1 (103%) in control fish 12??h after transfer. Levels of GHR 1 (155%), GHR 2 (121%), IGF-1 (200%), IGF-1 receptor A (IGFR1A; 62%), and IGFR1B (157%) increased in the gills of control fish 12??h after transfer. SS-14 abolished or attenuated SW-induced changes in the expression of GHR, IGF-1, and IGFR mRNAs in liver and gill. These results indicate that SS-14 reduces seawater adaptability by inhibiting the GH-IGF-1 axis. ?? 2007 Elsevier B.V. All rights reserved.

  10. Aggression and feeding of hatchery-reared and naturally reared steelhead (Oncorhynchus mykiss) fry in a laboratory flume and a comparison with observations in natural streams

    USGS Publications Warehouse

    Riley, S.C.; Tatara, C.P.; Scheurer, J.A.

    2005-01-01

    We quantified the aggression and feeding of naturally reared steelhead (Oncorhynchus mykiss) fry stocked into a laboratory flume with naturally reared fry or hatchery-reared fry from conventional and enriched rearing environments at three densities in the presence and absence of predators, and compared the aggression and feeding observed in the flume to that observed in two streams. Steelhead fry attack rate increased with density and was reduced in the presence of predators, but was not affected by rearing treatment. Threat rate appeared to increase with density and was significantly affected by rearing treatment combination, but was not significantly affected by predator presence. Feeding rate was not affected by density or rearing treatment, but was reduced in the presence of predators. The rate of aggression by steelhead fry in two streams was lower than that observed in the laboratory and did not increase with density. Rates of aggression and feeding of hatchery-reared and wild steelhead fry were not significantly different in the streams. Overall, we found no evidence that hatchery rearing environments caused higher aggression in steelhead fry. Laboratory observations of salmonid aggression, particularly at high density, may not reflect aggression levels in the wild. ?? 2005 NRC.

  11. Effects of Waterborne Copper, Cyanide, Ammonia, and Nitrite on Stress Parameters and Changes in Susceptibility to Saprolegniosis in Rainbow Trout (Oncorhynchus mykiss)

    PubMed Central

    Carballo, M.; Munoz, M. J.; Cuellar, M.; Tarazona, J. V.

    1995-01-01

    The effects of toxic exposures on the susceptibility of rainbow trout (Oncorhynchus mykiss) to saprolegniosis were evaluated. Fish were exposed to sublethal concentrations of copper (0.25 mg/liter), cyanide (0.07 mg/liter), ammonia (0.5 mg/liter), and nitrite (0.24 mg/liter) for 24 h. After exposure, the fish were challenged by Saprolegnia parasitica (3.6 x 10(sup6) zoospores per liter) for 10 min. Cortisol and cholesterol were used to indicate stress response. Similar increases of cortisol were found for the four tested chemicals. All fish with cortisol levels higher than 370 ng/ml developed the disease, while only 24% of the fish with cortisol levels lower than 370 ng/ml were infected. Cholesterol levels remained unchanged after toxic exposure. Increased susceptibilities to the pathogen were observed for ammonia (71%), copper (57%), nitrite (50%), and cyanide (33%). The increases in susceptibility as a result of cyanide and nitrite exposure could be explained by the stress response. For copper and ammonia, the combination of two different effects, the stress response and specific impairments of the defense mechanism of trout against saprolegniosis, should be considered. PMID:16535039

  12. The effects of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) on fuel stores and ion balance in a non-target fish, the rainbow trout (Oncorhynchus mykiss).

    PubMed

    Birceanu, Oana; Sorensen, Lisa A; Henry, Matthew; McClelland, Grant B; Wang, Yuxiang S; Wilkie, Michael P

    2014-03-01

    The pesticide 3-trifluoromethyl-4-nitrophenol (TFM) is used to control sea lamprey (Petromyzon marinus) populations in the Great Lakes through its application to nursery streams containing larval sea lampreys. TFM uncouples oxidative phosphorylation, impairing mitochondrial ATP production in sea lampreys and rainbow trout (Oncorhynchus mykiss). However, little else is known about its sub-lethal effects on non-target aquatic species. The present study tested the hypotheses that TFM exposure in hard water leads to (i) marked depletion of energy stores in metabolically active tissues (brain, muscle, kidney, liver) and (ii) disruption of active ion transport across the gill, adversely affecting electrolyte homeostasis in trout. Exposure of trout to 11.0mgl(-1) TFM (12-h LC50) led to increases in muscle TFM and TFM-glucuronide concentrations, peaking at 9h and 12h, respectively. Muscle and brain glycogen was reduced by 50%, while kidney and muscle lactate increased with TFM exposure. Kidney ATP and phosphocreatine decreased by 50% and 70%, respectively. TFM exposure caused no changes in whole body ion (Na(+), Cl(-), Ca(2+), K(+)) concentrations, gill Na(+)/K(+) ATPase activity, or unidirectional Na(+) movements across the gills. We conclude that TFM causes a mismatch between ATP supply and demand in trout, leading to increased reliance on glycolysis, but it does not have physiologically relevant effects on ion balance in hard water.

  13. Effects of triploidy on growth and protein degradation in skeletal muscle during recovery from feed deprivation in juvenile rainbow trout (Oncorhynchus mykiss).

    PubMed

    Cleveland, Beth M; Weber, Gregory M

    2013-09-01

    Identifying physiological differences between diploid and triploid rainbow trout will help define how ploidy affects mechanisms that impact growth and nutrient utilization. Juvenile diploid and triploid female rainbow trout (Oncorhynchus mykiss) were either continually fed or fasted for one week, followed by four weeks of refeeding, and indices of growth and proteolysis-related gene expression in skeletal muscle were measured. Fasting reduced growth, and based on gene expression analysis, increased capacity for protein degradation. Regardless of feeding treatment, triploids displayed slightly greater feed intake and specific growth rates than diploids. Continually fed triploids displayed lower expression of several autophagy-related genes than diploids, suggesting that reduced rates of protein degradation contributed to their faster growth. Reduced expression of ubiquitin ligases fbxo32 and fbxo25 and autophagy-related genes during refeeding implicates reduced proteolysis in recovery growth. At one week of refeeding triploids exhibited greater gains in eviscerated body weight and length, whereas diploids exhibited greater gains in gastrointestinal tract weights. During refeeding two autophagy-related genes, atg4b and lc3b, decreased within one week to continually fed levels in the triploids, but in diploids overshot in expression at one and two weeks of refeeding then rebounding above continually fed levels by week four, suggesting a delayed return to basal levels of proteolysis.

  14. Effects of dietary cholesterol supplementation on growth and cholesterol metabolism of rainbow trout (Oncorhynchus mykiss) fed diets with cottonseed meal or rapeseed meal.

    PubMed

    Deng, Junming; Zhang, Xi; Long, Xiaowen; Tao, Linli; Wang, Zhen; Niu, Guoyi; Kang, Bin

    2014-12-01

    This study was conducted to evaluate the effects of cholesterol on growth and cholesterol metabolism of rainbow trout (Oncorhynchus mykiss) fed diets with cottonseed meal (CSM) or rapeseed meal (RSM). Four experimental diets were formulated to contain 550 g kg(-1) CSM or 450 g kg(-1) RSM with or without 9 g kg(-1) supplemental cholesterol. Growth rate and feed utilization efficiency of fish fed diets with 450 g kg(-1) RSM were inferior to fish fed diets with 550 g kg(-1) CSM regardless of cholesterol level. Dietary cholesterol supplementation increased the growth rate of fish fed diets with RSM, and growth rate and feed utilization efficiency of fish fed diets with CSM. Similarly, dietary cholesterol supplementation increased the plasma total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triiodothyronine levels, but decreased the plasma triglycerides and cortisol levels of fish fed diets with RSM or CSM. In addition, supplemental cholesterol increased the free cholesterol and TC levels in intestinal contents, but decreased the hepatic 3-hydroxy-3-methyl-glutaryl-CoA reductase activity of fish fed diets with RSM or CSM. These results indicate that 9 g kg(-1) cholesterol supplementation seems to improve the growth of rainbow trout fed diets with CSM or RSM, and the growth-promoting action may be related to the alleviation of the negative effects caused by antinutritional factors and/or make up for the deficiency of endogenous cholesterol in rainbow trout.

  15. Effects of water temperature on the toxicity of 4-nitrophenol and 2,4-dinitrophenol to developing rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Howe, G.E.; Marking, L.L.; Bills, T.D.; Boogaard, M.A.; Mayer, F.L.

    1994-01-01

    Early-life-stage (ELS) toxicity tests were conducted to determine the effect of selected water temperatures on the toxicity of 4-nitrophenol and 2,4-dinitrophenol to rainbow trout (Oncorhynchus mykiss). NOECs were determined for growth and mortality at selected time intervals and water temperatures of 7, 12, and 17 degree C. As tests progressed, NOECs leveled to constant time-independent values that were similar for tests at each temperature. In 4-nitrophenol tests, the time-independent NOEC values at 7, 12, and 17 degree C, respectively, were 1.16, 1.20, and 1.16 mg/L for growth and 3.40, 3.38, and 2.20 mg/L for mortality. For 2,4-dinitrophenol, time-independent NOEC values at 7, 12, and 17 degree C, respectively, were 1.07, 0.50, and 0.80 mg/L for growth and 1.30, 1.89, and 1.60 mg/L for mortality. Temperature did, however, affect the rate at which time- independent NOECs were reached. More time was required to reach time-independent NOECs as temperature decreased. For example, the time-independent NOEC in 4-nitrophenol tests at 17 degree C was reached in 14 d, whereas it required 42 d at 7 degree C.

  16. Exploring early micronutrient deficiencies in rainbow Trout (Oncorhynchus mykiss) by next-generation sequencing technology--from black box to functional genomics.

    PubMed

    Olsvik, Pål A; Hemre, Gro-Ingunn; Waagbø, Rune

    2013-01-01

    This work studies final nutritional status and transcriptional responses of rainbow trout (Oncorhynchus mykiss Walbaum 1792) (28 g) after a 10 week feeding experiment designed to elucidate the effect of adding a vitamin and mineral premix on growth, health, and nutritional endpoints. Juvenile fish were fed a either a diet supplemented with a vitamin and mineral premix (Diet S) or the same diet without premix supplementation (Diet U). The analyzed micronutrient composition of diets differed accordingly. Pooled livers from 15 fish from each dietary group were used to create suppression subtractive hybridization (SSH) cDNA libraries that were sequenced with 454 FLX GS Titanium Technology. In total 552 812 reads were sequenced from the two cDNA libraries. Ingenuity pathway analysis (IPA) was then used to characterize the hepatic transcriptome of the two dietary groups of rainbow trout. In the present communication we discuss how selected micronutrients may affect the transcriptome at suboptimal status by directly impacting the cellular metabolism, functions, and structures, and by introducing respective compensatory mechanisms. Processes related to lipid metabolism, peptide hydrolysis, oxygen transportation, and growth development were mostly affected. Considering the transcriptomics data relative to changes in nutritional status from the feeding study and the background phenotypic outcome of growth performance and gill histopathology, the outcome of the transcriptional profiling are suggested to be mainly related to suboptimal pantothenic acid and vitamin C nutrition.

  17. Determination of malachite green residues in the eggs, fry, and adult muscle-tissue of rainbow-trout (Oncorhynchus-mykiss)

    USGS Publications Warehouse

    Allen, John L.; Gofus, J.E.; Meinertz, Jeffery R.

    1994-01-01

    Malachite green, an effective antifungal therapeutant used in fish culture, is a known teratogen. We developed a method to simultaneously detect both the chromatic and leuco forms of malachite green residues in the eggs, fry, and adult muscle tissue of rainbow trout (oncorhynchus mykiss). Homogenates of these tissues were fortified with [c-14] malachite green chloride and extracted with 1% (v/v) acetic acid in acetonitrile or in methanol. The extracts were partitioned with chloroform, dried, redissolved in mobile phase, and analyzed by liquid chromatography (lc) with postcolumn oxidation of leuco malachite green to the chromatic form. Lc fractions were collected every 30 s for quantitation by scintillation counting. Recoveries of total [c-14] malachite green chloride residue were 85 and 98% in eggs fortified with labeled malachite green at concentrations of 0.5 And 1.00 Mug/g, respectively; 68% in fry similarly fortified at a concentration of 0.65 Mug/g; and 66% in muscle homogenate similarly fortified at a level of 1.00 Mug/g. The method was tested under operational conditions by exposing adult rainbow trout to 1.00 Mg/l [c-14] malachite green chloride bath for 1 h. Muscle samples analyzed by sample oxidation and scintillation counting contained 1.3 And 0.5 Mug/g total malachite green chloride residues immediately after exposure and after a 5-day withdrawal period, respectively.

  18. Efficacy of an extract from garlic, Allium sativum, against infection with the furunculosis bacterium, Aeromonas salmonicida, in rainbow trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    Breyer, Kate E.; Getchell, Rodman G.; Cornwell, Emily R.; Wooster, Gregory A.; Ketola, H. George; Bowser, Paul R.

    2015-01-01

    Juvenile rainbow trout, Oncorhynchus mykiss, were fed diets containing 0, 0.5, 1.0, and 2.0% of a garlic extract, challenged with a modified 50% lethal dose of Aeromonas salmonicida and monitored for 28 d. There were significant increases in survival of trout fed 0.5 and 1.0% garlic extract as compared to the control and 2.0% garlic extract groups. A target animal safety study was performed at varying increments using the target dose of 0.5% garlic extract at 0× (0% garlic extract), 1× (0.5% garlic extract), 3× (1.5% garlic extract), and 5× (2.5% garlic extract) for 3× (6 wk) the duration of the original study. There was a significant increase in the level of circulating lymphocytes and a significant decrease in the level of circulating monocytes. The latter correlated to an increased level of pigment-containing macrophage centers within the renal tissue as garlic extract dosing increased, denoting a potential deleterious inflammatory effect as macrophage infiltration became severe at the highest dose. These studies suggest that feeding low-dose (0.5% or 1.0%) garlic extract improves survivability in rainbow trout when challenged with A. salmonicida and appears safe; however, higher levels do not appear to be effective and may cause deleterious effects on health.

  19. Study of the viral interference between infectious pancreatic necrosis virus (IPNV) and infectious haematopoietic necrosis virus (IHNV) in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Byrne, N; Castric, J; Lamour, F; Cabon, J; Quentel, C

    2008-05-01

    The resistance of rainbow trout (Oncorhynchus mykiss) to an infectious haematopoietic necrosis virus (IHNV) challenge following a preceding non-lethal infection with infectious pancreatic necrosis virus (IPNV) was investigated through experimental dual infections. Trout initially infected with IPNV were inoculated 14 days later with IHNV. Single infections of trout with 1 of the 2 viruses or with cell culture supernatant were also carried out and constituted control groups. No mortality was noted in fish after a single infection with IPNV. This virus had no influence on the head kidney leucocyte phagocytic activity and plasma haemolytic complement activity. IHNV induced a high mortality (72%) and reduced the macrophage phagocytic activity and complement haemolytic activity. It also induced a late production of anti-IHNV antibodies which occurred after clearance of the virus in the fish. In trout co-infected with both viruses, a mortality rate of 2% occurred and the immune parameters were similar to those observed in the fish infected with IPNV only, demonstrating that in co-infected trout IPNV inhibits the effects of IHNV. The studied parameters did not allow us to define the mechanism of interference occurring between these 2 viruses, but some hypothesis are put forward to explain the interference between the 2 viruses.

  20. Virulence of infectious hematopoietic necrosis virus and Infectious pancreatic necrosis virus coinfection in rainbow trout ( Oncorhynchus mykiss) and nucleotide sequence analysis of the IHNV glycoprotein gene.

    PubMed

    Alonso, M; Rodríguez Saint-Jean, S; Pérez-Prieto, S I

    2003-08-01

    The outcomes of a coinfection of rainbow trout ( Oncorhynchus mykiss) with Infectious hematopoietic necrosis virus (IHNV) strain S46 and Infectious pancreatic necrosis virus (IPNV) strain S46 was determined after waterborne infection. Trout infected with the IHNV/IPNV.S46 sample, (a mixed sample containing equal infectious titers of the viruses) showed 50% less mortality than fish infected with either of the reference viruses alone. Forty-five days after the coinfection, IPNV antigens were detected by flow cytometry in 49 to 63% of the leukocytes from the surviving trout; whereas, only 9-15.6% of the leukocytes expressed IHNV viral antigens. IPNV was easily detected by reverse transcription-polymerase chain reaction (RT-PCR), whereas, for IHNV, a second step of amplification of a 753 bp fragment corresponding to the internal sequences of the IHNV G gene was necessary to optimize viral detection. The sequence of the IHNV gene involved in virulence, the glycoprotein (G) gene, was determined for the IHNV.S46 and compared with other sequences available in the GenBank. Changes found were not located in the antigenic domains of the glycoprotein and were considered not significant.

  1. Effects of ozone, ultraviolet and peracetic acid disinfection of a primary-treated municipal effluent on the immune system of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Hébert, N; Gagné, F; Cejka, P; Bouchard, B; Hausler, R; Cyr, D G; Blaise, C; Fournier, M

    2008-08-01

    Municipal sewage effluents are complex mixtures that are known to compromise the health condition of aquatic organisms. The aim of this study was to evaluate the impacts of various wastewater disinfection processes on the immune system of juvenile rainbow trout (Oncorhynchus mykiss). The trout were exposed to a primary-treated effluent for 28 days before and after one of each of the following treatments: ultraviolet (UV) radiation, ozonation and peracetic acid. Immune function was characterized in leucocytes from the anterior head kidney by the following three parameters: phagocytosis activity, natural cytotoxic cells (NCC) function and lymphocyte (B and T) proliferation assays. The results show that the fish mass to length ratio was significantly decreased for the primary-treated and all three disinfection processes. Exposure to the primary-treated effluent led to a significant increase in macrophage-related phagocytosis; the addition of a disinfection step was effective in removing this effect. Both unstimulated and mitogen-stimulated T lymphocyte proliferation in fish decreased dramatically in fish exposed to the ozonated effluent compared to fish exposed to either the primary-treated effluent or to aquarium water. Stimulation of T lymphocytes proliferation was observed with the peracetic acid treatment group. In conclusion, the disinfection strategy used can modify the immune system in fish at the level of T lymphocyte proliferation but was effective to remove the effects on phagocytosis activity.

  2. Phase I metabolism of 3-methylindole, an environmental pollutant, by hepatic microsomes from carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss).

    PubMed

    Zlabek, Vladimir; Burkina, Viktoriia; Borrisser-Pairó, Francesc; Sakalli, Sidika; Zamaratskaia, Galia

    2016-05-01

    We studied the in vitro metabolism of 3-methylindole (3MI) in hepatic microsomes from fish. Hepatic microsomes from juvenile and adult carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) were included in the study. Incubation of 3MI with hepatic microsomes revealed the time-dependent formation of two major metabolites, 3-methyloxindole (3MOI) and indole-3-carbinol (I3C). The rate of 3MOI production was similar in both species at both ages. No differences in kinetic parameters were observed (p = 0.799 for Vmax, and p = 0.809 for Km). Production of I3C was detected only in the microsomes from rainbow trout. Km values were similar in juvenile and adult fish (p = 0.957); Vmax was higher in juvenile rainbow trout compared with adults (p = 0.044). In rainbow trout and carp, ellipticine reduced formation of 3MOI up to 53.2% and 81.9% and ketoconazole up to 65.8% and 91.3%, respectively. The formation of I3C was reduced by 53.7% and 51.5% in the presence of the inhibitors ellipticine and ketoconazole, respectively. These findings suggest that the CYP450 isoforms CYP1A and CYP3A are at least partly responsible for 3MI metabolism. In summary, 3MI is metabolised in fish liver to 3MOI and I3C by CYP450, and formation of these metabolites might be species-dependent.

  3. Protective effect of essential oils on the shelf life of smoked and vacuum packed rainbow trout (Oncorhynchus mykiss W.1792) fillets.

    PubMed

    Emir Çoban, Ozlem; Patir, Bahri; Yilmaz, Okkeş

    2014-10-01

    This study was investigated the effects of some oils on chemical, microbiological and sensory quality in vacuum packed smoked rainbow trout (Oncorhynchus mykiss W.1792) fillets. Acceptability scores for appearance, taste and odour of untreated and treated smoked trout decreased with storage time. The limit of sensory acceptance was reached after 56 days for the untreated samples, after 84 days for with rosemary and thyme oil-treated samples after 98 days for with sage oil-treated and after 112 days for with clove oil-treated samples. Significant differences were not found between groups as microbiological (p > 0.05). However, significant differences were found both among groups and during the storage in term of TBA (thiobarbituric acid) and PV (peroxide value), FFA (free fatty acid) values (p < 0.05). Essential oils as natural antioxidant can be used in conjunction with vacuum packed to enhance hot smoked fish quality.

  4. Estimating recruitment dynamics and movement of rainbow trout (Oncorhynchus mykiss) in the Colorado River in Grand Canyon using an integrated assessment model

    USGS Publications Warehouse

    Korman, Josh; Martell, Steven J.D.; Walters, Carl J.; Makinster, Andrew S.; Coggins, Lewis G.; Yard, Michael D.; Persons, William R.

    2012-01-01

    We used an integrated assessment model to examine effects of flow from Glen Canyon Dam, Arizona, USA, on recruitment of nonnative rainbow trout (Oncorhynchus mykiss) in the Colorado River and to estimate downstream migration from Glen Canyon to Marble Canyon, a reach used by endangered native fish. Over a 20-year period, recruitment of rainbow trout in Glen Canyon increased with the annual flow volume and when hourly flow variation was reduced and after two of three controlled floods. The model predicted that approximately 16 000 trout·year–1 emigrated to Marble Canyon and that the majority of trout in this reach originate from Glen Canyon. For most models that were examined, over 70% of the variation in emigration rates was explained by variation in recruitment in Glen Canyon, suggesting that flow from the dam controls in large part the extent of potential negative interactions between rainbow trout and native fish. Controlled floods and steadier flows, which were originally aimed at partially restoring conditions before the dam (greater native fish abundance and larger sand bars), appear to have been more beneficial to nonnative rainbow trout than to native fish.

  5. The peptide hormone cholecystokinin modulates the tonus and compliance of the bulbus arteriosus and pre-branchial vessels of the rainbow trout (Oncorhynchus mykiss).

    PubMed

    Seth, Henrik; Axelsson, Michael; Gräns, Albin

    2014-12-01

    The bulbus arteriosus is a compliant structure between the ventricle and ventral aorta of teleost fish. It serves as a "wind-kessel" that dampens pressure variations during the cardiac cycle allowing a continuous flow of blood into the gills. The bulbus arteriosus receives sympathetic innervation and is affected by several circulating substances, indicating neurohumoral control. We have previously shown that the peptide hormone, cholecystokinin (CCK), affects the hemodynamics of the cardiovascular system in rainbow trout (Oncorhynchus mykiss) by increasing flow pulse amplitude without affecting cardiac output. We hypothesized that this could be explained by an altered tonus or compliance/distensibility of the bulbus arteriosus. Our results show that there is a substantial effect of CCK on the bulbus arteriosus. Concentrations of CCK that altered the cardiac function of in situ perfused hearts also contracted the bulbus arteriosus in vitro. Pressure-volume curves revealed a change in both the tonus and the compliance/distensibility of this structure. Furthermore, the stimulatory (constricting) effect of CCK was also evident in the ventricle and vasculature leading to the gills, but absent in the atrium, efferent branchial arteries and dorsal aorta. In conclusion, CCK alters the mechanical properties of the ventricle, bulbus arteriosus, ventral aorta and afferent gill vasculature, thus maintaining adequate branchial and systemic blood flow and pressure when cardiorespiratory demands change, such as after feeding.

  6. Short Communication: Effect of heat stress on heat-shock protein (Hsp60) mRNA expression in rainbow trout Oncorhynchus mykiss.

    PubMed

    Shi, H N; Liu, Z; Zhang, J P; Kang, Y J; Wang, J F; Huang, J Q; Wang, W M

    2015-05-18

    The enhanced expression of heat shock proteins (hsps) in organisms can be detected in response to many kinds of stressor. For fish, high temperature is an important stressor, and hsp expression is associated with differences in environmental temperature. In this study, rainbow trout (Oncorhynchus mykiss) that were accustomed to an aquatic temperature of 18°C were exposed to an elevated temperature (25°C), and hsp60 expression in the gill, liver, spleen, heart, and head kidney was quantified using real-time polymerase chain reaction in unstressed and heat-stressed animals. The fish responded to heat stress in a time- and tissue-specific manner. Cardiac hsp60 mRNA levels were largely unchanged, and the greatest induction of hsp60 in heat-stressed animals was recorded in the liver, suggesting that protein damage and the consequent requirement for the Hsp60 protein are probably greater in hepatic tissue. Therefore, fish must be provided with optimal temperature conditions in order to realize their potential growth and maximize fish farm profits.

  7. Quality of water used during cage cultivation of rainbow trout (Oncorhynchus mykiss) in Bereket HES IV Dam Lake (Muğla, Turkey).

    PubMed

    Ozdemir, Nedim; Demirak, Ahmet; Keskin, Feyyaz

    2014-12-01

    A thorough investigation of the impact of rainbow trout (Oncorhynchus mykiss) cultivation on surface water quality in the area known as Bereket HES IV Dam Lake was conducted. Water samples were collected from October 2009 to June 2010 from four stations in the Dam Lake and analyzed for water temperature, pH, dissolved oxygen, electrical conductivity, nitrite nitrogen, nitrate nitrogen, and orthophosphate. Surface water quality was then evaluated based on the comparison of samples collected from three stations located near fish cages to those collected from a reference station outside the cultivation area as well as by the comparison with standards specified in the Water Pollution Registration Act. According to the Water Pollution Registration Act, the surface water quality of the Dam Lake was class I. Additionally, there were no significant differences in water quality within the Dam Lake among any of the sampling stations, including the reference station. Overall, these findings indicate that cage cultivation of rainbow trout may have a negative impact on the entire Dam Lake.

  8. Analysis of nuclear abnormalities in erythrocytes of rainbow trout (Oncorhynchus mykiss) treated with Cu and Zn and after 4-, 8-, and 12-day depuration (post-treatment recovery).

    PubMed

    Stankevičiūtė, Milda; Butrimavičienė, Laura; Valskienė, Roberta; Greiciūnaitė, Janina; Baršienė, Janina; Vosylienė, Milda Zita; Svecevičius, Gintaras

    2016-02-01

    The induction of micronuclei (MN), nuclear buds (NB), bi-nucleated erythrocytes with nucleoplasmic bridge (BNb), vacuolated (VacNuc), blebbed (BL), 8-shaped nuclei, bi-nucleated (BN) and fragmented-apoptotic (FA) erythrocytes was analysed in the peripheral blood, cephalic kidney and liver of rainbow trout Oncorhynchus mykiss after 4-day treatment with copper (Cu) and zinc (Zn) mixture solutions and in 4-, 8- and 12-day depuration process. Fish (three treatment and one control group, N=40) were exposed to 0.0625, 0.125 and 0.25 fractions of 96-h LC50, respectively under semi-static conditions. Exposure of O. mykiss to Cu and Zn induced significant increase of MN (in blood in all test groups; in liver 0.125, 0.25 and in kidney 0.25 groups, respectively), NB and BL (in blood and kidney 0.25 group), 8-shaped (in blood 0.25; in liver 0.125, 0.25 and in kidney all test groups, respectively) and VacNuc (in liver and kidney 0.0625 and 0.125 groups). After 4-day recovery, significantly elevated levels of MN (in blood 0.0625, 0.125; in liver and kidney 0.125 group, respectively) and 8-shaped (in kidney-0.0625 group) were observed in fish. Significant recovery was observed in 0.0625 group after 12-day depuration, estimating the formation of MN in erythrocytes of blood, of 8-shaped nuclei erythrocytes in liver and kidney (after 8-, 12-day and 8-day recovery, respectively). Significant decrease of MN in blood (after 8- and 12-day recovery), in liver (after 8-day recovery), of NB in blood and kidney (after 8-day recovery) and of 8-shaped nuclei erythrocytes in blood (after 8 and 12-day recovery), kidney and liver (after 8-day recovery) was determined in 0.25 group. Changes in gross morphometric indices and biological parameters were observed. The binary metal mixture did not induce FA erythrocytes in any tissue at any test concentration.

  9. 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.

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

    PubMed

    Peñaranda, Ma Michelle D; Lapatra, Scott E; Kurath, Gael

    2011-07-01

    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. Spatial ecological processes and local factors predict the distribution and abundance of spawning by steelhead (Oncorhynchus mykiss) across a complex riverscape

    USGS Publications Warehouse

    Falke, Jeffrey A.; Dunham, Jason B.; Jordan, Christopher E.; McNyset, Kris M.; Reeves, Gordon H.

    2013-01-01

    Processes that influence habitat selection in landscapes involve the interaction of habitat composition and configuration and are particularly important for species with complex life cycles. We assessed the relative influence of landscape spatial processes and local habitat characteristics on patterns in the distribution and abundance of spawning steelhead (Oncorhynchus mykiss), a threatened salmonid fish, across ~15,000 stream km in the John Day River basin, Oregon, USA. We used hurdle regression and a multi-model information theoretic approach to identify the relative importance of covariates representing key aspects of the steelhead life cycle (e.g., site access, spawning habitat quality, juvenile survival) at two spatial scales: within 2-km long survey reaches (local sites) and ecological neighborhoods (5 km) surrounding the local sites. Based on Akaike’s Information Criterion, models that included covariates describing ecological neighborhoods provided the best description of the distribution and abundance of steelhead spawning given the data. Among these covariates, our representation of offspring survival (growing-season-degree-days, °C) had the strongest effect size (7x) relative to other predictors. Predictive performances of model-averaged composite and neighborhood-only models were better than a site-only model based on both occurrence (percentage of sites correctly classified = 0.80±0.03 SD, 0.78±0.02 vs. 0.62±0.05, respectively) and counts (root mean square error = 3.37, 3.93 vs. 5.57, respectively). The importance of both temperature and stream flow for steelhead spawning suggest this species may be highly sensitive to impacts of land and water uses, and to projected climate impacts in the region and that landscape context, complementation, and connectivity will drive how this species responds to future environments.

  12. Effect of chronic exposure to pendimethalin on the susceptibility of rainbow trout, Oncorhynchus mykiss L., to viral hemorrhagic septicemia virus (VHSV).

    PubMed

    Danion, Morgane; Le Floch, Stéphane; Castric, Jeanne; Lamour, François; Cabon, Joëlle; Quentel, Claire

    2012-05-01

    In this study, the in vivo effects of chronic pollution by the active substance (AS) pendimethalin, a dinitroaniline herbicide, on the susceptibility of rainbow trout, Oncorhynchus mykiss L., to an experimental challenge with viral hemorrhagic septicemia virus (VHSV) were assessed. After four weeks of exposure to fresh water (C group) or 500 ng L(-1) of AS (P500 group), the fish were challenged by immersion in water containing 10(4) TCID(50) mL(-1) of VHSV. While exposure to pendimethalin was maintained throughout the experiment, mortalities were recorded during the 40 days post-infection (dpi) and organs were collected from dead fish for virological examination. At the end of the experiment, anti-VHSV antibodies and the classical pathway of complement activity were assessed in trout plasma. Exposure to pendimethalin significantly affected the distribution of cumulative mortality accelerating death in fish infected by VHSV. Pendimethalin appeared to decrease the Mean Time to Death (MTD) after virus treatment from 14.9 days (C-VHSV) to 10.2 days (P500-VHSV). Nevertheless, by the end of the experiment, differences in cumulative mortality were no longer observed between the two groups, which had reached the same stage (50 percent). Furthermore, a higher concentration of the virus was recovered from the pools of organs from the P500-VHSV group than the C-VHSV group. Moreover, at 40 dpi, although no significant difference was observed in the immune response between the two groups, more fish in the P500-VHSV group had set up an immune response by secreting antibodies than in the control viral group (C-VSHV).

  13. Evaluation of the antifungal activity of Zataria multiflora, Geranium herbarium, and Eucalyptus camaldolensis essential oils on Saprolegnia parasitica-infected rainbow trout (Oncorhynchus mykiss) eggs.

    PubMed

    Khosravi, Ali Reza; Shokri, Hojjatollah; Sharifrohani, Mostafa; Mousavi, Hosseinali Ebrahimzadeh; Moosavi, Zahra

    2012-07-01

    The purpose of the present study was to evaluate and assess the capability of Zataria multiflora, Geranium herbarium, and Eucalyptus camaldolensis essential oils in treating Saprolegnia parasitica-infected rainbow (Oncorhynchus mykiss) trout eggs. A total of 150 infected eggs were collected and plated on glucose-pepton agar at 24°C for 2 weeks. The antifungal assay of essential oils against S. parasitica was determined by a macrodilution broth technique. The eggs were treated with essential oils at concentrations of 1, 5, 10, 25, 50, and 100 ppm daily with three repetitions until the eyed eggs stage. Of 150 eggs examined, S. parasitica (54.3%), Saprolegnia spp. (45%), and Fusarium solani (0.7%) were isolated. The minimum inhibitory concentrations of Z. multiflora, E. camaldolensis, and G. herbarium essential oils against S. parasitica were 0.9, 2.3, and 4.8 ppm, respectively. Zataria multiflora and E. camaldolensis at concentrations of 25, 50, and 100 ppm, and G. herbarium at concentration of 100 ppm had significant differences in comparison with negative control (p<0.05). The results revealed that malachite green, followed by Z. multiflora, E. camaldolensis, and G. herbarium treated eggs had remained the most number of final eyed eggs after treatment. The highest final larvae rates belonged to malachite green, E. camaldolensis, Z. multiflora, and G. herbarium, respectively. The most hatching rates were recorded with malachite green (22%), and then Z. multiflora (11%), E. camaldolensis (7%), G. herbarium (3%), and negative control (1%). Zataria multiflora and E. camaldolensis were more effective than G. herbarium for the treatment of S. parasitica-infected rainbow trout eggs in aquaculture environment.

  14. Aquacultured rainbow trout (Oncorhynchus mykiss) possess a large core intestinal microbiota that is resistant to variation in diet and rearing density.

    PubMed

    Wong, Sandi; Waldrop, Thomas; Summerfelt, Steven; Davidson, John; Barrows, Frederic; Kenney, P Brett; Welch, Timothy; Wiens, Gregory D; Snekvik, Kevin; Rawls, John F; Good, Christopher

    2013-08-01

    As global aquaculture fish production continues to expand, an improved understanding of how environmental factors interact in fish health and production is needed. Significant advances have been made toward economical alternatives to costly fishmeal-based diets, such as grain-based formulations, and toward defining the effect of rearing density on fish health and production. Little research, however, has examined the effects of fishmeal- and grain-based diets in combination with alterations in rearing density. Moreover, it is unknown whether interactions between rearing density and diet impact the composition of the fish intestinal microbiota, which might in turn impact fish health and production. We fed aquacultured adult rainbow trout (Oncorhynchus mykiss) fishmeal- or grain-based diets, reared them under high- or low-density conditions for 10 months in a single aquaculture facility, and evaluated individual fish growth, production, fin indices, and intestinal microbiota composition using 16S rRNA gene sequencing. We found that the intestinal microbiotas were dominated by a shared core microbiota consisting of 52 bacterial lineages observed across all individuals, diets, and rearing densities. Variations in diet and rearing density resulted in only minor changes in intestinal microbiota composition despite significant effects of these variables on fish growth, performance, fillet quality, and welfare. Significant interactions between diet and rearing density were observed only in evaluations of fin indices and the relative abundance of the bacterial genus Staphylococcus. These results demonstrate that aquacultured rainbow trout can achieve remarkable consistency in intestinal microbiota composition and suggest the possibility of developing novel aquaculture strategies without overtly altering intestinal microbiota composition.

  15. Aquacultured Rainbow Trout (Oncorhynchus mykiss) Possess a Large Core Intestinal Microbiota That Is Resistant to Variation in Diet and Rearing Density

    PubMed Central

    Wong, Sandi; Waldrop, Thomas; Summerfelt, Steven; Davidson, John; Barrows, Frederic; Kenney, P. Brett; Welch, Timothy; Wiens, Gregory D.; Snekvik, Kevin

    2013-01-01

    As global aquaculture fish production continues to expand, an improved understanding of how environmental factors interact in fish health and production is needed. Significant advances have been made toward economical alternatives to costly fishmeal-based diets, such as grain-based formulations, and toward defining the effect of rearing density on fish health and production. Little research, however, has examined the effects of fishmeal- and grain-based diets in combination with alterations in rearing density. Moreover, it is unknown whether interactions between rearing density and diet impact the composition of the fish intestinal microbiota, which might in turn impact fish health and production. We fed aquacultured adult rainbow trout (Oncorhynchus mykiss) fishmeal- or grain-based diets, reared them under high- or low-density conditions for 10 months in a single aquaculture facility, and evaluated individual fish growth, production, fin indices, and intestinal microbiota composition using 16S rRNA gene sequencing. We found that the intestinal microbiotas were dominated by a shared core microbiota consisting of 52 bacterial lineages observed across all individuals, diets, and rearing densities. Variations in diet and rearing density resulted in only minor changes in intestinal microbiota composition despite significant effects of these variables on fish growth, performance, fillet quality, and welfare. Significant interactions between diet and rearing density were observed only in evaluations of fin indices and the relative abundance of the bacterial genus Staphylococcus. These results demonstrate that aquacultured rainbow trout can achieve remarkable consistency in intestinal microbiota composition and suggest the possibility of developing novel aquaculture strategies without overtly altering intestinal microbiota composition. PMID:23770898

  16. The relative importance of water hardness and chloride levels in modifying the acute toxicity of silver to rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Galvez, F.; Wood, C.M.

    1997-11-01

    Static-renewal 7-d toxicity tests for silver nitrate (AgNO{sub 3}) were performed with juvenile rainbow trout (Oncorhynchus mykiss Walbaum). The relative influences of calcium and chloride concentrations on median lethal time (LT50) were assessed. For both calcium salts, a 100-fold elevation in concentration increased the LT50 approximately 10-fold. However, a 100-fold elevation in KCl ameliorated silver (Ag) toxicity at least 100-fold, while NaCl protected against Ag toxicity even more substantially, demonstrating the much greater protective effect of chloride relative to calcium. In a separate series of bioassays, fish were exposed to 0.92 {micro}M Ag with varying amounts of NaCl titrated into each tank to alter the free [Ag{sup +}]. The 7-d LC50 occurred at a [NaCl] of 2,500 {micro}M. Using MINEQL{sup +}, the predicted free [Ag{sup +}] at this LC50 value is 0.0285 {micro}M. Further bioassays were performed in which [chloride] was maintained at either 50 or 225 {micro}M, while total [Ag] was independently varied from 0.0092 to 0.0694 {micro}M (1.0--7.5 {micro}g/L). The 7-d LC50 value was calculated at 0.0294 {micro}M Ag (3.18 {micro}g/L) at a chloride concentration of 50 {micro}M, very similar to the free [Ag{sup +}] value of 0.031 {micro}M calculated from an earlier LC50 test at a fixed [chloride] of 730 {micro}M. Elevating chloride concentrations from 50 to 225 {micro}M did not alter the accumulation of Ag in the liver. In addition, there were no significant differences in hepatic Ag accumulation between any of the Ag-exposed fish, irrespective of the total Ag concentration used during the exposure.

  17. Dietary Myrtle (Myrtus communis L.) improved non-specific immune parameters and bactericidal activity of skin mucus in rainbow trout (Oncorhynchus mykiss) fingerlings.

    PubMed

    Mansouri Taee, Hadis; Hajimoradloo, Abdolmajid; Hoseinifar, Seyed Hossein; Ahmadvand, Hassan

    2017-03-19

    The present study examined the effects of dietary Myrtle (Myrtus communis L.) on non-specific immune parameters and bactericidal activity of skin mucus in rainbow trout (Oncorhynchus mykiss) fingerlings. Three hundred and sixty fingerlings (6.50 ± 0.55 g (were distributed in twelve cages (65 × 65 × 65 cm) with a metal framework. The study included four treatments repeated in triplicates. The treatments were feeding trouts with experimental diets containing different levels (0, 0.5, 1 and 1.5%) of Myrtle powder. The fingerlings were fed on experimental diet for sixty days and then skin mucus non-specific immune parameters as well as bactericidal activity were measured. At the end of the trial, the highest skin mucus soluble protein level was observed in group fed with 1.5% Myrtle (P < 0.05). The alkaline phosphatase (ALP) activity was significantly increased in fish groups fed 1 and 1.5% Myrtle compared with the control group (P < 0.05). However, evaluation of skin mucus lysozyme activity showed no significant difference between treatments and control group (P > 0.05). Also, no antibacterial activity was detected against Escherichia coli, Staphylococcus aureus and Salmonella enterica in all treatments and control group. Whereas skin mucus of rainbow trout showed antimicrobial activity against fish pathogens (Aeromonas hydrophila and Yersinia ruckeri) in 1 and 1.5% Myrtle treatments. These results indicated beneficial effects of dietary Myrtle on mucosal immune parameters of fingerling rainbow trout.

  18. Assessment of energetic costs of AhR activation by β-naphthoflavone in rainbow trout (Oncorhynchus mykiss) hepatocytes using metabolic flux analysis

    SciTech Connect

    Nault, Rance; Abdul-Fattah, Hiba; Mironov, Gleb G.; Berezovski, Maxim V.; Moon, Thomas W.

    2013-08-15

    Exposure to environmental contaminants such as activators of the aryl hydrocarbon receptor (AhR) leads to the induction of defense and detoxification mechanisms. While these mechanisms allow organisms to metabolize and excrete at least some of these environmental contaminants, it has been proposed that these mechanisms lead to significant energetic challenges. This study tests the hypothesis that activation of the AhR by the model agonist β-naphthoflavone (βNF) results in increased energetic costs in rainbow trout (Oncorhynchus mykiss) hepatocytes. To address this hypothesis, we employed traditional biochemical approaches to examine energy allocation and metabolism including the adenylate energy charge (AEC), protein synthesis rates, Na{sup +}/K{sup +}-ATPase activity, and enzyme activities. Moreover, we have used for the first time in a fish cell preparation, metabolic flux analysis (MFA) an in silico approach for the estimation of intracellular metabolic fluxes. Exposure of trout hepatocytes to 1 μM βNF for 48 h did not alter hepatocyte AEC, protein synthesis, or Na{sup +}/K{sup +}-ATPase activity but did lead to sparing of glycogen reserves and changes in activities of alanine aminotransferase and citrate synthase suggesting altered metabolism. Conversely, MFA did not identify altered metabolic fluxes, although we do show that the dynamic metabolism of isolated trout hepatocytes poses a significant challenge for this type of approach which should be considered in future studies. - Highlights: • Energetic costs of AhR activation by βNF was examined in rainbow trout hepatocytes. • Metabolic flux analysis was performed on a fish cell preparation for the first time. • Exposure to βNF led to sparing of glycogen reserves and altered enzyme activities. • Adenylate energy charge was maintained despite temporal changes in metabolism.

  19. Protein profile of seminal plasma and functionality of spermatozoa during the reproductive season in the common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss).

    PubMed

    Shaliutina-Kolešová, Anna; Kotas, Petr; Štěrba, Jan; Rodina, Marek; Dzyuba, Borys; Cosson, Jacky; Linhart, Otomar

    2016-11-01

    The purpose of the study was to analyze seminal plasma composition, sperm production, and sperm motility over the course of the spawning season in the common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss). The highest mean percent of motile sperm (carp, 98.3 ± 1.6%; rainbow trout, 92.8 ± 5.6%) and highest spermatozoon velocity (carp, 286.3 ± 7.8 μm sec(-1) ; rainbow trout, 245.3 ± 8.3 μm sec(-1) ) were observed in the middle phase of the spawning period, at 5 sec post-activation. Sperm volume and concentration increased in the early spawning period, then decreased significantly toward the end of the season in both species. Seminal plasma osmolality was 262-270 mOsmol kg(-1) from carp and 232-248 mOsmol kg(-1) from rainbow trout, with little variation over the spawning period. Protein concentration in carp seminal plasma was stable throughout the reproductive season, whereas the highest protein level (2.1 ± 0.3 mg mL(-1) ) in rainbow trout was observed in the middle phase of the spawning period. Seminal plasma composition in both species was analyzed using two-dimensional polyacrylamide gel electrophoresis combined with mass spectrometry. Thirteen differentially expressed protein spots in carp seminal plasma and sixteen spots in rainbow trout seminal plasma varied over the course of the reproductive season. The unique proteins identified are involved in the regulation of spermatogenesis, sperm motility, maintenance of sperm membrane lipid stability, and antioxidant protection. These results provide a deeper understanding of the role of fish seminal plasma proteins as well as a list of novel markers of sperm quality. Mol. Reprod. Dev. 83: 968-982, 2016 © 2016 Wiley Periodicals, Inc.

  20. Identification of differentially expressed genes of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) in response to Tetracapsuloides bryosalmonae (Myxozoa).

    PubMed

    Kumar, Gokhlesh; Abd-Elfattah, Ahmed; El-Matbouli, Mansour

    2015-03-01

    Tetracapsuloides bryosalmonae Canning et al., 1999 (Myxozoa) is the causative agent of proliferative kidney disease in various species of salmonids in Europe and North America. We have shown previously that the development and distribution of the European strain of T. bryosalmonae differs in the kidney of brown trout (Salmo trutta) Linnaeus, 1758 and rainbow trout (Oncorhynchus mykiss) Walbaum, 1792, and that intra-luminal sporogonic stages were found in brown trout but not in rainbow trout. We have now compared transcriptomes from kidneys of brown trout and rainbow trout infected with T. bryosalmonae using suppressive subtractive hybridization (SSH). The differentially expressed transcripts produced by SSH were cloned, transformed, and tested by colony PCR. Differential expression screening of PCR products was validated using dot blot, and positive clones having different signal intensities were sequenced. Differential screening and a subsequent NCBI-BLAST analysis of expressed sequence tags revealed nine clones expressed differently between both fish species. These differentially expressed genes were validated by quantitative real-time PCR of kidney samples from both fish species at different time points of infection. Expression of anti-inflammatory (TSC22 domain family protein 3) and cell proliferation (Prothymin alpha) genes were upregulated significantly in brown trout but downregulated in rainbow trout. The expression of humoral immune response (immunoglobulin mu) and endocytic pathway (Ras-related protein Rab-11b) genes were significantly upregulated in rainbow trout but downregulated in brown trout. This study suggests that differential expression of host anti-inflammatory, humoral immune and endocytic pathway responses, cell proliferation, and cell growth processes do not inhibit the development of intra-luminal sporogonic stages of the European strain of T. bryosalmonae in brown trout but may suppress it in rainbow trout.

  1. Influence of the forms and levels of dietary selenium on antioxidant status and oxidative stress-related parameters in rainbow trout (Oncorhynchus mykiss) fry.

    PubMed

    Fontagné-Dicharry, Stéphanie; Godin, Simon; Liu, Haokun; Antony Jesu Prabhu, Philip; Bouyssière, Brice; Bueno, Maïté; Tacon, Philippe; Médale, Françoise; Kaushik, Sadasivam J

    2015-06-28

    Se is an essential micronutrient required for normal growth, development and antioxidant defence. The objective of the present study was to assess the impact of dietary Se sources and levels on the antioxidant status of rainbow trout (Oncorhynchus mykiss) fry. First-feeding fry (initial body weight: 91 mg) were fed either a plant- or fishmeal-based diet containing 0·5 or 1·2 mg Se/kg diet supplemented or not with 0·3 mg Se/kg diet supplied as Se-enriched yeast or sodium selenite for 12 weeks at 17°C. Growth and survival of rainbow trout fry were not significantly affected by dietary Se sources and levels. Whole-body Se was raised by both Se sources and to a greater extent by Se-yeast. The reduced:oxidised glutathione ratio was raised by Se-yeast, whereas other lipid peroxidation markers were not affected by dietary Se. Whole-body Se-dependent glutathione peroxidase (GPX) activity was enhanced in fish fed Se-yeast compared to fish fed sodium selenite or non-supplemented diets. Activity and gene expression of this enzyme as well as gene expression of selenoprotein P (SelP) were reduced in fish fed the non-supplemented plant-based diet. Catalase, glutamate-cysteine ligase and nuclear factor-erythroid 2-related factor 2 (Nrf2) gene expressions were reduced by Se-yeast. These results suggest the necessity to supplement plant-based diets with Se for rainbow trout fry, and highlight the superiority of organic form of Se to fulfil the dietary Se requirement and sustain the antioxidant status of fish. GPX and SelP expression proved to be good markers of Se status in fish.

  2. Chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures

    USGS Publications Warehouse

    Wang, Ning; Ingersoll, Christopher G.; Dorman, Rebecca A.; Brumbaugh, William G.; Mebane, Christopher A.; Kunz, James L.; Hardesty, Douglas K.

    2014-01-01

    Chronic toxicity of cadmium, copper, lead, or zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) was evaluated in water-only exposures started with newly hatched larvae or approximately 1-mo-old juveniles. The 20% effect concentration (EC20) for cadmium from the sturgeon tests was higher than the EC20 from the trout tests, whereas the EC20 for copper, lead, or zinc for the sturgeon were lower than those EC20s for the trout. When the EC20s from the present study were included in compiled toxicity databases for all freshwater species, species mean chronic value for white sturgeon was in a relatively low percentile of the species sensitivity distribution for copper (9th percentile) and in the middle percentile for cadmium (55th percentile), zinc (40th percentile), or lead (50th percentile). However, the species mean chronic value for rainbow trout was in a high percentile for copper, lead, and zinc (∼68th–82nd percentile), but in a low percentile for cadmium (23rd percentile). The trout EC20s for each of the 4 metals and the sturgeon EC20s for cadmium or lead were above US Environmental Protection Agency chronic ambient water quality criteria (AWQC) or Washington State chronic water quality standards (WQS), whereas the sturgeon EC20s for copper or zinc were approximately equal to or below the chronic AWQC and WQS. In addition, acute 50% effect concentrations (EC50s) for copper obtained in the first 4 d of the chronic sturgeon test were below the final acute value used to derive acute AWQC and below acute WQS for copper.

  3. Effect of stocking density on water quality and (Growth, Body Composition and Plasma Cortisol Content) performance of pen-reared rainbow trout ( Oncorhynchus mykiss)

    NASA Astrophysics Data System (ADS)

    Liu, Qun; Hou, Zhishuai; Wen, Haishen; Li, Jifang; He, Feng; Wang, Jinhuan; Guan, Biao; Wang, Qinglong

    2016-08-01

    The goal of the study was to examine the effect of stocking density on the water quality of culture area, as well as the growth, body composition and cortisol content of rainbow trout ( Oncorhynchus mykiss). Pen-reared trout were stocked in densities of 40, 60, 80 fish individuals m-3 (4.6, 6.6, 8.6 kg m-3, SD1, SD2 and SD3 groups, respectively) for 300 days. Compared to the water from SD1 and SD2, that from SD3 exhibited significantly higher NH 4 + -N content and COD (chemical-oxygen-demand), and a significant reduction of dissolved oxygen in day 180 (40.6 kg m-3). Stocking density was significantly associated with body weight, standard length, VSI (viscerosomatic index), CF (condition factor) and FC (food coefficient) in group SD3, particularly in day 240 and day 300 (45 or 49.3 kg m-3). Increased crude fat and decreased crude protein were displayed in high density group when the density reached to 36 kg m-3. As a cumulative effect of density-related stress, VSI, CF, FC, moisture, and crude protein content varied over time in each density group (SD1, SD2, and SD3). In summary, trout exhibited a better growth performance in low density (26.3 kg m-3) than those reared in high densities (36 and 45 kg m-3). The results indicate that rainbow trout (114.44 g ± 6.21 g, 19.69 cm ± 0.31 cm) initially stocked in 6.6 or 8.6 kg m-3 should be lightened to less than 36 kg m-3 after an intensive rearing for 240 days.

  4. Immune gene expression profiling of Proliferative Kidney Disease in rainbow trout Oncorhynchus mykiss reveals a dominance of anti-inflammatory, antibody and T helper cell-like activities.

    PubMed

    Gorgoglione, Bartolomeo; Wang, Tiehui; Secombes, Christopher J; Holland, Jason W

    2013-07-16

    The myxozoan Tetracapsuloides bryosalmonae is the causative agent of Proliferative Kidney Disease (PKD) targeting primarily the kidney of infected fish where it causes a chronic lymphoid immunopathology. Although known to be associated with suppression of some cellular aspects of innate immunity and a prominent lymphocytic hyperplasia, there remains a considerable knowledge gap in our understanding of the underlying immune mechanisms driving PKD pathogenesis. To provide further insights, the expression profiles of a panel of innate/inflammatory and adaptive immune molecules were examined in rainbow trout Oncorhynchus mykiss following a natural exposure to the parasite. Relative to controls, fish with early to advanced stages of kidney pathology exhibited up-regulation of the inflammatory cytokines interleukin (IL)-6 and IL-11, although remaining refractory towards genes indicative of macrophage activity. Antimicrobial peptides (AMPs) and anti-inflammatory markers, including cathelicidin (CATH) and IL-10 were markedly up-regulated during clinical disease. Up-regulation of adaptive immune molecules, including cell markers and antibody genes reflect the lymphocytic dominance of this disease and the likely importance of lymphocyte subsets in PKD pathogenesis. Up-regulation of T helper (TH) cell-like response genes and transcription factors implies that T. bryosalmonae may elicit a complex interplay between TH cell subsets. This work, for the first time in the study of fish-myxozoan interactions, suggests that PKD pathogenesis is shaped by an anti-inflammatory phenotype, a profound B cell/antibody response and dysregulated TH cell-like activities. A better understanding of the functional roles of fish immune cells and molecules in PKD pathogenesis may facilitate future development of control measures against this disease.

  5. Effect of dietary β-glucan on growth, survival and regulation of immune processes in rainbow trout (Oncorhynchus mykiss) infected by Aeromonas salmonicida.

    PubMed

    Ji, Liqin; Sun, Guoxiang; Li, Jun; Wang, Yi; Du, Yishuai; Li, Xian; Liu, Ying

    2017-03-07

    The present study evaluated the effects of dietary β-glucan (0, 0.05%, 0.1%, and 0.2%) on growth performance after 42 days of feeding. Thereafter, rainbow trout (Oncorhynchus mykiss) were infected with Aeromonas salmonicida, and survival rates as well as the regulating processes of stress- and immune-related factors were analyzed. In general, higher dietary β-glucan levels obviously improved specific growth rate (SGR), weight gain (WG) and feed efficiency (FE) (P ≤ 0.05). Survival rates in β-glucan groups increased significantly compared with the control group after A. salmonicida infection (P ≤ 0.05). Serum total superoxide dimutase (T-SOD), peroxidase (POD) as well as catalase (CAT) activities, and their mRNA expressions in the head kidney of fish in the β-glucan groups generally increased to higher levels after infection, and more quickly, compared with in the control group. Serum lysozyme (LSZ) and its expression in the head kidney in β-glucan groups reached a higher peak earlier than in the control group. Serum glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels in the β-glucan groups were significantly lower than in the control group (P ≤ 0.05). The peak of heat shock protein 70 (HSP70) expression in the 0.2% β-glucan group was higher and occurred earlier than in other groups (P ≤ 0.05). These results confirm that 0.1% and 0.2% dietary β-glucan are beneficial for promoting growth in rainbow trout and enhancing resistance against A. salmonicida. Furthermore, β-glucan could play an important role in regulating stress- and immune-related factors in rainbow trout to more quickly fight against bacterial infection.

  6. Hybrid zone structure and the potential role of selection in hybridizing populations of native westslope cutthroat trout (Oncorhynchus clarki lewisi) and introduced rainbow trout (O. mykiss).

    PubMed

    Rubidge, Emily M; Taylor, Eric B

    2004-12-01

    Introgressive hybridization is a common feature of many zones of contact between divergent lineages of fishes. This is particularly common when taxa that are normally allopatric come into artificial (human-induced) secondary contact. We examined 18 native populations of westslope cutthroat trout (Oncorhynchus clarki lewisi, WCT) to determine the extent of introgressive hybridization with introduced rainbow trout (O. mykiss, RBT) and the genetic structure of hybridizing populations in the upper Kootenay River, southeastern British Columbia, Canada. Using four diagnostic nuclear loci we calculated a hybrid index, inbreeding coefficient, FIS, and the linkage disquilibrium correlation coefficient, Rij, for each locality to determine the distribution of genotypes in each population. We also categorized the 142 hybrid individuals found across localities into four hybrid classes based on their genotypes. The majority of localities (11/18) showed a unimodal distribution of genotypes skewed towards genotypes of WCT. Two localities, however (lower Gold Creek and Lodgepole Creek) showed a flat to bimodal distribution and one site (lower Bull River) showed a unimodal distribution skewed towards RBT genotypes. The majority of hybrid individuals were classified genotypically as WCT backcrosses (59%) and post-F1 individuals (24%). We found a skewed ratio of pure WCT to pure RBT (17:1) and only four F1 hybrids (3%), suggesting that the spread of RBT alleles may be facilitated by hybrids straying to neighbouring populations. We also tested for the action of selection in one population using cohort analyses, but found little evidence of differential selection between pure WCT and hybrid individuals. Pooled across age classes there were significant differences in genotypic frequencies among loci suggesting differential introgression. There was no asymmetry to the hybridization between rainbow trout and westslope cutthroat trout because both species' mitochondrial DNA haplotypes were

  7. 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.

    PubMed

    Lo, Jay H; Chiou, Pinwen Peter; Lin, C M; Chen, Thomas T

    2007-08-01

    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/EBPdelta1, C/EBPdelta2, from the liver. Comparison of the deduced amino acid sequence of rainbow trout C/EBPs with those of other vertebrates revealed that C/EBP isoforms are highly conserved. The profiles of tissue-specific expression of individual C/EBP isoform mRNA, determined by quantitative real-time (RT)-PCR showed distinct patterns. Furthermore, injection of bovine GH into yearling rainbow trout resulted in a significant increase of mRNA levels of C/EBPbeta1, C/EBPbeta2, and C/EBPdelta2 but not C/EBPalpha and C/EBPdelta1 in the liver. GH-dependent increase of mRNA levels of C/EBPbeta1, C/EBPbeta2, C/EBPdelta2, and IGF-II were also confirmed by treating rainbow trout hepatoma cells expressing a goldfish GH receptor with bGH. Together with our previous findings, the results presented in this paper strengthen our previous hypothesis that GH may regulate the expression of the IGF-II gene via mediating the expression of C/EBPbeta1, C/EBPbeta2, and C/EBPdelta2 mRNA.

  8. An egg injection method for assessing early life stage mortality of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in rainbow trout, (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Walker, M.K.; Hufnagle, L.C.; Clayton, M.K.; Peterson, R.E.

    1992-01-01

    To characterize the risk that polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) pose to salmonid early life stage survival, we developed a method to expose rainbow trout (Oncorhynchus mykiss) eggs to graded doses of PCDD, PCDF, and PCB congeners, using 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as a prototype. Rainbow trout eggs were injected 24–50 h post-fertilization with 0.2 μl of 50 mM phosphatidylcholine (PC) liposomes (control) or 0.2 μl of 5–7 graded doses of TCDD incorporated into 50 mM PC liposomes. Injection volume never exceeded 0.6% egg volume. Immediately following injection, the injection site was sealed with Super glue®, resulting in 92–97% of TCDD dose retained by the egg. Following both egg injection and waterborne egg exposure. TCDD toxicity in rainbow trout was manifested by half-hatching mortality but predominantly by sac fry mortality associated with hemorrhages, pericardial edema, and yolk sac edema. TCDD LD50s, following injection and waterborne exposure of rainbow trout eggs, were 421 (331–489) and 439 (346–519) pg TCDD/g egg (LD50, 95% fiducial limits), respectively. As in rainbow trout, TCDD toxicity in lake trout (Salvelinus namaycush) following the same two routes of exposure was manifested by half-hatching mortality but predominantly by sac fry mortality preceded by hemorrhages and yolk sac edema. LD50s, based on the dose of TCDD in lake trout eggs, were 47 (21–65) and 65 (60–71) pg/g following injection and waterborne exposure, respectively. The egg injection method is ideal for assessing the relationship between early life stage mortality in rainbow trout and graded egg doses of individual PCDD, PCDF, or PCB congeners.

  9. Insights into the fish thioredoxin system: expression profile of thioredoxin and thioredoxin reductase in rainbow trout (Oncorhynchus mykiss) during infection and in vitro stimulation.

    PubMed

    Pacitti, D; Wang, T; Martin, S A M; Sweetman, J; Secombes, C J

    2014-02-01

    Production of reactive oxygen species (ROS) is the first biological response during a disease outbreak and after injury. ROS are highly reactive molecules that can either endanger cell homeostasis or mediate cell signaling in several physiological pathways, including the immune response. Thioredoxin (Trx) and thioredoxin reductase (TrxR) are the essential components of the thioredoxin system, one of the main intracellular redox systems and are therefore important regulators of ROS accumulation. Through the regulation of the intracellular redox milieu, the thioredoxin system plays a key role within the immune system, linking immunology and free radical science. In this study we have firstly identified TrxRs in fish and used this new sequence information to reevaluate the evolution of the thioredoxin system within the vertebrate lineage. We next measured the expression of rainbow trout (Oncorhynchus mykiss) Trx and TrxR transcripts during infection in vivo and in vitro after stimulation of a macrophage cell line and primary macrophage cultures with pathogen associated molecular patterns (PAMPs). Our results showed that both Trx and TrxR were induced during infection at the transcriptional level, confirming their likely involvement in the innate immune response of fish. Since TrxRs are selenium-containing proteins (selenoproteins), we also measured the modulation of their expression upon organic and inorganic selenium exposure in vitro. TrxR was found to be responsive to selenium exposure in vitro, suggesting that it may represent a key mediator in the selenium modulation of innate immunity. In conclusion, our study highlights the need to investigate the involvement of the cell antioxidant pathways, especially the thioredoxin system, within the immune system of vertebrate species.

  10. Temperature Increase Negatively Affects the Fatty Acid Bioconversion Capacity of Rainbow Trout (Oncorhynchus mykiss) Fed a Linseed Oil-Based Diet

    PubMed Central

    Mellery, Julie; Geay, Florian; Tocher, Douglas R.; Kestemont, Patrick; Debier, Cathy; Rollin, Xavier; Larondelle, Yvan

    2016-01-01

    Aquaculture is meant to provide fish rich in omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA). This objective must be reached despite (1) the necessity to replace the finite and limited fish oil in feed production and (2) the increased temperature of the supply water induced by the global warming. The objective of the present paper was to determine to what extent increased water temperature influences the fatty acid bioconversion capacity of rainbow trout (Oncorhynchus mykiss) fed a plant-derived diet. Fish were fed two diets formulated with fish oil (FO) or linseed oil (LO) as only added lipid source at the optimal water temperature of 15°C or at the increased water temperature of 19°C for 60 days. We observed that a temperature increase close to the upper limit of the species temperature tolerance range negatively affected the feed efficiency of rainbow trout fed LO despite a higher feed intake. The negative impact of increased water temperature on fatty acid bioconversion capacity appeared also to be quite clear considering the reduced expression of fatty acid desaturase 2 in liver and intestine and the reduced Δ6 desaturase enzymatic activity in intestinal microsomes. The present results also highlighted a negative impact of increased temperature on the apparent in vivo enzymatic activity of Δ5 and Δ6 desaturases of fish fed LO. Interestingly, this last parameter appeared less affected than those mentioned above. This study highlights that the increased temperature that rainbow trout may face due to global warming could reduce their fatty acid bioconversion capacity. The unavoidable replacement of finite fish oil by more sustainable, readily available and economically viable alternative lipid sources in aquaculture feeds should take this undeniable environmental issue on aquaculture productivity into account. PMID:27736913

  11. Immune gene expression profiling of Proliferative Kidney Disease in rainbow trout Oncorhynchus mykiss reveals a dominance of anti-inflammatory, antibody and T helper cell-like activities

    PubMed Central

    2013-01-01

    The myxozoan Tetracapsuloides bryosalmonae is the causative agent of Proliferative Kidney Disease (PKD) targeting primarily the kidney of infected fish where it causes a chronic lymphoid immunopathology. Although known to be associated with suppression of some cellular aspects of innate immunity and a prominent lymphocytic hyperplasia, there remains a considerable knowledge gap in our understanding of the underlying immune mechanisms driving PKD pathogenesis. To provide further insights, the expression profiles of a panel of innate / inflammatory and adaptive immune molecules were examined in rainbow trout Oncorhynchus mykiss following a natural exposure to the parasite. Relative to controls, fish with early to advanced stages of kidney pathology exhibited up-regulation of the inflammatory cytokines interleukin (IL)-6 and IL-11, although remaining refractory towards genes indicative of macrophage activity. Antimicrobial peptides (AMPs) and anti-inflammatory markers, including cathelicidin (CATH) and IL-10 were markedly up-regulated during clinical disease. Up-regulation of adaptive immune molecules, including cell markers and antibody genes reflect the lymphocytic dominance of this disease and the likely importance of lymphocyte subsets in PKD pathogenesis. Up-regulation of T helper (TH) cell-like response genes and transcription factors implies that T. bryosalmonae may elicit a complex interplay between TH cell subsets. This work, for the first time in the study of fish-myxozoan interactions, suggests that PKD pathogenesis is shaped by an anti-inflammatory phenotype, a profound B cell / antibody response and dysregulated TH cell-like activities. A better understanding of the functional roles of fish immune cells and molecules in PKD pathogenesis may facilitate future development of control measures against this disease. PMID:23865616

  12. Apparent low ability of liver and muscle to adapt to variation of dietary carbohydrate:protein ratio in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Skiba-Cassy, Sandrine; Panserat, Stéphane; Larquier, Mélanie; Dias, Karine; Surget, Anne; Plagnes-Juan, Elisabeth; Kaushik, Sadasivam; Seiliez, Iban

    2013-04-28

    The rainbow trout (Oncorhynchus mykiss) exhibits high dietary amino acid requirements and an apparent inefficiency to use dietary carbohydrates. Using this species, we investigated the metabolic consequences of long-term high carbohydrates/low protein feeding. Fish were fed two experimental diets containing either 20% carbohydrates/50% proteins (C20P50), or high levels of carbohydrates at the expense of proteins (35% carbohydrates/35% proteins--C35P35). The expression of genes related to hepatic and muscle glycolysis (glucokinase (GK), pyruvate kinase and hexokinase) illustrates the poor utilisation of carbohydrates irrespective of their dietary levels. The increased postprandial GK activity and the absence of inhibition of the gluconeogenic enzyme glucose-6-phosphatase activity support the hypothesis of the existence of a futile cycle around glucose phosphorylation extending postprandial hyperglycaemia. After 9 weeks of feeding, the C35P35-fed trout displayed lower body weight and feed efficiency and reduced protein and fat gains than those fed C20P50. The reduced activation of eukaryotic translation initiation factor 4-E binding protein 1 (4E-BP1) in the muscle in this C35P35 group suggests a reduction in protein synthesis, possibly contributing to the reduction in N gain. An increase in the dietary carbohydrate:protein ratio decreased the expression of genes involved in amino acid catabolism (serine dehydratase and branched-chain α-keto acid dehydrogenase E1α and E1β), and increased that of carnitine palmitoyltransferase 1, suggesting a higher reliance on lipids as energy source in fish fed high-carbohydrate and low-protein diets. This probably also contributes to the lower fat gain. Together, these results show that different metabolic pathways are affected by a high-carbohydrate/low-protein diet in rainbow trout.

  13. Growth performance and antioxidant enzyme activities in rainbow trout (Oncorhynchus mykiss) juveniles fed diets supplemented with sage, mint and thyme oils.

    PubMed

    Sönmez, Adem Yavuz; Bilen, Soner; Alak, Gonca; Hisar, Olcay; Yanık, Talat; Biswas, Gouranga

    2015-02-01

    This study evaluated effects of dietary supplementation of sage (Salvia officinalis), mint (Mentha spicata) and thyme (Thymus vulgaris) oils on growth performance, lipid peroxidation level (melondialdehyde, MDA) and liver antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; glucose-6-phosphate dehydrogenase, G6PD; glutathione reductase, GR; glutathione-S-transferase, GST and glutathione peroxidase, GPx) in rainbow trout (Oncorhynchus mykiss) juveniles. For this purpose, triplicate groups of rainbow trout were fed daily ad libitum with diets containing sage, mint and thyme oils at 500, 1,000 and 1,500 mg kg(-1) for 60 days. While weight gain percentage of fish fed the diets containing sage and thyme oils was significantly higher than the control group, that of fish fed mint oil was the lowest. Similarly, specific growth rate was found to be the highest in all groups of the sage and thyme oil feeding and the lowest in the mint groups. Moreover, feed conversion ratio was significantly higher in the mint oil administered groups. Survival rate was also significantly reduced in the fish fed the diet containing mint oil. It was observed that SOD, G6PD and GPx activities were significantly increased in liver tissues of all the treated fish groups compared to that of control diet-fed group. However, CAT, GST and GR activities were significantly decreased in experimental diet-fed fish groups at the end of the experiment. On the other hand, a significant reduction was found in MDA levels in the fish fed the diets with sage and thyme oils compared to control and mint diets on the 30th and 60th days of experiment. Overall, dietary inclusion of sage and thyme oils is effective in enhancing rainbow trout growth, reduction in MDA and least changing antioxidant enzyme activities at a low level of 500 mg kg(-1) diet, and they can be used as important feed supplements for rainbow trout production.

  14. Nonspecific immune response of rainbow trout (Oncorhynchus mykiss Walbaum) in relation to different status of vitamin E and highly unsaturated fatty acids.

    PubMed

    Puangkaew, J; Kiron, V; Somamoto, T; Okamoto, N; Satoh, S; Takeuchi, T; Watanabe, T

    2004-01-01

    This study was designed to examine the effects of dietary vitamin E (VE) on modulation of immune responses when supplied with two levels of n-3 highly unsaturated fatty acids (n-3 HUFA) in rainbow trout, Oncorhynchus mykiss. Six semipurified diets were prepared containing three levels of dietary VE (0, 100 or 1000 mg alpha-tocopheryl acetate kg(-1) diet) and n-3 HUFA either at 20 or 48% of dietary lipid provided from fish oil or docosahexaenoic acid (DHA) concentrated fish oil respectively. The diets were fed to rainbow trout (100 g initial mean weight) for 15 weeks. The VE, vitamin C (VC) content in plasma and tissues and the nonspecific immune responses, both humoral (alternative complement activity, total immunoglobulin) and cellular (phagocytosis, nonspecific cytotoxicity) were examined. VE contents in the kidney reflected the dietary input but were lower in fish fed 48% n-3 HUFA diets, and could have impaired some of immune responses compared to fish fed 20% n-3 HUFA. VC contents in kidney followed the same pattern as VE. Both humoral and cellular immune functions deteriorated in fish fed VE deficient diets whereas improvement in most of the parameters corresponded to its supplementation. However, the higher dose of dietary VE did not substantially enhance the responses assayed compared to the 100 mg dose. Besides clearly indicating the role of VE in maintaining the immune functions in fish in relation to dietary n-3 HUFA, this study has revealed that optimum health benefits could be achieved when VE is maintained slightly above the levels generally recommended for normal growth.

  15. Characterization of BAFF and APRIL subfamily receptors in rainbow trout (Oncorhynchus mykiss). Potential role of the BAFF / APRIL axis in the pathogenesis of proliferative kidney disease

    PubMed Central

    Granja, Aitor G.; Holland, Jason W.; Pignatelli, Jaime; Secombes, Christopher J.; Tafalla, Carolina

    2017-01-01

    Proliferative kidney disease (PKD) is a parasitic infection of salmonid fish characterized by hyper-secretion of immunoglobulins in response to the presence of the myxozoan parasite, Tetracapsuloides bryosalmonae. In this context, we hypothesized that the BAFF/APRIL axis, known to play a major role in B cell differentiation and survival in mammals, could be affected by the parasite and consequently be involved in the apparent shift in normal B cell activity. To regulate B cell activity, BAFF and APRIL bind to transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) and B cell maturation antigen (BCMA), whereas BAFF also binds to BAFF receptor (BAFF-R). In teleost fish, although some BAFF and APRIL sequences have been reported, their receptors have not been identified. Thus, as a first step in the current work, we have identified homologues to mammalian TACI, BCMA and BAFF-R in rainbow trout (Oncorhynchus mykiss), that constitute the first report of BAFF and APRIL receptor sequences in fish. Subsequently we studied the transcriptional modulation of BAFF, APRIL, and the fish-specific related cytokine, BALM and their putative receptors in fish naturally exposed to T. bryosalmonae. Finally, to gain further insights on the functional role that these cytokines play during the course of PKD, we have studied their effect on the survival of kidney IgM+ B cells and on immunoglobulin transcription. Our results support the premise that the BAFF / APRIL axis could play an important role during PKD, which may open the possibility of new therapeutic treatments against the disease. PMID:28323891

  16. Chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures.

    PubMed

    Wang, Ning; Ingersoll, Christopher G; Dorman, Rebecca A; Brumbaugh, William G; Mebane, Christopher A; Kunz, James L; Hardesty, Doug K

    2014-10-01

    Chronic toxicity of cadmium, copper, lead, or zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) was evaluated in water-only exposures started with newly hatched larvae or approximately 1-mo-old juveniles. The 20% effect concentration (EC20) for cadmium from the sturgeon tests was higher than the EC20 from the trout tests, whereas the EC20 for copper, lead, or zinc for the sturgeon were lower than those EC20s for the trout. When the EC20s from the present study were included in compiled toxicity databases for all freshwater species, species mean chronic value for white sturgeon was in a relatively low percentile of the species sensitivity distribution for copper (9th percentile) and in the middle percentile for cadmium (55th percentile), zinc (40th percentile), or lead (50th percentile). However, the species mean chronic value for rainbow trout was in a high percentile for copper, lead, and zinc (∼68th-82nd percentile), but in a low percentile for cadmium (23rd percentile). The trout EC20s for each of the 4 metals and the sturgeon EC20s for cadmium or lead were above US Environmental Protection Agency chronic ambient water quality criteria (AWQC) or Washington State chronic water quality standards (WQS), whereas the sturgeon EC20s for copper or zinc were approximately equal to or below the chronic AWQC and WQS. In addition, acute 50% effect concentrations (EC50s) for copper obtained in the first 4 d of the chronic sturgeon test were below the final acute value used to derive acute AWQC and below acute WQS for copper.

  17. Effects of water temperature on the toxicity of 4-nitrophenol and 2,4-dinitrophenol to developing rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Howe, G.E.; Marking, L.L.; Bills, T.D.; Boogaard, M.A. . National Fisheries Research Center); Mayer, F.L. Jr. . Environmental Protection Agency)

    1994-01-01

    Early-life-stage (ELS) toxicity tests were conducted to determine the effect of selected water temperature on the toxicity of 4-nitrophenol and 2,4-dinitrophenol to rainbow trout (Oncorhynchus mykiss). NOECs were determined for growth and mortality at selected time intervals and water temperatures of 7, 12, and 17 C. As tests progressed, NOECs leveled to constant time-independent values that were similar for tests at each temperature. In 4-nitrophenol tests, the time-independent NOEC values at 7, 12, and 17 C, respectively, were 1.16, 1.20, and 1.16 mg/L for growth and 3.40, 3.38, and 2.20 mg/L for mortality. For 2,4-dinitrophenol, time-independent NOEC values at 7, 12, and 17 C, respectively, were 1.07, 0.50, and 0.80 mg/L for growth and 1.30, 1.89, and 1.60 mg/L for mortality. Temperature did, however, affect the rate at which time-independent NOECs were reached. More time was required to reach time-independent NOECs as temperature decreased. For example, the time-independent NOEC in 4-nitrophenol tests at 17 C was reached in 14 d, whereas it required 42 d at 7 C. The effect of temperature on toxicity must be considered in hazard assessment protocols to assess risk accurately and protect aquatic organisms adequately. Chronic toxicity tests are necessary to assess risk because acute toxicity tests cannot provide the information necessary to predict the long-term effects of factors such as temperature in natural environments.

  18. Effects on Biotransformation, Oxidative Stress, and Endocrine Disruption in Rainbow Trout (Oncorhynchus mykiss) Exposed to Hydraulic Fracturing Flowback and Produced Water.

    PubMed

    He, Yuhe; Folkerts, Erik J; Zhang, Yifeng; Martin, Jonathan W; Alessi, Daniel S; Goss, Greg G

    2017-01-17

    The effects of hydraulic fracturing (HF) flowback and produced water (HF-FPW), a complex saline mixture of injected HF fluids and deep formation water that return to the surface, was examined in rainbow trout (Oncorhynchus mykiss). Exposure to HF-FPWs resulted in significant induction of ethoxyresorufin-O-deethylase (EROD) activity in both liver and gill tissues. Increased lipid peroxidation via oxidative stress was also detected by thiobarbituric acid reactive substances (TBARS) assay. The mRNA expressions of a battery of genes related to biotransformation, oxidative stress, and endocrine disruption were also measured using quantitative real-time polymerase chain reaction (Q-RT-PCR). The increased expression of cyp1a (2.49 ± 0.28-fold), udpgt (2.01 ± 0.31-fold), sod (1.67 ± 0.09-fold), and gpx (1.58 ± 0.10-fold) in raw sample exposure group (7.5%) indicated elevated metabolic enzyme activity, likely through the aryl hydrocarbon receptor pathway, and generation of reactive oxygen species. In addition, the elevated vtg and era2 expression demonstrated endocrine disrupting potential exerted by HF-FPW in rainbow trout. The overall results suggested HF-FPW could cause significant adverse effects on fish, and the organic contents might play the major role in its toxicity. Future studies are needed to help fully determine the toxic mechanism(s) of HF-FPW on freshwater fish, and aid in establishing monitoring, treatment, and remediation protocols for HF-FPW.

  19. Spatial Ecological Processes and Local Factors Predict the Distribution and Abundance of Spawning by Steelhead (Oncorhynchus mykiss) across a Complex Riverscape

    PubMed Central

    Falke, Jeffrey A.; Dunham, Jason B.; Jordan, Christopher E.; McNyset, Kristina M.; Reeves, Gordon H.

    2013-01-01

    Processes that influence habitat selection in landscapes involve the interaction of habitat composition and configuration and are particularly important for species with complex life cycles. We assessed the relative influence of landscape spatial processes and local habitat characteristics on patterns in the distribution and abundance of spawning steelhead (Oncorhynchus mykiss), a threatened salmonid fish, across ∼15,000 stream km in the John Day River basin, Oregon, USA. We used hurdle regression and a multi-model information theoretic approach to identify the relative importance of covariates representing key aspects of the steelhead life cycle (e.g., site access, spawning habitat quality, juvenile survival) at two spatial scales: within 2-km long survey reaches (local sites) and ecological neighborhoods (5 km) surrounding the local sites. Based on Akaike’s Information Criterion, models that included covariates describing ecological neighborhoods provided the best description of the distribution and abundance of steelhead spawning given the data. Among these covariates, our representation of offspring survival (growing-season-degree-days, °C) had the strongest effect size (7x) relative to other predictors. Predictive performances of model-averaged composite and neighborhood-only models were better than a site-only model based on both occurrence (percentage of sites correctly classified = 0.80±0.03 SD, 0.78±0.02 vs. 0.62±0.05, respectively) and counts (root mean square error = 3.37, 3.93 vs. 5.57, respectively). The importance of both temperature and stream flow for steelhead spawning suggest this species may be highly sensitive to impacts of land and water uses, and to projected climate impacts in the region and that landscape context, complementation, and connectivity will drive how this species responds to future environments. PMID:24265762

  20. Increasing levels of dietary crystalline methionine affect plasma methionine profiles, ammonia excretion, and the expression of genes related to the hepatic intermediary metabolism in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Rolland, Marine; Skov, Peter V; Larsen, Bodil K; Holm, Jørgen; Gómez-Requeni, Pedro; Dalsgaard, Johanne

    2016-08-01

    Strictly carnivorous fish with high requirements for dietary protein, such as rainbow trout (Oncorhynchus mykiss) are interesting models for studying the role of amino acids as key regulators of intermediary metabolism. Methionine is an essential amino acid for rainbow trout, and works as a signalling factor in different metabolic pathways. The study investigated the effect of increasing dietary methionine intake on the intermediary metabolism in the liver of juvenile rainbow trout. For this purpose, five diets were formulated with increasing methionine levels from 0.60 to 1.29% dry matter. The diets were fed in excess for six weeks before three sampling campaigns carried out successively to elucidate (i) the hepatic expression of selected genes involved in lipid, glucose and amino acid metabolism; (ii) the postprandial ammonia excretion; and (iii) the postprandial plasma methionine concentrations. The transcript levels of enzymes involved in lipid metabolism (fatty acid synthase, glucose 6 phosphate dehydrogenase and carnitine palmitoyl transferase 1 a), gluconeogenesis (fructose-1,6-biphosphatase) and amino acid catabolism (alanine amino transferase and glutamate dehydrogenase) were significantly affected by the increase in dietary methionine. Changes in gene expression reflected to some extent the decrease in ammonia excretion (P=0.022) and in the hepatosomatic index (HSI; P<0.001) when dietary methionine increased. Postprandial plasma methionine concentrations correlated positively with the dietary level (P<0.001) at the different sampling points. The study shows that the expression of several genes related to the hepatic intermediary metabolism in rainbow trout responded in a dose-dependent manner to increasing levels of dietary methionine.

  1. Mx mRNA expression and RFLP analysis of rainbow trout Oncorhynchus mykiss genetic crosses selected for susceptibility or resistance to IHNV.

    PubMed

    Trobridge, G D; LaPatra, S E; Kim, C H; Leong, J C

    2000-02-24

    Three interferon-inducible Mx genes have been identified in rainbow trout Oncorhynchus mykiss and their roles in virus resistance have yet to be determined. In mice, expression of the Mx1 protein is associated with resistance to influenza virus. We report a study to determine whether there was a correlation between the expression of Mx in rainbow trout and resistance to a fish rhabdovirus, infectious hematopoietic necrosis virus (IHNV). A comparison of Mx mRNA expression was made between different families of cultured rainbow trout selected for resistance or for susceptibility to IHNV. A trout-specific Mx cDNA gene probe was used to determine whether there was a correlation between Mx mRNA expression and resistance to the lethal effects of IHNV infection. Approximately 99% of trout injected with a highly virulent strain of the fish rhabdovirus, IHNV, were able to express full length Mx mRNA at 48 h post infection. This is markedly different from the expression of truncated, non-functional Mx mRNA found in most laboratory strains of mice, and the ability of only 25% of wild mice to express functional Mx protein. A restriction fragment length polymorphism (RFLP) assay was developed to compare the Mx locus between individual fish and between rainbow trout genetic crosses bred for IHNV resistance or susceptibility. The assay was able to discriminate 7 distinct RFLP patterns in the rainbow trout crosses. One cross was identified that showed a correlation between homozygosity at the Mx locus and greater susceptibility to IHN-caused mortality.

  2. Bioaccumulation of dietary 2,2{prime},4,4{prime},5,5{prime}-hexachlorobiphenyl and induction of hepatic arylhydrocarbon hydroxylase in rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Costa, E.G. da; Curtis, L.R.

    1995-10-01

    Juvenile rainbow trout (Oncorhynchus mykiss) were fed either 5 or 20 {micro}g, 2,2{prime},4,4{prime},5,5{prime}-hexachlorobiphenyl (245-HxCB)/g diet (wet wt.) for 4,8, or 12 weeks. Hepatic xenobiotic-metabolizing enzyme activities and dietary 245-HxCB accumulation in liver, muscle, and remaining carcass were determined. Liver-to-body weight ratios were not altered by either of the two 245-HxCB concentrations. Relative growth rate increased with time but was not altered by 245-HxCB concentration. Bioaccumulation of 245-HxCB was dose and time dependent in all tissues without reaching apparent stayed state. Hepatic arylhydrocarbon hydroxylase (AHH) activities increased with 245-HxCB dose and with time. Ethoxyresorufin-O-deethylase (EROD) activities also increased in fish fed 20 {micro}g 245-HxCB/g diet. No 245-HxCB-induced changes in uridine diphosphoglucuronosyl transferase (UDP-DT) or NADPH-dytochrome-c reductase (NCCR) activities were determined. High-resolution GC-MS analysis of the 245-HxCB standard revealed trace (0.4--0.5%) contamination by two mono-ortho pentachlorobiphenyls (PnCBs): 2,3,3{prime},4,4{prime}-PnCB and 2,3,4,4{prime},5-PnCB. Total liver accumulation of these contaminants was inversely related with corresponding EROD and AHH activities and estimated to contribute minimally to their induction. Results from this study suggested that long-term dietary 245-HxCB exposure induced cytochrome P4501A activities in rainbow trout liver.

  3. Cloning and expression analysis of two ROR-γ homologues (ROR-γa1 and ROR-γa2) in rainbow trout Oncorhynchus mykiss.

    PubMed

    Monte, Milena M; Wang, Tiehui; Costa, Maria M; Harun, Nor Omaima; Secombes, Chris J

    2012-08-01

    This paper describes the cloning and characterisation of two retinoid-related orphan receptor (ROR)-γ homologues (ROR-γa1 and -γa2) in rainbow trout (Oncorhynchus mykiss). The coding region predicted for both homologues consists of 1410 base pairs (bp), which translate into two 469 amino acid (aa) proteins. The trout ROR-γs revealed a high conservation of both DNA- and ligand-binding domains (functional regions of the nuclear receptor family), and shared a high homology to mammalian ROR-γt. A phylogenetic tree containing ROR family members confirmed that both trout homologues clustered within the ROR-γ group. Both results suggested that these molecules are likely to be ROR-γ homologues, more similar to the mammalian splice variant ROR-γt than the full length ROR-γ. Expression analysis of tissues obtained from healthy fish revealed highest constitutive expression of trout ROR-γ in muscle, followed by the brain, heart and skin. This suggests that these genes may play an important role in such tissues. In vitro studies, using trout cell lines, demonstrated that ROR-γ is induced significantly by LPS and down-regulated by the presence of PolyI:C and recombinant interferon (IFN)-γ. Moreover, analysis of this gene in head kidney macrophages and mixed primary leucocyte cultures indicated that differences were apparent between the different cell types/sources used, indicating that its expression may be cell-type dependent. Additional studies to investigate the regulation of this gene in vivo demonstrated that its expression was significantly higher in vaccinated vs unvaccinated fish following bacterial (Yersinia ruckeri) challenge but it was down-regulated after a viral (VHSV) infection. This suggests a potential role of trout ROR-γ, a putative T(H)17 transcription factor, in protection against extracellular bacteria.

  4. Acute toxicity of three fire-retardant and two fire-suppressant foam formulations to the early life stages of rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Gaikowski, Mark P.; Hamilton, Steven J.; Buhl, Kevin J.; McDonald, Susan F.; Summers, Cliff H.; Linder, G.; Krest, S.; Sparling, D.; Little, E.

    1996-01-01

    Laboratory studies were conducted with five early life stages of rainbow trout, Oncorhynchus mykiss, to determine the acute toxicities of five fire-fighting chemical formulations in standardized soft and hard water. Eyed egg, embryo–larvae, swim-up fry, and 60- and 90-d posthatch juveniles were exposed to three fire retardants (Fire-Trol LCG-R, Fire-Trol GTS-R, and Phos-Chek D75-F) and two fire-suppressant foams (Phos-Chek WD-881 and Silv-Ex). Swim-up fry were generally the most sensitive life stage, whereas the eyed-egg was the least sensitive. Toxicity of fire-fighting formulations was greater in hard water than in soft water for all life stages tested with Fire-Trol GTS-R and Silv-Ex and for 90-d-old juveniles tested with Fire-Trol LCG-R. The fire-suppressant foams were more toxic than the fire retardants. The 96-h median lethal concentrations (LC50s) were ranked from the most toxic to the least toxic formulation as follows (ranges are the lowest and highest 96-h LC50 calculated for each formulation): Phos-Chek WD-881 (11–44 mg/L), Silv-Ex (11–78 mg/L), Phos-Chek D75-F (218–>3,600 mg/L), Fire-Trol GTS-R (207–>6,000 mg/L), and Fire-Trol LCG-R (872–>10,000 mg/L). Toxicity values suggest that accidental entry of fire-fighting chemicals into aquatic environments could adversely affect fish populations.

  5. Comparative accumulation efficiency of [sup 109]cadmium from natural food (Hyalella azteca) and artificial diet by rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Harrison, S.E. ); Curtis, P.J. )

    1992-11-01

    Bioaccumulation models have been proposed to predict the accumulation of chemicals throughout aquatic food-chains. The efficiency with which organisms at each trophic level absorb these substances from their diet is an important component of such models. Metal absorption from food is typically estimated by applying metal salts surficially to commercial fish diets. However, this method may not provide an accurate estimate of in situ accumulation because the efficiency of absorption of metals applied surficially to commercial diets may differ from that of metals absorbed through the food chain. For example, both sunfish (Lepomis gibbosus) and plaice (Pleuronectes platessa) accumulated [sup 65]zinc applied surficially to foods more efficiently than [sup 65]zinc incorporated into live foods. There have apparently been no similar comparisons made for cadmium using fish. Furthermore, few studies have fitted data to exponential equations to provide estimates of the absorption efficiency coefficient (E) and the excretion coefficient (k[sub 2]) for cadmium. We report here the results of direct comparisons of cadmium absorption from commercial trout diet surficially-contaminated with [sup 109]Cd and from natural food (the amphipod Hyalella azteca) cultured in [sup 109]Cd-contaminated microcosms. We calculated absorption efficiency and excretion coefficients for cadmium by monitoring [sup 109]Cd accumulation and excretion in rainbow trout fingerlings fed on the two diets. 19 refs., 2 figs., 1 tab.

  6. Selected techniques in radioecology: Model development and comparison for internal dosimetry of rainbow trout (Oncorhynchus mykiss) and feasibiltiy assessment of reflectance spectroscopy use as a tool in phytoremediation

    NASA Astrophysics Data System (ADS)

    Martinez, Nicole

    The first study in Part 1 examines the effects of lake tropic structure on the uptake of iodine-131 (131I) in rainbow trout (Oncorhynchus mykiss) and considers a simple computational model for the estimation of resulting radiation dose. Iodine-131 is a major component of the atmospheric releases following reactor accidents, and the passage of 131I through food chains from grass to human thyroids has been extensively studied. By comparison, the fate and effects of 131I deposition onto lakes and other aquatic systems has been less studied. In this study we reanalyze 1960s data from experimental releases of 131I into two small lakes and compare the effects of differences in lake trophic structures on 131I accumulation in fish. The largest concentrations in the thyroids of trout may occur from 8 to 32 days post initial release. DCFs for trout for whole body as well as thyroid were computed using Monte Carlo modeling with an anatomically-appropriate model of trout thyroid structure. Activity concentration data was used in conjunction with the calculated DCFs to estimate dose rates and ultimately determine cumulative radiation dose (Gy) to the thyroids after 32 days. The estimated cumulative thyroid doses at 32 days post-release ranged from 6 mGy to 18 mGy per 1 Bq mL-1 of initial 131I in the water, depending upon fish size. The subsequent studies in Part 1 seek to develop and compare different, increasingly detailed anatomical phantoms for O. mykiss for the purpose of estimating organ radiation dose and dose rates from 131I uptake and from molybdenum-99 (99Mo) uptake. Model comparison and refinement is important to the process of determining both dose rates and dose effects, and we develop and compare three models for O. mykiss: a simplistic geometry considering a single organ, a more specific geometry employing anatomically relevant organ size and location, and voxel reconstruction of internal anatomy obtained from CT imaging (referred to as CSUTROUT). Dose Conversion

  7. Cellular transport of microcystin-LR in rainbow trout (Oncorhynchus mykiss) across the intestinal wall: possible involvement of multidrug resistance-associated proteins.

    PubMed

    Bieczynski, Flavia; De Anna, Julieta S; Pirez, Macarena; Brena, Beatríz M; Villanueva, Silvina S M; Luquet, Carlos M

    2014-09-01

    We studied Abcc mediated-transport in middle and posterior intestine of the rainbow trout, Oncorhynchus mykiss. Luminal and serosal transport were evaluated in everted and non-everted intestinal sacs, respectively, incubated with 1-chloro-2,4-dinitrobenzene (CDNB; 200 μM). CDNB enters the cells and is conjugated with glutathione via glutathione S-transferase (GST) to form 2,4-dinitrophenyl-S-glutathione (DNP-SG), a known Abcc substrate. DNP-SG concentration in the bath was recorded every 10 min, in order to calculate the mass-specific transport rate. For evaluating the possible involvement of Abcc proteins in microcystin-LR (MCLR) transport, 1.135 μM MCLR was added to the bath or inside the sacs, in everted or non-everted preparations, respectively. Both luminal and serosal DNP-SG efflux were significantly inhibited by MCLR. A concentration-response curve obtained using strips from middle intestine yielded an IC50 value of 1.33 μM MCLR. The Abcc inhibitor, MK571 produced concentration-dependent inhibition of DNP-SG similar to that produced by MCLR. Since competition of MCLR and CDNB as GST substrates could bias the DNP-SG transport results, we evaluated the effects of MCLR on calcein efflux, which does not depend on GST activity. We applied the non-fluorescent, cell-permeant compound calcein-AM (0.25 μM) to middle intestinal strips and recorded the efflux of its hydrolysis product, the fluorescent Abcc substrate calcein. 2.27 μM MCLR and 3 μM MK571 inhibited calcein efflux (17.39 and 20.2%, respectively). Finally, MCLR interaction with Abcc transporters was evaluated by measuring its toxic intracellular effects. Middle intestinal segments were incubated in saline solution with 1.135 μM MCLR (MC1), 2.27 μM MCLR (MC2), 3 μM MK571 (MK) or 1.135 μM MCLR+3 μM MK571 (MC1/MK). After 1h, GSH concentration, protein phosphatase 1 and 2A (PP1, PP2A) and GST activities were measured in each segment. MC1did not produce significant effect while MC1/MK and MC2

  8. Yersinia ruckeri Isolates Recovered from Diseased Atlantic Salmon (Salmo salar) in Scotland Are More Diverse than Those from Rainbow Trout (Oncorhynchus mykiss) and Represent Distinct Subpopulations

    PubMed Central

    Ormsby, Michael J.; Caws, Thomas; Burchmore, Richard; Wallis, Tim; Verner-Jeffreys, David W.

    2016-01-01

    ABSTRACT Yersinia ruckeri is the etiological agent of enteric redmouth (ERM) disease of farmed salmonids. Enteric redmouth disease is traditionally associated with rainbow trout (Oncorhynchus mykiss, Walbaum), but its incidence in Atlantic salmon (Salmo salar) is increasing. Yersinia ruckeri isolates recovered from diseased Atlantic salmon have been poorly characterized, and very little is known about the relationship of the isolates associated with these two species. Phenotypic approaches were used to characterize 109 Y. ruckeri isolates recovered over a 14-year period from infected Atlantic salmon in Scotland; 26 isolates from infected rainbow trout were also characterized. Biotyping, serotyping, and comparison of outer membrane protein profiles identified 19 Y. ruckeri clones associated with Atlantic salmon but only five associated with rainbow trout; none of the Atlantic salmon clones occurred in rainbow trout and vice versa. These findings suggest that distinct subpopulations of Y. ruckeri are associated with each species. A new O serotype (designated O8) was identified in 56 biotype 1 Atlantic salmon isolates and was the most common serotype identified from 2006 to 2011 and in 2014, suggesting an increased prevalence during the time period sampled. Rainbow trout isolates were represented almost exclusively by the same biotype 2, serotype O1 clone that has been responsible for the majority of ERM outbreaks in this species within the United Kingdom since the 1980s. However, the identification of two biotype 2, serotype O8 isolates in rainbow trout suggests that vaccines containing serotypes O1 and O8 should be evaluated in both rainbow trout and Atlantic salmon for application in Scotland. IMPORTANCE Vaccination plays an important role in protecting Atlantic salmon against the bacterial pathogen Yersinia ruckeri, but, in recent years, there has been an increasing incidence of vaccine breakdown in salmon. This is largely because current vaccines are aimed at

  9. Acute sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to copper, cadmium, or zinc in water-only laboratory exposures.

    PubMed

    Calfee, Robin D; Little, Edward E; Puglis, Holly J; Scott, Erinn; Brumbaugh, William G; Mebane, Christopher A

    2014-10-01

    The acute toxicity of cadmium, copper, and zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) were determined for 7 developmental life stages in flow-through water-only exposures. Metal toxicity varied by species and by life stage. Rainbow trout were more sensitive to cadmium than white sturgeon across all life stages, with median effect concentrations (hardness-normalized EC50s) ranging from 1.47 µg Cd/L to 2.62 µg Cd/L with sensitivity remaining consistent during later stages of development. Rainbow trout at 46 d posthatch (dph) ranked at the 2nd percentile of a compiled database for Cd species sensitivity distribution with an EC50 of 1.46 µg Cd/L and 72 dph sturgeon ranked at the 19th percentile (EC50 of 3.02 µg Cd/L). White sturgeon were more sensitive to copper than rainbow trout in 5 of the 7 life stages tested with biotic ligand model (BLM)-normalized EC50s ranging from 1.51 µg Cu/L to 21.9 µg Cu/L. In turn, rainbow trout at 74 dph and 95 dph were more sensitive to copper than white sturgeon at 72 dph and 89 dph, indicating sturgeon become more tolerant in older life stages, whereas older trout become more sensitive to copper exposure. White sturgeon at 2 dph, 16 dph, and 30 dph ranked in the lower percentiles of a compiled database for copper species sensitivity distribution, ranking at the 3rd (2 dph), 5th (16 dph), and 10th (30 dph) percentiles. White sturgeon were more sensitive to zinc than rainbow trout for 1 out of 7 life stages tested (2 dph with an biotic ligand model-normalized EC50 of 209 µg Zn/L) and ranked in the 1st percentile of a compiled database for zinc species sensitivity distribution.

  10. The expression of insulin and insulin receptor mRNAs is regulated by nutritional state and glucose in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Caruso, Michael A; Sheridan, Mark A

    2012-01-15

    Many species of fish, including rainbow trout, possess multiple INS- and IR-encoding mRNAs. In this study, rainbow trout (Oncorhynchus mykiss) were used as a model to study the regulation of INS (INS1, INS2) and IR (IR1, IR2, IR3, and IR4) mRNA expression by nutritional state and glucose. In the nutritional state study, fish were either fed continuously, fasted (4 or 6 weeks), or fasted 4 weeks, then refed for 2 weeks. Nutritional state regulated INS and IR mRNA expression in a subtype- and tissue-specific manner. A 4-week fast reduced INS1 expression in endocrine pancreas (Brockmann body) and of INS1 and INS2 in brain, whereas a 6-week fast reduced the expression of both INS1 and INS2 in pancreas but only of INS1 in brain. Refeeding only restored INS2 levels in pancreas. In adipose tissue, by contrast, a 4-week fast increased INS1 expression, and a 6-week fast increased the expression of both INS1 and INS2. Nutritional state also modulated the pattern of IR mRNA expression. Fasting for 4 weeks resulted in no significant change in IR expression. Prolonged fasting (6 weeks) increased the expression of IR4 mRNA in the pancreas, adipose tissue, cardiac muscle, and gill; however, fasting decreased expression of IR3 mRNA in liver. Refeeding restored fasting-associated increases in IR4 expression in pancreas, adipose tissue, cardiac muscle, and gill, but had no effect on the fasting-associated decrease in IR3 expression in liver. Glucose differentially regulated the expression of INS and IR mRNAs in Brockmann bodies and liver pieces incubated in vitro, respectively. Low glucose (1 mM) reduced pancreatic expression of both INS1 and INS2 mRNAs compared to levels observed at 4 or 10 mM glucose. In the liver, IR1 and IR2 mRNA expression was insensitive to glucose concentration, whereas expression of IR3 and IR4 was attenuated at 1 and 10 mM compared to 4 mM glucose. These findings indicate that the pattern of INS and IR expression in selected tissues is regulated by

  11. The effects of exogenous extracellular carbonic anhydrase on CO2 excretion in rainbow trout (Oncorhynchus mykiss): role of plasma buffering capacity.

    PubMed

    Desforges, P R; Gilmour, K M; Perry, S F

    2001-08-01

    The buffering capacity (beta) of rainbow trout (Oncorhynchus mykiss) plasma was manipulated prior to intravascular injection of bovine carbonic anhydrase to test the idea that proton (H+) availability limits the catalysed dehydration of HCO3- within the extracellular compartment. An extracorporeal blood shunt was employed to continuously monitor blood gases in vivo in fish exhibiting normal plasma beta (-3.9+/-0.3 mmol 1(-1) pH unit(-1)), and in fish with experimentally (using N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid]) elevated plasma beta (-12.1+/-1.1 mmol 1(-1) pH unit(-1)). An injection of 5 mg kg(-1) carbonic anhydrase equally reduced (after 90 min) the arterial partial pressure of CO2 in trout with regular (-0.23+/-0.05 Torr) or high (-0.20+/-0.05 Torr) plasma beta; saline injection was without effect. Because ventilation and venous blood gases were unaffected by carbonic anhydrase, the effect of extracellular carbonic anhydrase in lowering arterial partial pressure of CO2 was likely caused solely by a specific enhancement of CO2 excretion owing to acceleration of HCO3- dehydration within the plasma. The lowering of arterial partial pressure of CO2 in trout after injection of exogenous carbonic anhydrase provides the first in vivo evidence that the accessibility of plasma HCO3- to red blood cell carbonic anhydrase constrains CO2 excretion under resting conditions. Because the velocity of red blood cell Cl-/HCO3- exchange governs HCO3- accessibility to red blood cell carbonic anhydrase, the present study also provides evidence that CO2 excretion at rest is limited by the relatively slow rate of Cl-/HCO3- exchange. The effect of carbonic anhydrase in lowering arterial partial pressure of CO2 was unrelated to plasma buffering capacity. While these data could suggest that H+ availability does not limit extracellular HCO3- dehydration in vivo at resting rates of CO2 excretion, it is more likely that the degree to which plasma beta was elevated in the

  12. The effects of endothelin-1 on the cardiorespiratory physiology of the freshwater trout (Oncorhynchus mykiss) and the marine dogfish (Squalus acanthias).

    PubMed

    Perry, S F; Montpetit, C J; McKendry, J; Desforges, P R; Gilmour, K M; Wood, C M; Olson, K R

    2001-11-01

    The aim of the present study was to evaluate the effects of endothelin-l-elicited cardiovascular events on respiratory gas transfer in the freshwater rainbow trout (Oncorhynchus mykiss) and the marine dogfish (Squalus acanthias). In both species, endothelin-1 (666 pmol kg(-1)) caused a rapid (within 4 min) reduction (ca. 30-50 mmHg) in arterial blood partial pressure of O2. The effects of endothelin-1 on arterial blood partial pressure of CO2 were not synchronised with the changes in O2 partial pressure and the responses were markedly different in trout and dogfish. In trout, arterial CO2 partial pressure was increased transiently by approximately 1.0 mmHg but the onset of the response was delayed and occurred 12 min after endothelin-1 injection. In contrast, CO2 partial pressure remained more-or-less constant in dogfish after injection of endothelin-1 and was increased only slightly (approximately 0.1 mmHg) after 60 min. Pre-treatment of trout with bovine carbonic anhydrase (5 mg ml(-1)) eliminated the increase in CO2 partial pressure that was normally observed after endothelin-1 injection. In both species, endothelin-1 injection caused a decrease in arterial blood pH that mirrored the changes in CO2 partial pressure. Endothelin-1 injection was associated with transient (trout) or persistent (dogfish) hyperventilation as indicated by pronounced increases in breathing frequency and amplitude. In trout, arterial blood pressure remained constant or was decreased slightly and was accompanied by a transient increase in systemic resistance, and a temporary reduction in cardiac output. The decrease in cardiac output was caused solely by a reduction in cardiac frequency; cardiac stroke volume was unaffected. In dogfish, arterial blood pressure was lowered by approximately 10 mmHg at 6-10 min after endothelin-1 injection but then was rapidly restored to pre-injection levels. The decrease in arterial blood pressure reflected an increase in branchial vascular resistance (as

  13. Chromosome rearrangements, recombination suppression, and limited segregation distortion in hybrids between Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) and rainbow trout (O. mykiss)

    PubMed Central

    2013-01-01

    Background Introgressive hybridization is an important evolutionary process that can lead to the creation of novel genome structures and thus potentially new genetic variation for selection to act upon. On the other hand, hybridization with introduced species can threaten native species, such as cutthroat trout (Oncorhynchus clarkii) following the introduction of rainbow trout (O. mykiss). Neither the evolutionary consequences nor conservation implications of rainbow trout introgression in cutthroat trout is well understood. Therefore, we generated a genetic linkage map for rainbow-Yellowstone cutthroat trout (O. clarkii bouvieri) hybrids to evaluate genome processes that may help explain how introgression affects hybrid genome evolution. Results The hybrid map closely aligned with the rainbow trout map (a cutthroat trout map does not exist), sharing all but one linkage group. This linkage group (RYHyb20) represented a fusion between an acrocentric (Omy28) and a metacentric chromosome (Omy20) in rainbow trout. Additional mapping in Yellowstone cutthroat trout indicated the two rainbow trout homologues were fused in the Yellowstone genome. Variation in the number of hybrid linkage groups (28 or 29) likely depended on a Robertsonian rearrangement polymorphism within the rainbow trout stock. Comparison between the female-merged F1 map and a female consensus rainbow trout map revealed that introgression suppressed recombination across large genomic regions in 5 hybrid linkage groups. Two of these linkage groups (RYHyb20 and RYHyb25_29) contained confirmed chromosome rearrangements between rainbow and Yellowstone cutthroat trout indicating that rearrangements may suppress recombination. The frequency of allelic and genotypic segregation distortion varied among parents and families, suggesting few incompatibilities exist between rainbow and Yellowstone cutthroat trout genomes. Conclusions Chromosome rearrangements suppressed recombination in the hybrids. This result

  14. Acute sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to copper, cadmium, or zinc in water-only laboratory exposures

    USGS Publications Warehouse

    Calfee, Robin D.; Little, Edward E.; Puglis, Holly J.; Scott, Erinn L.; Brumbaugh, William G.; Mebane, Christopher A.

    2014-01-01

    The acute toxicity of cadmium, copper, and zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) were determined for 7 developmental life stages in flow-through water-only exposures. Metal toxicity varied by species and by life stage. Rainbow trout were more sensitive to cadmium than white sturgeon across all life stages, with median effect concentrations (hardness-normalized EC50s) ranging from 1.47 µg Cd/L to 2.62 µg Cd/L with sensitivity remaining consistent during later stages of development. Rainbow trout at 46 d posthatch (dph) ranked at the 2nd percentile of a compiled database for Cd species sensitivity distribution with an EC50 of 1.46 µg Cd/L and 72 dph sturgeon ranked at the 19th percentile (EC50 of 3.02 µg Cd/L). White sturgeon were more sensitive to copper than rainbow trout in 5 of the 7 life stages tested with biotic ligand model (BLM)-normalized EC50s ranging from 1.51 µg Cu/L to 21.9 µg Cu/L. In turn, rainbow trout at 74 dph and 95 dph were more sensitive to copper than white sturgeon at 72 dph and 89 dph, indicating sturgeon become more tolerant in older life stages, whereas older trout become more sensitive to copper exposure. White sturgeon at 2 dph, 16 dph, and 30 dph ranked in the lower percentiles of a compiled database for copper species sensitivity distribution, ranking at the 3rd (2 dph), 5th (16 dph), and 10th (30 dph) percentiles. White sturgeon were more sensitive to zinc than rainbow trout for 1 out of 7 life stages tested (2 dph with an biotic ligand model–normalized EC50 of 209 µg Zn/L) and ranked in the 1st percentile of a compiled database for zinc species sensitivity distribution.

  15. Heat shock protein (Hsp70) induced by a mild heat shock slightly moderates plasma osmolarity increases upon salinity transfer in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Niu, C J; Rummer, J L; Brauner, C J; Schulte, P M

    2008-11-01

    We have investigated whether mild heat shock, and resulting Hsp70 expression, can confer cross-protection against the stress associated with transfer from freshwater (FW) to seawater (SW) in juvenile rainbow trout (Oncorhynchus mykiss). In experimental Series I, juvenile trout reared in FW were transferred from 13.5 degrees C to 25.5 degrees C in FW, held for 2 h, returned to 13.5 degrees C for 12 h, and then transferred to 32 ppt SW at 13.5 degrees C. Branchial Hsp70 increased approximately 10-fold in the heat-shocked fish relative to the control by the end of recovery and remained high 2, 8, and 24 h post-salinity transfer. However, no clear differences could be detected in blood parameters (blood hemoglobin, hematocrit, MCHC, plasma Na(+) and plasma osmolarity) or muscle water content between heat-shocked and sham-shocked fish in SW at any sampling interval (0, 2, 8, 24, 48, 120, 240 and 360 h post-SW transfer). In experimental Series II, trout acclimated to 8 degrees C were heat-shocked at 22 degrees C for 2 h, allowed to recover 18 h, and exposed to a more severe salinity transfer (either 36 or 45 ppt) than in Series I. Branchial Hsp70 levels increased approximately 6-fold in heat-shocked fish, but had declined to baseline after 120 h in SW. Plasma osmolarity and chloride increased in both groups upon transfer to 36 ppt; however, the increase was significantly less in heat-shocked fish when compared to the increase observed in sham-shocked fish at 24 h. No significant differences could be detected in branchial Na(+)/K(+)-ATPase activity or Na(+)/K(+)-ATPase alpha1a and alpha1b mRNA expression between the two groups. Our data indicate that a mild temperature shock has only modest effects on the ability of rainbow trout to resist osmotic stress during FW to SW transfer.

  16. Temporal Genetic Variance and Propagule-Driven Genetic Structure Characterize Naturalized Rainbow Trout (Oncorhynchus mykiss) from a Patagonian Lake Impacted by Trout Farming

    PubMed Central

    Seeb, Lisa W.; Seeb, James E.; Arismendi, Ivan; Hernández, Cristián E.; Gajardo, Gonzalo; Galleguillos, Ricardo; Cádiz, Maria I.; Musleh, Selim S.

    2015-01-01

    Knowledge about the genetic underpinnings of invasions—a theme addressed by invasion genetics as a discipline—is still scarce amid well documented ecological impacts of non-native species on ecosystems of Patagonia in South America. One of the most invasive species in Patagonia’s freshwater systems and elsewhere is rainbow trout (Oncorhynchus mykiss). This species was introduced to Chile during the early twentieth century for stocking and promoting recreational fishing; during the late twentieth century was reintroduced for farming purposes and is now naturalized. We used population- and individual-based inference from single nucleotide polymorphisms (SNPs) to illuminate three objectives related to the establishment and naturalization of Rainbow Trout in Lake Llanquihue. This lake has been intensively used for trout farming during the last three decades. Our results emanate from samples collected from five inlet streams over two seasons, winter and spring. First, we found that significant intra- population (temporal) genetic variance was greater than inter-population (spatial) genetic variance, downplaying the importance of spatial divergence during the process of naturalization. Allele frequency differences between cohorts, consistent with variation in fish length between spring and winter collections, might explain temporal genetic differences. Second, individual-based Bayesian clustering suggested that genetic structure within Lake Llanquihue was largely driven by putative farm propagules found at one single stream during spring, but not in winter. This suggests that farm broodstock might migrate upstream to breed during spring at that particular stream. It is unclear whether interbreeding has occurred between “pure” naturalized and farm trout in this and other streams. Third, estimates of the annual number of breeders (Nb) were below 73 in half of the collections, suggestive of genetically small and recently founded populations that might experience

  17. Food selection, growth and physiology in relation to dietary sodium chloride content in rainbow trout (Oncorhynchus mykiss) under chronic waterborne Cu exposure.

    PubMed

    Niyogi, S; Kamunde, C N; Wood, C M

    2006-05-01

    Waterborne Cu is toxic to Na(+) and Cl(-) regulation in freshwater fish, and Cu is taken up, at least in part, via the Na(+)-transport pathway in the gills. Therefore, we hypothesized that freshwater fish may mitigate the toxic effects of waterborne Cu by selecting a NaCl-enriched diet over a normal diet. We tested this hypothesis in juvenile rainbow trout (Oncorhynchus mykiss) by offering them the choice between NaCl-enriched (1.9 mmol g(-1)Na(+)) and normal (0.2 mmol g(-1)Na(+)) diets under a chronic waterborne Cu exposure of 55 microg L(-1) for a period of 28 days. Contrary to expectation, trout exhibited a preference for NaCl-enriched diet under control conditions, while exposure to chronic waterborne Cu severely disrupted their normal feeding pattern with an accompanying loss of preference for the NaCl-enriched diet. Waterborne Cu exposure also severely affected appetite and growth. Both appetite and growth gradually recovered with time, but remained significantly impaired relative to Cu-unexposed fish until the end of the exposure. Waterborne Cu exposure also significantly increased Cu accumulations in target organs (gill, liver, and gut), plasma and whole body. However, Cu accumulation decreased substantially towards the end of the exposure in target organs and whole body as well as in plasma in Cu-exposed fish with dietary choice relative to Cu-exposed fish with normal diet. These adjustments were concurrent with the gradual recovery of appetite, which also led to increased ingestion of the NaCl-enriched diet. Interestingly, this elevated dietary uptake of NaCl produced significant stimulation of Na(+) efflux in Cu-exposed fish. Subsequently, it also led to significant elevation of Na(+) levels in target organs and whole body, and restored the decrease of plasma Na(+) and Cl(-) levels in Cu-exposed fish. The NaCl supplemented diet appeared to be beneficial in compensating Na(+) and Cl(-) losses from the body induced by waterborne Cu. Overall, these results

  18. Temporal Genetic Variance and Propagule-Driven Genetic Structure Characterize Naturalized Rainbow Trout (Oncorhynchus mykiss) from a Patagonian Lake Impacted by Trout Farming.

    PubMed

    Benavente, Javiera N; Seeb, Lisa W; Seeb, James E; Arismendi, Ivan; Hernández, Cristián E; Gajardo, Gonzalo; Galleguillos, Ricardo; Cádiz, Maria I; Musleh, Selim S; Gomez-Uchida, Daniel

    2015-01-01

    Knowledge about the genetic underpinnings of invasions-a theme addressed by invasion genetics as a discipline-is still scarce amid well documented ecological impacts of non-native species on ecosystems of Patagonia in South America. One of the most invasive species in Patagonia's freshwater systems and elsewhere is rainbow trout (Oncorhynchus mykiss). This species was introduced to Chile during the early twentieth century for stocking and promoting recreational fishing; during the late twentieth century was reintroduced for farming purposes and is now naturalized. We used population- and individual-based inference from single nucleotide polymorphisms (SNPs) to illuminate three objectives related to the establishment and naturalization of Rainbow Trout in Lake Llanquihue. This lake has been intensively used for trout farming during the last three decades. Our results emanate from samples collected from five inlet streams over two seasons, winter and spring. First, we found that significant intra- population (temporal) genetic variance was greater than inter-population (spatial) genetic variance, downplaying the importance of spatial divergence during the process of naturalization. Allele frequency differences between cohorts, consistent with variation in fish length between spring and winter collections, might explain temporal genetic differences. Second, individual-based Bayesian clustering suggested that genetic structure within Lake Llanquihue was largely driven by putative farm propagules found at one single stream during spring, but not in winter. This suggests that farm broodstock might migrate upstream to breed during spring at that particular stream. It is unclear whether interbreeding has occurred between "pure" naturalized and farm trout in this and other streams. Third, estimates of the annual number of breeders (Nb) were below 73 in half of the collections, suggestive of genetically small and recently founded populations that might experience substantial

  19. Impact of carbon dioxide level, water velocity, and feeding regimen on growth and fillet attributes of cultured rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Mazik, Patricia M.; Mazik, P.M.; Kenney, P.B.; Silverstein, J.T

    2016-01-01

    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 to growth and fillet attributes to find the right balance between input costs and fish performance. Two studies, of 84 and 90 days duration, were conducted to determine the effects of CO2 level, water velocity, and feed frequency on rainbow trout growth, fillet yield, and fillet quality. In the first study, two CO2levels (30 and 49 mg/L) and two velocity levels (0.5 and 2.0 body lengths/s) were tested. In the second study two CO2 levels (30 and 49 mg/L) and two feeding regimens (fed once daily to satiation or three times daily to satiation) were tested. In the first study, after 84 days, fillet weight from high CO2 tanks was 13.5% lower than the fillet weights of fish from low CO2 tanks. Percent fat of fillets was higher in low CO2 fish (P = 0.05) after 84 days and, fish from the low CO2 treatment were larger (P < 0.01). Both studies had similar results in regards to fat content and weight of fillets in response to elevated CO2levels. Velocity had little affect on either whole wet weight or fillet attributes of rainbow trout in this study. Muscle tissue contained more (P < 0.01) fat when fish were fed three times daily (7.3%; day 90) compared to once daily (5.4%; day 90). Also, fish were larger (P < 0.05) when fed 3 times per day (1079 g; day 90) in comparison to only one daily feeding (792 g; day 90). Fish in high feed/high CO2 tanks were larger and had more fillet fat than fish from low feed/low CO2 tanks. To maximize rainbow trout growth at aquaculture facilities, management strategies should attempt to keep CO2 levels below 30 mg/L when cost efficient. However, feeding 2–3 times daily should reduce production losses if CO2 cannot be minimized. The

  20. Examination of isomer specific bioaccumulation parameters and potential in vivo hepatic metabolites of syn- and anti-Dechlorane Plus isomers in juvenile rainbow trout (Oncorhynchus mykiss).

    PubMed

    Tomy, Gregg T; Thomas, Caden R; Zidane, Thane M; Murison, Kathryn E; Pleskach, Kerri; Hare, Jonathon; Arsenault, Gilles; Marvin, Chris H; Sverko, Ed

    2008-08-01

    Juvenile rainbow trout (Oncorhynchus mykiss) were exposed in the laboratory to elevated doses of syn- and anti-isomers of Dechlorane Plus (DP) via their diet for 49 days (uptake phase), followed by 112 days of untreated food (depuration phase) to examine bioaccumulation parameters and possible metabolic products. Three groups of 60 fish were used in the study. Two groups were exposed separately to food fortified with known concentrations of syn- (0.79 +/- 0.03 microg/g, lipid weight) and anti-DP (1.17 +/- 0.12 microg/g, lipid weight) while a third control group was fed unfortified food. Neither isomer reached steady-state after 49 days of exposure. Only the syn-isomer accumulated linearly in the fish (whole-body minus liver) during the dosing phase with a calculated uptake rate constant of 0.045 +/- 0.005 (arithmetic mean +/- 1 x standard error) nmoles per day. A similar uptake rate was also observed for this isomer in the liver. The elimination of both isomers from the whole fish (minus liver) obeyed first order depuration kinetics (syn-: r2 = 0.6427, p < 0.001, anti-: r2 = 0.5350, p < 0.005) with calculated half-lives (t1/2) of 53.3 +/- 13.1 (syn-) and 30.4 +/- 5.7 (anti-) days. Elimination of the isomers from the liver was difficult to interpret because of suspected enterohepatic circulation and redistribution of the isomers in the liver during clearance from other tissues. The biomagnification factor (BMF, determined in whole fish minus liver) of the syn-isomer (5.2) was greater than the anti-isomer (1.9) suggesting that the former isomer is more bioavailable. A suite of metabolites were screened for in the liver including dechlorinated, hydroxylated, methoxylated and methyl sulfone degradates. Even with the purposely high dose used in the uptake phase, none of these degradates could be detected in the extracts. This suggests that if metabolites of DP are detected in fish from aquatic food webs their presence is likely not from in vivo biotransformation of the

  1. Immunomodulatory effects of dietary β-1,3-glucan from Euglena gracilis in rainbow trout (Oncorhynchus mykiss) immersion vaccinated against Yersinia ruckeri.

    PubMed

    Skov, Jakob; Kania, Per Walter; Holten-Andersen, Lars; Fouz, Belén; Buchmann, Kurt

    2012-07-01

    Potential immunostimulatory effects of orally administered β-glucan were investigated in combination with immersion vaccination against enteric redmouth disease caused by Yersinia ruckeri in rainbow trout (Oncorhynchus mykiss). A linear, unbranched and pure (purity ≥98%) β-1,3-glucan (syn. paramylon) from the alga Euglena gracilis was applied at an inclusion level of 1% β-glucan in feed administered at a rate of 1% biomass day(-1) for 84 consecutive days. Fish were vaccinated after two weeks of experimental feeding and bath challenged with live Y. ruckeri six weeks post-vaccination. Blood and head kidney were sampled at day 0, 13 (1 day pre-vaccination), 15, 55, 59 (day 3 post-challenge (p.c.)), 70 and 84. Vaccination induced significantly increased survival p.c., whereas the β-glucan had no effect on survival in either unvaccinated or vaccinated fish. Expression in head kidney of genes related to the acute phase response, i.e. interleukin-1β (IL-1β), serum amyloid A (SAA), precerebellin, and hepcidin, was significantly different in vaccinated fish receiving β-glucan compared to vaccinated controls at day 3 p.c., while no effect of β-glucan was observed among unvaccinated fish. Significant interaction between β-glucan and vaccination was found for the regulation of IL-1β, tumour necrosis factor-α, interferon-γ, SAA, precerebellin and hepcidin p.c. For SAA, the significant effect of β-glucan in vaccinated fish persisted at day 14 p.c. and 28 p.c. The difference in gene expression among vaccinated fish was mainly observed as down-regulations in vaccinated, β-glucan fed fish compared to up-regulations or no regulation in vaccinated controls. Slightly increased levels of plasma lysozyme activity were found in fish (both unvaccinated and vaccinated) receiving β-glucan at day 3 p.c. compared to control fed groups. This was associated with a faster clearance of Y. ruckeri in unvaccinated fish receiving β-glucan. In contrast to the trend towards a

  2. Toxicity of cobalt-complexed cyanide to Oncorhynchus mykiss, Daphnia magna, and Ceriodaphnia dubia: Potentiation by ultraviolet radiation and attenuation by dissolved organic carbon and adaptive UV tolerance

    USGS Publications Warehouse

    Little, Edward E.; Calfee, Robin D.; Theodorakos, Peter M.; Brown, Zoe Ann; Johnson, Craig A.

    2007-01-01

    BackgroundCobalt cyanide complexes often result when ore is treated with cyanide solutions to extract gold and other metals. These have recently been discovered in low but significant concentrations in effluents from gold leach operations. This study was conducted to determine the potential toxicity of cobalt-cyanide complexes to freshwater organisms and the extent to which ultraviolet radiation (UV) potentiates this toxicity. Tests were also conducted to determine if humic acids or if adaptation to UV influenced sensitivity to the cyanide complexes.MethodsRainbow trout (Oncorhynchus mykiss), Daphnia magna, and Ceriodaphnia dubia were exposed to potassium hexacyanocobaltate in the presence and absence of UV radiation, in the presence and absence of humic acids. Cyano-cobalt exposures were also conducted with C. dubia from cultures adapted to elevated UV.ResultsWith an LC50 concentration of 0.38 mg/L, cyanocobalt was over a 1000 times more toxic to rainbow trout in the presence of UV at a low, environmentally relevant irradiance level (4 μW/cm2 as UVB) than exposure to this compound in the absence of UV with an LC50 of 112.9 mg/L. Toxicity was immediately apparent, with mortality occurring within an hour of the onset of exposure at the highest concentration. Fish were unaffected by exposure to UV alone. Weak-acid dissociable cyanide concentrations were observed in irradiated aqueous solutions of cyanocobaltate within hours of UV exposure and persisted in the presence of UV for at least 96 hours, whereas negligible concentrations were observed in the absence of UV. The presence of humic acids significantly diminished cyanocobalt toxicity to D. magna and reduced mortality from UV exposure. Humic acids did not significantly influence survival among C. dubia. C. dubia from UV-adapted populations were less sensitive to metallocyanide compounds than organisms from unadapted populations.ConclusionsThe results indicate that metallocyanide complexes may pose a hazard to

  3. Acute sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to copper, cadmium, or zinc in water-only laboratory exposures

    PubMed Central

    Calfee, Robin D; Little, Edward E; Puglis, Holly J; Scott, Erinn; Brumbaugh, William G; Mebane, Christopher A

    2014-01-01

    The acute toxicity of cadmium, copper, and zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) were determined for 7 developmental life stages in flow-through water-only exposures. Metal toxicity varied by species and by life stage. Rainbow trout were more sensitive to cadmium than white sturgeon across all life stages, with median effect concentrations (hardness-normalized EC50s) ranging from 1.47 µg Cd/L to 2.62 µg Cd/L with sensitivity remaining consistent during later stages of development. Rainbow trout at 46 d posthatch (dph) ranked at the 2nd percentile of a compiled database for Cd species sensitivity distribution with an EC50 of 1.46 µg Cd/L and 72 dph sturgeon ranked at the 19th percentile (EC50 of 3.02 µg Cd/L). White sturgeon were more sensitive to copper than rainbow trout in 5 of the 7 life stages tested with biotic ligand model (BLM)-normalized EC50s ranging from 1.51 µg Cu/L to 21.9 µg Cu/L. In turn, rainbow trout at 74 dph and 95 dph were more sensitive to copper than white sturgeon at 72 dph and 89 dph, indicating sturgeon become more tolerant in older life stages, whereas older trout become more sensitive to copper exposure. White sturgeon at 2 dph, 16 dph, and 30 dph ranked in the lower percentiles of a compiled database for copper species sensitivity distribution, ranking at the 3rd (2 dph), 5th (16 dph), and 10th (30 dph) percentiles. White sturgeon were more sensitive to zinc than rainbow trout for 1 out of 7 life stages tested (2 dph with an biotic ligand model–normalized EC50 of 209 µg Zn/L) and ranked in the 1st percentile of a compiled database for zinc species sensitivity distribution. Environ Toxicol Chem 2014;33:2259–2272. © 2014. The Authors. This article is a US government work and, as such, is in the public domain in the United States of America. Environmental Toxicology and Chemistry published byWiley Periodicals, Inc. on behalf of SETAC. This is an open access article

  4. Venous responses during exercise in rainbow trout, Oncorhynchus mykiss: alpha-adrenergic control and the antihypotensive function of the renin-angiotensin system.

    PubMed

    Sandblom, Erik; Axelsson, Michael; McKenzie, David J

    2006-08-01

    The role of the alpha-adrenergic system in the control of cardiac preload (central venous blood pressure; P(ven)) and venous capacitance during exercise was investigated in rainbow trout (Oncorhynchus mykiss). In addition, the antihypotensive effect of the renin-angiotesin system (RAS) was investigated during exercise after alpha-adrenoceptor blockade. Fish were subjected to a 20-min exercise challenge at 0.66 body lengths s(-1) (BL s(-1)) while P(ven), dorsal aortic blood pressure (P(da)) and relative cardiac output (Q) was recorded continuously. Heart rate (f(H)), cardiac stroke volume (SV) and total systemic resistance (R(sys)) were derived from these variables. The mean circulatory filling pressure (MCFP) was measured at rest and at the end of the exercise challenge, to investigate potential exercise-mediated changes in venous capacitance. The protocol was repeated after alpha-adrenoceptor blockade with prazosin (1 mg kg(-1)M(b)) and again after additional blockade of angiotensin converting enzyme (ACE) with enalapril (1 mg kg(-1)M(b)). In untreated fish, exercise was associated with a rapid (within approx. 1-2 min) and sustained increase in Q and P(ven) associated with a significant increase in MCFP (0.17+/-0.02 kPa at rest to 0.27+/-0.02 kPa at the end of exercise). Prazosin treatment did not block the exercise-mediated increase in MCFP (0.25+/-0.04 kPa to 0.33+/-0.04 kPa at the end of exercise), but delayed the other cardiovascular responses to swimming such that Q and P(ven) did not increase significantly until around 10-13 min of exercise, suggesting that an endogenous humoral control mechanism had been activated. Subsequent enalapril treatment revealed that these delayed responses were in fact due to activation of the RAS, because resting P(da) and R(sys) were decreased further and essentially all cardiovascular changes during exercise were abolished. This study shows that the alpha-adrenergic system normally plays an important role in the control of

  5. Depletion of selected polychlorinated biphenyl, dibenzodioxin, and dibenzofuran congeners in farmed rainbow trout (Oncorhynchus mykiss): a hint for safer fish farming.

    PubMed

    Brambilla, Gianfranco; Dellatte, Elena; Fochi, Igor; Iacovella, Nicola; Miniero, Roberto; di Domenico, Alessandro

    2007-01-01

    Farmed fish can be exposed to persistent organic contaminants--such as polychlorinated biphenyls (PCBs), dibenzodioxins (PCDDs), and dibenzofurans (PCDFs)--via feed, this eventually resulting in accumulation levels of health concern. To study the correlation between feed contamination, chemical accumulation in fish muscle (fillet), and chemical depletion, an all-vegetal base (or blank) feed was prepared and fortified with a commercial PCB mixture (Aroclor 1254) and six PCDD and PCDF congeners (namely, 2,3,7,8-T(4)CDD, 2,3,7,8-T(4)CDF, 1,2,3,7,8-P(5)CDD, 1,2,3,7,8-P(5)CDF, O(8)CDD, and O(8)CDF) to reproduce realistic low, medium, and high contamination levels. After a 1-month exposure, trout (Oncorhynchus mykiss) were fed with the blank feed and sacrificed every 0.5 months over a 3-month period from exposure end; fillet specimens were sampled at each time. In all groups, the average fish weight increased linearly through the observation period. The chemical diminishing patterns observed were due to the combined effect of clearance and growth dilution: for 10 PCB and four PCDD and PCDF congeners, patterns were described with an empirical one-compartment (fish muscle) model. The canonical pseudo-first-order kinetic equation used was also modified into the form C=[C(0)exp(-k(C)t)] (m(W)t+1)(-1) to distinguish between the contributions to depletion from clearance, exp(-k(C)t), and growth dilution, (m(W)t+1)(-1). Most mean clearance half-life (HL(C)) estimates appear to be greater than 4 months, in a number of cases reaching magnitudes well over 10 months or even negative, thus clearly indicating a non-negligible contribution from a second compartment. Based on means and their 95% confidence intervals, the depletion HL(D) estimates of the 14 selected congeners seem to be comprised between 1.2-3.4 and 1.0-5.0 months, respectively: these values, accounting for both clearance and growth dilution, provide an indication of the relevance of a blank feed as a management option

  6. Interactive effects of waterborne metals in binary mixtures on short-term gill-metal binding and ion uptake in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Niyogi, Som; Nadella, Sunita R; Wood, Chris M

    2015-08-01

    Metal binding to fish gills forms the basis of the biotic ligand model (BLM) approach, which has emerged as a useful tool for conducting site-specific water quality assessments for metals. The current BLMs are designed to assess the toxicity of individual metals, and cannot account for the interactive effects of metal mixtures to aquatic organisms including fish. The present study was designed mainly to examine the interactive effects of waterborne metals (Cd, Zn, Cu, Ag, and Ni) in specific binary combinations on short-term (3h) gill-metal binding and essential ion (Ca(2+) and Na(+)) uptake (a physiological index of toxicity) in fish, using juvenile freshwater rainbow trout (Oncorhynchus mykiss) as the model species. We hypothesized that binary mixtures of metals that share a common mode of uptake and toxicity (e.g., Cd and Zn - Ca(2+) antagonists, Cu and Ag - Na(+) antagonists) would reduce the gill binding of each other via competitive interactions and induce less than additive effects on ion transport. In addition, the mixture of metals that have different modes of uptake and toxicity (e.g., Cd and Cu, or Cd and Ni) would not exhibit any interactive effects either on gill-metal binding or ion transport. We found that both Zn and Cu reduced gill-Cd binding and vice versa, however, Ni did not influence gill-Cd binding in fish. Surprisingly, Ag was found to stimulate gill-Cu binding especially at high exposure concentrations, whereas, Cu had no effect on gill-Ag binding. The inhibitory effect of Cd and Zn in mixture on branchial Ca(2+) uptake was significantly greater than that of Cd or Zn alone. Similarly, the inhibitory effect of Cu and Ag in mixture on branchial Na(+) uptake was significantly greater than that of Cu or Ag alone. The inhibitory effects of Cd and Zn mixture on Ca(2+) uptake as well as Cu and Ag mixture on Na(+) uptake were found to follow the principles of simple additivity. In contrast, no significant additive effect on either Ca(2+) or Na

  7. Rainbow trout (Oncorhynchus mykiss) pro-oxidant and genotoxic responses following acute and chronic exposure to the antibiotic oxytetracycline.

    PubMed

    Rodrigues, Sara; Antunes, Sara C; Correia, Alberto T; Nunes, Bruno

    2017-01-01

    Oxytetracycline (OTC), an antibacterial agent, is extensively used in aquaculture practices all over the world, but also in human and veterinary medicines. Because of its intensive use, low rates of absorption by treated animals, inadequate disposal, and low efficiency of removal in wastewater treatment plants, the potential harmful effects on aquatic organisms are of great concern. This work aimed to assess the effects of this antibiotic in rainbow trout, following both acute and chronic exposures. Catalase (CAT), total glutathione peroxidase (GPx), glutathione reductase (GRed) activities and lipid peroxidation (TBARS levels) were quantified as oxidative stress biomarkers, in gills and liver. Genotoxic endpoints, reflecting different types of genetic damage in blood cells, were also determined, by analysis of genetic damage (determination of the genetic damage index, GDI, measured by comet assay) and erythrocytic nuclear abnormalities (ENAs). The obtained results showed a mild pattern of antioxidant response, with modifications in CAT and GPx activities in gills, and lipid peroxidation in liver. These results suggest that despite the occurrence of oxidative effects, a full scenario of oxidative stress is not likely. However, exposure to OTC resulted in the establishment of genotoxic alterations with the induction of DNA strand breaks in blood cells (increase of GDI), and of chromosome breakage and/or segregational abnormalities (increase of ENAs). Considering that the oxidative response was not totally devisable, other mechanisms may be involved in the genotoxic effects reported.

  8. Effect of tricainemethanesulfonate (MS222), clove oil and electro-anaesthesia on respiratory burst activity in whole blood and serum alternative complement response in rainbow trout (Oncorhynchus mykiss), during the narcosis stage.

    PubMed

    Kanani, H Gholipour; Soltani, M; Mirzargar, S S

    2013-02-01

    There is a little available information on the suppressive effect of anaesthesia on immune response in fish, especially electro-anaesthesia. In the present study, two anaesthetics, MS222 (50 ppm), clove oil (25 ppm), and electro-anaesthesia were tested in rainbow trout (Oncorhynchus mykiss) during the narcosis stage in order to observe their effects on the innate immune system. The results showed that electro-anaesthesia reduces light emission in chemiluminescence assay both 1 and 24 h post anaesthesia. Clove oil and MS222 decreased light emission 24 h post anaesthesia. In addition, clove oil, MS222 and electro-anaesthesia had no effect on alternative complement (ACH50) response. From the perspective of aquaculture practice, these data show that the type of anaesthesia should be taken into account to avoid possible immunosuppression in rainbow trout.

  9. Differential gene expression associated with dietary methylmercury (MeHg) exposure in rainbow trout (Oncorhynchus mykiss) and zebrafish (Danio rerio)

    PubMed Central

    Liu, Qing; Basu, Niladri; Goetz, Giles; Jiang, Nan; Hutz, Reinhold J.; Tonellato, Peter J.; Carvan, Michael J.

    2013-01-01

    The objective of this study was to identify and evaluate conserved biomarkers that could be used in most species of teleost fish at most life-stages. We investigated the effects of sublethal methylmercury (MeHg) exposure on developing rainbow trout and zebrafish. Juvenile rainbow trout and young adult zebrafish were fed food with MeHg added at 0, 0.5, 5 and 50 ppm. Atomic absorption spectrometry was applied to measure whole body total Hg levels, and pathologic analysis was performed to identify MeHg-induced toxicity. Fish at six weeks were sampled from each group for microarray analysis using RNA from whole fish. MeHg-exposed trout and zebrafish did not show overt signs of toxicity or pathology, nor were significant differences seen in mortality, length, mass, or condition factor. The accumulation of MeHg in trout and zebrafish exhibited dose- and time-dependent patterns during six weeks, and zebrafish exhibited greater assimilation of total Hg than rainbow trout. The dysregulated genes in MeHg-treated fish have multiple functional annotations, such as iron ion homeostasis, glutathione transferase activity, regulation of muscle contraction, troponin I binding and calcium-dependent protein binding. Genes were selected as biomarker candidates based on their microarray data and their expression was evaluated by QPCR. Unfortunately, these genes are not good consistent biomarkers for both rainbow trout and zebrafish from QPCR evaluation using individual fish. Our conclusion is that biomarker analysis for aquatic toxicant assessment using fish needs to be based on tissue-, sex- and species-specific consideration. PMID:23529582

  10. An in vitro analysis of intestinal ammonia handling in fasted and fed freshwater rainbow trout (Oncorhynchus mykiss).

    PubMed

    Rubino, Julian G; Zimmer, Alex M; Wood, Chris M

    2014-01-01

    face of elevated mucosal ammonia. Thus T amm of the intestinal tissue remained relatively constant regardless of feeding status and exposure to HLA. Ammonia production by the gut may explain up to 18 % of whole-body ammonia excretion in vivo under fasting conditions, and 47 % after feeding, of which more than half originates from endogenous production rather than from absorption from the lumen.

  11. Investigations of Bull Trout (Salvelinus Confluentus), Steelhead Trout (Oncorhynchus Mykiss), and Spring Chinook Salmon (O. Tshawytscha) Interactions in Southeast Washington Streams : 1991 Annual Report.

    SciTech Connect

    Martin, Steven W.

    1992-07-01

    Bull trout (Salvelinus confluentus) are native to many tributaries of the Snake River in southeast Washington. The Washington Department of Wildlife (WDW) and the American Fisheries Society (AFS) have identified bull trout as a species of special concern which means that they may become threatened or endangered by relatively, minor disturbances to their habitat. Steelhead trout/rainbow trout (Oncorhynchus mykiss) and spring chinook salmon (O.tshawytscha) are also native to several tributaries of the Snake river in southeast Washington. These species of migratory fishes are depressed, partially due to the construction of several dams on the lower Snake river. In response to decreased run size, large hatchery program were initiated to produce juvenile steelhead and salmon to supplement repressed tributary stocks, a practice known as supplementation. There is a concern that supplementing streams with artificially high numbers of steelhead and salmon may have an impact on resident bull trout in these streams. Historically, these three species of fish existed together in large numbers, however, the amount of high-quality habitat necessary for reproduction and rearing has been severely reduced in recent years, as compared to historic amounts. The findings of the first year of a two year study aimed at identifying species interactions in southeast Washington streams are presented in this report. Data was collected to assess population dynamics; habitat utilization and preference, feeding habits, fish movement and migration, age, condition, growth, and the spawning requirements of bull trout in each of four streams. A comparison of the indices was then made between the study streams to determine if bull trout differ in the presence of the putative competitor species. Bull trout populations were highest in the Tucannon River (supplemented stream), followed by Mill Creek (unsupplemented stream). Young of the year bull trout utilized riffle and cascade habitat the most in all

  12. Identification, characterization and genetic mapping of TLR7, TLR8a1 and TLR8a2 genes in rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Palti, Yniv; Gahr, Scott A.; Purcell, Maureen K.; Hadidi, Sima; Rexroad, Caird E.; Wiens, Gregory A.

    2010-01-01

    Induction of the innate immune pathways is critical for early anti-viral defense but there is limited understanding of how teleost fish recognize viral molecules and activate these pathways. In mammals, Toll-like receptors (TLR) 7 and 8 bind single-stranded RNA of viral origin and are activated by synthetic anti-viral imidazoquinoline compounds. Herein, we identify and describe the rainbow trout (Oncorhynchus mykiss) TLR7 and TLR8 gene orthologs and their mRNA expression. Two TLR7/8 loci were identified from a rainbow trout bacterial artificial chromosome (BAC) library using DNA fingerprinting and genetic linkage analyses. Direct sequencing of two representative BACs revealed intact omTLR7 and omTLR8a1 open reading frames (ORFs) located on chromosome 3 and a second locus on chromosome 22 that contains an omTLR8a2 ORF and a putative TLR7 pseudogene. We used the omTLR8a1/2 nomenclature for the two trout TLR8 genes as phylogenetic analysis revealed that they and all the other teleost TLR8 genes sequenced to date are similar to the zebrafish TLR8a, but are distinct from the zebrafish TLR8b. The duplicated trout loci exhibit conserved synteny with other fish genomes extending beyond the tandem of TLR7/8 genes. The trout TLR7 and 8a1/2 genes are composed of a single large exon similar to all other described TLR7/8 genes. The omTLR7 ORF is predicted to encode a 1049 amino acid (aa) protein with 84% similarity to the Fugu TLR7 and a conserved pattern of predicted leucine-rich repeats (LRR). The omTLR8a1 and omTLR8a2 are predicted to encode 1035- and 1034-aa proteins, respectively, and have 86% similarity to each other. omTLR8a1 is likely the ortholog of the only Atlantic salmon TLR8 gene described to date as they have 95% aa sequence similarity. The tissue expression profiles of omTLR7, omTLR8a1 and omTLR8a2 in healthy trout were highest in spleen tissue followed by anterior and then posterior kidney tissues. Rainbow trout anterior kidney leukocytes produced elevated

  13. Acute and chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures

    USGS Publications Warehouse

    Ingersoll, Christopher G.; Contributions by Wang, Ning; Calfee, Robin D.; Beahan, Erinn; Brumbaugh, William G.; Dorman, Rebecca A.; Hardesty, Doug K.; Kunz, James L.; Little, Edward E.; Mebane, Christopher A.; Puglis, Holly J.

    2014-01-01

    White sturgeon (Acipenser transmontanus) are experiencing poor recruitment in the trans boundary reach of the upper Columbia River in eastern Washington State. Limited toxicity data indicated that early life stages of white sturgeon are sensitive to metals. In acute 4-day (d) exposures with larval white sturgeon, previous studies have reported that the 4-day median lethal concentrations (LC50) based on biotic ligand model (BLM) normalization for copper were below the U.S. Environmental Protection Agency national recommended acute water-quality criterion. In previously published chronic 66-d exposures starting with newly fertilized eggs of white sturgeon, 20-percent lethal effect concentrations (LC20s) for copper, cadmium, or zinc generally were within a factor of two of the chronic values of the most sensitive fish species in the databases of the U.S. Environmental Protection Agency water-quality criteria (WQC) for the three metals. However, there were some uncertainties in the chronic exposures previously performed with white sturgeon, including (1) low control survival (37 percent), (2) more control fish tested in each replicate compared to other treatments, (3) limited replication of treatments (n=2), (4) lack of reported growth data (such as dry weight), and (5) wide dilution factors for exposure concentrations (6- to 8-fold dilutions). The U.S. Environmental Protection Agency concluded that additional studies are needed to generate more toxicity data to better define lethal and sublethal toxicity thresholds for metals for white sturgeon. The objective of the study was to further evaluate the acute and chronic toxicity of cadmium, copper, lead, or zinc to early life stages of white sturgeon in water-only exposures. Toxicity tests also were performed with commonly tested rainbow trout (Oncorhynchus mykiss) under similar test conditions to determine the relative sensitivity between white sturgeon and rainbow trout to these metals. Toxicity data generated from

  14. Fish Research Project Oregon; Aspects of Life History and Production of Juvenile Oncorhynchus Mykiss in the Grande Ronde River Basin, Northeast Oregon, 1995-1999 Summary Report.

    SciTech Connect

    Van Dyke, Erick S.; Jonnasson, Brian C.; Carmichael, Richard W.

    2001-07-01

    Rotary screw traps, located at four sites in the Grande Ronde River basin, were used to characterize aspects of early life history exhibited by juvenile Onchorhychus mykiss during migration years 1995-99. The Lostine, Catherine Creek and upper Grande Ronde traps captured fish as they migrated out of spawning areas into valley rearing habitats. The Grande Ronde Valley trap captured fish as they left valley habitats downstream of Catherine Creek and upper Grande Ronde River rearing habitats. Dispersal downstream of spawning areas was most evident in fall and spring, but movement occurred during all seasons that the traps were fished. Seaward migration occurred primarily in spring when O. mykiss smolts left overwintering area located in both spawning area and valley habitats. Migration patterns exhibited by O. mykiss suggest that Grande Ronde Valley habitats are used for overwintering and should be considered critical rearing habitat. We were unable to positively differentiate anadromous and resident forms of O. mykiss in the Grande Ronde River basin because both forms occur in our study area. The Grande Ronde Valley trap provided the best information on steelhead production in the basin because it fished below valley habitats where O. mykiss overwinter. Length frequency histograms of O. mykiss captured below upper spawning and rearing habitats showed a bimodal distribution regardless of the season of capture. Scale analyses suggested that each mode represents a different brood year. Length frequency histograms of O. mykiss captured in the Grande Ronde Valley trap were not bimodal, and primarily represented a size range consistent with other researchers' accounts of anadromous smolts.

  15. Emigration of Natural and Hatchery Naco x (Chinook salmon; Oncorhynchus tshawytscha) and Heeyey (Steelhead; Oncorhynchus mykiss) Smolts from the Imnaha River, Oregon from 5 October 2006 to 21 June 2007, Annual Report 2007.

    SciTech Connect

    Michaels, Brian; Espinosa, Neal

    2009-02-18

    This report summarizes the Nez Perce Tribe (NPT) Department of Fisheries Resources Management (DFRM) results for the Lower Snake River Compensation Plan (LSRCP) Hatchery Evaluation studies and the Imnaha River Smolt Monitoring Program (SMP) for the 2007 smolt migration from the Imnaha River, Oregon. These studies are closely coordinated and provide information about juvenile natural and hatchery spring/summer Naco x (Chinook Salmon; Oncorhynchus tshawytscha) and Heeyey (steelhead; O. mykiss) biological characteristics, emigrant timing, survival, arrival timing and travel time to the Snake River dams and McNary Dam (MCD) on the Columbia River. These studies provide information on listed Naco x (Chinook salmon) and Heeyey (steelhead) for the Federal Columbia River Power System (FCRPS) Biological Opinion (NMFS 2000). The Lower Snake River Compensation Plan program's goal is to maintain a hatchery production program of 490,000 Naco x (Chinook salmon) and 330,000 Heeyey (steelhead) for annual release in the Imnaha River (Carmichael et al. 1998, Whitesel et al. 1998). These hatchery releases occur to compensate for fish losses due to the construction and operation of the four lower Snake River hydroelectric facilities. One of the aspects of the LSRCP hatchery evaluation studies in the Imnaha River is to determine natural and hatchery Naco x (Chinook salmon) and Heeyey (steelhead) smolt performance, emigration characteristics and survival (Kucera and Blenden 1998). A long term monitoring effort was established to document smolt emigrant timing and post release survival within the Imnaha River, estimate smolt survival downstream to McNary Dam, compare natural and hatchery smolt performance, and collect smolt-to-adult return information. This project collects information for, and is part of, a larger effort entitled Smolt Monitoring by Federal and Non-Federal Agencies (BPA Project No. 198712700). This larger project provides data on movement of smolts out of major drainages

  16. The effect of chitosan-based edible film and high hydrostatic pressure process on the microbiological and chemical quality of rainbow trout (Oncorhynchus mykiss Walbaum) fillets during cold storage (4±1°C)

    NASA Astrophysics Data System (ADS)

    Günlü, Ali; Sipahioğlu, Sinem; Alpas, Hami

    2014-01-01

    The objective of this study is to determine the changes in the chemical and microbiological quality of fresh rainbow trout (Oncorhynchus mykiss Walbaum) fillets during storage at 4±1°C as a result of chitosan-based edible film coating, vacuum packaging and high pressure application processes. Chemical (pH, total volatile basic nitrogen and thiobarbituric acid index) and microbiological (total mesophilic and total psychrophilic microorganism) shelf life analyses were carried out in 4-day intervals for samples that were vacuum packaged (C), subjected to high pressure after vacuum packaging (high hydrostatic pressure (HHP)), vacuum packaged after being wrapped by chitosan-based film (CFW) and subjected to high pressure after vacuum packaging and being wrapped by chitosan-based film (HHP+CFW ). According to the chemical and microbiological shelf life analysis results of rainbow trout fillets, shelf life increases of 4 days in HHP group samples, 8 days in CFW group samples and 24 days in HHP+CFW group samples were provided in comparison with the control group. In conclusion, it was determined that high pressure and wrapping with chitosan-based film had protective effect both chemically and microbiologically and that the most effective protection was obtained when both methods were used together.

  17. The effect of dietary n-3/n-6 polyunsaturated fatty acid ratio on salmonid alphavirus subtype 1 (SAV-1) replication in tissues of experimentally infected rainbow trout (Oncorhynchus mykiss).

    PubMed

    Lopez-Jimena, Benjamin; Lyons, Philip; Herath, Tharangani; Richards, Randolph H; Leaver, Michael; Bell, J Gordon; Adams, Alexandra; Thompson, Kim D

    2015-07-09

    Salmon pancreas disease (SPD) is one of the most commercially significant viral diseases of farmed Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) in Europe. In this study, the potential for dietary mitigation of the disease using different polyunsaturated fatty acid (PUFA) profiles was assessed in rainbow trout. We experimentally infected fish with salmonid alphavirus subtype 1 (SAV-1), the causative agent of SPD. These fish were fed two diets with different n-3/n-6 PUFA ratio (high omega 3, 3.08, and high omega 6, 0.87). We assessed the influence of the diets on the fatty acid composition of the heart at 0 days post infection (d.p.i.) (after 4 weeks of feeding the experimental diets prior to SAV-1 infection), and sampled infected and control fish at 5, 15 and 30d.p.i. Viral E1 and E2 glycoprotein genes were quantified by two absolute real-time PCRs in all the organs sampled, and significantly lower levels of the virus were evident in the organs of fish fed with high omega 6. Characteristic pathological lesions were identified in infected fish as early as 5d.p.i., with no significant differences in the pathology lesion scores between the two dietary regimes. This study shows that decreasing the n-3/n-6 PUFA ratio in experimental diets of rainbow trout changes the fatty acid content of the fish, and is associated with reduced SAV-1 replication in rainbow trout.

  18. Comparison of the susceptibility of brown trout (Salmo trutta) and four rainbow trout (Oncorhynchus mykiss) strains to the myxozoan Tetracapsuloides bryosalmonae, the causative agent of proliferative kidney disease (PKD).

    PubMed

    Grabner, Daniel S; El-Matbouli, Mansour

    2009-11-12

    Differences in susceptibility to the myxozoan parasite Tetracapsuloides bryosalmonae, the causative agent of proliferative kidney disease (PKD), between four strains of rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) were evaluated. Fish were exposed to water enzootic for the parasite in the field for 5 days and were subsequently transferred to the laboratory. Relative parasite load was determined after 2, 3 and 4 weeks post-exposure (wpe) by quantitative real-time PCR (qPCR) of kidney samples and number of parasite stages was determined in immunohistochemical stained sections of kidney, liver and spleen tissues. According to qPCR results, the highest amount of parasite DNA per equal amount of host tissue at all time points was measured in brown trout. Two of the rainbow trout strains showed lower relative parasite load than all other groups at the beginning of the experiment, but the parasite multiplied faster in these strains resulting in an equal level of relative parasite load for all rainbow trout strains at 4 wpe. A weak negative correlation of fish size and parasite load was detected. Only in samples of a few fish, single stages of T. bryosalmonae were found in sections stained by immunohistochemistry impeding quantitative evaluation of parasite numbers by this method. The results indicate a differential resistance to T. bryosalmonae between the rainbow trout strains investigated and between rainbow trout and brown trout.

  19. Effects of dehulling, steam-cooking and microwave-irradiation on digestive value of white lupin (Lupinus albus) seed meal for rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar).

    PubMed

    Saez, Patricio; Borquez, Aliro; Dantagnan, Patricio; Hernández, Adrián

    2015-01-01

    A digestibility trial was conducted to assess the effect of dehulling, steam-cooking and microwave-irradiation on the apparent digestibility of nutrients in white lupin (Lupinus albus) seed meal when fed to rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). Six ingredients, whole lupin seed meal (LSM), dehulled LSM, dehulled LSM steam-cooked for 15 or 45 min (SC15 and SC45, respectively) and LSM microwave-irradiated at 375 or 750 W (MW375 and MW750, respectively), were evaluated for digestibility of dry matter, crude protein (CP), lipids, nitrogen-free extractives (NFE) and gross energy (GE). The diet-substitution approach was used (70% reference diet + 30% test ingredient). Faeces from each tank were collected using a settlement column. Dehulled LSM showed higher levels of proximate components (except for NFE and crude fibre), GE and phosphorus in comparison to whole LSM. Furthermore, SC15, SC45, MW375 and MW750 showed slight variations of chemical composition in comparison to dehulled LSM. Results from the digestibility trial indicated that dehulled LSM, SC15, SC45 and MW375 are suitable processing methods for the improvement of nutrients' apparent digestibility coefficient (ADC) in whole LSM. MW750 showed a lower ADC of nutrients (except for CP and lipids for rainbow trout) in comparison with MW350 for rainbow trout and Atlantic salmon, suggesting a heat damage of the ingredient when microwave-irradiation exceeded 350 W.

  20. Purified deoxynivalenol or feed restriction reduces mortality in rainbow trout, Oncorhynchus mykiss (Walbaum), with experimental bacterial coldwater disease but biologically relevant concentrations of deoxynivalenol do not impair the growth of Flavobacterium psychrophilum.

    PubMed

    Ryerse, I A; Hooft, J M; Bureau, D P; Hayes, M A; Lumsden, J S

    2015-09-01

    Diets containing deoxynivalenol (DON) were fed to rainbow trout Oncorhynchus mykiss (Walbaum) for 4 weeks followed by experimental infection (intraperitoneal) with Flavobacterium psychrophilum (4.1 × 10(6) colony-forming units [CFU] mL(-1) ). Mortality of rainbow trout fed either 6.4 mg kg(-1) DON or trout pair-fed the control diet was significantly reduced (P < 0.05) in comparison with trout fed the control diet to apparent satiation (<0.1 mg kg(-1) DON). In a second experiment, trout were fed one of three experimental diets; a control diet, a diet produced with corn naturally contaminated with DON (3.3 mg kg(-1) DON) or a diet containing purified DON (3.8 mg kg(-1) ); however, these fish were not experimentally infected. The presence of DON resulted in significant reduction (P < 0.0001) in feed intake as well as weight gain after 4 weeks. Respiratory burst of head-kidney leucocytes isolated from rainbow trout fed diets containing purified DON (3.8 mg kg(-1) ) was significantly higher (P < 0.05) at 35 day post-exposure compared with controls. The antimicrobial activity of DON was examined by subjecting F. psychrophilum in vitro to serial dilutions of the chemical. Complete inhibition occurred at a concentration of 75 mg L(-1) DON, but no effect was observed below this concentration (0-30 mg L(-1) ).

  1. First Description of a New Disease in Rainbow Trout (Oncorhynchus mykiss (Walbaum)) Similar to Heart and Skeletal Muscle Inflammation (HSMI) and Detection of a Gene Sequence Related to Piscine Orthoreovirus (PRV)

    PubMed Central

    Olsen, Anne Berit; Hjortaas, Monika; Tengs, Torstein; Hellberg, Hege; Johansen, Renate

    2015-01-01

    In fall 2013, anorexia, lethargy and mortalities up to 10-12,000 dead fish per week were observed in rainbow trout Oncorhynchus mykiss in three fresh water hatcheries (salinity 0-1 ‰) on the west coast of Norway. The fish (25-100 g) showed signs of circulatory failure with haemorrhages, ascites and anaemia. The histopathological findings comprised inflammation of the heart and red muscle and liver necrosis. The affected fish had a common origin. Disease and mortalities were also observed up to four months after sea water transfer. Microbiological examination did not reveal presence of any known pathogens. Based on histopathological similarities to heart and skeletal inflammation (HSMI) in Atlantic salmon, associated with piscine orthoreovirus (PRV), extended investigations to detect a virus within the family Reoviridae were conducted. By the use of primer sets targeting the PRV genome, a sequence with 85% identity to a part of segment S1 of PRV was obtained. Further analysis showed that the virus sequence could only be aligned with PRV and no other reoviruses both on amino acid and nucleotide level. Two PCR assays were developed for specific detection of the virus. High amounts of the virus were detected in diseased fish at all affected farms and low amounts were detected in low prevalence at the broodfish farms. Further investigations are needed to determine if the virus is associated with the new disease in rainbow trout and to further characterize the virus with respect to classification, relationship with PRV, virulence, pathology and epidemiology. PMID:26176955

  2. Trace metal concentrations in single specimens of the intestinal broad flatworm ( Diphyllobothrium latum), compared to their fish host ( Oncorhynchus mykiss) measured by total reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Woelfl, Stefan; Mages, Margarete; Torres, Patricio

    2008-12-01

    The aim of this study was to investigate (1) whether intestine endoparasites ( Diphyllobothrium latum) accumulate trace elements related to its body size and (2) whether parasites bioconcentrate more trace elements than their host. Freshwater fish (rainbow trout Oncorhynchus mykiss) were sampled in the deep, oligotrophic and uncontaminated Lake Riñihue in Southern Chile. The element concentration of different organs (intestine, muscle, liver) and of the intestine endoparasites were analyzed using total reflection X-ray fluorescence spectrometry. The results showed that the mass fraction for Mn, Fe, Ni, Cu, and Pb decreased significantly with the body size (dry weight) of the endoparasite. Only Zn did not reveal such a relationship. Small parasites accumulated up to 80 times more Fe, Ni, Mn, Pb, and Cu than large parasites. Compared to the fish organs, small parasites accumulated in maximum 35 to 307 times more Mn, 5 to 255 times more Fe, 98 to 220 times more Ni, 3 to 175 times more Cu, and 0.4 to 12 times more Zn than the fish. Lead was only found in the endoparasite, but not in the fish organs. We conclude that (1) D. latum is a good indicator for trace element accumulation in fishes and that (2) small endoparasites are more sensitive as bioindicators because they showed higher bioconcentrations of trace metals than larger parasites.

  3. Measurement of total Zn and Zn isotope ratios by quadrupole ICP-MS for evaluation of Zn uptake in gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Wolf, R.E.; Todd, A.S.; Brinkman, S.; Lamothe, P.J.; Smith, K.S.; Ranville, J.F.

    2009-01-01

    This study evaluates the potential use of stable zinc isotopes in toxicity studies measuring zinc uptake by the gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). The use of stable isotopes in such studies has several advantages over the use of radioisotopes, including cost, ease of handling, elimination of permit requirements, and waste disposal. A pilot study using brown trout was performed to evaluate sample preparation methods and the ability of a quadrupole inductively coupled plasma mass spectrometer (ICP-MS) system to successfully measure changes in the 67Zn/66Zn ratios for planned exposure levels and duration. After completion of the pilot study, a full-scale zinc exposure study using rainbow trout was performed. The results of these studies indicate that there are several factors that affect the precision of the measured 67Zn/66Zn ratios in the sample digests, including variations in sample size, endogenous zinc levels, and zinc uptake rates by individual fish. However, since these factors were incorporated in the calculation of the total zinc accumulated by the gills during the exposures, the data obtained were adequate for their intended use in calculating zinc binding and evaluating the influences of differences in water quality parameters.

  4. Nisin Z Production by Lactococcus lactis subsp. cremoris WA2-67 of Aquatic Origin as a Defense Mechanism to Protect Rainbow Trout (Oncorhynchus mykiss, Walbaum) Against Lactococcus garvieae.

    PubMed

    Araújo, Carlos; Muñoz-Atienza, Estefanía; Pérez-Sánchez, Tania; Poeta, Patrícia; Igrejas, Gilberto; Hernández, Pablo E; Herranz, Carmen; Ruiz-Zarzuela, Imanol; Cintas, Luis M

    2015-12-01

    Probiotics represent an alternative to chemotherapy and vaccination to control fish diseases, including lactococcosis caused by Lactococcus garvieae. The aims of this study were (i) to determine the in vitro probiotic properties of three bacteriocinogenic Lactococcus lactis subsp. cremoris of aquatic origin, (ii) to evaluate in vivo the ability of L. cremoris WA2-67 to protect rainbow trout (Oncorhynchus mykiss, Walbaum) against infection by L. garvieae, and (iii) to demonstrate the role of nisin Z (NisZ) production as an anti-infective mechanism. The three L. cremoris strains survived in freshwater at 18 °C for 7 days, withstood exposure to pH 3.0 and 10 % (v/v) rainbow trout bile, and showed different cell surface hydrophobicity (37.93-58.52 %). The wild-type NisZ-producer L. cremoris WA2-67 and its non-bacteriocinogenic mutant L. cremoris WA2-67 ∆nisZ were administered orally (10(6) CFU/g) to rainbow trout for 21 days and, subsequently, fish were challenged with L. garvieae CLG4 by the cohabitation method. The fish fed with the bacteriocinogenic strain L. cremoris WA2-67 reduced significantly (p < 0.01) the mortality (20 %) compared to the fish treated with its non-bacteriocinogenic knockout isogenic mutant (50 %) and the control (72.5 %). We demonstrated the effectiveness of L. cremoris WA2-67 to protect rainbow trout against infection with the invasive pathogen L. garvieae and the relevance of NisZ production as an anti-infective mechanism. This is the first report demonstrating the effective in vivo role of LAB bacteriocin (NisZ) production as a mechanism to protect fish against bacterial infection. Our results suggest that the wild-type NisZ-producer strain L. cremoris WA2-67 could be used in fish farming to prevent lactococcosis in rainbow trout.

  5. An enriched stable-isotope approach to determine the gill-zinc binding properties of juvenile rainbow trout (Oncorhynchus mykiss) during acute zinc exposures in hard and soft waters

    USGS Publications Warehouse

    Todd, A.S.; Brinkman, S.; Wolf, R.E.; Lamothe, P.J.; Smith, K.S.; Ranville, J.F.

    2009-01-01

    The objective of the present study was to employ an enriched stable-isotope approach to characterize Zn uptake in the gills of rainbow trout (Oncorhynchus mykiss) during acute Zn exposures in hard water (???140 mg/L as CaCO 3) and soft water (???30 mg/L as CaCO3). Juvenile rainbow trout were acclimated to the test hardnesses and then exposed for up to 72 h in static exposures to a range of Zn concentrations in hard water (0-1,000 ??g/L) and soft water (0-250 ??g/L). To facilitate detection of new gill Zn from endogenous gill Zn, the exposure media was significantly enriched with 67Zn stable isotope (89.60% vs 4.1% natural abundance). Additionally, acute Zn toxicity thresholds (96-h median lethal concentration [LC50]) were determined experimentally through traditional, flow-through toxicity tests in hard water (580 ??g/L) and soft water (110 ??g/L). Following short-term (???3 h) exposures, significant differences in gill accumulation of Zn between hard and soft water treatments were observed at the three common concentrations (75, 150, and 250 ??g/L), with soft water gills accumulating more Zn than hard water gills. Short-term gill Zn accumulation at hard and soft water LC50s (45-min median lethal accumulation) was similar (0.27 and 0.20 ??g/g wet wt, respectively). Finally, comparison of experimental gill Zn accumulation, with accumulation predicted by the biotic ligand model, demonstrated that model output reflected short-term (<1 h) experimental gill Zn accumulation and predicted observed differences in accumulation between hard and soft water rainbow trout gills. Our results indicate that measurable differences exist in short-term gill Zn accumulation following acclimation and exposure in different water hardnesses and that short-term Zn accumulation appears to be predictive of Zn acute toxicity thresholds (96-h LC50s). ?? 2009 SETAC.

  6. Dietary accumulation and quantitative structure-activity relationships for depuration and biotransformation of short (C{sub 10}), medium (C{sub 14}), and long (C{sub 18}) carbon-chain polychlorinated alkanes by juvenile rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Fisk, A.T.; Tomy, G.T.; Cymbalisty, C.D.; Muir, D.C.G.

    2000-06-01

    Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to three [{sup 14}C]-polychlorinated alkanes at nominal concentrations of 1.5 and 15 {micro}g/g for 40 d, followed by 160 d of clean food, to measure bioaccumulation parameters and biotransformation. These PCSs are identical in carbon-chain length and chlorine content to industrial chlorinated paraffin products, although their method of synthesis differs from that of chlorinated paraffin products. Half-lives ranged from 26 to 91 d, biomagnification factors ranged from 0.9 to 2.8, and both exhibited increasing trends with increasing carbon-chain length. Data from this work and others on PCAs were used to determine biotransformation rates and to examine quantitative structure-activity relationships for bioaccumulation and biotransformation. Quantitative structure-activity relationships developed for half-life and biomagnification factor showed positive linear relationships with the number of carbon atoms, or chlorine atoms, of total carbon and chlorine atoms, and log K{sub ow}. The PCA biotransformation rates (per day) ranged from -0.00028 to 8.4 and exhibited negative relationships with the number of carbon atoms, of chlorine atoms, of total carbon and chlorine atoms, and log K{sub ow}. Results suggest that PCAs with a total number of carbon and chlorine atoms between 22 and 30 are slowly, or are not, biotransformed in juvenile rainbow trout. Increasing carbon-chain length and chlorine content result in greater bioaccumulation of PCAs by reducing partition-based (i.e., diffusion) and metabolic (i.e., biotransformation) elimination processes. High bioaccumulation potential and low biotransformation rates of medium (C{sub 14--18}) and long (C{sub 18--30}) carbon-chain PCAs and highly chlorinated PCAs indicate that information is needed regarding the environmental concentrations of these PCAs in aquatic food chains.

  7. Tracing metabolic routes of dietary carbohydrate and protein in rainbow trout (Oncorhynchus mykiss) using stable isotopes ([¹³C]starch and [¹⁵N]protein): effects of gelatinisation of starches and sustained swimming.

    PubMed

    Felip, Olga; Ibarz, Antoni; Fernández-Borràs, Jaume; Beltrán, Marta; Martín-Pérez, Miguel; Planas, Josep V; Blasco, Josefina

    2012-03-01

    Here we examined the use of stable isotopes, [¹³C]starch and [¹⁵N]protein, as dietary tracers to study carbohydrate assimilation and distribution and protein utilisation, respectively, by rainbow trout (Oncorhynchus mykiss). The capacity of glucose uptake and use by tissues was studied, first, by varying the digestibility of carbohydrate-rich diets (30 % carbohydrate), using raw starch and gelatinised starch (GS) and, second, by observing the effects of two regimens of activity (voluntary swimming, control; sustained swimming at 1·3 body lengths/s, exercise) on the GS diet. Isotopic ratio enrichment (¹³C and ¹⁵N) of the various tissue components (protein, lipid and glycogen) was measured in the liver, muscles, viscera and the rest of the fish at 11 and 24 h after a forced meal. A level of 30 % of digestible carbohydrates in the food exceeded the capacity of rainbow trout to use this nutrient, causing long-lasting hyperglycaemia that raises glucose uptake by tissues, and the synthesis of glycogen and lipid in liver. Total 13C recovered 24 h post-feeding in the GS group was lower than at 11 h, indicating a proportional increase in glucose oxidation, although the deposition of lipids in white muscle (WM) increased. Prolonged hyperglycaemia was prevented by exercise, since sustained swimming enhances the use of dietary carbohydrates, mainly through conversion to lipids in liver and oxidation in muscles, especially in red muscle (RM). Higher recoveries of total 15N for exercised fish at 24 h, mainly into the protein fraction of both RM and WM, provide evidence that sustained swimming improves protein deposition, resulting in an enhancement of the protein-sparing effect.

  8. Protein Retention Assessment of Four Levels of Poultry By-Product Substitution of Fishmeal in Rainbow Trout (Oncorhynchus mykiss) Diets Using Stable Isotopes of Nitrogen (δ15N) as Natural Tracers

    PubMed Central

    Badillo, Daniel; Herzka, Sharon Z.; Viana, Maria Teresa

    2014-01-01

    This is second part from an experiment where the nitrogen retention of poultry by-product meal (PBM) compared to fishmeal (FM) was evaluated using traditional indices. Here a quantitative method using stable isotope ratios of nitrogen (δ15N values) as natural tracers of nitrogen incorporation into fish biomass is assessed. Juvenile rainbow trout (Oncorhynchus mykiss) were fed for 80 days on isotopically distinct diets in which 0, 33, 66 and 100% of FM as main protein source was replaced by PBM. The diets were isonitrogenous, isolipidic and similar in gross energy content. Fish in all treatments reached isotopic equilibrium by the end of the experiment. Two-source isotope mixing models that incorporated the isotopic composition of FM and PBM as well as that of formulated feeds, empirically derived trophic discrimination factors and the isotopic composition of fish that had reached isotopic equilibrium to the diets were used to obtain a quantitative estimate of the retention of each source of nitrogen. Fish fed the diets with 33 and 66% replacement of FM by PBM retained poultry by-product meal roughly in proportion to its level of inclusion in the diets, whereas no differences were detected in the protein efficiency ratio. Coupled with the similar biomass gain of fishes fed the different diets, our results support the inclusion of PBM as replacement for fishmeal in aquaculture feeds. A re-feeding experiment in which all fish were fed a diet of 100% FM for 28 days indicated isotopic turnover occurred very fast, providing further support for the potential of isotopic ratios as tracers of the retention of specific protein sources into fish tissues. Stable isotope analysis is a useful tool for studies that seek to obtain quantitative estimates of the retention of different protein sources. PMID:25226392

  9. Protein retention assessment of four levels of poultry by-product substitution of fishmeal in rainbow trout (Oncorhynchus mykiss) diets using stable isotopes of nitrogen (δ15N) as natural tracers.

    PubMed

    Badillo, Daniel; Herzka, Sharon Z; Viana, Maria Teresa

    2014-01-01

    This is second part from an experiment where the nitrogen retention of poultry by-product meal (PBM) compared to fishmeal (FM) was evaluated using traditional indices. Here a quantitative method using stable isotope ratios of nitrogen (δ(15)N values) as natural tracers of nitrogen incorporation into fish biomass is assessed. Juvenile rainbow trout (Oncorhynchus mykiss) were fed for 80 days on isotopically distinct diets in which 0, 33, 66 and 100% of FM as main protein source was replaced by PBM. The diets were isonitrogenous, isolipidic and similar in gross energy content. Fish in all treatments reached isotopic equilibrium by the end of the experiment. Two-source isotope mixing models that incorporated the isotopic composition of FM and PBM as well as that of formulated feeds, empirically derived trophic discrimination factors and the isotopic composition of fish that had reached isotopic equilibrium to the diets were used to obtain a quantitative estimate of the retention of each source of nitrogen. Fish fed the diets with 33 and 66% replacement of FM by PBM retained poultry by-product meal roughly in proportion to its level of inclusion in the diets, whereas no differences were detected in the protein efficiency ratio. Coupled with the similar biomass gain of fishes fed the different diets, our results support the inclusion of PBM as replacement for fishmeal in aquaculture feeds. A re-feeding experiment in which all fish were fed a diet of 100% FM for 28 days indicated isotopic turnover occurred very fast, providing further support for the potential of isotopic ratios as tracers of the retention of specific protein sources into fish tissues. Stable isotope analysis is a useful tool for studies that seek to obtain quantitative estimates of the retention of different protein sources.

  10. Effects of water temperature and pH on toxicity of terbufos, trichlorfon, 4-nitrophenol and 2,4- dinitrophenol to the amphipod Gammarus pseudolimnaeus and rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Howe, G.E.; Marking, L.L.; Bills, T.D.; Rach, J.J.; Mayer, F.L.

    1994-01-01

    Acute toxicity tests were conducted to determine (a) the individual and interactive effects of water temperature (7, 12, 17 degree C), pH (6.5, 7.5, 8.5, 9.5), and time on the toxicity of terbufos, trichlorfon, 4- nitrophenol, and 2,4-dinitrophenol to rainbow trout (Oncorhynchus mykiss) and the amphipod Gammarus pseudolimnaeus, and (b) the individual and interactive effects of water temperature and pH on chemical bioconcentration during acute tests with rainbow trout and Gammarus exposed to terbufos, 4-nitrophenol, and 2,4-dinitrophenol. The toxicity of all four chemicals was significantly affected by pH in all tests, except for Gammarus exposed to terbufos. The toxicity of terbufos to rainbow trout and Gammarus was less at pH 7.5 than at higher or lower pH. The toxicity of both nitrophenols decreased as pH increased, whereas the toxicity of trichlorfon increased with pH. The effect of pH on trichlorfon toxicity decreased with temperature. Temperature significantly affected the toxicity of all four chemicals to both species. Toxicity increased with temperature in all tests, except for rainbow trout exposed to nitrophenols; toxicity decreased as temperature increased for rainbow trout. Chemical bioconcentration was also significantly affected by temperature and pH and was directly related to toxicity in most tests. Significant interactive effects between toxicity-modifying factors were also frequently observed. Temperature and pH effects on chemical toxicity need to be considered in chemical hazard assessment to ensure adequate protection of aquatic organisms.

  11. Effects of water temperature and pH on toxicity of terbufos, trichlorfon, 4-nitrophenol and 2,4-dinitrophenol to the amphipod Gammarus pseudolimnaeus and rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Howe, G.E.; Marking, L.L.; Bills, T.D.; Rach, J.J. . National Fisheries Research Center); Mayer, F.L. Jr. . Environmental Research Lab.)

    1994-01-01

    Acute toxicity tests were conducted to determine (a) the individual and interactive effects of water temperature (7, 12, 17 C), pH (6.5, 7.5, 8.5, 9.5), and time on the toxicity of terbufos, trichlorfon, 4-nitrophenol, and 2,4-dinitrophenol to rainbow trout (Oncorhynchus mykiss) and the amphipod Gammarus pseudolimnaeus, and (b) the individual and interactive effects of water temperature and pH on chemical bioconcentration during acute tests with rainbow trout and Gammarus exposed to terbufos, 4-nitrophenol, and 2,4-dinitrophenol. The toxicity of all four chemicals was significantly affected by pH in all tests, except for Gammarus exposed to terbufos. The toxicity of terbufos to rainbow trout and Gammarus was less at pH 7.5 than at higher or lower pH. The toxicity of both nitrophenols decreased as pH increased, whereas the toxicity of trichlorfon increased with pH. The effect of pH on trichlorfon toxicity decreased with temperature. Temperature significantly affected the toxicity of all four chemicals to both species. Toxicity increased with temperature in all tests, except for rainbow trout exposed to nitrophenols; toxicity decreased as temperature increased for rainbow trout. Chemical bioconcentration was also significantly affected by temperature and pH and was directly related to toxicity in most tests. Significant interactive effects between toxicity-modifying factors were also frequently observed. Temperature and pH effects on chemical toxicity need to be considered in chemical hazard assessment to ensure adequate protection of aquatic organisms.

  12. The association between metabolic rate, immune parameters, and growth performance of rainbow trout, Oncorhynchus mykiss (Walbaum), following the injection of a DNA vaccine alone and concurrently with a polyvalent, oil-adjuvanted vaccine.

    PubMed

    Skinner, Lisa A; Schulte, P M; Balfry, S K; McKinley, R S; LaPatra, S E

    2010-02-01

    This research demonstrates a significant increase in routine metabolic rate (RMR) following injection of a DNA vaccine concurrently with a polyvalent, oil-adjuvanted vaccine. The increase in RMR was transient and associated with increased activity of both the non-specific and specific immune responses. Rainbow trout (Oncorhynchus mykiss) were injected with a DNA vaccine (DV), a commercially available polyvalent, oil-adjuvanted vaccine (AV), or the two vaccines in combination and sampled at 203, 305, and 406 days (dd) post-vaccine injection (pvi) for RMR and key immune parameters (serum lysozyme activity, serum neutralization antibody titres). The RMR of fish that received both the DV and the AV was significantly higher at 203 dd pvi, compared to fish from all other treatment groups which included the control, the AV, and the DV groups. The increased RMR corresponded to elevated levels of serum lysozyme activity and an earlier seroconversion of virus-specific neutralizing antibodies. To determine if growth performance was affected by the transient increase in RMR, specific growth rate (SGR), percent daily weight gain (WG), and feed conversion ratio (FCR) were determined at 798, 1204, and 1610 dd pvi. Although fish in all three vaccine groups showed significant increases in SGR and WG at 798 and 1610 dd pvi compared to the control group, the overall weight of the fish was not different at the end of the experiment. In summary, this study shows that concurrent injection of a DV and an AV transiently increases the RMR of rainbow trout and changes the manner in which the immune response occurs, but does not affect the overall growth performance of the fish.

  13. [Effects of the dietary incorporation of carotenoid pigments on gonad development and oocyte maturity in females of rainbow trout (Oncorhynchus mykiss, Walbaum, 1972)].

    PubMed

    de la Mora, Genoveva Ingle; Arredondo-Figueroa, J L; Barriga-Sosa, Irene de los Angeles; Bazán-Arias, J; Vernon-Carter, J

    2004-06-01

    Four groups of rainbow trout (Onchorhynchus mykiss) each with 60 females with an average body weight of 467 g were submitted to an aleatory assay in order to compare the efficiency of four diets containing different concentrations of carotenoid pigments, and to determine if pigment concentration and source had an influence on female gonad development and oocyte maturity. The first diet was the non-pigmented control (C). The second diet contained 100 mg kg(-1) of Carophyll Pink (CR). The third and fourth diets contained 200 (RC200) and 250 (RC250) mg kg(-1) of saponified red chili oleoresin, respectively. The results indicated significant differences (p < or = 0.05) between C and RC250, with respect to the gonado-somatic index (IGS), average gonad weight (PG) and average diameter of oocyte (DO), with CR250 showing higher IGS, PG and DO values. Treatments CR and CR200 presented similar values. At the end of the experimental period, only 10% of oocytes were mature in the RC250 diet.

  14. Increased stocking density causes changes in expression of selected stress- and immune-related genes, humoral innate immune parameters and stress responses of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Yarahmadi, Peyman; Miandare, Hamed Kolangi; Fayaz, Sahel; Caipang, Christopher Marlowe A

    2016-01-01

    The present study investigated the effects of various stocking densities on the health status (stress and immune responses) of rainbow trout (Onchorhynchus mykiss). Juvenile rainbow trout were acclimated, placed in circular tanks under stocking densities of 10, 40 and 80 kg m(-3) and reared for 30 days. The relative expression of genes involved in stress and immunity such as HSP70, LyzII, TNF-1α, IL-1β, IL-8 and IFN-γ1 in the head kidney was determined. Serum cortisol, ACTH, total antioxidant capacity, osmolality and lactate were measured after 30 days of culture at different stocking densities (D1:10 kg m(-3), D2: 40 kg m(-3) and D3: 80 kg m(-3)) as indices of stress responses. In addition, the effects of stocking densities on serum complement, bactericidal activity, agglutinating antibody titers, serum IgM, anti-protease activity, serum total protein and alkaline phosphatase of the fish were measured. HSP70 gene expression was significantly density-dependent upregulated in D2 and D3 densities compared to D1 (P < 0.05). Also, there was significant downregulation in expression of LyzII, TNF-1α, IL-1β, IL-8 and IFN-γ1 in fish reared at density of either D2 or D3 (P < 0.05). In terms of stress responses, serum ACTH, cortisol and lactate level showed significant density-dependent increase (P < 0.05) while serum osmolality and total antioxidant capacity showed significant decline (P < 0.05) in fish reared at higher densities (D2 and D3) compared to fish reared at lower density (D1) (P < 0.05). Concordant with the expression of the immune-related genes, the serum complement and bactericidal activity as well as specific antibody titer against Aeromonas hydrophila, IgM and anti-protease activity decreased along with elevation of stocking density from D1 to D3 (P < 0.05). However, different stocking densities had no significant effect on serum total protein level and alkaline phosphatase activity. These results suggested that elevation of stocking

  15. Protein and lipid binding parameters in rainbow trout (Oncorhynchus mykiss) blood and liver fractions to extrapolate from an in vitro metabolic degradation assay to in vivo bioaccumulation potential of hydrophobic organic chemicals.

    PubMed

    Escher, Beate I; Cowan-Ellsberry, Christina E; Dyer, Scott; Embry, Michelle R; Erhardt, Susan; Halder, Marlies; Kwon, Jung-Hwan; Johanning, Karla; Oosterwijk, Mattheus T T; Rutishauser, Sibylle; Segner, Helmut; Nichols, John

    2011-07-18

    Binding of hydrophobic chemicals to colloids such as proteins or lipids is difficult to measure using classical microdialysis methods due to low aqueous concentrations, adsorption to dialysis membranes and test vessels, and slow kinetics of equilibration. Here, we employed a three-phase partitioning system where silicone (polydimethylsiloxane, PDMS) serves as a third phase to determine partitioning between water and colloids and acts at the same time as a dosing device for hydrophobic chemicals. The applicability of this method was demonstrated with bovine serum albumin (BSA). Measured binding constants (K(BSAw)) for chlorpyrifos, methoxychlor, nonylphenol, and pyrene were in good agreement with an established quantitative structure-activity relationship (QSAR). A fifth compound, fluoxypyr-methyl-heptyl ester, was excluded from the analysis because of apparent abiotic degradation. The PDMS depletion method was then used to determine partition coefficients for test chemicals in rainbow trout (Oncorhynchus mykiss) liver S9 fractions (K(S9w)) and blood plasma (K(bloodw)). Measured K(S9w) and K(bloodw) values were consistent with predictions obtained using a mass-balance model that employs the octanol-water partition coefficient (K(ow)) as a surrogate for lipid partitioning and K(BSAw) to represent protein binding. For each compound, K(bloodw) was substantially greater than K(S9w), primarily because blood contains more lipid than liver S9 fractions (1.84% of wet weight vs 0.051%). Measured liver S9 and blood plasma binding parameters were subsequently implemented in an in vitro to in vivo extrapolation model to link the in vitro liver S9 metabolic degradation assay to in vivo metabolism in fish. Apparent volumes of distribution (V(d)) calculated from the experimental data were similar to literature estimates. However, the calculated binding ratios (f(u)) used to relate in vitro metabolic clearance to clearance by the intact liver were 10 to 100 times lower than values

  16. Potencies of polychlorinated dibenzo-p-dioxin, dibenzofuran, and biphenyl congeners, relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin, for producing early life stage mortality in rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Walker, Mary K.; Peterson, Richard E.

    1991-01-01

    The presence of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in feral lake trout eggs (Salvelinus namaycush) may increase the risk of lake trout early life stage mortality in the Great Lakes. To assess the combined toxicity of PCDDs, PCDFs, and PCBs to lake trout early development, toxic potencies, relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), were determined for individual PCDD, PCDF, and PCB congeners, based on rainbow trout (Oncorhynchus mykiss) early life stage mortality. Newly fertilized rainbow trout eggs were injected with graded doses of 2,3,7,8-TCDD, or a PCDD, PCDF, or PCB congener. LD50 values were determined based on the egg dose that caused mortality from hatching onset to swim-up. Toxic equivalency factors (TEFs) were calculated as 2,3,7,8-TCDD LD50/congener LD50. TEFs were for PCDDs: 2,3,7,8-TCDD = 1.0; 1,2,3,7,8-PeCDD = 0.730;and 1,2,3,4,7,8-HxCDD = 0.319; for PCDFs: 2,3,4,7,8-PeCDF = 0.359; 1,2,3,4,7,8-HxCDF = 0.280; 1,2,3,7,8-PeCDF = 0.034; and 2,3,7,8-TCDF = 0.028; and for PCBs: 3,3',4,4',5-PeCB = 0.005; 3,3',4,4'-TCB = 0.00016; 2,3,3',4,4'-PeCB and 2,3',4,4',5-PeCB ortho-chlorinated analogues of the coplanar PCBs fish-specific TEFs were 1/14 to 1/80 less than both those determined in H4IIE cells and proposed for risk assessment. Using these fish-specific TEFs, the risk associated with exposure of early life stages of Sake trout to complex mixtures of PCDDs, PCDFs, and PCBs in the Great Lakes can be estimated.

  17. Sequence and expression analysis of two T helper master transcription factors, T-bet and GATA3, in rainbow trout Oncorhynchus mykiss and analysis of their expression during bacterial and parasitic infection.

    PubMed

    Wang, Tiehui; Holland, Jason W; Martin, Sam A M; Secombes, Christopher J

    2010-11-01

    The polarization of naïve CD4+ T cells to T helper (Th)1 or Th2 cells is specified by two master transcription factors, T-bet and GATA3, and is an essential feature of mammalian adaptive immune responses to pathogens and the development of long-lasting immunity. We report here the cloning of rainbow trout Oncorhynchus mykiss T-bet and GATA3, to allow the future evaluation of the existence of Th1 and Th2 cells in salmonid fish. The trout T-bet translation shares high amino acid identities to other fish T-bet molecules (71-72%) but low identities to mammalian T-bet genes (41-42%), although the middle T-box DNA binding domain is highly conserved among all the T-bet proteins from fish and mammals. The trout GATA3 has high amino acid sequence identities (73-88%) to all known vertebrate molecules, with two highly conserved zinc finger motifs. The identity of the trout T-bet and GATA3 molecules was confirmed by phylogenetic tree analysis. A comparable expression level of T-bet and GATA3 was seen in the spleen, head kidney and muscle in healthy trout, but a higher expression level of GATA3 was seen in the gills, brain, skin and intestine relative to that of T-bet. T-bet and GATA3 expression was modulated by different stimulants. The T cell stimulant PHA up-regulated the expression of both T-bet and GATA3 in splenocytes, suggesting that they may be mainly expressed by activated T cells. The expression of T-bet and GATA3 in the spleen was increased by acute stress, but their expression was inhibited by bacterial (Yersinia ruckeri) infection. In a parasitic infection model, Tetracapsuloides bryosalmonae infection induced a biased gene expression profile where a large increase in the expression of T-bet, IFN-gamma and IL-2 was seen, suggesting that a Th1-like response is likely induced by this disease. A better understanding of pathogen modulated expression of T-bet and GATA3, and the potential underlying host immune responses elicited as a consequence of their expression

  18. The influence of 17β-estradiol on intestinal calcium carbonate precipitation and osmoregulation in seawater-acclimated rainbow trout (Oncorhynchus mykiss).

    PubMed

    Al-Jandal, Noura J; Whittamore, Jonathan M; Santos, Eduarda M; Wilson, Rod W

    2011-08-15

    The intestine of marine teleosts produces carbonate precipitates from ingested calcium as part of their osmoregulatory strategy in seawater. The potential for estrogens to control the production of intestinal calcium carbonate and so influence osmoregulation was investigated in seawater-acclimated rainbow trout following intraperitoneal implantation of 17β-estradiol (E2) at two doses (0.1 and 10 μg E2 g(-1)). Levels of plasma vitellogenin provided an indicator of estrogenic effect, increasing significantly by three and four orders of magnitude at the low and high doses, respectively. Plasma osmolality and muscle water content were unaffected, whereas E2-treated fish maintained lower plasma [Na(+)] and [Cl(-)]. Plasma [Ca(2+)] and [Mg(2+)] and muscle [Ca(2+)] increased with vitellogenin induction, whereas the intestinal excretion of calcium carbonate was reduced. This suggests that elevated levels of circulating E2 may enhance Ca(2+) uptake via the gut and simultaneously reduce CaCO(3) formation, which normally limits intestinal availability of Ca(2+). Increasing E2 caused an elevation of [Na(+)] and [Cl(-)] and a reduction of [HCO(3(-))] in intestinal fluid. We speculate that E2 may influence a number of intestinal ion transport processes that ultimately may influence water absorption: (1) reduced NaCl cotransport, (2) reduced Cl(-) uptake via Cl(-)/HCO(3(-)) exchange and (3) reduced precipitation of Ca(2+) and Mg(2+) carbonates. Despite these effects on intestinal ion and water transport, overall osmoregulatory status was not compromised in E2-treated fish, suggesting the possibility of compensation by other organs.

  19. VIRULENCE OF Flavobacterium columnare GENOMOVARS IN RAINBOW TROUT (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 five genetic types or genomovars have been described based on restriction fragment length polymorphism of the 16S rR...

  20. A new rainbow trout (Oncorhynchus mykiss) reference genome assembly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to improve the rainbow trout reference genome assembly, we have re-sequenced the doubled-haploid Swanson line using the longest available reads from the Illumina technology. Overall we generated over 510 million 260nt paired-end shotgun reads, and 1 billion 160nt mate-pair reads from f...

  1. Creatine metabolism differs between mammals and rainbow trout (Oncorhynchus mykiss).

    PubMed

    Borchel, Andreas; Verleih, Marieke; Rebl, Alexander; Kühn, Carsten; Goldammer, Tom

    2014-01-01

    Creatine plays an important role in the cell as an energy buffer. As the energy system is a basic element of the organism it may possibly contribute to differences between rainbow trout strains selected for the traits growth and robustness, respectively. The cDNA sequences of creatine-related genes encoding glycine amidinotransferase (GATM), guanidinoacetate N-methyltransferase (GAMT), creatine kinase muscle-type (CKM) and creatine transporter 1 (CT1, encoded by gene solute carrier family 6, member 8 (SLC6A8)) were characterized in rainbow trout. Transcripts of the respective genes were quantified in kidney, liver, brain and skeletal muscle in both trout strains that had been acclimated to different temperatures. Several differences between the compared trout strains were found as well as between temperatures indicating that the energy system may contribute to differences between both strains. In addition to that, the expression data showed clear differences between the creatine system in rainbow trout and mammals, as the spatial distribution of the enzyme-encoding gene expression was clearly different from the patterns described for mammals. In rainbow trout, creatine synthesis seems to take place to a big extent in the skeletal muscle.

  2. Ontogenetic taurine biosynthesis ability in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Wang, Xuan; He, Gen; Mai, Kangsen; Xu, Wei; Zhou, Huihui

    2015-07-01

    Taurine (2-aminoethane sulfonic acid) plays important roles in multiple physiological processes including osmoregulation, bile salt conjugation and membrane protection. It is known that taurine biosynthesis varies in different fish species. However, its ontogenetic regulation has not been clear. In the present study, we found that the hepatic concentrations of taurine increased marginally with rainbow trout growth. The mRNA expression, protein levels and enzyme activities of key enzymes involved in taurine biosynthesis, cysteine dioxygenase (CDO) and cysteine sulfinate decarboxylase (CSD), were analyzed. Our results showed that the mRNA levels and protein abundances of CSD increased dramatically with the development of rainbow trout stages while the enzyme activities showed a slight improvement. However, the expression and activities of CDO decreased with rainbow trout growth. These results provide valuable information on defining the exact supplementation of taurine in diets for different stages of rainbow trout and give new insights into elucidating the regulation of taurine metabolism in rainbow trout.

  3. Cadmium affects the social behaviour of rainbow trout, Oncorhynchus mykiss.

    PubMed

    Sloman, Katherine A; Scott, Graham R; Diao, Zhongyu; Rouleau, Claude; Wood, Chris M; McDonald, D Gord

    2003-10-29

    The present study investigated both the effects of cadmium on the social interactions of rainbow trout and the differential accumulation of waterborne cadmium among social ranks of fish. Fish exposed to waterborne cadmium concentrations of 2 microg l(-1) for 24 h, followed by a 1, 2 or 3 day depuration period in clean water, had a decreased ability to compete with non-exposed fish. However, the competitive ability of exposed fish given a 5 day depuration period was not significantly impaired. Cadmium accumulated in the olfactory apparatus of fish exposed to waterborne cadmium for 24 h and decreased significantly only after 5 days depuration in clean water. Among groups of ten fish held in stream tanks, where all fish were exposed to cadmium, there were significant effects on social behaviour and growth rate. Dominance hierarchies formed faster among fish exposed to cadmium than among control fish, and overall growth rates were higher in the cadmium treatment. In groups of ten fish, social status also affected tissue accumulation of cadmium during waterborne exposure, with dominant fish accumulating more cadmium at the gill. In conclusion, exposure to low levels of cadmium, affects the social behaviour of fish, in part due to accumulation in the olfactory apparatus, and dominant fish accumulate more gill cadmium than subordinates during chronic waterborne exposure.

  4. Toxicokinetics of perfluorooctanoate (PFOA) in rainbow trout(Oncorhynchus mykiss)

    EPA Science Inventory

    Perfluoroalkyl acids (PFAAs) are widely used as stain resistant coatings for cloth, paper, and leather, and as surfactants, fire-fighting foams, and photographic developers. Individual PFAAs have been shown to accumulate in fish and wildlife; however, the extent of this accumulat...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is the causative agent for columnaris disease and responsible for significant economic loss in the aquaculture industry. F. columnare is a gram negative bacteria with several genomovar classifications, based on the restriction fragment length polymorphism of the 16S rDNA gen...

  6. A second generation genetic map for rainbow trout (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background Genetic maps characterizing the inheritance patterns of traits and markers have been developed for a wide range of species and used to study questions in biomedicine, agriculture, ecology and evolutionary biology. The status of rainbow trout genetic maps has progressed significantly over...

  7. Characterization of 13 microsatellites for Lahontan cutthroat trout (Oncorhynchus clarki henshawi) and cross-amplification in six other salmonids.

    PubMed

    Robinson, M L; Kirchoff, V S; Peacock, M M

    2009-01-01

    Thirteen newly developed tri- and tetranucleotide repeat microsatellite markers were developed for Lahontan cutthroat trout (Oncorhynchus clarki henshawi), a threatened subspecies endemic to the Lahontan hydrographic basin in the western USA. These loci are highly polymorphic with five to 30 alleles per locus and observed heterozygosities ranging from 0.4 to 0.7. Cross-species amplification of these markers was most successful in the closely related rainbow trout, Oncorhynchus mykiss, with only three loci amplifying in brown trout, Salmo trutta. Nonoverlapping allelic distributions for many of these loci among the six salmonid species screened suggest these markers may be useful for hybrid determination.

  8. Chinook salmon (Oncorhynchus tshawytscha) and rainbow trout (Oncorhynchus mykiss) exposed to copper: Neurophysiological and histological effects on the olfactory system

    SciTech Connect

    Hansen, J.A.; Rose, J.D.; Jenkins, R.A.; Gerow, K.G.; Bergman, H.L.

    1999-09-01

    Olfactory epithelial structure and olfactory bulb neurophysiological responses were measured in chinook salmon and rainbow trout in response to 25 to 300 {micro}g copper (Cu)/L. Using confocal laser scanning microscopy, the number of olfactory receptors was significantly reduced in chinook salmon exposed to {ge}50 {micro}g Cu/L and in rainbow trout exposed to {ge}200 {micro}g cu/L for 1 h. The number of receptors was significantly reduced in both species following exposure to 25 {micro}g Cu/L for 4 h. Transmission electron microscopy of olfactory epithelial tissue indicated that the loss of receptors was from cellular necrosis. Olfactory bulk electroencephalogram (EEG) responses to 10{sup {minus}3} M L-serine were initially reduced by all Cu concentrations but were virtually eliminated in chinook salmon exposed to {ge}50 {micro}g Cu/L and in rainbow trout exposed to {ge}200 {micro}g Cu/L within 1 h of exposure. Following Cu exposure, EEG response recovery rates were slower in fish exposed to higher Cu concentrations. The higher sensitivity of the chinook salmon olfactory system to Cu-induced histological damage and neurophysiological impairment parallels the relative species sensitivity observed in behavioral avoidance experiments. This difference in species sensitivity may reduce the survival and reproductive potential of chinook salmon compared with that of rainbow trout in Cu-contaminated waters.

  9. Rainbow trout (Oncorhynchus mykiss) secretory component binds to commensal bacteria and pathogens

    PubMed Central

    Kelly, Cecelia; Takizawa, Fumio; Sunyer, J. Oriol; Salinas, Irene

    2017-01-01

    Commensal bacteria co-exist on the mucosal surfaces of all vertebrates. The host’s mucosal immune system must tolerate commensals while fighting pathogens. One of the mechanisms used by the mucosal immune system to maintain homeostasis is the secretion of immunoglobulins (Igs) across epithelial barriers, which is achieved via the polymeric immunoglobulin receptor (pIgR). Rainbow trout pIgR is known to transport IgT and IgM across epithelia. However, other biological functions for trout pIgR or trout secretory component (tSC) remain unknown. This study investigates the interaction of tSC with commensal bacteria, pathogenic bacteria and a fungal pathogen. Our results show that the majority of trout skin and gut bacteria are coated in vivo by tSC. In vitro, tSC present in mucus coats trout commensal isolates such as Microbacterium sp., Staphylococcus warneri, Flectobacillus major, Arthrobacter stackebrantii, and Flavobacterium sp. and the pathogens Vibrio anguillarum and Edwardsiella ictaluri with coating levels ranging from 8% to 70%. Moreover, we found that the majority of tSC is in free form in trout mucus and free tSC is able to directly bind bacteria. We propose that binding of free SC to commensal bacteria is a key and conserved mechanism for maintenance of microbial communities in vertebrate mucosal surfaces. PMID:28150752

  10. The effect of diet on dorsal fin erosion in steelhead trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Lellis, W.A.; Barrows, F.T.

    1997-01-01

    A 2 X 2 factorial experiment of diet type (krill vs. fish meal) and steroid supplementation (0 vs. 30 ??g 17??-methyltestosterone kg-1) was conducted to determine the effects on dorsal fin erosion in steelhead trout. Triplicate tanks of 250 fry were fed one of the four diets at a rate calculated to produce 115 g fish in 34 weeks. Fish were transferred to larger tanks when mean density index reached 0.40. Dorsal fin index (DFI, measured as mean dorsal fin height X 100/total fish length) was greater (P < 0.001) among fish fed krill-based diets than for fish fed fish-based diets at weeks 12, 22, and 34 of the trial. Added testosterone decreased (p = 0.04) DFI among fish fed the krill diet at week 12 but otherwise had no effect on fin condition. Addition of testosterone to either diet type decreased (P = 0.02) critical thermal maximum, which is a measure of fish resistance to thermal stress. The results suggest that diet composition can influence the rate of dorsal fin erosion in steelhead trout through a metabolic, behavioral, or combined change.

  11. Ammonia excretion in rainbow trout (Oncorhynchus mykiss): evidence for Rh glycoprotein and H+-ATPase involvement.

    PubMed

    Nawata, C Michele; Hung, Carrie C Y; Tsui, Tommy K N; Wilson, Jonathan M; Wright, Patricia A; Wood, Chris M

    2007-11-14

    Branchial ammonia transport in freshwater teleosts is not well understood. Most studies conclude that NH(3) diffuses out of the gill and becomes protonated to NH(4)(+) in an acidified gill boundary layer. Rhesus (Rh) proteins are new members of the ammonia transporter superfamily and rainbow trout possess genes encoding for Rh30-like1 and Rhcg2. We identified seven additional full-length trout Rh cDNA sequences: one Rhag and two each of Rhbg, Rhcg1, and Rh30-like. The mRNA expression of Rhbg, Rhcg1, and Rhcg2 was examined in trout tissues (blood, brain, eye, gill, heart, intestine, kidney, liver, muscle, skin, spleen) exposed to high external ammonia (HEA; 1.5 mmol/l NH(4)HCO(3), pH 7.95, 15 degrees C). Rhbg was expressed in all tissues, Rhcg1 was expressed in brain, gill, liver, and skin, and Rhcg2 was expressed in gill and skin. Brain Rhbg and Rhcg1 were downregulated, blood Rh30-like and Rhag were downregulated, and skin Rhbg and Rhcg2 were upregulated with HEA. After an initial uptake of ammonia into the fish during HEA, excretion was reestablished, coinciding with upregulations of gill Rh mRNA in the pavement cell fraction: Rhcg2 at 12 and 48 h, and Rhbg at 48 h. NHE2 expression remained unchanged, but upregulated H(+)-ATPase (V-type, B-subunit) and downregulated carbonic anhydrase (CA2) expression and activity were noted in the gill and again expression changes occurred in pavement cells, and not in mitochondria-rich cells. Together, these results indicate Rh glycoprotein involvement in ammonia transport and excretion in the rainbow trout while underscoring the significance of gill boundary layer acidification by H(+)-ATPase.

  12. Leucine and isoleucine reduce protein degradation in rainbow trout (Oncorhynchus mykiss) primary myoblast cultures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Myogenic precursor cells were isolated from rainbow trout skeletal muscle and incubated in media containing 10% fetal bovine serum for 7 days, thereby differentiating into myoblasts. Rates of protein degradation were determined in response to minimal essential media (MEM) of various amino acid (AA)...

  13. Determination of metabolic stability using cryopreserved hepatocytes from rainbow trout (Oncorhynchus mykiss)

    EPA Science Inventory

    Standard protocols for isolating, cryopreserving, and thawing rainbow trout hepatocytes are described, along with procedures for using fresh or cryopreserved hepatocytes to assess chemical metabolic stability in fish by means of a substrate depletion approach. Variations on thes...

  14. A New and Improved Rainbow Trout (Oncorhynchus mykiss) Reference Genome Assembly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to improve the rainbow trout reference genome assembly, we re-sequenced the doubled-haploid Swanson line using the longest available reads from the Illumina technology; generating over 510 million paired-end shotgun reads (2x260nt), and 1 billion mate-pair reads (2x160nt) from four sequ...

  15. Proteomic analysis of muscle tissue from rainbow trout (Oncorhynchus mykiss) fed dietary β-glucan.

    PubMed

    Ghaedi, Gh; Keyvanshokooh, S; Mohammadi Azarm, H; Akhlaghi, M

    2016-01-01

    The aim of this study was to examine the changes in muscle proteome of the rainbow trout fed dietary β-glucan. The experimental diets contained 0 (control), 0.1% and 0.2% β-1,3/1,6 yeast glucan. First, feeding larvae were fed to apparent satiation nine times per day with their respective diets over two months. The percentage of body weight gain and feed efficiency of fish fed 0.2% diet was significantly higher than those of fish fed the control and 0.1% diets. Fish fed the control and 0.2% diets were subjected to proteomic analysis. Proteins of the muscle tissue were analyzed using two-dimensional electrophoresis and mass spectrometry. Spots that were found to differ significantly in abundance between control and β-glucan fed fish were selected for identification. Out of 8 protein spots showing differential expression, 7 spots were successfully identified. Two protein spots that were found to be increased in abundance in the β-glucan treated rainbow trout corresponded to tropomyosin alpha-1 chain (spot 1) and slow myotomal muscle tropomyosin (spot 2). The five spots that were down-regulated with dietary β-glucan supplementation were identified as different forms of myosin: myosin light polypeptide 3-2 (spot 3), myosin light chain 1 (spots 4 and 5), fast myosin light chain 2 (spot 6) and myosin heavy chain (spot 7). The altered expression of structural proteins in fish fed β-glucan may be related to higher growth rate in rainbow trout. These findings provide basic information to understand possible mechanisms of dietary β-glucan contribution to better growth in rainbow trout.

  16. The trenbolone acetate affects the immune system in rainbow trout, Oncorhynchus mykiss.

    PubMed

    Massart, Sophie; Redivo, Baptiste; Flamion, Enora; Mandiki, S N M; Falisse, Elodie; Milla, Sylvain; Kestemont, Patrick

    2015-06-01

    In aquatic systems, the presence of endocrine-disrupting chemicals (EDC) can disrupt the reproductive function but also the immune system of wildlife. Some studies have investigated the effects of androgens on the fish immune parameters but the mechanisms by which the xenoandrogens alter the immunity are not well characterized. In order to test the effects of trenbolone acetate (TbA) on fish immune system, we exposed rainbow trout male juveniles during three weeks to TbA levels at 0.1 and 1μg/L. The present results suggest that TbA impacts, in a tissue-dependent manner, the rainbow trout immunity by affecting primarily the humoral immunity. Indeed, TbA inhibited lysozyme activity in plasma and liver and enhanced the alternative complement pathway activity (ACH50) in kidney. In plasma, the modulation of the complement system was time-dependent. The mRNA expression of genes encoding some cytokines such as renal TGF-β1, TNF-α in skin and hepatic IL-1β was also altered in fish exposed to TbA. Regarding the cellular immunity, no effect was observed on the leucocyte population. However, the expression of genes involved in the development and maturation of lymphoid cells (RAG-1 and RAG-2) was decreased in TbA-treated fish. Among those effects, we suggest that the modulation of RAG-1 and mucus apolipoprotein-A1 gene expression as well as plasma and hepatic lysozyme activities are mediated through the action of the androgen receptor. All combined, we conclude that trenbolone affects the rainbow trout immunity.

  17. Germ Cell-Specific Excision of loxP-Flanked Transgenes in Rainbow Trout Oncorhynchus mykiss.

    PubMed

    Katayama, Naoto; Kume, Sachi; Hattori-Ihara, Shoko; Sadaie, Sakiko; Hayashi, Makoto; Yoshizaki, Goro

    2016-04-01

    Cre/loxP-mediated DNA excision in germ cell lineages could contribute substantially to the study of germ cell biology in salmonids, which are emerging as a model species in this field. However, a cell type-specific Cre/loxPsystem has not been successfully developed for any salmonid species. Therefore, we examined the feasibility of Cre/loxP-mediated, germ cell-specific gene excision and transgene activation in rainbow trout. Double-transgenic (wTg) progeny were obtained by mating a transgenic male carryingcrewith a transgenic female carrying thehsc-LRLGgene;crewas driven by rainbow troutvasaregulatory regions and thehsc-LRLGgene was made up of the rainbow troutheat-shock-cognate71promoter, theDsRedgene flanked by twoloxPsites, and theEgfpgene. PCR analysis, fluorescence imaging, and histological analysis revealed that excision of theloxP-flanked sequence and activation ofEgfpoccurred only in germ cells of wTg fish. However, progeny tests revealed that the excision efficiency ofloxP-flanked sequence in germ cells was low (≤3.27%). In contrast, the other wTg fish derived from two differentcre-transgenic males frequently excised theloxP-flanked sequence in germ cells (≤89.25%). Thus, we showed for the first time successful germ cell-specific transgene manipulation via the Cre/loxPsystem in rainbow trout. We anticipate that this technology will be suitable for studies of cell function through cell targeting, cell-linage tracing, and generating cell type-specific conditional gene knockouts and separately for developing sterile rainbow trout in aquaculture.

  18. Quality assessment of rainbow trout (Oncorhynchus mykiss) fillets during super chilling and chilled storage.

    PubMed

    Shen, Song; Jiang, Yan; Liu, Xiaochang; Luo, Yongkang; Gao, Liang

    2015-08-01

    In order to evaluate the effect of super chilling (-3 °C) and chilled (3 °C) storage on the quality of rainbow trout fillets, total volatile base nitrogen (TVB-N), drip loss, pH, electric conductivity (EC), total aerobic count (TAC), K and related values, adenosine triphosphate (ATP) and related compounds, color and sensory score were determined and correlation between these indicators were analyzed. According to the comprehensive evaluation of TAC, K value and sensory score, the limit for acceptability of rainbow trout fillets was 5 days at 3 °C and 11 days at -3 °C. Additionally, the correlation coefficients between TVB-N and other freshness indicators (TAC, K value, sensory score) were relatively low. TVB-N may be inadequate for evaluating freshness changes of rainbow trout fillets compared with other indicators. Among the K and related values, H value was a better freshness indicator in rainbow trout fillets during chilled and super chilling storage for its better correlation coefficients with other freshness indicators. Super chilling storage could extend the shelf life of rainbow trout fillets by 6 days compared to chilled storage.

  19. Skeletal anomaly monitoring in rainbow trout (Oncorhynchus mykiss, Walbaum 1792) reared under different conditions.

    PubMed

    Boglione, Clara; Pulcini, Domitilla; Scardi, Michele; Palamara, Elisa; Russo, Tommaso; Cataudella, Stefano

    2014-01-01

    The incidence of skeletal anomalies could be used as an indicator of the "quality" of rearing conditions as these anomalies are thought to result from the inability of homeostatic mechanisms to compensate for environmentally-induced stress and/or altered genetic factors. Identification of rearing conditions that lower the rate of anomalies can be an important step toward profitable aquaculture as malformed market-size fish have to be discarded, thus reducing fish farmers' profits. In this study, the occurrence of skeletal anomalies in adult rainbow trout grown under intensive and organic conditions was monitored. As organic aquaculture animal production is in its early stages, organic broodstock is not available in sufficient quantities. Non-organic juveniles could, therefore, be used for on-growing purposes in organic aquaculture production cycle. Thus, the adult fish analysed in this study experienced intensive conditions during juvenile rearing. Significant differences in the pattern of anomalies were detected between organically and intensively-ongrown specimens, although the occurrence of severe, commercially important anomalies, affecting 2-12.5% of individuals, was comparable in the two systems. Thus, organic aquaculture needs to be improved in order to significantly reduce the incidence of severe anomalies in rainbow trout.

  20. Skeletal Anomaly Monitoring in Rainbow Trout (Oncorhynchus mykiss, Walbaum 1792) Reared under Different Conditions

    PubMed Central

    Boglione, Clara; Pulcini, Domitilla; Scardi, Michele; Palamara, Elisa; Russo, Tommaso; Cataudella, Stefano

    2014-01-01

    The incidence of skeletal anomalies could be used as an indicator of the “quality” of rearing conditions as these anomalies are thought to result from the inability of homeostatic mechanisms to compensate for environmentally-induced stress and/or altered genetic factors. Identification of rearing conditions that lower the rate of anomalies can be an important step toward profitable aquaculture as malformed market-size fish have to be discarded, thus reducing fish farmers’ profits. In this study, the occurrence of skeletal anomalies in adult rainbow trout grown under intensive and organic conditions was monitored. As organic aquaculture animal production is in its early stages, organic broodstock is not available in sufficient quantities. Non-organic juveniles could, therefore, be used for on-growing purposes in organic aquaculture production cycle. Thus, the adult fish analysed in this study experienced intensive conditions during juvenile rearing. Significant differences in the pattern of anomalies were detected between organically and intensively-ongrown specimens, although the occurrence of severe, commercially important anomalies, affecting 2–12.5% of individuals, was comparable in the two systems. Thus, organic aquaculture needs to be improved in order to significantly reduce the incidence of severe anomalies in rainbow trout. PMID:24809347

  1. Differential effects of temperature and glucose on glycogenolytic enzymes in tissues of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Bolinger, Mark T; Rodnick, Kenneth J

    2014-05-01

    The pathways and regulatory mechanisms of glycogenolysis remain relatively unexplored in non-mammalian vertebrates, especially poikilotherms. We studied the temperature sensitivity and inhibition of glycogenolytic enzymes in liver, ventricle, and white muscle of rainbow trout acclimated to 14 °C. Glycogen phosphorylase (GP) and acid α-glucosidase (GAA) activities were measured in homogenates of tissues at physiological temperatures (4, 14, and 24 °C), and in the presence of allosteric inhibitor, glucose. Higher GP versus GAA activity in all three tissues suggested a predominance of phosphorolytic glycogenolysis over the lysosomal glucosidic pathway. GP activities at 14 °C were ~2-fold higher in the ventricle and white muscle versus the liver and selectively increased by AMP in striated muscle. Conversely, the activities of GAA and lysosomal marker acid phosphatase were 8- to 10-fold higher in the liver compared with the ventricle and white muscle. Thermal sensitivity (Q10) was increased for GP in all tissues below 14 °C and decreased in striated muscle in the absence of AMP above 14 °C. GAA had lower Q10 values than GP below 14 °C, and, unlike GP, Q10s for GAA were not different between tissues or affected by temperature. Both GP (in the absence of AMP) and GAA were inhibited by glucose in a dose-dependent manner, with the lowest IC50 values observed in the white muscle (1.4 and 6.3 mM, respectively). In conclusion, despite comparatively low kinetic potential, lysosomal GAA might facilitate glycogenolysis at colder body temperatures in striated muscle and intracellular glucose could limit phosphorolytic and glucosidic glycogenolysis in multiple tissues of the rainbow trout.

  2. Characterization of rainbow trout (Oncorhynchus mykiss) spleen transcriptome and identification of immune-related genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance against specific diseases is affecting profitability in fish production systems including rainbow trout. Limited information is known about functions and mechanisms of the immune gene pathways in teleosts. Immunogenomics are powerful tools to determine immune-related genes/gene pathways a...

  3. ASSESSMENT OF MAXIMUM SUSTAINABLE SWIMMING PERFORMANCE IN RAINBOW TROUT (ONCORHYNCHUS MYKISS)

    PubMed

    Wilson; Egginton

    1994-07-01

    Levels of swimming activity in fishes have been divided into three categories on the basis of the time a given speed can be maintained before the onset of fatigue (Beamish, 1978): sustained (more than 200 min), prolonged (20 s to 200 min) and burst swimming (less than 20 s). The locomotory capacity of a given species reflects both its lifestyle and its body form, although definitions of performance may vary. It is generally accepted that only the aerobic ('red') muscle fibres should be active at truly sustainable swimming speeds, i.e. at speeds that can be maintained indefinitely without fatigue. However, the standard laboratory method of evaluating the maximum sustainable swimming speed (Ucrit; Brett, 1964) almost certainly entails the recruitment of at least some of the rapidly fatigable fast glycolytic ('white') fibres at sub-critical speeds and undoubtedly complicates the evaluation of maximal cardiovascular performance. It would therefore be useful to have an objective and reproducible measure of truly sustainable performance that, by definition, relies solely on aerobic muscle activity. Electromyography (EMG) has been used to examine the pattern of white muscle recruitment following thermal acclimation in striped bass, Morine saxatilis (Sisson and Sidell, 1987). We wished to incorporate this method into a study of the acclimatory responses to chronic changes in environmental temperature of the cardiovascular and locomotory systems in rainbow trout (Wilson and Egginton, 1992). The present communication presents results on the cardiovascular performance and blood chemistry, at rest and during maximal aerobic exercise, of rainbow trout acclimated to 11 °C, as a validation of the methodology currently in use with fish acclimated to seasonal temperature extremes (Taylor et al. 1992). Different acclimation temperatures are known to produce compensatory changes in the relative proportions of red and white muscle mass (Sidell and Moerland, 1989). The aim of these continuing investigations is to compare the anatomical, cardiovascular and locomotory limitations to aerobic exercise over the full temperature range of a eurythermal fish species.

  4. Contaminant levels in rainbow trout, oncorhynchus mykiss, and their diets from Missouri coldwater hatcheries.

    PubMed

    McKee, Michael J; Kromrey, George B; May, Thomas W; Orazio, Carl E

    2008-05-01

    Organochlorine and metal contaminants often occur in commercial fish diets and can accumulate in fish to levels of concern for human consumption. Contaminant levels were investigated in diet and rainbow trout fillets from Missouri coldwater hatcheries used in "put and take" fisheries. The average fillet:diet ratio was <0.1 for lead and cadmium, 0.4-0.6 for organochlorine compounds, and about 0.8 for mercury. Trout fillet concentrations for all contaminants were low (<50 ng/g) and below Missouri's fish consumption advisory trigger levels.

  5. Intra-strain dioxin sensitivity and morphometric effects in swim-up rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Carvalho, Paulo S. M.; Noltie, Douglas B.; Tillitt, D.E.

    2004-01-01

    Inter and intra-specific differences in sensitivity of early life stage salmonids to 2,3,7,8-TCDD exposure have been reported, but intra-strain differences have not been found in the literature. Our results indicate that intra-strain variability in terms of embryo mortality (LD50) is small in Eagle Lake strain of rainbow trout, LD50 values ranging from 285 to 457 pg TCDD egg g-1. These results confirm Eagle Lake as a less sensitive strain within rainbow trout, and do not indicate overlap with reported LD50 values for brook or lake trout. Our results also demonstrate that although generalized edema in regions including the yolk-sac are frequently associated with mortality following dioxin exposure, not all edematous fish die. We detected dose-dependent decreases in cranial length, eye diameter, mass, and total length (P<0.05) in viable swim-up rainbow trout. These effects are presumed to indicate more subtle dose-dependent disruptions of the viteline vein vasculature and, therefore, in access to energy sources. A tendency for dose-dependent decrease in liver glycogen reserves concurred with previous results on salmonids and with the well described TCDD-induced alterations in intermediate metabolism of rats and chicken embryos (wasting syndrome). This syndrome could be contributing to the reduced growth that we observed. ?? 2004 Elsevier Inc. All rights reserved.

  6. Claudin tight junction proteins in rainbow trout (Oncorhynchus mykiss) skin: Spatial response to elevated cortisol levels.

    PubMed

    Gauberg, Julia; Kolosov, Dennis; Kelly, Scott P

    2017-01-01

    This study examined regional distribution and corticosteroid-induced alterations of claudin (cldn) transcript abundance in teleost fish skin. Regional comparison of mRNA encoding 20 Cldns indicated that 12 exhibit differences in abundance along the dorsoventral axis of skin. However, relative abundance of cldns (i.e. most to least abundant) remained similar in different skin regions. Several cldns appear to be present in the epidermis and dermal vasculature whereas others are present only in the epidermis. Increased circulating cortisol levels significantly altered mRNA abundance of 10 cldns in a region specific manner, as well as corticosteroid receptors and 11β-hydroxysteroid dehydrogenase (type 2). Epidermis and epidermal mucous cell morphometrics also altered in response to cortisol, exhibiting changes that appear to enhance skin barrier properties. Taken together, data provide a first look at spatial variation in the molecular physiology of the teleost fish integument TJ complex and region-specific sensitivity to an endocrine factor.

  7. Photobacterium damselae subsp. damselae, an emerging pathogen in Danish rainbow trout, Oncorhynchus mykiss (Walbaum), mariculture.

    PubMed

    Pedersen, K; Skall, H F; Lassen-Nielsen, A M; Bjerrum, L; Olesen, N J

    2009-05-01

    A selection of 16 field isolates of Photobacterium damselae from marine rainbow trout farms in Denmark was subjected to phenotypic and genotypic characterization and pathogenicity to fish. All isolates belonged to the subspecies damselae, being positive for haemolysis, motility and urease. There were considerable differences in haemolytic properties, some isolates presenting a broad zone of haemolysis and others only a narrow zone. Pulsed-field gel electrophoresis revealed a high diversity indicating that P. damselae subsp. damselae is an opportunistic, not clonal pathogen in Danish marine rainbow trout. Virulence of the strains to rainbow trout was highly variable with LD(50) values ranging from 3.9 x 10(3) to 1.5 x 10(8) cfu at 20 degrees C. The virulence was significantly higher at 20 degrees C than at 13 degrees C. The strains with the strongest haemolytic properties were the most virulent suggesting a strong involvement of haemolysin in the pathogenesis. The pathological changes were consistent with a bacterial septicaemia and the haemorrhages were more pronounced than for most other bacterial infections.

  8. Transcriptional Heterogeneity of IgM+ Cells in Rainbow Trout (Oncorhynchus mykiss) Tissues

    PubMed Central

    Abós, Beatriz; Castro, Rosario; Pignatelli, Jaime; Luque, Alfonso; González, Lucia; Tafalla, Carolina

    2013-01-01

    Two major classes of B lymphocytes have been described to date in rainbow trout: IgM+ and IgT+ cells. IgM+ cells are mainly localized in the spleen, peripheral blood and kidney but are also found in other tissues. However, differences among IgM+ cell populations attending to its location are poorly defined in fish. Thus, the aim of this work was to characterize the expression of different immune molecules such as chemokine receptors, Toll-like receptors (TLRs) and transcription factors on sorted IgM+ lymphocytes from different rainbow trout tissues. IgM+ populations from blood, spleen, kidney, gills, intestine and liver were isolated by cell sorting and the constitutive levels of transcription of these genes evaluated by real-time PCR. To further characterize B cells, we identified an MS4A sequence. In humans, the MS4A family includes several genes with immune functions, such as the B cell marker CD20 or FcRβ. Subsequently, we have also evaluated the mRNA levels of this MS4A gene in the different IgM+ populations. The relevant differences in transcriptional patterns observed for each of these IgM+ populations analyzed, point to the presence of functionally different tissue-specific B cell populations in rainbow trout. The data shown provides a pattern of genes transcribed in IgM+ B cells not previously revealed in teleost fish. Furthermore, the constitutive expression of all the TLR genes analyzed in IgM+ cells suggests an important role for these cells in innate immunity. PMID:24324826