Salvelinus alpinus

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Eva Brannas - One of the best experts on this subject based on the ideXlab platform.

  • proof of concept visual categorization of carotenoid pigmentation in arctic charr Salvelinus alpinus l can predict stress response
    Journal of Fish Biology, 2021
    Co-Authors: Tobias Backstrom, Eva Brannas, Jan Nilsson, Hanna Carlberg, Kajsa Johansson, Carin Magnhagen
    Abstract:

    Carotenoid pigmentation in Salvelinus alpinus has been connected to stress responsiveness in earlier studies. This has, however, only been tested with time-consuming image analysis from photos. Here, we used quick visual categorization of carotenoid pigmentation to investigate the stress responsiveness of the extreme groups. The visually selected charr were then exposed to a net restraint stressor. Arctic charr with few spots also had a lower stress responsiveness compared to charr with many spots. Thus, visual selection could be used as a simple method within aquaculture.

  • metabolomics approach to evaluate a baltic sea sourced diet for cultured arctic char Salvelinus alpinus l
    Journal of Agricultural and Food Chemistry, 2017
    Co-Authors: Ken Cheng, Eva Brannas, Hanna Carlberg, Ali A Moazzami, Elisabeth Mullner, Jana Pickova
    Abstract:

    Aqua feeds traditionally rely on fishmeal as a protein source, which is costly and unsustainable. A new feed was formulated in the study with Baltic Sea sourced decontaminated fishmeal, Mytilus edulis and Saccharomyces cerevisiae, and given to Arctic char (Salvelinus alpinus) for ten months. The diet-induced changes on metabolic profile in fish plasma, liver, and muscle were studied relative to a fishmeal-based standard diet by using a 1H NMR-based metabolomics approach. Fish fed the test diet had higher content of betaine and lower levels of trimethylamine-N-oxide and aromatic amino acids in plasma or tissues, which were mainly caused by the diet. The metabolomics results are useful to understand the mechanism of lower body mass, smaller Fulton’s condition factor, and a tendency of less lipid content observed in fish fed the test diet. Thus, modifications on the dietary levels of these compounds in the feed are needed to achieve better growth performance.

  • decontaminated fishmeal and fish oil from the baltic sea are promising feed sources for arctic char Salvelinus alpinus l studies of flesh lipid quality and metabolic profile
    European Journal of Lipid Science and Technology, 2016
    Co-Authors: Ken Cheng, Eva Brannas, Liane Wagner, Ali A Moazzami, Pedro Gomezrequeni, Annalotta Schiller Vestergren, Jana Pickova, Sofia Trattner
    Abstract:

    The Baltic Sea is one of the world's most pollution-threatened brackish environments and limited direct consumption of fatty fish from the Baltic Sea is recommended. The use of decontaminated Baltic Sea fish raw materials as fish feed could be a strategy to recycle Baltic Sea nutrients back into food chain, while relieving pressure on aqua-feed in the growing aquaculture industry. In this study, defatted fishmeal and semi-purified fish oil from the Baltic Sea were used in fish feeds for Arctic char (Salvelinus alpinus L.). The effects of the Baltic Sea-sourced fish feeds on flesh lipid quality and fish metabolomics, compared with a standard commercial feed as a control, were determined. 1H NMR-based metabolomics studies indicated disturbances in energy metabolism and hepatic toxicity in fish fed both crude fishmeal and crude fish oil, associated with up-regulation (IGF-I, GHR-I, PPARα, PPARβ1A) and down-regulation (SREBP-1 and FAS) of hepatic genes expression. The content of n-3 long chain polyunsaturated fatty acids was not affected by the decontamination process. Thus, this short-term study demonstrates that decontaminating Baltic Sea-sourced fishmeal and fish oil reduces adverse effects in Arctic char. Practical applications: Decontaminated fish materials from the Baltic Sea were shown to be promising feed ingredients for Arctic char (Salvelinus alpinus L.) compared with untreated Baltic Sea-sourced fish feed, which induced changes in fish physiology associated with energy metabolism and hepatotoxicity. Baltic Sea-sourced fish materials containing high levels of long chain polyunsaturated fatty acids are valuable feed ingredients. The Baltic Sea-sourced fishmeal (CFM and DFM) and fish oil (CFO and SPFO) were tested in fish feeds for Arctic charr (Salvelinus alpinus), compared with a commercial diet as a control. Flesh lipid quality, metabolic profile in liver and muscle and hepatic gene expression (IGF-I, GHR-I, SREBP-1, etc.) were evaluated.

  • behavioural responses in a net restraint test predict interrenal reactivity in arctic charr Salvelinus alpinus
    Journal of Fish Biology, 2015
    Co-Authors: Carin Magnhagen, Svante Winberg, Oyvind Overli, Tobias Backstrom, Jan Nilsson, Marco A Vindas, Eva Brannas
    Abstract:

    In this study, a 1 min net restraint test was evaluated as a method to predict stress-coping style in Arctic charr Salvelinus alpinus, by investigating the relationship between behaviour during the test and levels of plasma cortisol sampled after 30 min confinement. In two separate groups of S. alpinus, general linearized model revealed significant correlations between cortisol levels and principal component scores extracted from principal component analysis, combining measures of activity in the tests. With the use of glmulti, the model selection ruled out any effects of size, sex and order of capture on interrenal reactivity. In general, S. alpinus that were more active in the net restraint test also had low levels of circulating cortisol, suggesting a proactive coping style. The results from two repeated runs were not correlated, but both runs, performed eight days apart, show a negative correlation between post-stress cortisol level and activity in the net. The lack of consistency could be explained by different treatments before each run and individual differences in behavioural plasticity. The net restraint test is thus predictive of stress-coping style in S. alpinus, and has the benefit of being less time-consuming than the commonly used confinement stress test.

  • the effect of anesthetics on carotenoid pigmentation and behavior in arctic char Salvelinus alpinus
    Journal of Veterinary Behavior-clinical Applications and Research, 2015
    Co-Authors: Tobias Backstrom, Eva Brannas, Jan Nilsson, Martina Heynen, Carin Magnhagen
    Abstract:

    Abstract Status of individual animals is often shown in pigmentation. For instance, stress responsiveness is associated with melanin-based pigmentation in vertebrates in general. This pattern is evident in Atlantic salmon ( Salmo salar ) and rainbow trout ( Oncorhynchus mykiss ), with melanin-based spots indicating stress coping style. Arctic char ( Salvelinus alpinus ) differ from other salmonids in pigmentation but have an association between carotenoid-based pigmentation and stress coping style. These pigmentation differences could be used as a fast and simple tool for improving breeding programs. However, the procedure for photographing individuals is stressful. Therefore, we wanted to investigate if 3 common inhalation anesthetics could be used to reduce the stress involved in the procedure compared to a no-anesthetics group. Behavior was also monitored during the anesthetization. All 3 anesthetics (Aquacalm, Benzocaine, and MS-222) differed in pigmentation compared to the no-anesthetics group by having a higher number of spots. In the anesthetic treatments as well as the no-anesthetics group, the fish had elevated plasma cortisol levels. In fact, the no-anesthetics group had higher cortisol than treated fish. This was probably because of procedural differences such as time affecting the stress response. Furthermore, in a long-term experiment, all fish survived and had similar condition factors 1 week after photographing as before. Therefore, the method for photographing Arctic char is deemed safe and could be used as a tool for estimating stress coping style, but careful planning is needed for experiments using it.

Moira M Ferguson - One of the best experts on this subject based on the ideXlab platform.

  • phenotypic plasticity heterochrony and ontogenetic repatterning during juvenile development of divergent arctic charr Salvelinus alpinus
    Journal of Evolutionary Biology, 2011
    Co-Authors: Kevin J Parsons, Skuli Skulason, H D Sheets, Moira M Ferguson
    Abstract:

    Phenotypic plasticity is a developmental process that plays a role as a source of variation for evolution. Models of adaptive divergence make the prediction that increasing ecological specialization should be associated with lower levels of plasticity. We tested for differences in the magnitude, rate and trajectory of morphological plasticity in two lake populations of Arctic charr (Salvelinus alpinus) that exhibited variation in the degree of resource polymorphism. We reared offspring on diet treatments that mimicked benthic and pelagic prey. Offspring from the more divergent population had lower levels of morphological plasticity. Allometry influenced the rate of shape change over ontogeny, with differences in rate among ecomorphs being minimal when allometric variation was removed. However, plasticity in the spatial trajectory of development was extensive across ecomorphs, both with and without the inclusion of allometric variation, suggesting that different aspects of shape development can evolve independently.

  • evolution of adaptive diversity and genetic connectivity in arctic charr Salvelinus alpinus in iceland
    Heredity, 2011
    Co-Authors: Kalina H Kapralova, Sigurður S Snorrason, Michael B Morrissey, Bjarni K Kristjansson, Guðbjorg Asta Olafsdottir, Moira M Ferguson
    Abstract:

    The ecological theory of adaptive radiation predicts that the evolution of phenotypic diversity within species is generated by divergent natural selection arising from different environments and competition between species. Genetic connectivity among populations is likely also to have an important role in both the origin and maintenance of adaptive genetic diversity. Our goal was to evaluate the potential roles of genetic connectivity and natural selection in the maintenance of adaptive phenotypic differences among morphs of Arctic charr, Salvelinus alpinus, in Iceland. At a large spatial scale, we tested the predictive power of geographic structure and phenotypic variation for patterns of neutral genetic variation among populations throughout Iceland. At a smaller scale, we evaluated the genetic differentiation between two morphs in Lake Thingvallavatn relative to historically explicit, coalescent-based null models of the evolutionary history of these lineages. At the large spatial scale, populations are highly differentiated, but weakly structured, both geographically and with respect to patterns of phenotypic variation. At the intralacustrine scale, we observe modest genetic differentiation between two morphs, but this level of differentiation is nonetheless consistent with strong reproductive isolation throughout the Holocene. Rather than a result of the homogenizing effect of gene flow in a system at migration-drift equilibrium, the modest level of genetic differentiation could equally be a result of slow neutral divergence by drift in large populations. We conclude that contemporary and recent patterns of restricted gene flow have been highly conducive to the evolution and maintenance of adaptive genetic variation in Icelandic Arctic charr.

  • morphological variation over ontogeny and environments in resource polymorphic arctic charr Salvelinus alpinus
    Evolution & Development, 2010
    Co-Authors: Kevin J Parsons, Skuli Skulason, Moira M Ferguson
    Abstract:

    Natural selection requires genetically based phenotypic variation to facilitate its action and cause adaptive evolution. It has become increasingly recognized that morphological development can become canalized likely as a result of selection. However, it is largely unknown how selection may influence canalization over ontogeny and differing environments. Changes in environments or colonization of a novel one is expected to result in adaptive divergence from the ancestral population when selection favors a new phenotypic optimum. In turn, a novel environment may also expose variation previously hidden from natural selection. We tested for changes in phenotypic variation over ontogeny and environments among ecomorphs of Arctic charr (Salvelinus alpinus) from two Icelandic lakes. Populations represented varying degrees of ecological specialization, with one lake population possessing highly specialized ecomorphs exhibiting a large degree of phenotypic divergence, whereas the other displayed more subtle divergence with more ecological overlap. Here we show that ecomorphs hypothesized to be the most specialized in each lake possess significant reductions in shape variation over ontogeny regardless of environmental treatment suggesting canalized development. However, environments did change the amount of shape variation expressed in these ecomorphs, with novel environments slowing the rate at which variation was reduced over ontogeny. Thus, environmental conditions may play an important role in determining the type and amount of genetically based phenotypic variation exposed to natural selection.

  • microsatellite genetic variation within and among arctic charr Salvelinus alpinus from aquaculture and natural populations in north america
    Aquaculture, 2005
    Co-Authors: Tricia A Lundrigan, James D Reist, Moira M Ferguson
    Abstract:

    The amount of genetic variation in aquaculture strains of North American Arctic charr (Salvelinus alpinus) originating from the Fraser River (Labrador), Nauyuk Lake and Tree River (Nunavut), and Lake Aleknagik (Alaska) was compared to that in natural populations using six microsatellite markers. Aquaculture strains originating from Nauyuk Lake and Tree River had less genetic variability than their wild source populations in terms of allelic diversity, but not necessarily in observed heterozygosity. In aquaculture strains, the average number of alleles is positively associated with the number of fish used to produce each strain. Pairwise tests for genetic differentiation between populations were significant for all but three comparisons. These comparisons consisted of consecutive year classes of cultured Labrador and Nauyuk fish originating from the same wild collections. A neighbour joining tree grouped samples according to their geographic origin. These results indicate that hatchery strains and natural populations of Arctic charr are genetically differentiated and that small founding population sizes have contributed to reduced genetic variation in aquaculture strains. This genetic survey is intended as a baseline for future genetic monitoring of Arctic charr aquaculture strains and will aid in the development of breeding programs for production and management.

  • distribution of temperature tolerance quantitative trait loci in arctic charr Salvelinus alpinus and inferred homologies in rainbow trout oncorhynchus mykiss
    Genetics, 2003
    Co-Authors: Ildiko M L Somorjai, Roy G Danzmann, Moira M Ferguson
    Abstract:

    We searched for quantitative trait loci (QTL) affecting upper temperature tolerance (UTT) in crosses between the Nauyuk Lake and Fraser River strains of Arctic charr (Salvelinus alpinus) using survival analysis. Two QTL were detected by using two microsatellite markers after correcting for experiment-wide error. A comparative mapping approach localized these two QTL to homologous linkage groups containing UTT QTL in rainbow trout (Oncorhynchus mykiss). Additional marginal associations were detected in several families in regions homologous to those with QTL in rainbow trout. Thus, the genes underlying UTT QTL may antedate the divergence of these two species, which occurred by approximately 16 MYA. The data also indicate that one pair of homeologs (ancestrally duplicated chromosomal segments) have contained QTL in Arctic charr since the evolution of salmonids from a tetraploid ancestor 25-100 MYA. This study represents one of the first examples of comparative QTL mapping in an animal polyploid group and illustrates the fate of QTL after genome duplication and reorganization.

Gunnarssonguðmundur Smari - One of the best experts on this subject based on the ideXlab platform.

  • contrasting patterns of territoriality and foraging mode in two stream dwelling salmonids arctic char Salvelinus alpinus and brown trout salmo trutta
    Canadian Journal of Fisheries and Aquatic Sciences, 2011
    Co-Authors: Gunnarssonguðmundur Smari, Steingrimssonstefan Oli
    Abstract:

    Territoriality and foraging behaviour play major roles in determining the abundance and distribution of mobile animals. To date, territorial behaviour of young-of-the-year (YOY) salmonids is typically described for sit-and-wait individuals that defend territories from one foraging station, but rarely for more mobile fish. We examined the territorial behaviour and foraging mode of 31 YOY Arctic char (Salvelinus alpinus) and 30 YOY brown trout (Salmo trutta) in relation to ecological factors in six rivers in northern Iceland. Arctic char used larger territories than brown trout, corresponding with high and low mobility prior to attacking prey, respectively. Within species, more mobile fish also used larger territories. Territory size increased with body size and declined with increased food abundance as predicted, but surprisingly increased with rising intruder pressure. Finally, Arctic char territories overlapped more and were less exclusively defended than brown trout territories. This study shows that te...

Arnfinn Langeland - One of the best experts on this subject based on the ideXlab platform.

Malcolm Jobling - One of the best experts on this subject based on the ideXlab platform.

  • food intake and spontaneous swimming activity in arctic char Salvelinus alpinus role of brain serotonergic activity and social interactions
    Canadian Journal of Zoology, 1998
    Co-Authors: Oyvind Overli, Svante Winberg, Borge Damsgard, Malcolm Jobling
    Abstract:

    We investigated the relationship between social interactions, brain serotonergic activity, and two behavioural patterns in juvenile Arctic char (Salvelinus alpinus): feeding and spontaneous swimming activity. Dominant and subordinate individuals were observed during rearing in pairs, followed by rearing in isolation. Throughout the experiment, levels of both food intake and swimming activity remained high in dominant fish. When they were in pairs, food intake was completely inhibited in subordinate fish; thus, dominant fish were able to monopolise food. At the same time, brain serotonergic activity, as indexed by the ratio of 5-hydroxyindoleacetic acid (5-HIAA) to serotonin (5-hydroxytryptamine, 5-HT) was elevated in the hypothalamus and brain stem of subordinate fish compared with dominants. During subsequent rearing in isolation, food intake, but not spontaneous locomotor activity, gradually increased in previously subordinate fish, while serotonergic activity fell to near that of dominants. Thus, appetite inhibition in subordinate fish can be reversed by rearing in isolation, an effect that may be related to the reversal of a stress-induced activation of brain serotonergic neurones accompanying social subordination. Reduced swimming activity is either a long-lasting response to social subordination or reflects permanently different behavioural strategies of subordinate and dominant individuals. Resume : Nous avons etudie la relation entre les interactions sociales, l'activite serotonergique du cerveau et deux types d'activite, l'alimentation et la nage spontanee, chez des Ombles chevaliers ( Salvelinus alpinus) juveniles. Des individus dominants et subordonnes ont ete observes, d'abord en groupes de deux, puis isoles. Pendant toute la duree de l'experience, les deux genres d'activite ont ete intenses chez les individus dominants. Lorsque les poissons etaient en groupes de deux, l'alimentation etait completement inhibee chez les poissons subordonnes et le poisson dominant avait alors le monopole de la nourriture. Pendant ce temps, l'activite serotonergique du cerveau, telle qu'evaluee par le rapport entre l'acide hydroxy-5-indoleacetique (5-HIAA) et la serotonine (hydroxy-5 tryptamine, 5-HT) etait elevee dans l'hypothalamus et le pedoncule cervical des poissons subordonnes comparativement a celle enregistree chez les poissons dominants. Apres l'isolement des poissons, l'alimentation, mais pas l'activite locomotrice spontanee, a augmente graduellement chez les poissons subordonnes et l'activite serotonergique de ces poissons est redevenue semblable a celle des poissons dominants. L'inhibition de l'appetit chez les poissons subordonnes peut donc etre inversee par l'isolement des poissons, sans doute par renversement de l'activation des neurones serotonergiques sous l'action du stress qui accompagne la subordination sociale. La diminution de l'activite natatoire peut etre interpretee comme une reaction de longue duree a la subordination sociale, ou alors elle reflete les strategies comportementales differentes qui prevalent en permanence chez les poissons dominants et les poissons subordonnes.

  • effects of stocking density on food intake growth performance and oxygen consumption in arctic charr Salvelinus alpinus
    Aquaculture, 1993
    Co-Authors: Even H Jorgensen, J S Christiansen, Malcolm Jobling
    Abstract:

    Abstract Food intake, growth rates, and rates of oxygen consumption were measured in Arctic charr (Salvelinus alpinus), stocked at low (15 kg·m−3), medium (60 kg·m−3) and high (120 kg·m−3) densities. Growth rates were similar for fish stocked at the medium and high densities, but were markedly depressed at the lowest stocking density. Differences in growth were probably the result of similar differences in food intake. Low levels of food intake were probably also the prime reason for the low oxygen consumption rates recorded in the groups of fish stocked at low density. Stocking density affected the behaviour of the fish, and schooling behaviour was observed in the groups subjected to the medium and high stocking density. No significant correlations were found between initial body size, food intake and growth rates in the groups of fish held at any stocking density. Consequently, social constraints due to the formation of dominance hierarchies may not have been the prime reason for the appetite and growth reduction seen in groups stocked at low density.

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