Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
115
datasets available to search
ShareScore release 0.9.0
Dataset results
115 results for “brown trout”
Data from: Identifying footprints of selection in stocked brown trout populations: a spatio-temporal approach
Studies of interactions between farmed and wild salmonid fishes have suggested reduced fitness of farmed strains in the wild, but evidence for selection at the genic level is lacking. We studied three brown trout populations in Denmark which have been significantly admixed with stocked hatchery trout (19 to 64%), along with two hatchery strains used for stocking. The wild populations were represented by contemporary samples (2000-2006) and two of them by historical samples (1943-1956). We analyzed 61 microsatellite loci, nine of which showed putative functional relationships (EST-linked or quantitative trait loci). FST based outlier tests provided support for diversifying selection at chromosome regions marked by three loci, two anonymous and one EST-linked. Patterns of differentiation suggested that the loci were candidates for being under diversifying hitch-hiking selection in hatchery versus wild environments. Analysis of hatchery strain admixture proportions showed that in one wild population, two of the loci showed significantly lower admixture proportions than the putatively neutral loci, implying contemporary selection against alleles introduced by hatchery strain trout. In the most strongly admixed population, however, there was no evidence for selection, possibly due to immigration by stocked trout overcoming selection against hatchery-derived alleles or supportive breeding practices allowing hatchery strain trout to escape natural selection. To our knowledge, this is the first study demonstrating footprints of selection in wild salmonid populations subject to spawning intrusion by farmed fish.
Data from: Potential of a no-take marine reserve to protect home ranges of anadromous brown trout (Salmo trutta)
1. The extent to which no‐take marine reserves can benefit anadromous species requires examination. 2. Here, we used acoustic telemetry to investigate the spatial behavior of anadromous brown trout (sea trout, Salmo trutta) in relation to a small marine reserve(~1.5 km2) located inside a fjord on the Norwegian Skagerrak coast. 3. On average, sea trout spent 42.3 % (±5.0% SE) of their time in the fjord within the reserve, a proportion similar to the area of the reserve relative to that of the fjord. 4. On average, sea trout tagged inside the reserve received the most protection, although the level of protection decreased marginally with increasing home range size. Furthermore, individuals tagged outside the reserve received more protection with increasing home range size, potentially opposing selection toward smaller home range sizes inflicted on fish residing within reserves, or through selective fishing methods like angling. 5. Monthly sea trout home ranges in the marine environment were on average smaller than the reserve, with a mean of 0.430 (±0.0265 SE) km2. Hence, the reserve is large enough to protect the full home range of some individuals residing in the reserve. 6. Synthesis and applications: In general, the reserve protects sea trout to a varying degree depending on their individual behavior. These findings highlight evolutionary implications of spatial protection and can guide managers in the design of marine reserves and networks that preserve variation in target species' home range size and movement behavior.
Data from: Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system
Habitat discontinuity, anthropogenic disturbance, and overharvesting have led to population fragmentation and declines worldwide. Preservation of remaining natural genetic diversity is crucial to avoid continued genetic erosion. Brown trout (Salmo trutta L.) is an ideal model species for studying anthropogenic influences on genetic integrity, as it has experienced significant genetic alterations throughout its natural distribution range due to habitat fragmentation, overexploitation, translocations, and stocking. The Pasvik River is a subarctic riverine system shared between Norway, Russia and Finland, subdivided by seven hydroelectric power dams that destroyed about 70% of natural spawning and nursing areas. Stocking is applied in certain river parts to support the natural brown trout population. Adjacent river segments with different management strategies (stocked versus not stocked) facilitated the simultaneous assessment of genetic impacts of dams and stocking based on analyses of 16 short tandem repeat loci. Dams were expected to increase genetic differentiation between and reduce genetic diversity within river sections. Contrastingly, stocking was predicted to promote genetic homogenization and diversity, but also potentially lead to loss of private alleles and to genetic erosion. Our results showed comparatively low heterozygosity and clear genetic differentiation between adjacent sections in non-stocked river parts, indicating that dams prevent migration and contribute to genetic isolation and loss of genetic diversity. Furthermore, genetic differentiation was low and heterozygosity relatively high across stocked sections. However, in stocked river sections, we found signatures of recent bottlenecks and reductions in private alleles, indicating that only a subset of individuals contribute to reproduction, potentially leading to divergence away from the natural genetic state. Taken together, these results indicate that stocking counteracts the negative fragmentation effects of dams, but also that stocking practices should be planned carefully in order to ensure long-term preservation of natural genetic diversity and integrity in brown trout and other species in regulated river systems.
Data from: Effects of host genetics and environment on egg-associated microbiotas in brown trout (Salmo trutta)
Recent studies found fish egg-specific bacterial communities that changed over the course of embryogenesis, suggesting an interaction between the developing host and its microbiota. Indeed, single-strain infections demonstrated that the virulence of opportunistic bacteria is influenced by environmental factors and host immune genes. However, the interplay between a fish embryo host and its microbiota has not been studied yet at the community level. To test whether host genetics affects the assemblage of egg-associated bacteria, adult brown trout (Salmo trutta) were sampled from a natural population. Their gametes were used for full-factorial in vitro fertilizations to separate sire from dam effects. In total, 2520 embryos were singly raised under experimental conditions that differently support microbial growth. High-throughput 16S rRNA amplicon sequencing was applied to characterize bacterial communities on milt and fertilized eggs across treatments. Dam and sire identity influenced embryo mortality, time until hatching and composition of egg-associated microbiotas, but no link between bacterial communities on milt and on fertilized eggs could be found. Elevated resources increased embryo mortality and modified bacterial communities with a shift in their putative functional potential. Resource availability did not significantly affect any parental effects on embryo performance. Sire identity affected bacterial diversity that turned out to be a significant predictor of hatching time: embryos associated with high bacterial diversity hatched later. We conclude that both host genetics and the availability of resources define diversity and composition of egg-associated bacterial communities that then affect the life history of their hosts.
Data from: The effects of Medieval dams on genetic divergence and demographic history in brown trout populations
Background: Habitat fragmentation has accelerated within the last century, but may have been ongoing over longer time scales. We analyzed the timing and genetic consequences of fragmentation in two isolated lake-dwelling brown trout populations. They are from the same river system (the Gudenå River, Denmark) and have been isolated from downstream anadromous trout by dams established ca. 600-800 years ago. For reference, we included ten other anadromous populations and two hatchery strains. Based on analysis of 44 microsatellite loci we investigated if the lake populations have been naturally genetically differentiated from anadromous trout for thousands of years, or have diverged recently due to the establishment of dams. Results: Divergence time estimates were based on 1) Approximate Bayesian Computation and 2) a coalescent-based isolation-with-gene-flow model. Both methods suggested divergence times ca. 600-800 years bp, providing strong evidence for establishment of dams in the Medieval as the factor causing divergence. Bayesian cluster analysis showed influence of stocked trout in several reference populations, but not in the focal lake and anadromous populations. Estimates of effective population size using a linkage disequilibrium method ranged from 244 to > 1,000 in all but one anadromous population, but were lower (153 and 252) in the lake populations. Conclusions: We show that genetic divergence of lake-dwelling trout in two Danish lakes reflects establishment of water mills and impassable dams ca. 600-800 years ago rather than a natural genetic population structure. Although effective population sizes of the two lake populations are not critically low they may ultimately limit response to selection and thereby future adaptation. Our results demonstrate that populations may have been affected by anthropogenic disturbance over longer time scales than normally assumed.
Data from: Maternal allocation of carotenoids increases tolerance to bacterial infection in brown trout
Life-history theory predicts that iteroparous females allocate their resources differently among different breeding seasons depending on their residual reproductive value. In iteroparous salmonids there is typically much variation in egg size, egg number, and in the compounds that females allocate to their clutch. These compounds include various carotenoids whose functions are not sufficiently understood yet. We sampled 37 female and 35 male brown trout from natural streams, collected their gametes for in vitro fertilizations, experimentally produced 185 families in 7 full-factorial breeding blocks, raised the developing embryos singly (n = 2960), and either sham-treated or infected them with Pseudomonas fluorescens. We used female redness (as a measure of carotenoids stored in the skin) and their allocation of carotenoids to clutches to infer maternal strategies. Astaxanthin contents largely determined egg colour. Neither egg weight nor female size was correlated with the content of this carotenoid. However, astaxanthin content was positively correlated with larval growth and with tolerance against P. fluorescens. There was a negative correlation between female skin redness and the carotenoid content of their eggs. Although higher astaxanthin contents in the eggs were associated with an improvement of early fitness-related traits, some females appeared not to maximally support their current offspring as revealed by the negative correlation between female red skin colouration and egg carotenoid content. This correlation was not explained by female size and supports the prediction of a maternal trade-off between current and future reproduction.
Data from: Environmental stress linked to consumption of maternally derived carotenoids in brown trout embryos (Salmo trutta)
The yellow, orange, or red colors of salmonid eggs are due to maternally derived carotenoids whose functions are not sufficiently understood yet. Here, we studied the significance of naturally acquired carotenoids as maternal environmental effects during embryo development in brown trout (Salmo trutta). We collected eggs from wild females, quantified their egg carotenoid content, fertilized them in vitro in full-factorial breeding blocks to separate maternal from paternal effects, and raised 3,278 embryos singly at various stress conditions until hatching. We found significant sire effects that revealed additive genetic variance for embryo survival and hatching time. Dam effects were 5.4 times larger than these sire effects, indicating that maternal environmental effects play an important role in determining embryo stress tolerance. Of the eight pigment molecules that we targeted, only astaxanthin, zeaxanthin (that both affected egg redness), and lutein were detected above our confidence thresholds. No strong link could be observed between carotenoid content in unfertilized eggs and embryo mortality or hatching timing. However, the consumption of carotenoids during our stress treatment was negatively correlated to embryo survival among sib groups and explained about 14% of the maternal environmental variance. We conclude that maternally derived carotenoids play a role in the ability of embryos to cope with environmental stress, but that the initial susceptibility to the organic pollution was mainly determined by other factors.
Temperature regime during embryogenesis alters subsequent behavioural phenotypes of juvenile brown trout
<p><span>Climate warming imposes a serious threat, especially to freshwater ecosystems in temperate and (sub)polar regions, which are often dominated by cold-adapted ectotherms. Although relatively intense warming during winter is common across the climatic regions, comparably little focus has been put on the organismal impacts of winter warming. Embryonic development, which is exceptionally susceptible to ambient temperature, occurs during winter in various freshwater ectotherms. Yet, our knowledge of the effects of increased temperature during embryogenesis on later life stages is limited. Using brown trout (<em>Salmo trutta</em>), we examined how a 1.5°C temperature increase from fertilisation to hatching affects various traits at the onset of the free-swimming stage (i.e., a</span><span> compa</span><span>rison </span><span>between 3.5°C or 5.0°C treatments). Although all hatchlings were kept at the same temperature (7.0</span><span>°C)</span><span> from hatching to the onset of the free-swimming stage for about two months, the temperature increase during embryogenesis substantially reduced key ecological behaviours, i.e., activity and exploration levels, at the onset of the free-swimming stage despite only marginal temperature effects on morphological and physiological traits at this stage. Given the importance of behavioural traits in early growth and survival, our study suggests a likely pathway through which subtle changes in mean winter temperature affect early fitness.</span></p>
Data from: Melanin in a changing world: brown trout coloration reflects alternative reproductive strategies in variable environments
Melanins are the most widespread pigments in animals but their adaptive significance remains elusive. Recent studies suggest that intraspecific variation in melanin-based coloration reflects individual genetic-based alternative strategies to cope with environment variability, which could be crucial for their responses to climate changes. However, empirical evidence is still scarce. In this study, we tested how skin coloration in natural populations of brown trout Salmo trutta fario would reflect alternative reproductive strategies in different environments. We experimentally manipulated the flow regime (constant vs. variable) in artificial streams and compared the reproductive investment (body mass and plasma triglyceride variations), innate immunity (variations in plasma peroxidase and lysozyme activity) and reproductive success (number of mates and offspring) of differently colored brown trout over 2 reproductive seasons. Results show that darker males had a higher reproductive investment, but similar immune variations during reproduction compared to paler males. In addition, this reproductive investment was higher in variable environments. However, this did not translate into a higher reproductive success in variable environments, as darker males had a similar number of mates and offspring compared to their paler counterparts under a variable water flow. Since climate change will likely lead to an increased flow variability in the next decades, this suggests that darker brown trout could incur a higher energetic cost of reproduction and could be more impacted by climate changes than their paler counterparts. This highlights the need to take into account intraspecific variability to better forecast the response of natural populations to climate changes.
Data from: Consumption of carotenoids not increased by bacterial infection in brown trout embryos (Salmo trutta)
Carotenoids are organic pigment molecules that play important roles in signalling, control of oxidative stress, and immunity. Fish allocate carotenoids to their eggs, which gives them the typical yellow to red colouration and supports their resistance against microbial infections. However, it is still unclear whether carotenoids act mainly as a shield against infection or are used up during the embryos' immune defence. We investigated this question with experimental families produced from wild-caught brown trout (Salmo trutta). Singly raised embryos were either exposed to the bacterial pathogen Pseudomonas fluorescens or sham-treated at one of two stages during their development. A previous study on these experimental families reported positive effects of egg carotenoids on embryo growth and resistance against the infection. Here, we quantified carotenoid consumption, i.e. the active metabolization of carotenoids into compounds that are not other carotenoid types, in these infected and sham-infected maternal sib groups. We found that carotenoid contents mostly decreased during embryogenesis. However, these decreases were neither linked to the virulence induced by the pathogen nor dependent on the time point of infection. We conclude that egg carotenoids are not significantly used up by the embryos' immune defence.
Data from: Sixty years of anthropogenic pressure: a spatio-temporal genetic analysis of brown trout populations subject to stocking and population declines
Analyses of historical samples can provide invaluable information on changes to the genetic composition of natural populations resulting from human activities. Here, we analyze 21 microsatellite loci in historical (archived scales from 1927-1956) and contemporary samples of brown trout (Salmo trutta) from six neighbouring rivers in Denmark, to compare the genetic structure of wild populations before and after population declines and stocking with non-local strains of hatchery trout. We show that all populations have been strongly affected by stocking, with admixture proportions ranging from 14 to 64%. Historical population genetic structure was characterized by isolation-by-distance and by positive correlations between historical effective population sizes and habitat area within river systems. Contemporary population genetic structure still showed isolation-by-distance, but also reflected differences among populations in hatchery trout admixture proportions. Despite significant changes to the genetic composition within populations over time, dispersal rates among populations were roughly similar before and after stocking. We also assessed whether population declines or introgression by hatchery strain trout should be the most significant conservation concern in this system. Based on theoretical considerations, we argue that population declines have had limited negative effects for the persistence of adaptive variation, but admixture with hatchery trout may have resulted in reduced local adaptation. Collectively, our study demonstrates the usefulness of analyzing historical samples for identifying the most important consequences of human activities on the genetic structure of wild populations.
Repeated elevational clines of early life-history traits and their proximate mechanisms in brown trout
<p><span>1. Climate warming imposes a severe threat to freshwater ecosystems, which are dominated by ectotherms such as fish and aquatic insects. To better predict the effects of climate warming on thermally sensitive ecosystems, information on how temperature affects individual traits </span><span>within populations</span><span> is fundamental.</span></p> <p><span>2. Patterns of intraspecific variation in thermal reaction norms along geographic thermal gradients provide valuable information. </span><span>Immediate</span><span> temperature effects on individual traits can be inferred from the shape of the thermal reaction norm. </span><span>The way that</span><span> temperature and associated environmental conditions </span><span>(</span><span>to which populations have been exposed over generations</span><span>)</span><span> affect individual traits through </span><span>transgenerational plasticity in</span><span>,</span><span> and/or </span><span>natural selection on</span><span>,</span><span> </span><span>these</span><span> traits can also be inferred from patterns of trait variation along </span><span>a</span><span> geographic thermal gradient. </span></p> <p><span>3. Many studies have documented patterns of intraspecific variation in thermal reaction norms along geographic thermal gradients. However, most previous studies cannot exclude the possibility that the observed geographic patterns are solely explained by random processes, such as isolation by distance, due to the lack of </span><span>replication of</span><span> geographic gradients. Here, we show consistent patterns in intraspecific trait variation along geographic thermal gradients using <em>Salmo</em> <em>trutta</em> </span><span>(</span><span>brown trout</span><span>)</span><span>, which is an ecologically and economically important fish in alpine streams. </span></p> <p><span>4. We kept trout embryos collected from 52 families from 14 populations along wide and replicated elevational gradients from three Alpine drainages (Danube, Po, and Rhine) in two temperature treatments (3.2 and 6.2 °C). Timing and body size at emergence from the nest, which are key early life-history traits of trout affecting their early growth and survival, were measured. </span></p> <p><span>5. </span><span>Besides faster embryonic development at warmer temperatures, we found that offspring from low-elevation parents took</span><span> very</span><span> slightly more days to </span><span>reach</span><span> emergence </span><span>from fertilisation</span><span> and were larger than offspring from high-elevation parents. Importantly, this was evident for all three drainages. Further analyses found that the higher number of days until- and larger body length at- emergence of low-elevation trout were mainly due to the larger eggs laid by low-elevation females, which </span><span>had</span><span> larger body size than high-elevation females. </span></p> <p><span>6.</span><span> Trout female body size, which is positively correlated with egg size, is susceptible to temperatures and associated environmental conditions. </span><span>Consequently</span><span>, climate warming </span><span>may</span><span> not only </span><span>immediately</span><span> accelerate development rate but also shift timing and size at emergence through egg-size-mediated maternal effects within a relatively short time scale.</span></p>
Data from: Environmental stress linked to consumption of maternally derived carotenoids in brown trout embryos (Salmo trutta)
Open the record for dataset details and reuse information.
Data from: Sixty years of anthropogenic pressure: a spatio-temporal genetic analysis of brown trout populations subject to stocking and population declines
Open the record for dataset details and reuse information.
Data from: Identifying footprints of selection in stocked brown trout populations: a spatio-temporal approach
Open the record for dataset details and reuse information.
Data from: Mating patterns and determinants of individual reproductive success in brown trout (Salmo trutta) revealed by parentage analysis of an entire stream living population
Open the record for dataset details and reuse information.
Data from: The male handicap: male-biased mortality explains skewed sex ratios in brown trout embryos
Open the record for dataset details and reuse information.
Data from: Short-term genetic changes: evaluating effective population size estimates in a comprehensively described brown trout (Salmo trutta) population
Open the record for dataset details and reuse information.
Data from: Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system
Open the record for dataset details and reuse information.
Data from: Small coastal streams – critical reservoirs of genetic diversity for brown trout in the face of increasing anthropogenic stressors
Open the record for dataset details and reuse information.
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.