The structure of parasite component communities in brackish water fishes of the northeastern Baltic Sea

2001

We used nestedness analysis to seek non-random patterns in the structure of component communities of metazoan parasites collected from 31 sympatric fish species from the northeastern Bothnian Bay, the most oligohaline area of the Baltic Sea. Only 8 marine parasite species were found among the 63 species recorded, although some marine fish species reproduce in the bay and others occasionally visit the area. Marine parasite species can utilize both freshwater and marine fish species as intermediate or final hosts, and marine fish can harbour freshwater parasite species. This exchange of parasite species between marine and freshwater fish has probably resulted from ecological factors acting ov…

Environment may be the source of Flavobacterium columnare outbreaks at fish farms

2012

Summary Flavobacterium columnare, causing columnaris disease, was isolated for the first time from free water and biofilms in the environment outside fish farms. Fourteen isolates were found from Central Finland from a river by a water intake of a salmonid farm and 400 m upstream of the farm. One isolate was from a lake not under the influence of any fish farming. The bacterium could not be isolated from five other lakes in Central Finland or from three lakes in Eastern Finland, none of them in use for fish farming. Among the environmental isolates there was both genetic variability and difference in virulence, but the isolates were less virulent than the isolates originating from a disease…

Food stoichiometry affects the outcome of Daphnia–parasite interaction

2013

Phosphorus (P) is an essential nutrient for growth in consumers. P-limitation and parasite infection comprise one of the most common stressor pairs consumers confront in nature. We conducted a life-table study using a Daphnia–microsporidian parasite model, feeding uninfected or infected Daphnia with either P-sufficient or P-limited algae, and assessed the impact of the two stressors on life-history traits of the host. Both infection and P-limitation negatively affected some life-history traits tested. However, under P-limitation, infected animals had higher juvenile growth rate as compared with uninfected animals. All P-limited individuals died before maturation, regardless of infection. Th…

Screening of microalgae and LED grow light spectra for effective removal of dissolved nutrients from cold-water recirculating aquaculture system (RAS…

2019

Popularity of recirculating aquaculture systems (RAS) is increasing. Because of the high water recirculation rate, dissolved nutrients originating from fish feed are concentrated enough in RAS wastewater (WW) to enable growth of primary producers, e.g. microalgae. This study evaluated nitrate-nitrogen (NO3-N) and phosphate-phosphorus (PO4-P) removal efficiency of ten temperate zone freshwater microalgae species during their exponential growth phase in unfiltered RAS WW at 17 ± 0.5 °C. Growth and nutrient uptake efficiency of six green and four non-green microalgae strains were compared between WW and reference growth medium in batch monocultures. The effect of three different LED grow light…

No uniform associations between parasite prevalence and environmental nutrients

2014

The resource quality of the host has been shown to affect parasite transmission success, prevalence, and virulence. Seasonal availability of environmental nutrients alters density and stoichiometric quality (carbon–nutrient ratios) of both producers and consumers, suggesting that nutrient availability may drive fluctuations in parasite prevalence patterns observed in nature. We examined the interactions between the population dynamics of a keystone herbivore, Daphnia, and its parasites, and their associations with water nutrient concentrations, resource quantity and quality, and other environmental variables (temperature, pH, oxygen concentration) in a small lake, using general linear model…

Filtration of Nordic recirculating aquaculture system wastewater: Effects on microalgal growth, nutrient removal, and nutritional value

2021

Abstract Microalgal bioremediation of recirculating aquaculture system (RAS) wastewater represents an alternative for wastewater treatment with the potential to generate valuable biomass. This study evaluated the effects of removing biological contamination and suspended solids from Nordic area RAS wastewater through filtration with 0.45 μm filters on the performance and nutritional value of microalgae. All three tested green microalgae (Haematococcus pluvialis, Monoraphidium griffithii, and Selenastrum sp.) were able to grow in raw (unfiltered) and filtered RAS wastewater. Cultivation in raw RAS wastewater decreased the ω-3 and ω-6 fatty acid content of H. pluvialis as compared to filtered…

Thermal Tolerance is linked with Virulence in a Fish Pathogen

2017

ABSTRACTAlthough increase in temperatures may boost the number of pathogens, a complex process involving the interaction of a susceptible host, a virulent strain, and environmental factors would influence disease virulence in unpredictable ways. Here we explored if the virulence of an environmentally growing opportunistic fish pathogen,Flavobacterium columnare, would be malleable to evolutionary changes via correlated selection on thermal tolerance. Virulence among the strains increased over years, but tolerance to higher temperatures was associated with reduced virulence. Our results suggest that observed increase in frequency of columnaris epidemics over the last decade is most likely ass…

EFFECT OF TRIAENOPHORUS CRASSUS (CESTODA) INFECTION ON BEHAVIOR AND SUSCEPTIBILITY TO PREDATION OF THE FIRST INTERMEDIATE HOST CYCLOPS STRENUUS (COPE…

2000

Some parasites have been shown to manipulate host behavior so that parasite transmission to the next host is enhanced. Infection with Triaenophorus crassus Forel (Cestoda) caused alterations in the activity and microhabitat selection of the first intermediate host Cyclops strenuus Fischer (Copepoda) in the laboratory. Infected copepods made more starts to swim but spent less time swimming than uninfected copepods. These changes were independent of the intensity of infection. In a water column illuminated from above, infected copepods approached the surface, whereas uninfected ones remained close to the bottom. In the dark both infected and uninfected copepods stayed near the bottom. Finally…

Rich resource environment of fish farms facilitates phenotypic variation and virulence in an opportunistic fish pathogen

2020

Phenotypic variation is suggested to facilitate the persistence of environmentally growing pathogens under environmental change. Here, we hypothesized that the intensive farming environment induces higher phenotypic variation in microbial pathogens than natural environment, because of high stochasticity for growth and stronger survival selection compared to the natural environment. We tested the hypothesis with an opportunistic fish pathogen Flavobacterium columnare isolated either from fish farms or from natural waters. We measured growth parameters of two morphotypes from all isolates in different resource concentrations and two temperatures relevant for the occurrence of disease epidemic…

Phosphorus limitation enhances parasite impact: feedback effects at the population level

2014

Background Nutrient deficiency affects the growth and population dynamics of consumers. Endoparasites can be seen as consumers that drain carbon (C) or energy from their host while simultaneously competing for limiting resources such as phosphorus (P). Depending on the relative demands of the host and the parasite for the limiting nutrient, intensified resource competition under nutrient limitation can either reduce the parasite’s effect on the host or further reduce the fitness of the nutrient-limited host. So far, knowledge of how nutrient limitation affects parasite performance at the host population level and how this affects the host populations is limited. Results We followed the popu…

Higher resource level promotes virulence in an environmentally transmitted bacterial fish pathogen

2017

Diseases have become a primary constraint to sustainable aquaculture, but remarkably little attention has been paid to a broad class of pathogens: the opportunists. Opportunists often persist in the environment outside the host, and their pathogenic features are influenced by changes in the environment. To test how environmental nutrient levels influence virulence, we used strains of Flavobacterium columnare, an environmentally transmitted fish pathogen, to infect rainbow trout and zebra fish in two different nutrient concentrations. To separate the effects of dose and nutrients, we used three infective doses and studied the growth of bacteria in vitro. High nutrient concentration promoted …

Indirect effects of invasive crayfish on native fish parasites

2013

Interactions between invasive and native species are often modified by parasites. One little-studied scenario is that invasive species affect parasite transmission to native hosts by altering the relative abundance of hosts needed in parasite life cycles, for example by predation on these hosts. Here we show that presence of an invasive crayfish species, Pacifastacus leniusculus, decreases the mean abundance of native parasites transmitted from snails and aquatic isopods to perch, Perca fluviatilis, in two large boreal lakes in Finland. In contrast, parasites transmitted to the fish from planktonic copepods or mussels, hosts not readily preyed on by crayfish, were not affected by crayfish p…

Glochidial infection by the endangered Margaritifera margaritifera (Mollusca) increased survival of salmonid host (Pisces) during experimental Flavob…

2021

AbstractCo-infections are common in host-parasite interactions, but studies about their impact on the virulence of parasites/diseases are still scarce. The present study compared mortality induced by a fatal bacterial pathogen, Flavobacterium columnare between brown trout infected with glochidia from the endangered freshwater pearl mussel, Margaritifera margaritifera, and uninfected control fish during the parasitic period and after the parasitic period (i.e. glochidia detached) in a laboratory experiment. We hypothesised that glochidial infection would increase host susceptibility to and/or pathogenicity of the bacterial infection. We found that the highly virulent strain of F. columnare c…

Does the freshwater mussel Anodonta anatina remove the fish pathogen Flavobacterium columnare from water?

2021

AbstractGlobal decline of freshwater mussels (Unionoida) is threatening biodiversity and the essential ecosystem services that mussels provide. As filter-feeding organisms, freshwater mussels remove phytoplankton and suspended particles from the water. By filtering bacteria, freshwater mussels also decrease pathogen loads in the water. The objective of this study was to evaluate whether the common freshwater bivalve Anodonta anatina (duck mussel) could remove the bacterial fish pathogen Flavobacterium columnare from the water. Mussels reduced bacteria in both of the two experiments performed, so that the bacterial concentration at the end of the 96-h monitoring in mussel treatments was only…

Supplementing air with CO2 stripped from recirculating aquaculture improves growth of two green microalgae in aquaculture wastewater

2023

To improve sustainability and to implement the principles of circular economy in aquaculture, we tested the possibility to boost the capture of nitrate by two green microalgal species from recirculating aquaculture system's (RAS) wastewater by supplementing air with carbon dioxide stripped from a RAS. Carbon dioxide addition increased cell densities of Monoraphidium griffithii and Haematococcus pluvialis in photobioreactors during 9-day growing periods. However, growth rates and nitrate uptake rates were only improved for M. griffithii. Addition of CO2 decreased pH of the medium with M. griffithii which likely also affected positively on algal growth and nutrient uptake. These laboratory sc…

The influence of food competition and host specificity on the transmission of Triaenophorus crassus (Cestoda) and Cystidicola farionis (Nematoda) to …

2000

Abstract As a superior competitor for planktonic food, vendace ( Coregonus albula ), when abundant, is expected to displace whitefish ( Coregonus lavaretus ) from feeding on plankton and to force it to rely more on benthic food. The predicted result would be a reduced abundance of the copepod-transmitted cestode Triaenophorus crassus in whitefish, but an increase in the abundance of the nematode Cystidicola farionis transmitted via benthic amphipods. We studied the occurrence of both parasites in whitefish during 1991–1996 in three interconnected areas at Lake Saimaa, Finland, where the densities of the vendace stocks varied due to natural fluctuation in year-class strengths. In accordance …

Intensive fish farming and the evolution of pathogen virulence: the case of columnaris disease in Finland.

2009

Ecological changes affect pathogen epidemiology and evolution and may trigger the emergence of novel diseases. Aquaculture radically alters the ecology of fish and their pathogens. Here we show an increase in the occurrence of the bacterial fish disease Flavobacterium columnare in salmon fingerlings at a fish farm in northern Finland over 23 years. We hypothesize that this emergence was owing to evolutionary changes in bacterial virulence. We base this argument on several observations. First, the emergence was associated with increased severity of symptoms. Second, F. columnare strains vary in virulence, with more lethal strains inducing more severe symptoms prior to death. Third, more vir…

The influence of bacteria-dominated diets on Daphnia magna somatic growth, reproduction, and lipid composition

2012

We explored how dietary bacteria affect the life history traits and biochemical composition of Daphnia magna, using three bacteria taxa with very different lipid composition. Our objectives were to (1) examine whether and how bacteria-dominated diets affect Daphnia survival, growth, and fecundity, (2) see whether bacteria-specific fatty acid (FA) biomarkers accrued in Daphnia lipids, and (3) explore the quantitative relationship between bacteria availability in Daphnia diets and the amounts of bacterial FA in their lipids. Daphnia were fed monospecific and mixed diets of heterotrophic (Micrococcus luteus) or methanotrophic bacteria (Methylomonas methanica and Methylosinus trichosporium) and…

Application of high resolution melting assay (HRM) to study temperature-dependent intraspecific competition in a pathogenic bacterium

2017

AbstractStudies on species’ responses to climate change have focused largely on the direct effect of abiotic factors and in particular temperature, neglecting the effects of biotic interactions in determining the outcome of climate change projections. Many microbes rely on strong interference competition; hence the fitness of many pathogenic bacteria could be a function of both their growth properties and intraspecific competition. However, due to technical challenges in distinguishing and tracking individual strains, experimental evidence on intraspecific competition has been limited so far. Here, we developed a robust application of the high-resolution melting (HRM) assay to study head-to…

The Effect of Echinorhynchus borealis (Acanthocephala) Infection on the Anti-Predator Behavior of a Benthic Amphipod

2008

In benthic habitats, predators can generally not be detected visually, so olfaction may be particularly important for inducing anti-predation behaviors in prey organisms. Manipulative parasites infecting benthic hosts could suppress these responses so as to increase the probability of predation and thus trophic transmission. We studied how infection with the acanthocephalan Echinorhynchus borealis affects the response of the benthic amphipod Pallasea quadrispinosa to water conditioned by burbot (Lota lota), the parasite's definitive host. In normal lake water, refuge use by infected and uninfected amphipods was similar, but when exposed to burbot-conditioned water, uninfected amphipods spen…

Accumulation of plerocercoids of Triaenophorus crassus in the second intermediate host Coregonus lavaretus and their effect on growth of the host

1999

Patterns of accumulation of Triaenophorus crassus in its second intermediate host whitefish Coregonus lavaretus s.l. were studied between 1991 and 1996 from two host populations in two separate areas of Lake Saimaa, Finland. Whitefish were infected commonly with several T. crassus plerocercoids and the parasites were aggregated into the oldest hosts. In one host population the annual parasite accumulation was 0·9 parasites in all host age groups between 3 and 8 years. In the other host population the annual accumulation was 1·6 parasites in 3–5-year-old fish, but increased up to 3 to 4 parasites per year in fish over 5 years old. The increase did not coincide with the period of maturation o…

Broad thermal tolerance is negatively correlated with virulence in an opportunistic bacterial pathogen

2018

Predicting the effects of global increase in temperatures on disease virulence is challenging, especially for environmental opportunistic bacteria, because pathogen fitness may be differentially affected by temperature within and outside host environment. So far, there is very little empirical evidence on the connections between optimal temperature range and virulence in environmentally growing pathogens. Here, we explored whether the virulence of an environmentally growing opportunistic fish pathogen, Flavobacterium columnare, is malleable to evolutionary changes via correlated selection on thermal tolerance. To this end, we experimentally quantified the thermal performance curves (TPCs) f…

A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2015

Background Columnaris disease caused by Flavobacterium columnare is a serious problem in aquaculture, annually causing large economic losses around the world. Despite considerable research, the molecular epidemiology of F. columnare remains poorly understood. Methods We investigated the population structure and spatiotemporal changes in the genetic diversity of F. columnare population in Finland by using a multilocus sequence typing (MLST) and analysis (MLSA) based on DNA sequence variation within six housekeeping genes. A total of 83 strains of F. columnare were collected from eight different areas located across the country between 2003 and 2012. Results Partial sequencing of six housekee…

Effect of resource availability on evolution of virulence and competition in an environmentally transmitted pathogen

2018

Understanding ecological and epidemiological factors driving pathogen evolution in contemporary time scales is a major challenge in modern health management. Pathogens that replicate outside the hosts are subject to selection imposed by ambient environmental conditions. Increased nutrient levels could increase pathogen virulence by pre-adapting for efficient use of resources upon contact to a nutrient rich host or by favouring transmission of fast-growing virulent strains. We measured changes in virulence and competition in Flavobacterium columnare, a bacterial pathogen of freshwater fish, under high and low nutrient levels. To test competition between strains in genotype mixtures, we devel…

Lowered nutritional quality of prey decrease the growth and biomolecule content of rainbow trout fry

2022

Diet quality is crucial for the development of offspring. Here, we examined how the nutritional quality of prey affects somatic growth and the lipid, carbohydrate, protein, amino acid, and polyunsaturated fatty acid content of rainbow trout (Oncorhynchus mykiss) fry using a three-trophic-level experimental setup. Diets differed especially in their content of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are physiologically essential polyunsaturated fatty acids for a fish fry. Trout were fed with an artificial diet (fish feed, DHA-rich), marine zooplankton diet (krill/Mysis, DHA-rich), or freshwater zooplankton diet (Daphnia, Cladocera, DHA-deficient). The Daphnia were gr…

Comparison of muscle and hair stable isotope ratios in three phocid seals

2020

Parasite infection alters host stable-isotope composition under controlled feeding

2016

1) Stable isotopes are widely used for studying trophic relationships, but variation driven by environmental conditions or food availability complicates the interpretation of trophic dynamics. Parasites are ubiquitous and known to affect physiological functions of their hosts, but only few studies have assessed the effects of parasites on isotope composition of hosts. 2) We measured the changes in two of the most commonly used stable isotopes in food-web studies, nitrogen (i.e. 15N:14N ratio; denoted as δ15N) and carbon (13C:12C; δ13C) in Daphnia hosts exposed to infection by a parasitic micosporidian in the laboratory. Isotopic signatures of hosts fed a standardised controlled diet were co…

Factors affecting abundance of Triaenophorus infection in Cyclops strenuus, and parasite-induced changes in host fitness.

2000

Factors affecting the abundance of Triaenophorus crassus and Triaenophorus nodulosus procercoids in their copepod first intermediate host, Cyclops strenuus, and effects of infection on feeding behaviour, reproduction and survival of the host were studied experimentally. When exposed to the same number of coracidia, copepods harboured considerably less procercoids in the trials where ciliates or Artemia salina nauplii were given as alternative food items. The prevalence of infection was higher in adult copepods as compared with copepodite stage IV and stage V, and higher in stage V than in stage IV. The prevalences in adult females and males did not differ significantly from each other. The …

Efficiency of Daphnia magna in removal of green microalgae cultivated in Nordic recirculating aquaculture system wastewater

2020

The increase of global aquaculture production has boosted the development of recirculating aquaculture systems not only because they reduce water use but also provide opportunities for waste management and the use of released nutrients. The dissolved nutrients can be efficiently removed from recirculating aquaculture system wastewater by microalgae, and microalgae can be harvested from the wastewater with low costs by zooplankton such as Daphnia. The purpose of this study was to evaluate the feasibility of using microalgae and Daphnia for bioremediation of recirculating aquaculture system wastewater in Nordic conditions. We evaluated the growth and filtration efficiency of the waterflea Dap…

A three-way perspective of stoichiometric changes on host–parasite interactions

2015

Changes in environmental nutrients play a crucial role in driving disease dynamics, but global patterns in nutrient-driven changes in disease are difficult to predict. In this paper we use ecological stoichiometry as a framework to review host–parasite interactions under changing nutrient ratios, focusing on three pathways: (i) altered host resistance and parasite virulence through host stoichiometry (ii) changed encounter or contact rates at population level, and (iii) changed host community structure. We predict that the outcome of nutrient changes on host–parasite interactions depends on which pathways are modified, and suggest that the outcome of infection could depend on the overlap in…

Genome size evolution in macroparasites.

2014

Reduction in genome size has been associated not only with a parasitic lifestyle in intracellular microparasites but also in some macroparasitic insects and nematodes. We collected the available data on genome size for flatworms, annelids, nematodes and arthropods, compared those with available data for the phylogenetically closest free-living taxa and found evidence of smaller genome sizes for parasites in six of nine comparisons. Our results suggest that despite great differences in evolutionary history and life cycles, parasitism as a lifestyle promotes convergent genome size reduction in macroparasites. We discuss factors that could be associated with small genome size in parasites whic…

Additional file 6 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

The concatenated tree based on six housekeeping MLSA genes (including trpB; right) and five MLSA gene sequences (rpoD, dnaK, tuf, gyrB, atpA; left). The arrow shows disagreement concerning the position of strain G2 (B399) between the two trees. (PDF 77 kb)

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Additional file 1 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

Site, year of isolation, source of isolation (fish or water), location of isolation, host species, sequence type (ST), and allelic profile data for the 83Â F. columnare strains from Finland analyzed by MLST. (DOCX 46 kb)

Filtration of Nordic recirculating aquaculture system wastewater : Effects on microalgal growth, nutrient removal, and nutritional value

2021

Microalgal bioremediation of recirculating aquaculture system (RAS) wastewater represents an alternative for wastewater treatment with the potential to generate valuable biomass. This study evaluated the effects of removing biological contamination and suspended solids from Nordic area RAS wastewater through filtration with 0.45 μm filters on the performance and nutritional value of microalgae. All three tested green microalgae (Haematococcus pluvialis, Monoraphidium griffithii, and Selenastrum sp.) were able to grow in raw (unfiltered) and filtered RAS wastewater. Cultivation in raw RAS wastewater decreased the ω-3 and ω-6 fatty acid content of H. pluvialis as compared to filtered wastewat…

Additional file 4 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

The fluorescence peak profiles for the ARISA genotypes analysed with ABI Prism 3130xl Genetic Analyser and the GeneMapper v.5.0 software (Applied Biosystems, Carlsbad, California, USA). For the 83 strains isolated from Finland, we also determined the ARISA (automated ribosomal intergenic spacer analysis) genotypes following the procedure described by Suomalainen et al. [8]. However, the previously published method was modified so that ABI Prism 3130xl Genetic Analyser is used instead of LI-COR 4200 automatic sequencer The analysis revealed that ARISA genotypes associate uniformly with the clusters from the MLSA scheme. Briefly, the PCR reaction mixture (total volume 10 ul) contained 1X Drea…

Additional file 3 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

Neighbor Joining phylogenetic trees based on the individual sequences of six MLST loci (trpB, rpoD, gyrB, dnaK, atpA,and tuf). MEGA v5.2 was used to evaluate the models for nucleotide substitution for each protein-coding locus and to construct the phylogenetic trees for Finnish F. columnare strains. The F. columnare type strain NCIMB 2248T isolated in the USA and two reference strains JIP39/87 and ATCC49512, both isolated in France, were also included in the phylogenetic analysis. The best model indicated by the lowest Bayesian Information Criterion (BIC) value was used to generate the Neighbor-Joining tree based on 1000 replicates. The T92 model was selected for dnaK, tuf, and gyrB, while …

Additional file 2 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

Target genes and primers for the housekeeping genes of F. columnare. The loci used for the MLST/MLSA scheme are shown in bold font. Length refers to the length of the target sequence. * Reference for 16S rDNA primers [52]. (DOCX 20 kb)

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Additional file 2 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

Target genes and primers for the housekeeping genes of F. columnare. The loci used for the MLST/MLSA scheme are shown in bold font. Length refers to the length of the target sequence. * Reference for 16S rDNA primers [52]. (DOCX 20 kb)

Does differential iron supply to algae affect Daphnia life history? : An ionome-wide study

2019

The availability of iron (Fe) varies considerably among diet items, as well as ecosystems. Availability of Fe has also changed due to anthropogenic environmental changes in oceanic as well as inland ecosystems. We know little about its role in the nutrition of ecologically important consumers, particularly in inland ecosystems. Physiological studies in several taxa indicate marked effects of dietary Fe on oogenesis. We predicted that differential Fe supply to algae will impact algal Fe concentration with consequences on the life history of the freshwater grazer, Daphnia magna. We found that algal Fe concentration increased with Fe supply, but did not affect algal growth, indicating that the…

Additional file 5 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

Phylogenetic tree based on the 16Â s rDNA sequence data obtained from the representatives of Finnish F .columnare genotypes (A-H) studied in this study and other F .columnare sequences obtained from the GenBank. The tree was constructed by a UPGMA clustering method with a resampling of 1,000 bootstrap replicates and the Jukes Cantor model. Two strains representative of each ARISA genotype/MLSA cluster studied in this study were used for tree construction (identical sequences removed for clarity of representation). (PDF 191 kb)

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

2019

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Appendix B. Supplementary results: description of stratification and ice cover, environmental variables, elemental composition of Daphnia, and propor…

2016

Supplementary results: description of stratification and ice cover, environmental variables, elemental composition of Daphnia, and proportion of Daphnia infected with Larssonia obtusa and Pasteuria ramosa during the study period.

Appendix A. Description of the study site, sampling procedure, and chemical analysis.

2016

Description of the study site, sampling procedure, and chemical analysis.

Data from: Broad thermal tolerance is negatively correlated with virulence in an opportunistic bacterial pathogen

2018

Predicting the effects of global increase in temperatures on disease virulence is challenging, especially for environmental opportunistic bacteria, because pathogen fitness may be differentially affected by temperature within and outside host environment. So far, there is very little empirical evidence on the connections between optimal temperature range and virulence in environmentally growing pathogens. Here we explored if the virulence of an environmentally growing opportunistic fish pathogen, Flavobacterium columnare, is malleable to evolutionary changes via correlated selection on thermal tolerance. To this end, we experimentally quantified the thermal performance curves (TPCs) for max…

Data from: Higher resource level promotes virulence in an environmentally transmitted bacterial fish pathogen

2017

Diseases have become a primary constraint to sustainable aquaculture, but remarkably little attention has been paid to a broad class of pathogens: the opportunists. Opportunists often persist in the environment outside the host and their pathogenic features are influenced by changes in the environment. To test how environmental nutrient levels influence virulence, we used strains of Flavobacterium columnare, an environmentally transmitted fish pathogen, to infect rainbow trout and zebra fish in two different nutrient concentrations. To separate the effects of dose and nutrients, we used three infective doses and studied the growth of bacteria in vitro. High nutrient concentration promoted b…

Data from: Phosphorus limitation enhances parasite impact: feedback effects at the population level

2014

Background: Nutrient deficiency affects the growth and population dynamics of consumers. Endoparasites can be seen as consumers that drain carbon (C) or energy from their host while simultaneously competing for limiting resources such as phosphorus (P). Depending on the relative demands of the host and the parasite for the limiting nutrient, intensified resource competition under nutrient limitation can either reduce the parasite?s effect on the host or further reduce the fitness of the nutrient-limited host. So far, knowledge of how nutrient limitation affects parasite performance at the host population level and how this affects the host populations is limited. Results: We followed the po…

The use of biological traps for water treatment in Recirculating Aquaculture Systems

2018

Increasing global demand for fish and the depletion of natural fish stocks has stimulated the development of aquaculture all over the world. One of the main restrictions for future growth and sustainability of the aquaculture lies in its waste discharge. The main concern includes dissolved or particulate organics, nitrogen and phosphorus, which may lead to eutrophication of aquatic ecosystems receiving the wastewaters. Therefore, nutrient removal is essential for aquaculture wastewater treatment for protection of the surrounding environment. Recirculating aquaculture systems (RAS), enable fish production in relative isolation from the surrounding environment, and they offer advantages in term…

Research data of an article: "Application of high resolution melting assay (HMR) to study temperature dependent infraspecific competition in an patho…

2017

Studies on species’ responses to climate change have focused largely on the direct effect of abiotic factors and in particular temperature, neglecting the effects of biotic interactions in determining the outcome of climate change projections. Many microbes rely on strong interference competition; hence the fitness of many pathogenic bacteria could be a function of both their growth properties and intraspecific competition. However, due to technical challenges in distinguishing and tracking individual strains, experimental evidence on intraspecific competition has been limited so far. Here, we developed a robust application of the high-resolution melting (HRM) assay to study head-to-head co…

Original data for article: Filtration of Nordic recirculating aquaculture system wastewater: effects on microalgal growth, nutrient removal and nutri…

2020

The data processed and analyzed in this study is divided if five files: Growth_and_Nutrient_removal.txt, FA_concentration.txt, FA_proportion.txt, AA_concentration.txt and AA_proportion.txt. For detailed descriptions of the motives, methods and results of the study, see the article.