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Ralf Schulz - One of the best experts on this subject based on the ideXlab platform.
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detection of the endangered european weather loach Misgurnus fossilis via water and sediment samples testing multiple edna workflows
Ecology and Evolution, 2020Co-Authors: Lena Maureen Kusanke, Ralf Schulz, Egbert Korte, Jorn Panteleit, Stefan Stoll, Eike Sunger, Kathrin TheissingerAbstract:The European weather loach (Misgurnus fossilis) is classified as highly endangered in several countries of Central Europe. Populations of M. fossilis are predominantly found in ditches with low water levels and thick sludge layers and are thus hard to detect using conventional fishing methods. Therefore, environmental DNA (eDNA) monitoring appears particularly relevant for this species. In previous studies, M. fossilis was surveyed following eDNA water sampling protocols, which were not optimized for this species. Therefore, we created two full factorial study designs to test six different eDNA workflows for sediment samples and twelve different workflows for water samples. We used qPCR to compare the threshold cycle (C t) values of the different workflows, which indicate the target DNA amount in the sample, and spectrophotometry to quantify and compare the total DNA amount inside the samples. We analyzed 96 water samples and 48 sediment samples from a pond with a known population of M. fossilis. We tested several method combinations for long-term sample preservation, DNA capture, and DNA extraction. Additionally, we analyzed the DNA yield of samples from a ditch with a natural M. fossilis population monthly over one year to determine the optimal sampling period. Our results showed that the long-term water preservation method commonly used for eDNA surveys of M. fossilis did not lead to optimal DNA yields, and we present a valid long-term sample preservation alternative. A cost-efficient high salt DNA extraction led to the highest target DNA yields and can be used for sediment and water samples. Furthermore, we were able to show that in a natural habitat of M. fossilis, total and target eDNA were higher between June and September, which implies that this period is favorable for eDNA sampling. Our results will help to improve the reliability of future eDNA surveys of M. fossilis.
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towards more ecological relevance in sediment toxicity testing with fish evaluation of multiple bioassays with embryos of the benthic weatherfish Misgurnus fossilis
Science of The Total Environment, 2018Co-Authors: Benjamin Schreiber, Henner Hollert, Jonas Fischer, Sabrina Schiwy, Ralf SchulzAbstract:The effects of sediment contamination on fish are of high significance for the protection of ecosystems, human health and economy. However, standardized sediment bioassays with benthic fish species, that mimic bioavailability of potentially toxic compounds and comply with the requirements of alternative test methods, are still scarce. In order to address this issue, embryos of the benthic European weatherfish (Misgurnus fossilis) were exposed to freeze-dried sediment (via sediment contact assays (SCA)) and sediment extracts (via acute fish embryo toxicity tests) varying in contamination level. The extracts were gained by accelerated solvent extraction with (i) acetone and (ii) pressurized hot water (PHWE) and subsequently analyzed for polycyclic aromatic hydrocarbons, polychlorinated biphenyls and polychlorinated dibenzodioxins and dibenzofurans. Furthermore, embryos of the predominately used zebrafish (Danio rerio) were exposed to extracts from the two most contaminated sediments. Results indicated sufficient robustness of weatherfish embryos towards varying test conditions and sensitivity towards relevant sediment-bound compounds. Furthermore, a compliance of effect concentrations derived from weatherfish embryos exposed to sediment extracts (96h-LC50) with both measured gradient of sediment contamination and previously published results was observed. In comparison to zebrafish, weatherfish embryos showed higher sensitivity to the bioavailability-mimicking extracts from PHWE but lower sensitivity to extracts gained with acetone. SCAs conducted with weatherfish embryos revealed practical difficulties that prevented an implementation with three of four sediments tested. In summary, an application of weatherfish embryos, using bioassays with sediment extracts from PHWE might increase the ecological relevance of sediment toxicity testing: it allows investigations using benthic and temperate fish species considering both bioavailable contaminants and animal welfare concerns.
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reintroduction and stock enhancement of european weatherfish Misgurnus fossilis l in rhineland palatinate and hesse germany
Knowledge and Management of Aquatic Ecosystems, 2018Co-Authors: Benjamin Schreiber, Egbert Korte, Thomas Schmidt, Ralf SchulzAbstract:A stocking program for the endangered European weatherfish (Misgurnus fossilis L.) was conducted in the German federal states of Rhineland-Palatinate and Hesse, southwest Germany. An initial monitoring enabled to identify local broodstock and to assess habitats regarding their ecological suitability for reintroduction. In a second step, broodstock were caught for artificial propagation and cultured fry were released in previously selected river sectors. Furthermore, reintroduction sectors were biannually monitored to assess stocking success. Within the study period (2014–2016), a total number of approximately 83,500 juveniles were stocked in three river sectors for reintroduction and approximately 85,000 juveniles were stocked in four other river sectors to strengthen existing populations. During the post-release monitoring, 45 individuals were recaptured in two sectors. The documented short-term reintroduction success (i.e. survival of released individuals) indicates appropriateness of the selected stocking strategy. Furthermore, the provided course of action might be transferred to further states or countries and thereby contribute to weatherfish conservation at larger scales.
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Reintroduction and stock enhancement of European weatherfish (
'EDP Sciences', 2018Co-Authors: Benjamin Schreiber, Egbert Korte, Thomas Schmidt, Ralf SchulzAbstract:A stocking program for the endangered European weatherfish (Misgurnus fossilis L.) was conducted in the German federal states of Rhineland-Palatinate and Hesse, southwest Germany. An initial monitoring enabled to identify local broodstock and to assess habitats regarding their ecological suitability for reintroduction. In a second step, broodstock were caught for artificial propagation and cultured fry were released in previously selected river sectors. Furthermore, reintroduction sectors were biannually monitored to assess stocking success. Within the study period (2014–2016), a total number of approximately 83,500 juveniles were stocked in three river sectors for reintroduction and approximately 85,000 juveniles were stocked in four other river sectors to strengthen existing populations. During the post-release monitoring, 45 individuals were recaptured in two sectors. The documented short-term reintroduction success (i.e. survival of released individuals) indicates appropriateness of the selected stocking strategy. Furthermore, the provided course of action might be transferred to further states or countries and thereby contribute to weatherfish conservation at larger scales
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weatherfish Misgurnus fossilis as a new species for toxicity testing
Aquatic Toxicology, 2017Co-Authors: Benjamin Schreiber, Bořek Drozd, Marius Petrenz, Julian Monka, Henner Hollert, Ralf SchulzAbstract:Abstract Selection of appropriate test species is a critical issue when assessing effects of environmental contamination on fish because the ecological relevance of commonly used test species might be restricted due to their exotic origin. In the present study, a European freshwater fish with frequent occurrence in agricultural areas is suggested as a potential alternative: the European weatherfish (Misgurnus fossilis). Its suitability for acute embryo toxicity tests (FET) was investigated with regard to practical implementation, sensitivity to contaminants and tolerance against environmental conditions of concern. For this purpose, weatherfish embryos were exposed (72 h) to the reference substance 3,4-dichloroaniline (DCA) in three independent tests. Furthermore, the effects of dissolved oxygen (DO) deficiency on weatherfish embryos were studied to evaluate their suitability e.g. for sediment bioassays. Obtained results revealed that the sensitivity of weatherfish embryos towards DCA (72 h-EC50 = 0.52 mg/l; 72 h-LC50 = 0.71 mg/l) was highest compared to other species and three times higher than that reported for the commonly used zebrafish (Danio rerio). Even though knowledge of DO requirements during the embryonic period of European fish species is scarce, weatherfish can be stated as one of the most tolerant native species (LC90 for DO = 0.53 mg/l after 48 h exposure plus 72 h post-exposure). Its high ecological relevance for Europe, the particular sensitivity towards DCA and high tolerance against DO depletion highlight the potential of weatherfish as additional species for toxicity testing.
V P Bozhkova - One of the best experts on this subject based on the ideXlab platform.
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local changes in gap junctional permeability accompany regionalization of the mesoderm in early fish loach Misgurnus fossilis embryos
Membrane and Cell Biology, 2000Co-Authors: V P Bozhkova, N V RozanovaAbstract:The marginal area of early loach (Misgurnus fossilis) embryos in the proximity of the yolk cell (YC), the zone of early activation of mesoderm-specific genes, was revealed to be characterized by regional changes in the permeability and selectivity of gap junctional (GJ) channels. Comparison of the efficiency of GJ transfer of negatively (Lucifer Yellow, LY and fluorescein, F) and positively (4',6-diamidino-2-phenylindole, DAPI) charged dyes showed that, at the early gastrula stage, GJs formed between blastomeres of the presumptive mesoderm layer and the YC acquired a higher permeability for LY and F and became virtually impenetrable for DAPI over most of the germ ring area, except for its dorsal side. GJs in the dorsal-anterior region were permeable for both LY and DAPI. The dorsal-posterior area was labelled with neither of the dyes. Observations of the fate of embryonic shield blastomeres stained with both LY and DAPI showed that their progenies were confined to the head mesoderm, whereas the paraxial somite mesoderm and the ventral mesoderm contained the cells labelled only with LY or F. The presumptive notochord region was not labelled at all. These data support the hypothesis that GJs between the embryonic cells may be involved in the spatial organization of development due to their ability to transfer different regulatory factors in different directions, filtering molecules in accordance with the electric charge, conformation and size.
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lateral mobility of plasma membrane proteins in dividing eggs of the loach Misgurnus fossilis regional differences and changes during the cell cycle
Journal of Fluorescence, 1994Co-Authors: V P Bozhkova, Monika Budayova, Peter Kvasnicka, Natalia Cigankova, Dusan ChorvatAbstract:Regional differences in lateral diffusion rates of fluorescence-labeled proteins have been studied in the plasma membrane of dividing eggs of the loach (Misgurnus fossilis) by fluorescence recovery after photobleaching (FRAP). Apparent animal-vegetal differences in fluorescence intensity, lateral diffusion coefficients, and fractions of mobile proteins have been found, with all these quantities being higher in the animal pole region than in the yolk region. Cyclic changes in protein diffusion coefficients and mobile fractions during the first few cell cycles have also been recorded. Soon after the end of a cleavage, the diffusion coefficient reaches its minimal value and increases rapidly before the next cleavage.
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Cyclic changes of membrane conductivity in fertilized and activated eggs of teleost (Misgurnus fossilis) and their relation to the cell shape.
The International journal of developmental biology, 1992Co-Authors: V P Bozhkova, M Sh Gedevanishvili, I S Kvavilashvili, D A VoronovAbstract:Oscillations of membrane ionic conductivity, with a period similar to cell cycle duration, were observed in fertilized and activated loach (Misgurnus fossilis) eggs. In cleaving eggs the decrease in conductivity coincided with mitosis. Synchronously with the oscillations of membrane conductivity in activated as well as in fertilized eggs, rhythmic changes in blastodisc shape occurred. The blastodisc rounded up during the period of increasing membrane conductivity and flattened while conductivity decreased. Scanning microscopy of fertilized and activated eggs revealed differences in the surface relief of rounded and flattened blastodiscs.
Miroslaw Przybylski - One of the best experts on this subject based on the ideXlab platform.
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does habitat otherness affect weatherfish Misgurnus fossilis reproductive traits
The European Zoological Journal, 2021Co-Authors: Kacper Pyrzanowski, Grzegorz Zieba, Grazyna Chwatko, Miroslaw PrzybylskiAbstract:The fecundity and sexual structure of weatherfish (Misgurnus fossilis) population, an inperilled and protected freshwater fish with a poorly known life history, was studied in three waterbodies: th...
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food resource partitioning between juvenile and mature weatherfish Misgurnus fossilis
Ecology and Evolution, 2021Co-Authors: Kacper Pyrzanowski, Grzegorz Zieba, Joanna Leszczynska, Malgorzata Adamczuk, Malgorzata Dukowska, Miroslaw PrzybylskiAbstract:This study represents a description of the diet composition of one of the largest European cobitids, the weatherfish Misgurnus fossilis. Specimens were collected in a drainage canal, representing a typical habitat for weatherfish, and with gut content analysis conducted with regard to individual total length and maturity stage. Overall, the weatherfish diet mainly consisted of Copepoda, Cladocera, Ostracoda, Oligochaeta, Asellus aquaticus, Chironomidae and Coleoptera larvae, Gastropoda, and detritus. To evaluate size-related patterns of resource use, fish were assigned to two size classes, defined according to size at first maturation. ANOSIM analyses revealed major ontogenetic shifts in feeding strategy, which were related to size and maturity, with a significant ontogenetic shift in feeding pattern, marked by differences in the proportions of the main taxonomic groups of prey consumed. Copepoda and Cladocera dominated in the diet of small and immature individuals, while large weatherfish primarily fed on detritus. Similarly, cluster analysis of diet classified into these food types showed distinct two groups comprising juvenile and mature fish. The weatherfish is a food opportunist using all available resources, but spatially showed a change in feeding sites. Smaller and sexually immature individuals more often use prey caught in the water column and among macrophytes, while larger (sexually mature) individuals occupying the bottom, much more often use detritus as a food base.
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endangered weatherfish Misgurnus fossilis age and growth is affected by the size of the watercourses
Journal of Vertebrate Biology, 2020Co-Authors: Kacper Pyrzanowski, Grzegorz Zieba, Miroslaw PrzybylskiAbstract:The age and growth of weatherfish (Misgurnus fossilis), an endangered and protected freshwater fish with a poorly known life history, was studied in two watercourses (the River Ner and the Nowy Row canal, Poland). The weight, length and sagittal otoliths of 166 specimens collected in April 2015 were measured for weight-length relationships, ageing and back-calculation of length at age. At both sites sex ratio did not differ from 1:1. Weatherfish otoliths were small, elliptic (1.85 mm longer axes of the largest otolith) and the annuli were clearly visible. Female lifespan was six years but the oldest males were four and five years. In both sites populations were dominated by 2+ (the River Ner) and 3+ (the Nowy Row canal) specimens. In general, weatherfish grows isometrically (b = 3) and the intercept of the weight-length relationship differ between study sites but not between sexes. Its total length (TL) was predicted by an interaction between sex and age, as well as capture site and age. Back-calculated estimates of TL fitted a von Bertalanffy growth function, though Taylor's criterion showed that the asymptotic length were overestimated. Multiple comparisons of the von Bertalanffy growth function parameter revealed difference between sexes and sites.
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the role of detritivory as a feeding tactic in a harsh environment a case study of weatherfish Misgurnus fossilis
Scientific Reports, 2019Co-Authors: Kacper Pyrzanowski, Grzegorz Zieba, Malgorzata Dukowska, Carl Smith, Miroslaw PrzybylskiAbstract:The weatherfish (Misgurnus fossilis) is a species that is tolerant of unfavourable environmental conditions and can survive low dissolved oxygen concentrations and high water temperatures. Although this species occurs across almost the whole of Europe, and is protected in many countries, relatively little is known regarding its ecology. To determine the diet of weatherfish, 120 individuals from an artificial drainage canal in central Poland were collected in two seasons (spring and late summer) with contrasting abiotic condition (oxygen concentration, water temperature and transparency). Analysis of gut fullness showed that weatherfish consumed a greater quantity of food in spring (0.92 ± 0.90) compared with summer (0.20 ± 0.26). Contrary to other cobitid taxa, weatherfish fed actively during daytime in both seasons. An estimate of the importance of each dietary component indicated that the most important food categories were chironomids, copepods, Asellus aquaticus and detritus. SIMPER analysis indicated that these four categories together constituted over 65.8% of cumulative dissimilarity in the diet between seasons. Additionally, trophic niche breadth differed significantly between seasons. The study demonstrated that the weatherfish is an opportunistic feeder, consuming large quantities of detritus despite possessing a gut morphology that is atypical of a detritivore. The quantity of detritus in the gut of weatherfish was positively associated with fish total length and varied seasonally, with a greater quantity of detritus in the diet in late summer. These results demonstrate the importance of detritus as a source of energy, particularly during periods of scarcity of alternative prey categories.
Kathrin Theissinger - One of the best experts on this subject based on the ideXlab platform.
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detection of the endangered european weather loach Misgurnus fossilis via water and sediment samples testing multiple edna workflows
Ecology and Evolution, 2020Co-Authors: Lena Maureen Kusanke, Ralf Schulz, Egbert Korte, Jorn Panteleit, Stefan Stoll, Eike Sunger, Kathrin TheissingerAbstract:The European weather loach (Misgurnus fossilis) is classified as highly endangered in several countries of Central Europe. Populations of M. fossilis are predominantly found in ditches with low water levels and thick sludge layers and are thus hard to detect using conventional fishing methods. Therefore, environmental DNA (eDNA) monitoring appears particularly relevant for this species. In previous studies, M. fossilis was surveyed following eDNA water sampling protocols, which were not optimized for this species. Therefore, we created two full factorial study designs to test six different eDNA workflows for sediment samples and twelve different workflows for water samples. We used qPCR to compare the threshold cycle (C t) values of the different workflows, which indicate the target DNA amount in the sample, and spectrophotometry to quantify and compare the total DNA amount inside the samples. We analyzed 96 water samples and 48 sediment samples from a pond with a known population of M. fossilis. We tested several method combinations for long-term sample preservation, DNA capture, and DNA extraction. Additionally, we analyzed the DNA yield of samples from a ditch with a natural M. fossilis population monthly over one year to determine the optimal sampling period. Our results showed that the long-term water preservation method commonly used for eDNA surveys of M. fossilis did not lead to optimal DNA yields, and we present a valid long-term sample preservation alternative. A cost-efficient high salt DNA extraction led to the highest target DNA yields and can be used for sediment and water samples. Furthermore, we were able to show that in a natural habitat of M. fossilis, total and target eDNA were higher between June and September, which implies that this period is favorable for eDNA sampling. Our results will help to improve the reliability of future eDNA surveys of M. fossilis.
Benjamin Schreiber - One of the best experts on this subject based on the ideXlab platform.
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towards more ecological relevance in sediment toxicity testing with fish evaluation of multiple bioassays with embryos of the benthic weatherfish Misgurnus fossilis
Science of The Total Environment, 2018Co-Authors: Benjamin Schreiber, Henner Hollert, Jonas Fischer, Sabrina Schiwy, Ralf SchulzAbstract:The effects of sediment contamination on fish are of high significance for the protection of ecosystems, human health and economy. However, standardized sediment bioassays with benthic fish species, that mimic bioavailability of potentially toxic compounds and comply with the requirements of alternative test methods, are still scarce. In order to address this issue, embryos of the benthic European weatherfish (Misgurnus fossilis) were exposed to freeze-dried sediment (via sediment contact assays (SCA)) and sediment extracts (via acute fish embryo toxicity tests) varying in contamination level. The extracts were gained by accelerated solvent extraction with (i) acetone and (ii) pressurized hot water (PHWE) and subsequently analyzed for polycyclic aromatic hydrocarbons, polychlorinated biphenyls and polychlorinated dibenzodioxins and dibenzofurans. Furthermore, embryos of the predominately used zebrafish (Danio rerio) were exposed to extracts from the two most contaminated sediments. Results indicated sufficient robustness of weatherfish embryos towards varying test conditions and sensitivity towards relevant sediment-bound compounds. Furthermore, a compliance of effect concentrations derived from weatherfish embryos exposed to sediment extracts (96h-LC50) with both measured gradient of sediment contamination and previously published results was observed. In comparison to zebrafish, weatherfish embryos showed higher sensitivity to the bioavailability-mimicking extracts from PHWE but lower sensitivity to extracts gained with acetone. SCAs conducted with weatherfish embryos revealed practical difficulties that prevented an implementation with three of four sediments tested. In summary, an application of weatherfish embryos, using bioassays with sediment extracts from PHWE might increase the ecological relevance of sediment toxicity testing: it allows investigations using benthic and temperate fish species considering both bioavailable contaminants and animal welfare concerns.
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reintroduction and stock enhancement of european weatherfish Misgurnus fossilis l in rhineland palatinate and hesse germany
Knowledge and Management of Aquatic Ecosystems, 2018Co-Authors: Benjamin Schreiber, Egbert Korte, Thomas Schmidt, Ralf SchulzAbstract:A stocking program for the endangered European weatherfish (Misgurnus fossilis L.) was conducted in the German federal states of Rhineland-Palatinate and Hesse, southwest Germany. An initial monitoring enabled to identify local broodstock and to assess habitats regarding their ecological suitability for reintroduction. In a second step, broodstock were caught for artificial propagation and cultured fry were released in previously selected river sectors. Furthermore, reintroduction sectors were biannually monitored to assess stocking success. Within the study period (2014–2016), a total number of approximately 83,500 juveniles were stocked in three river sectors for reintroduction and approximately 85,000 juveniles were stocked in four other river sectors to strengthen existing populations. During the post-release monitoring, 45 individuals were recaptured in two sectors. The documented short-term reintroduction success (i.e. survival of released individuals) indicates appropriateness of the selected stocking strategy. Furthermore, the provided course of action might be transferred to further states or countries and thereby contribute to weatherfish conservation at larger scales.
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Reintroduction and stock enhancement of European weatherfish (
'EDP Sciences', 2018Co-Authors: Benjamin Schreiber, Egbert Korte, Thomas Schmidt, Ralf SchulzAbstract:A stocking program for the endangered European weatherfish (Misgurnus fossilis L.) was conducted in the German federal states of Rhineland-Palatinate and Hesse, southwest Germany. An initial monitoring enabled to identify local broodstock and to assess habitats regarding their ecological suitability for reintroduction. In a second step, broodstock were caught for artificial propagation and cultured fry were released in previously selected river sectors. Furthermore, reintroduction sectors were biannually monitored to assess stocking success. Within the study period (2014–2016), a total number of approximately 83,500 juveniles were stocked in three river sectors for reintroduction and approximately 85,000 juveniles were stocked in four other river sectors to strengthen existing populations. During the post-release monitoring, 45 individuals were recaptured in two sectors. The documented short-term reintroduction success (i.e. survival of released individuals) indicates appropriateness of the selected stocking strategy. Furthermore, the provided course of action might be transferred to further states or countries and thereby contribute to weatherfish conservation at larger scales
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weatherfish Misgurnus fossilis as a new species for toxicity testing
Aquatic Toxicology, 2017Co-Authors: Benjamin Schreiber, Bořek Drozd, Marius Petrenz, Julian Monka, Henner Hollert, Ralf SchulzAbstract:Abstract Selection of appropriate test species is a critical issue when assessing effects of environmental contamination on fish because the ecological relevance of commonly used test species might be restricted due to their exotic origin. In the present study, a European freshwater fish with frequent occurrence in agricultural areas is suggested as a potential alternative: the European weatherfish (Misgurnus fossilis). Its suitability for acute embryo toxicity tests (FET) was investigated with regard to practical implementation, sensitivity to contaminants and tolerance against environmental conditions of concern. For this purpose, weatherfish embryos were exposed (72 h) to the reference substance 3,4-dichloroaniline (DCA) in three independent tests. Furthermore, the effects of dissolved oxygen (DO) deficiency on weatherfish embryos were studied to evaluate their suitability e.g. for sediment bioassays. Obtained results revealed that the sensitivity of weatherfish embryos towards DCA (72 h-EC50 = 0.52 mg/l; 72 h-LC50 = 0.71 mg/l) was highest compared to other species and three times higher than that reported for the commonly used zebrafish (Danio rerio). Even though knowledge of DO requirements during the embryonic period of European fish species is scarce, weatherfish can be stated as one of the most tolerant native species (LC90 for DO = 0.53 mg/l after 48 h exposure plus 72 h post-exposure). Its high ecological relevance for Europe, the particular sensitivity towards DCA and high tolerance against DO depletion highlight the potential of weatherfish as additional species for toxicity testing.
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thermal requirements for growth survival and aerobic performance of weatherfish larvae Misgurnus fossilis
Journal of Fish Biology, 2017Co-Authors: Benjamin Schreiber, Bořek Drozd, J Monka, Matthias Hundt, Monika Weiss, T Oswald, Rene Gergs, Ralf SchulzAbstract:Thermal requirements of larval weatherfish Misgurnus fossilis were investigated in terms of growth, survival and aerobic performance. Growth and survival of M. fossilis larvae acclimated to five temperatures (11, 15, 19, 23 and 27° C) were measured over 25 days. In the upper temperature treatments (19, 23 and 27° C), survival of larvae was stable throughout the entire rearing period (>75%), whereas 11 and 15° C resulted in severe declines in survival (to 27° C. All larvae of the 35° C regime, however, died within the ṀO2 measurement period. M. fossilis larvae show greater than expected tolerance of high temperatures. On the other hand, low temperatures that are within the range of likely habitat conditions are critical because they might lead to high mortality rates when larvae are exposed over periods >10 days. These findings help to improve rearing conditions and to identify suitable waters for stocking and thus support the management of re-introduction activities for endangered M. fossilis.