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Leon Blaustein - One of the best experts on this subject based on the ideXlab platform.
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Effects of a Fire retardant on the Near Eastern Fire Salamander Salamandra infraimmaculata and aquatic community structure: an experimental approach
Hydrobiologia, 2021Co-Authors: Lital Ozeri, Leon Blaustein, Antonina Polevikov, Jamie Kneitel, Eyal Rahav, Rael HorwitzAbstract:Fire retardants are commonly used for fighting wildFires. Retardant chemicals washed via runoff into aquatic systems may be concentrated, thus exposing aquatic species to high levels of ammonium, phosphate, and iron. These chemicals directly affect individual species, which can also cascade to the rest of the aquatic community. We investigated the effects of a prevalent Fire retardant, FR CROS 134 (FR), at various concentrations (0 to 11.4 × 10^2 mg l^−1) on larval Fire Salamander ( Salamandra infraimmaculata ) and aquatic community structure (bacteria, algae and invertebrates) using mesocosms. We show a negative effect of the presence of FR on the survivorship and time to metamorphosis of Salamander larvae (94–17% and 48–64 days, respectively). Moreover, increasing FR concentrations were found to inhibit the predation rate of Salamander larvae on mosquito larvae (89–14%). FR decreased the invertebrate community diversity with changes in composition and shifts in evenness and dominance (e.g., cladoceran species abundance increased, whereas calanoid copepod species declined). Finally, cyanobacteria and eukaryotic algal abundance increased, while heterotrophic bacterial abundance decreased with FR addition. The effects of Fire retardants on biodiversity found here and the growing use of Fire retardants worldwide call for additional evidence-based assessment of their impact, especially in aquatic ecosystems.
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genetic diversity and gene flow decline with elevation in the near eastern Fire Salamander salamandra infraimmaculata at mount hermon golan heights
Amphibia-reptilia, 2020Co-Authors: Kathleen Preisler, Leon Blaustein, Eliane Kupfer, Fabian Loffler, Arlo Hinckley, Sebastian SteinfartzAbstract:The Near Eastern Fire Salamander (Salamandra infraimmaculata) reaches its southern distribution range in Israel. Although the population structure has been analysed in central Israel and at the southern distribution limit, we lack knowledge on populations in the northern area, such as along Mount Hermon. S. infraimmaculata occurs at Mt. Hermon along an altitudinal gradient and appears to be fragmented by urban and agricultural landscape. We studied the genetic structure of four populations based on microsatellite loci and the mitochondrial D-loop to determine the genetic diversity and connectivity between populations. We observed moderate gene flow at lower parts, i.e. from Tel Dan and Nimrod Castle to Banias indicating extant but limited connectivity. Genetic diversity and gene flow declined along the altitudinal gradient at Mt. Hermon, reaching rock-bottom levels in the highest located population of Nimrod Pool. The observed isolation-by-elevation gradient might induce a higher extinction risk for the highland populations of S. infraimmaculata.
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Relationships among breeding site characteristics and adult population size of the Fire Salamander, Salamandra infraimmaculata
Hydrobiologia, 2020Co-Authors: Iftah Sinai, Ori Segev, Avi Koplovich, Alan R. Templeton, Leon Blaustein, Lior BlankAbstract:Effective amphibian conservation requires knowledge of both the aquatic and terrestrial phases of life. As extinction probabilities are a function of population size, it is crucial not only to understand the habitat requirement of the species but also to estimate its population size. In this work, we studied the endangered Fire Salamander, Salamandra infraimmaculata , and analyzed the population size at a total of 14 sites—eight temporary and six permanent. For identifying the local and landscape scales factors predicting S. infraimmaculata ’s breeding sites we monitored 54 aquatic sites. We found that permanent sites support larger populations of adult Salamanders. The breeding site characteristics analyses revealed that at the local scale water depth and shade were the most important factors and two regional variables were found to be important: proximity to another breeding site and elevation. This work provides two clear conservation implications permanent breeding sites will support much larger populations compared to temporary sites, particularly if close to other potential breeding sites, and both terrestrial and aquatic features are important for a site to be suitable for breeding.
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Estimating the effects of road-kills on the Fire Salamander population along a river
Journal for Nature Conservation, 2020Co-Authors: Iftah Sinai, Avi Koplovich, Alan R. Templeton, Leon Blaustein, Talya Oron, Gilad Weil, Roni Sachal, Lior BlankAbstract:Abstract A number of factors contribute to the process of amphibian decline, among them population fragmentation and road-kills. In this work we evaluated the effects of a road that separates the hibernation area of the Fire Salamander population from their breeding site on the demography and movement behavior. For that we monitored the population for four years using transects along the road and along a river that runs in parallel to the road and serve as the breeding site. We found that the estimated percent of the population killed on the road steadily increased minimally from 2.56 % to 10.78 % over a four year period of increasing vehicular activity. Interestingly, only a small number of individuals were documented on both sides of the road, suggesting there is a potential for population fragmentation due to the road. Additionally, we used geostatistics to reveal that the spatial distribution pattern of the population and road-kills along the road is not random. Thus, conservation efforts that focus on preventing Salamanders from accessing the road surface should focus on the areas where the population and road-kills aggregate.
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Phenotypic plasticity and local adaptations to dissolved oxygen in larvae Fire Salamander (Salamandra infraimmaculata)
Oecologia, 2019Co-Authors: Ori Segev, Alan R. Templeton, Valentina Rovelli, Nadav Pezaro, Olga Rybak, Leon BlausteinAbstract:A key environmental factor that varies both spatially and temporally in surface waters is dissolved oxygen (DO). In stagnant ephemeral freshwater ponds, DO can fluctuate diurnally and seasonally, while the constant mixing of water in streams typically maintain DO levels close to saturation with only minor fluctuations. Larvae of the Near Eastern Fire Salamander ( Salamandra infraimmaculata ) develop in a range of waterbodies that vary in flow and permanence. To study inter-population variation in larval response to environmental change, we translocated larvae between stream and pond habitats and exposed larvae sampled from different habitat types to hypoxic and normoxic conditions in the laboratory. Larvae transferred from stream to pond retain gill size, while larvae transferred from pond to stream show a reduction in gill size. Larvae that were caged within their native habitat, either stream or pond, display a decrease in gill size similar to larvae transferred from pond to stream. When exposed to experimentally manipulated levels of DO in the laboratory larvae, respectively, increase and decrease gill size under hypoxic and normoxic conditions. Habitat-type origin had a significant effect on the degree of change in gill size with larvae from permanent streams demonstrating the lowest absolute variation in gill size. There was no interaction between DO level (hypoxic/normoxic) and the larvae habitat-type origin. These results suggest that S. infraimmaculata larvae are locally adapted to their aquatic breeding habitat through the plastic ability to respond to the prevailing respiratory conditions by rapidly decreasing or increasing gill size.
Ori Segev - One of the best experts on this subject based on the ideXlab platform.
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Relationships among breeding site characteristics and adult population size of the Fire Salamander, Salamandra infraimmaculata
Hydrobiologia, 2020Co-Authors: Iftah Sinai, Ori Segev, Avi Koplovich, Alan R. Templeton, Leon Blaustein, Lior BlankAbstract:Effective amphibian conservation requires knowledge of both the aquatic and terrestrial phases of life. As extinction probabilities are a function of population size, it is crucial not only to understand the habitat requirement of the species but also to estimate its population size. In this work, we studied the endangered Fire Salamander, Salamandra infraimmaculata , and analyzed the population size at a total of 14 sites—eight temporary and six permanent. For identifying the local and landscape scales factors predicting S. infraimmaculata ’s breeding sites we monitored 54 aquatic sites. We found that permanent sites support larger populations of adult Salamanders. The breeding site characteristics analyses revealed that at the local scale water depth and shade were the most important factors and two regional variables were found to be important: proximity to another breeding site and elevation. This work provides two clear conservation implications permanent breeding sites will support much larger populations compared to temporary sites, particularly if close to other potential breeding sites, and both terrestrial and aquatic features are important for a site to be suitable for breeding.
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Phenotypic plasticity and local adaptations to dissolved oxygen in larvae Fire Salamander (Salamandra infraimmaculata)
Oecologia, 2019Co-Authors: Ori Segev, Alan R. Templeton, Valentina Rovelli, Nadav Pezaro, Olga Rybak, Leon BlausteinAbstract:A key environmental factor that varies both spatially and temporally in surface waters is dissolved oxygen (DO). In stagnant ephemeral freshwater ponds, DO can fluctuate diurnally and seasonally, while the constant mixing of water in streams typically maintain DO levels close to saturation with only minor fluctuations. Larvae of the Near Eastern Fire Salamander ( Salamandra infraimmaculata ) develop in a range of waterbodies that vary in flow and permanence. To study inter-population variation in larval response to environmental change, we translocated larvae between stream and pond habitats and exposed larvae sampled from different habitat types to hypoxic and normoxic conditions in the laboratory. Larvae transferred from stream to pond retain gill size, while larvae transferred from pond to stream show a reduction in gill size. Larvae that were caged within their native habitat, either stream or pond, display a decrease in gill size similar to larvae transferred from pond to stream. When exposed to experimentally manipulated levels of DO in the laboratory larvae, respectively, increase and decrease gill size under hypoxic and normoxic conditions. Habitat-type origin had a significant effect on the degree of change in gill size with larvae from permanent streams demonstrating the lowest absolute variation in gill size. There was no interaction between DO level (hypoxic/normoxic) and the larvae habitat-type origin. These results suggest that S. infraimmaculata larvae are locally adapted to their aquatic breeding habitat through the plastic ability to respond to the prevailing respiratory conditions by rapidly decreasing or increasing gill size.
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conservation genetics and genomics of the Fire Salamander salamandra infraimmaculata
Biochemistry & Molecular Biology Journal, 2018Co-Authors: Leon Blaustein, Ori Segev, Lior Blank, Iftach Sinai, Juha Merila, Shirli Bar David, Tamar Krugman, Antonina Polevikov, Valentina Rovelli, Nadav PezaroAbstract:Introduction: Salamandra infraimmaculata is considered as a threatened species in Israel. However, sincewhen we started studying Salamandra, we have found many more breeding sites in the past 10 years than were known previously. In addition, O. Rybak (unpublished results) has found that Salamandra does well in urban habitats on Mount Carmel. Salamandra infraimmaculata has strong pond site fidelity that likely results in differential genetic structure among breeding sites. Strong pond site fidelity has been found by multiple researchers. An exception is that on Mount Carmel, S Bar David found dispersal as far as 1280 m, which is likely to result in overlapping genetic structuring. During our first genetics study, in which-nine breeding sites in Mount Carmel and 11 sites in the Galilee were surveyed and tissue samples were taken from 475 adults. Microsatellites were used for observing differences in genetic structure in the study which was performed in Prof Juha Merila’s Lab (University of Helsinki, Finland). In this study, we found that there were substantial genetic differences between Mount Carmel and the Galilee. Allelic richness was much higher in the Galilee than in Mount Carmel; 40 unique alleles were found in the Galilee and 0 in Mount Carmel. Unrooted neighbour joining tree diagrams resulted in pure separations between Mount Carmel and the Galilee. Structure analysis showed strong differences between the Galilee and Mount Carmel. A second microsatellite study was conducted in Finland in Juha Merila’s Lab. The goal was to consider genetic diversity in peripheral populations compared to populations closer to the core. We collected 692 tissue samples from adult and juvenile Fire Salamanders from 33 breeding sites (13 from upper Galilee, ten from lower Galilee, nine from Mount Carmel and one from Tel Dan). This study also considered vegetation types and meteorological aspects such as elevation, average temperature and precipitation. Maximum entropy analysis was also used to score major regions. The lower Galilee had the lowest stability values of the three regions. Allelic richness increased with maximum entropy scores in the Upper Galilee. Allelic richness also increased with latitude. A Bayesian analysis of population structure (BAPS) also demonstrated that Mt Carmel and the upper Galilee were homogeneous genetically while the lower Galilee contained genetically differentiated populations. Lastly, we performed transcriptomics/gene expression studies on Fire Salamander larvae. We insisted that Salamandra tailfins (which do not cause damage to the Salamandra larvae) can demonstrate gene expression as opposed to using the whole body. We found that Salamandra larvae turn darker when exposed to ultra violet radiation and they turn darker with increased density. We are currently conducting gene expression studies on Salamandra larval development, oxygen ranges, colour change and temperature change.
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effects of tail clipping on larval performance and tail regeneration rates in the near eastern Fire Salamander salamandra infraimmaculata
PLOS ONE, 2015Co-Authors: Ori Segev, Avi Koplovich, Lior Blank, Daniel J Goedbloed, Eliane Kupfer, Antonina Polevikove, Anna Gershberg, Leon BlausteinAbstract:Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping – i.e., bites inflicted by predators including conspecifics - on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail) on Near Eastern Fire Salamander (Salamandra infraimmaculata) larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length) at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.
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influence of water velocity and predation risk on Fire Salamander salamandra infraimmaculata larval drift among temporary pools in ephemeral streams
Freshwater Science, 2014Co-Authors: Ori Segev, Leon BlausteinAbstract:AbstractIn ephemeral streams, floods can temporarily connect isolated pools and provide otherwise spatially restricted organisms with the option to stay in or leave a pool. A field survey of the middle-eastern Fire Salamander (Salamandra infraimmaculata) larvae demonstrated that 18% disappeared from pools during high-discharge events, and ∼2% were found subsequently in downstream pools. We conducted indoor experiments to test whether larvae alter drift rate in response to different velocities and perceived risk of predation. We manipulated flow velocities within the range of natural ephemeral streams during floods. Anesthetized larvae (passive drifters) drifted out of a central pool faster than conscious larvae at low velocities but not at high velocities, suggesting that conscious larvae actively resisted hydraulic pressures. Drift of small larvae out of a pool in the presence of a caged, larger cannibalistic conspecific was faster than in the absence of a predator, indicating that the larvae perceived a...
Lior Blank - One of the best experts on this subject based on the ideXlab platform.
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Relationships among breeding site characteristics and adult population size of the Fire Salamander, Salamandra infraimmaculata
Hydrobiologia, 2020Co-Authors: Iftah Sinai, Ori Segev, Avi Koplovich, Alan R. Templeton, Leon Blaustein, Lior BlankAbstract:Effective amphibian conservation requires knowledge of both the aquatic and terrestrial phases of life. As extinction probabilities are a function of population size, it is crucial not only to understand the habitat requirement of the species but also to estimate its population size. In this work, we studied the endangered Fire Salamander, Salamandra infraimmaculata , and analyzed the population size at a total of 14 sites—eight temporary and six permanent. For identifying the local and landscape scales factors predicting S. infraimmaculata ’s breeding sites we monitored 54 aquatic sites. We found that permanent sites support larger populations of adult Salamanders. The breeding site characteristics analyses revealed that at the local scale water depth and shade were the most important factors and two regional variables were found to be important: proximity to another breeding site and elevation. This work provides two clear conservation implications permanent breeding sites will support much larger populations compared to temporary sites, particularly if close to other potential breeding sites, and both terrestrial and aquatic features are important for a site to be suitable for breeding.
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Estimating the effects of road-kills on the Fire Salamander population along a river
Journal for Nature Conservation, 2020Co-Authors: Iftah Sinai, Avi Koplovich, Alan R. Templeton, Leon Blaustein, Talya Oron, Gilad Weil, Roni Sachal, Lior BlankAbstract:Abstract A number of factors contribute to the process of amphibian decline, among them population fragmentation and road-kills. In this work we evaluated the effects of a road that separates the hibernation area of the Fire Salamander population from their breeding site on the demography and movement behavior. For that we monitored the population for four years using transects along the road and along a river that runs in parallel to the road and serve as the breeding site. We found that the estimated percent of the population killed on the road steadily increased minimally from 2.56 % to 10.78 % over a four year period of increasing vehicular activity. Interestingly, only a small number of individuals were documented on both sides of the road, suggesting there is a potential for population fragmentation due to the road. Additionally, we used geostatistics to reveal that the spatial distribution pattern of the population and road-kills along the road is not random. Thus, conservation efforts that focus on preventing Salamanders from accessing the road surface should focus on the areas where the population and road-kills aggregate.
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conservation genetics and genomics of the Fire Salamander salamandra infraimmaculata
Biochemistry & Molecular Biology Journal, 2018Co-Authors: Leon Blaustein, Ori Segev, Lior Blank, Iftach Sinai, Juha Merila, Shirli Bar David, Tamar Krugman, Antonina Polevikov, Valentina Rovelli, Nadav PezaroAbstract:Introduction: Salamandra infraimmaculata is considered as a threatened species in Israel. However, sincewhen we started studying Salamandra, we have found many more breeding sites in the past 10 years than were known previously. In addition, O. Rybak (unpublished results) has found that Salamandra does well in urban habitats on Mount Carmel. Salamandra infraimmaculata has strong pond site fidelity that likely results in differential genetic structure among breeding sites. Strong pond site fidelity has been found by multiple researchers. An exception is that on Mount Carmel, S Bar David found dispersal as far as 1280 m, which is likely to result in overlapping genetic structuring. During our first genetics study, in which-nine breeding sites in Mount Carmel and 11 sites in the Galilee were surveyed and tissue samples were taken from 475 adults. Microsatellites were used for observing differences in genetic structure in the study which was performed in Prof Juha Merila’s Lab (University of Helsinki, Finland). In this study, we found that there were substantial genetic differences between Mount Carmel and the Galilee. Allelic richness was much higher in the Galilee than in Mount Carmel; 40 unique alleles were found in the Galilee and 0 in Mount Carmel. Unrooted neighbour joining tree diagrams resulted in pure separations between Mount Carmel and the Galilee. Structure analysis showed strong differences between the Galilee and Mount Carmel. A second microsatellite study was conducted in Finland in Juha Merila’s Lab. The goal was to consider genetic diversity in peripheral populations compared to populations closer to the core. We collected 692 tissue samples from adult and juvenile Fire Salamanders from 33 breeding sites (13 from upper Galilee, ten from lower Galilee, nine from Mount Carmel and one from Tel Dan). This study also considered vegetation types and meteorological aspects such as elevation, average temperature and precipitation. Maximum entropy analysis was also used to score major regions. The lower Galilee had the lowest stability values of the three regions. Allelic richness increased with maximum entropy scores in the Upper Galilee. Allelic richness also increased with latitude. A Bayesian analysis of population structure (BAPS) also demonstrated that Mt Carmel and the upper Galilee were homogeneous genetically while the lower Galilee contained genetically differentiated populations. Lastly, we performed transcriptomics/gene expression studies on Fire Salamander larvae. We insisted that Salamandra tailfins (which do not cause damage to the Salamandra larvae) can demonstrate gene expression as opposed to using the whole body. We found that Salamandra larvae turn darker when exposed to ultra violet radiation and they turn darker with increased density. We are currently conducting gene expression studies on Salamandra larval development, oxygen ranges, colour change and temperature change.
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effects of tail clipping on larval performance and tail regeneration rates in the near eastern Fire Salamander salamandra infraimmaculata
PLOS ONE, 2015Co-Authors: Ori Segev, Avi Koplovich, Lior Blank, Daniel J Goedbloed, Eliane Kupfer, Antonina Polevikove, Anna Gershberg, Leon BlausteinAbstract:Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping – i.e., bites inflicted by predators including conspecifics - on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail) on Near Eastern Fire Salamander (Salamandra infraimmaculata) larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length) at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.
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Landscape influences on dispersal behaviour: a theoretical model and empirical test using the Fire Salamander, Salamandra infraimmaculata
Oecologia, 2014Co-Authors: Arik Kershenbaum, Lior Blank, Leon Blaustein, Iftach Sinai, Juha Merila, Alan R. TempletonAbstract:When populations reside within a heterogeneous landscape, isolation by distance may not be a good predictor of genetic divergence if dispersal behaviour and therefore gene flow depend on landscape features. Commonly used approaches linking landscape features to gene flow include the least cost path (LCP), random walk (RW), and isolation by resistance (IBR) models. However, none of these models is likely to be the most appropriate for all species and in all environments. We compared the performance of LCP, RW and IBR models of dispersal with the aid of simulations conducted on artificially generated landscapes. We also applied each model to empirical data on the landscape genetics of the endangered Fire Salamander, Salamandra infraimmaculata , in northern Israel, where conservation planning requires an understanding of the dispersal corridors. Our simulations demonstrate that wide dispersal corridors of the low-cost environment facilitate dispersal in the IBR model, but inhibit dispersal in the RW model. In our empirical study, IBR explained the genetic divergence better than the LCP and RW models (partial Mantel correlation 0.413 for IBR, compared to 0.212 for LCP, and 0.340 for RW). Overall dispersal cost in Salamanders was also well predicted by landscape feature slope steepness (76 %), and elevation (24 %). We conclude that Fire Salamander dispersal is well characterised by IBR predictions. Together with our simulation findings, these results indicate that wide dispersal corridors facilitate, rather than hinder, Salamander dispersal. Comparison of genetic data to dispersal model outputs can be a useful technique in inferring dispersal behaviour from population genetic data.
Sebastian Steinfartz - One of the best experts on this subject based on the ideXlab platform.
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genetic diversity and gene flow decline with elevation in the near eastern Fire Salamander salamandra infraimmaculata at mount hermon golan heights
Amphibia-reptilia, 2020Co-Authors: Kathleen Preisler, Leon Blaustein, Eliane Kupfer, Fabian Loffler, Arlo Hinckley, Sebastian SteinfartzAbstract:The Near Eastern Fire Salamander (Salamandra infraimmaculata) reaches its southern distribution range in Israel. Although the population structure has been analysed in central Israel and at the southern distribution limit, we lack knowledge on populations in the northern area, such as along Mount Hermon. S. infraimmaculata occurs at Mt. Hermon along an altitudinal gradient and appears to be fragmented by urban and agricultural landscape. We studied the genetic structure of four populations based on microsatellite loci and the mitochondrial D-loop to determine the genetic diversity and connectivity between populations. We observed moderate gene flow at lower parts, i.e. from Tel Dan and Nimrod Castle to Banias indicating extant but limited connectivity. Genetic diversity and gene flow declined along the altitudinal gradient at Mt. Hermon, reaching rock-bottom levels in the highest located population of Nimrod Pool. The observed isolation-by-elevation gradient might induce a higher extinction risk for the highland populations of S. infraimmaculata.
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the role of plasticity and adaptation in the incipient speciation of a Fire Salamander population
Genes, 2019Co-Authors: Joana Sabinopinto, Daniel J Goedbloed, Eugenia Sanchez, Till Czypionka, Arne W Nolte, Sebastian SteinfartzAbstract:Phenotypic plasticity and local adaptation via genetic change are two major mechanisms of response to dynamic environmental conditions. These mechanisms are not mutually exclusive, since genetic change can establish similar phenotypes to plasticity. This connection between both mechanisms raises the question of how much of the variation observed between species or populations is plastic and how much of it is genetic. In this study, we used a structured population of Fire Salamanders (Salamandra salamandra), in which two subpopulations differ in terms of physiology, genetics, mate-, and habitat preferences. Our goal was to identify candidate genes for differential habitat adaptation in this system, and to explore the degree of plasticity compared to local adaptation. We therefore performed a reciprocal transfer experiment of stream- and pond-originated Salamander larvae and analyzed changes in morphology and transcriptomic profile (using species-specific microarrays). We observed that stream- and pond-originated individuals diverge in morphology and gene expression. For instance, pond-originated larvae have larger gills, likely to cope with oxygen-poor ponds. When transferred to streams, pond-originated larvae showed a high degree of plasticity, resembling the morphology and gene expression of stream-originated larvae (reversion); however the same was not found for stream-originated larvae when transferred to ponds, where the expression of genes related to reduction-oxidation processes was increased, possibly to cope with environmental stress. The lack of symmetrical responses between transplanted animals highlights the fact that the adaptations are not fully plastic and that some level of local adaptation has already occurred in this population. This study illuminates the process by which phenotypic plasticity allows local adaptation to new environments and its potential role in the pathway of incipient speciation.
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detection of elusive Fire Salamander larvae salamandra salamandra in streams via environmental dna
Amphibia-reptilia, 2019Co-Authors: Kathleen Preisler, Miguel Vences, Alexander Dennis Watzal, Sebastian SteinfartzAbstract:In the face of the global biodiversity crisis, the monitoring of species richness and diversity is experiencing an increased demand entailing a raise in cost and time investment. The analysis of species-specific DNA fragments in environmental samples (eDNA) such as from water or soil, facilitate the molecular detection of species without the specific sampling of individuals. The invasive chytrid fungus Batrachochytrium salamandrivorans ( Bsal ) is infecting natural Fire Salamander populations ( Salamandra salamandra ) and causes chytridiomycosis resulting in infrequent regional extinctions of populations across Central Europe. With regard to the expanding distribution of Bsal over the last years, cost-effective monitoring of Fire Salamanders is important for the conservation of this species. Based on a real-time quantitative PCR (qPCR) assay, we developed a new protocol to detect S. salamandra larvae in streams via eDNA, using species-specific primers of the mitochondrial control region (D-loop). We tested the efficiency of qPCR primer sets for six combinations of DNA extraction kits coupled with subsequent PCR inhibitor removal kits for obtaining qPCR-detectable S. salamandra eDNA from water filters, that were taken both from natural streams and artificial water tanks in the laboratory as positive controls. We found that the DNeasy Blood & Tissue Kit in combination with the DNeasy PowerClean CleanUp Kit performed best for detecting Salamander larvae from natural streams. Our experimental protocol paves the way for resource-saving approaches to monitor S. salamandra larvae, but also confirms the limits to this eDNA approach in that it requires optimized laboratory protocols.
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plasticity and evolutionary divergence in gene expression associated with alternative habitat use in larvae of the european Fire Salamander
Molecular Ecology, 2018Co-Authors: Till Czypionka, Sebastian Steinfartz, Daniel J Goedbloed, Arne W NolteAbstract:Transcriptomes of organisms reveal differentiation associated with the use of different habitats. However, this leaves open how much of the observed differentiation can be attributed to genetic differences or to transcriptional plasticity. In this study, we disentangle causes of differential gene expression in larvae of the European Fire Salamander from the Kottenforst forest in Germany. Larvae inhabit permanent streams and ephemeral ponds and represent an example of a young evolutionary split associated with contrasting ecological conditions. We hypothesized that adaptation towards differences in water temperature plays a role because the thermal regime between stream and pond habitats differs notably. Tissue samples from tail fins of larvae were collected to study gene expression using microarrays. We found ample evidence for differentiation among larvae occupying different habitats in nature with 2,800 of 11,797 genes being differentially expressed. We then quantified transcriptional plasticity towards temperature and genetic differentiation based on controlled temperature laboratory experiments. Gene-by-environment interactions modelling revealed that 28% of the gene expression divergence observed among samples in nature could be attributed to plasticity related to water temperature. Expression patterns of only a small number of 101 genes were affected by the genotype. Our analysis demonstrates that effects of environmental factors must be taken into account to explain variation of gene expression in Salamanders in nature. Notwithstanding, it provides first evidence that genetic factors determined gene expression divergence between pond and stream ecotypes and could be involved in adaptive evolution.
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morphological and transcriptomic analyses reveal three discrete primary stages of postembryonic development in the common Fire Salamander salamandra salamandra
Journal of Experimental Zoology, 2018Co-Authors: Eugenia Sanchez, Miguel Vences, Daniel J Goedbloed, Arne W Nolte, Eliane Kupfer, Tim Luddecke, Stefan Schulz, Sebastian SteinfartzAbstract:The postembryonic development of amphibians has been characterized as divided into three predominant periods, hereafter named primary developmental stages: premetamorphosis (PreM), prometamorphosis (ProM), metamorphic climax (Meta), and completion of metamorphosis (PostM), largely based on examination of anuran development. Here, we categorized the postembryonic development of larvae of a poisonous Fire Salamander (Salamandra salamandra) by integrating morphology and gene expression (transcriptomic) data. Morphological analysis revealed three distinct clusters suggestive of PreM, ProM, and Meta, which were confirmed in parallel by microarray-derived gene expression analysis. In total, 3,510 probes targeted transcripts differentially expressed between the clusters we identified. Genes upregulated in PreM related to organogenesis, and those upregulated in Meta underlie structural proteins and related to development of anatomical structures and pigmentation. Biosynthesis pathways of pigments (pteridines and melanin) were upregulated during late ProM and Meta. Gas chromatographic analysis of alkaloids indicated the onset of steroidal alkaloid biosynthesis at ProM. When comparing gene expression in the Fire Salamander to that in other amphibians-three anurans, Xenopus laevis, X. tropicalis, and Michrohyla fissipes, and one caudate, Ambystoma mexicanum- we identified genes with conserved expression patterns involved in basic metamorphic processes such as skin restructuring and tail fin resorption. Our results support that primary stages of postembryonic development in caudates are homologous to those of anurans, and offer a baseline for the study of the evolution of developmental modes.
Alan R. Templeton - One of the best experts on this subject based on the ideXlab platform.
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Relationships among breeding site characteristics and adult population size of the Fire Salamander, Salamandra infraimmaculata
Hydrobiologia, 2020Co-Authors: Iftah Sinai, Ori Segev, Avi Koplovich, Alan R. Templeton, Leon Blaustein, Lior BlankAbstract:Effective amphibian conservation requires knowledge of both the aquatic and terrestrial phases of life. As extinction probabilities are a function of population size, it is crucial not only to understand the habitat requirement of the species but also to estimate its population size. In this work, we studied the endangered Fire Salamander, Salamandra infraimmaculata , and analyzed the population size at a total of 14 sites—eight temporary and six permanent. For identifying the local and landscape scales factors predicting S. infraimmaculata ’s breeding sites we monitored 54 aquatic sites. We found that permanent sites support larger populations of adult Salamanders. The breeding site characteristics analyses revealed that at the local scale water depth and shade were the most important factors and two regional variables were found to be important: proximity to another breeding site and elevation. This work provides two clear conservation implications permanent breeding sites will support much larger populations compared to temporary sites, particularly if close to other potential breeding sites, and both terrestrial and aquatic features are important for a site to be suitable for breeding.
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Estimating the effects of road-kills on the Fire Salamander population along a river
Journal for Nature Conservation, 2020Co-Authors: Iftah Sinai, Avi Koplovich, Alan R. Templeton, Leon Blaustein, Talya Oron, Gilad Weil, Roni Sachal, Lior BlankAbstract:Abstract A number of factors contribute to the process of amphibian decline, among them population fragmentation and road-kills. In this work we evaluated the effects of a road that separates the hibernation area of the Fire Salamander population from their breeding site on the demography and movement behavior. For that we monitored the population for four years using transects along the road and along a river that runs in parallel to the road and serve as the breeding site. We found that the estimated percent of the population killed on the road steadily increased minimally from 2.56 % to 10.78 % over a four year period of increasing vehicular activity. Interestingly, only a small number of individuals were documented on both sides of the road, suggesting there is a potential for population fragmentation due to the road. Additionally, we used geostatistics to reveal that the spatial distribution pattern of the population and road-kills along the road is not random. Thus, conservation efforts that focus on preventing Salamanders from accessing the road surface should focus on the areas where the population and road-kills aggregate.
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Phenotypic plasticity and local adaptations to dissolved oxygen in larvae Fire Salamander (Salamandra infraimmaculata)
Oecologia, 2019Co-Authors: Ori Segev, Alan R. Templeton, Valentina Rovelli, Nadav Pezaro, Olga Rybak, Leon BlausteinAbstract:A key environmental factor that varies both spatially and temporally in surface waters is dissolved oxygen (DO). In stagnant ephemeral freshwater ponds, DO can fluctuate diurnally and seasonally, while the constant mixing of water in streams typically maintain DO levels close to saturation with only minor fluctuations. Larvae of the Near Eastern Fire Salamander ( Salamandra infraimmaculata ) develop in a range of waterbodies that vary in flow and permanence. To study inter-population variation in larval response to environmental change, we translocated larvae between stream and pond habitats and exposed larvae sampled from different habitat types to hypoxic and normoxic conditions in the laboratory. Larvae transferred from stream to pond retain gill size, while larvae transferred from pond to stream show a reduction in gill size. Larvae that were caged within their native habitat, either stream or pond, display a decrease in gill size similar to larvae transferred from pond to stream. When exposed to experimentally manipulated levels of DO in the laboratory larvae, respectively, increase and decrease gill size under hypoxic and normoxic conditions. Habitat-type origin had a significant effect on the degree of change in gill size with larvae from permanent streams demonstrating the lowest absolute variation in gill size. There was no interaction between DO level (hypoxic/normoxic) and the larvae habitat-type origin. These results suggest that S. infraimmaculata larvae are locally adapted to their aquatic breeding habitat through the plastic ability to respond to the prevailing respiratory conditions by rapidly decreasing or increasing gill size.
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Landscape influences on dispersal behaviour: a theoretical model and empirical test using the Fire Salamander, Salamandra infraimmaculata
Oecologia, 2014Co-Authors: Arik Kershenbaum, Lior Blank, Leon Blaustein, Iftach Sinai, Juha Merila, Alan R. TempletonAbstract:When populations reside within a heterogeneous landscape, isolation by distance may not be a good predictor of genetic divergence if dispersal behaviour and therefore gene flow depend on landscape features. Commonly used approaches linking landscape features to gene flow include the least cost path (LCP), random walk (RW), and isolation by resistance (IBR) models. However, none of these models is likely to be the most appropriate for all species and in all environments. We compared the performance of LCP, RW and IBR models of dispersal with the aid of simulations conducted on artificially generated landscapes. We also applied each model to empirical data on the landscape genetics of the endangered Fire Salamander, Salamandra infraimmaculata , in northern Israel, where conservation planning requires an understanding of the dispersal corridors. Our simulations demonstrate that wide dispersal corridors of the low-cost environment facilitate dispersal in the IBR model, but inhibit dispersal in the RW model. In our empirical study, IBR explained the genetic divergence better than the LCP and RW models (partial Mantel correlation 0.413 for IBR, compared to 0.212 for LCP, and 0.340 for RW). Overall dispersal cost in Salamanders was also well predicted by landscape feature slope steepness (76 %), and elevation (24 %). We conclude that Fire Salamander dispersal is well characterised by IBR predictions. Together with our simulation findings, these results indicate that wide dispersal corridors facilitate, rather than hinder, Salamander dispersal. Comparison of genetic data to dispersal model outputs can be a useful technique in inferring dispersal behaviour from population genetic data.
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genetic population structure of the endangered Fire Salamander salamandra infraimmaculata at the southernmost extreme of its distribution
Animal Conservation, 2013Co-Authors: Lior Blank, Iftah Sinai, Ori Segev, Asaf Sadeh, Shirli Bardavid, N Peleg, N M Kopelman, Alan R. TempletonAbstract:The negative effects of habitat fragmentation and population isolation on population viability, genetic variability and structuring are well documented, and conservation plans failing to take into account spatial population structure and connectivity can be ineffectual. Of special concern are populations at the periphery of the species range that might show reduced genetic diversity, thus affecting their adaptive potential at environmental margins. We investigated genetic variability and differentiation of the globally near threatened and locally endangered Fire Salamander Salamandra infraimmaculata in northern Israel, an area that represents the periphery of this species' distribution range. Analyses of variability in 15 microsatellite loci from 20 sites revealed substantial population structuring, most of which was due to a strong subdivision between two regions separated by a heavily urbanized valley. In addition, levels of genetic variability within populations were lowest in the peripheral, southernmost populations. These results suggest that the conservation plans for this species should recognize the lower diversity and increased divergence in the peripheral regions, and take into account the observed spatial population structure when devising strategies and measures to ensure the species persistence.