50 results on '"Blaustein L"'
Search Results
2. Sedum—Annual plant interactions on green roofs: Facilitation, competition and exclusion
- Author
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Vasl, A., Shalom, H., Kadas, G.J., and Blaustein, L.
- Published
- 2017
- Full Text
- View/download PDF
Catalog
3. Titrating Food and Safety in a Heterogeneous Environment: When Are the Risky and Safe Patches of Equal Value?
- Author
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Kotler, B. P. and Blaustein, L.
- Published
- 1995
- Full Text
- View/download PDF
4. Green roof research towards enhancing urban biodiversity, storm-water retention and air pollution abatement.
- Author
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Salman, I. N. A., primary, Schindler, B., additional, Agra, H., additional, Bawab, O., additional, Friedman-Heiman, A., additional, Kadas, G. J., additional, Seifan, M., additional, and Blaustein, L., additional more...
- Published
- 2019
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5. Seasonal aggregations of sharks near coastal power plants in Israel: an emerging phenomenon
- Author
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Barash, A, primary, Pickholtz, R, additional, Pickholtz, E, additional, Blaustein, L, additional, and Rilov, G, additional
- Published
- 2018
- Full Text
- View/download PDF
6. Abstracts of Papers Presented at the 51st Annual Meeting Eastern Branch Entomological Society of America Hershey, Pa. September 26, 27 and 28, 1979
- Author
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Akers, R. C., Robinson, W. H., Akram, M., Forgash, A. J., Averill, A. L., Prokopy, R. J., Bacon, N. P., Bajusz, B. A., Smilowitz, Z., Mack, T. P., Petitt, F. L., Martinka, C. A., Whalon, M. E., Beal, R., Bean, Richard A., Denno, Robert F., Bowman, J. S., Eaton, A. T., Briggs, S. P., Allen, W. A., Brushwein, J. R., Granett, J., Burger, T. L., Cannon, K. F., Clark, R. A., Cochran, D. G., Cope, S. E., Catts, E. P., Cowden, R. L., Cromartie, W. J., Rivera, M. A., Gfrorer, J., Maser, D., Davis, M. A., DeGrandi, G. L., Collison, C. H., Dodds, P. J., Dowd, P. F., Kok, L. T., Rabb, R. L., Van Duyn, J. W., Elliott, N. B., Shlotzhauer, T., Engebretson, J. A., Mullins, D. E., Evans, E. W., Fernald, G. P., Burger, J. F., Fiori, B. J., Lamb, R. C., Gelman, D. B., Hayes, D. K., Greenplate, J. T., Greenberg, S., Stuart, A. M., Hansens, E. J., Johnson, W. M., Crans, W. J., Kamran, M. A., Keil, C. B., Klemas, V., Kolodny-Hirsch, D. M., Harrison, F. P., Lake, D. J., Logan, P. A., Casagrande, R. A., McClintock, J. T., Reichelderfer, C. F., McClure, M. S., MacCollom, G. B., Baumann, G., Welch, J. G., Madhavan, M. M., Madhavan, K., Magnarelli, L. A., Mahaney, J. H., Maier, C. T., Mastro, V. C., Mather, T. N., Mellors, W. K., Helgesen, R. G., Michelotti, F. W., Seidenberger, J. W., Mkhize, J., Gupta, A. P., Murphy, J. W., Smith, J. C., Nechols, J. R., Newton, W. G., Parrella, M. P., Horsburgh, R. L., Nolan, E. S., Powell, P. K., Rajotte, E. G., Roberts, R. B., Raupp, M. J., Denno, R. F., Rexrode, C. O., Ringo, J. M., Roitberg, B. D., Rossiter, M. C., Schneider, J. C., Schultz, P. B., Schwalbe, C. P., Paszek, E. C., Schweitzer, D. F., Semtner, P. J., Terrill, T. R., Shapiro, J. P., Hagedorn, H. H., Herbert,, E. W., Shimanuki, H., Shasha, B. S., Smith,, I. B., Caron, D. M., Sofield, R. K., Stiller, D., Frerichs, W. M., Leatch, G., Kuttler, K. L., Sunzenauer, I. M., Elden, T., Steinhauer, A. L., Swift, F. C., Blaustein, L., Treichler, R., Trumble, J. T., Tweeten, K. A., Tysowsky, M., Uebel, E. C., Warthen,, J. D., Webb, J. W., Weires, R. W., Leeper, J. R., Wheeler,, A. G., Valley, K., and Winegar, J. J. more...
- Published
- 1980
7. Effects of flash flooding on mosquito and community dynamics in experimental pools
- Author
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Duchet, C., primary, Moraru, G. M., additional, Segev, O., additional, Spencer, M., additional, Hayoon, A. Gershberg, additional, and Blaustein, L., additional
- Published
- 2017
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8. Parallel habitat acclimatization is realized by the expression of different genes in two closely related salamander species (genus Salamandra)
- Author
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Goedbloed, D J, primary, Czypionka, T, additional, Altmüller, J, additional, Rodriguez, A, additional, Küpfer, E, additional, Segev, O, additional, Blaustein, L, additional, Templeton, A R, additional, Nolte, A W, additional, and Steinfartz, S, additional more...
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- 2017
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9. Parallel habitat acclimatization is realized by the expression of different genes in two closely related salamander species (genus Salamandra)
- Author
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Goedbloed, D. J., Czypionka, T., Altmueller, J., Rodriguez, A., Kuepfer, E., Segev, O., Blaustein, L., Templeton, A. R., Nolte, A. W., Steinfartz, S., Goedbloed, D. J., Czypionka, T., Altmueller, J., Rodriguez, A., Kuepfer, E., Segev, O., Blaustein, L., Templeton, A. R., Nolte, A. W., and Steinfartz, S. more...
- Abstract
The utilization of similar habitats by different species provides an ideal opportunity to identify genes underlying adaptation and acclimatization. Here, we analysed the gene expression of two closely related salamander species: Salamandra salamandra in Central Europe and Salamandra infraimmaculata in the Near East. These species inhabit similar habitat types: 'temporary ponds' and 'permanent streams' during larval development. We developed two species-specific gene expression microarrays, each targeting over 12 000 transcripts, including an overlapping subset of 8331 orthologues. Gene expression was examined for systematic differences between temporary ponds and permanent streams in larvae from both salamander species to establish gene sets and functions associated with these two habitat types. Only 20 orthologues were associated with a habitat in both species, but these orthologues did not show parallel expression patterns across species more than expected by chance. Functional annotation of a set of 106 genes with the highest effect size for a habitat suggested four putative gene function categories associated with a habitat in both species: cell proliferation, neural development, oxygen responses and muscle capacity. Among these high effect size genes was a single orthologue (14-3-3 protein zeta/YWHAZ) that was downregulated in temporary ponds in both species. The emergence of four gene function categories combined with a lack of parallel expression of orthologues (except 14-3-3 protein zeta) suggests that parallel habitat adaptation or acclimatization by larvae from S. salamandra and S. infraimmaculata to temporary ponds and permanent streams is mainly realized by different genes with a converging functionality. more...
- Published
- 2017
10. Genetic population structure of the endangered fire salamander (Salamandra infraimmaculata) at the southernmost extreme of its distribution
- Author
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Blank, L., primary, Sinai, I., additional, Bar-David, S., additional, Peleg, N., additional, Segev, O., additional, Sadeh, A., additional, Kopelman, N. M., additional, Templeton, A. R., additional, Merilä, J., additional, and Blaustein, L., additional more...
- Published
- 2012
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11. Deleterious effects by mosquitofish (Gambusia affinis) on the endangered fire salamander (Salamandra infraimmaculata)
- Author
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Segev, O., primary, Mangel, M., additional, and Blaustein, L., additional
- Published
- 2009
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12. Genetic population structure of the endangered fire salamander ( Salamandra infraimmaculata) at the southernmost extreme of its distribution.
- Author
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Blank, L., Sinai, I., Bar‐David, S., Peleg, N., Segev, O., Sadeh, A., Kopelman, N. M., Templeton, A. R., Merilä, J., and Blaustein, L.
- Subjects
GENETIC research ,AMPLIFIED fragment length polymorphism ,SALAMANDERS ,AMPHIBIANS ,SALAMANDRA - Abstract
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. [ABSTRACT FROM AUTHOR] more...
- Published
- 2013
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13. Titrating food and safety in the heterogeneous environment: when arethe risky and safe patches of equal value?
- Author
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Blaustein, L. and Kotler, B. P.
- Subjects
- *
FORAGING behavior - Published
- 1995
14. Larval Salamandra drive temporary pool community dynamics: evidence from an artificial pool experiment
- Author
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Friedman, J., Blaustein, L., and Fahima, T.
- Subjects
- *
COMMUNITIES - Published
- 1996
15. Priority effects in temporary pools: nature and outcome of mosquito larva-toad tadpole interactions depend on order of entrance
- Author
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Blaustein, L. and Margalit, J.
- Published
- 1996
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16. Mosquito larvae (Culiseta longiareolata) prey upon and compete with toad tadpoles (Bufo viridis)
- Author
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Margalit, J. and Blaustein, L.
- Subjects
COMPETITION ,PREDATION - Published
- 1994
17. Fine-scale substrate heterogeneity in green roof plant communities: The constraint of size.
- Author
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Vasl A, Schindler BY, Kadas GJ, and Blaustein L
- Abstract
Heterogeneity-diversity relationship (HDR) is commonly shown to be positive in accordance with classic niche processes. However, recent soil-based studies have often found neutral and even negative HDRs. Some of the suggested reasons for this discrepancy include the lack of resemblance between manipulated substrate and natural settings, the treated areas not being large enough to contain species' root span, and finally limited-sized plots may not sustain focal species' populations over time. Vegetated green roofs are a growing phenomenon in many cities that could be an ideal testing ground for this problem. Recent studies have focused on the ability of these roofs to sustain stable and diverse plant communities and substrate heterogeneity that would increase niches on the roof has been proposed as a method to attain this goal. We constructed an experimental design using green roof experimental modules (4 m
2 ) where we manipulated mineral and organic substrate component heterogeneity in different subplots (0.25 m2 ) within the experimental module while maintaining the total sum of mineral and organic components. A local annual plant community was seeded in the modules and monitored over three growing seasons. We found that plant diversity and biomass were not affected by experimentally created substrate heterogeneity. In addition, we found that different treatments, as well as specific subplot substrates, had an effect on plant community assemblages during the first year but not during the second and third years. Substrate heterogeneity levels were mostly unchanged over time. The inability to retain plant community composition over the years despite the maintenance of substrate differences supports the hypothesis that maintenance of diversity is constrained at these spatial scales by unfavorable dispersal and increased stochastic events as opposed to predictions of classic niche processes., Competing Interests: All authors declare they have no conflict of interest., (© 2019 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.) more...- Published
- 2019
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18. Phenotypic plasticity and local adaptations to dissolved oxygen in larvae fire salamander (Salamandra infraimmaculata).
- Author
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Segev O, Pezaro N, Rovelli V, Rybak O, Templeton AR, and Blaustein L
- Subjects
- Acclimatization, Adaptation, Physiological, Animals, Larva, Oxygen, Salamandra
- Abstract
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. more...
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- 2019
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19. Fine-scale substrate heterogeneity does not affect arthropod communities on green roofs.
- Author
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Schindler BY, Vasl A, Blaustein L, Gurevich D, Kadas GJ, and Seifan M
- Abstract
Green roofs, which are roofs with growing substrate and vegetation, can provide habitat for arthropods in cities. Maintaining a diversity of arthropods in an urban environment can enhance the functions they fill, such as pest control and soil development. Theory suggests that the creation of a heterogeneous environment on green roofs would enhance arthropod diversity. Several studies have examined how arthropod diversity can be enhanced on green roofs, and particularly whether substrate properties affect the arthropod community, but a gap remains in identifying the effect of substrate heterogeneity within a green roof on the arthropod community. In this paper, it is hypothesized that creating heterogeneity in the substrate would directly affect the diversity and abundance of some arthropod taxa, and indirectly increase arthropod diversity through increased plant diversity. These hypotheses were tested using green roof plots in four treatments of substrate heterogeneity: (1) homogeneous dispersion; (2) mineral heterogeneity-with increased tuff concentration in subplots; (3) organic heterogeneity-with decreased compost concentrations in subplots; (4) both mineral and organic heterogeneity. Each of the four treatments was replicated twice on each of three roofs (six replicates per treatment) in a Mediterranean region. There was no effect of substrate heterogeneity on arthropod diversity, abundance, or community composition, but there were differences in arthropod communities among roofs. This suggests that the location of a green roof, which can differ in local climatic conditions, can have a strong effect on the composition of the arthropod community. Thus, arthropod diversity may be promoted by building green roofs in a variety of locations throughout a city, even if the roof construction is similar on all roofs., Competing Interests: The authors declare there are no competing interests. more...
- Published
- 2019
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20. Molecular identification of Aedes phoeniciae (Diptera: Culicidae) in rockpools along the northern Israeli coast.
- Author
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Rosenfeld S, Porretta D, Rahav E, Mastrantonio V, Duchet C, and Blaustein L
- Subjects
- Aedes genetics, Animals, Ecosystem, Female, Genetic Markers genetics, Israel, Larva, Male, Mediterranean Sea, Aedes classification
- Published
- 2018
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21. Green roof and photovoltaic panel integration: Effects on plant and arthropod diversity and electricity production.
- Author
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Schindler BY, Blaustein L, Lotan R, Shalom H, Kadas GJ, and Seifan M
- Subjects
- Animals, Climate, Conservation of Natural Resources, Electricity, Arthropods, Biodiversity, Plants
- Abstract
The combination of green roofs with photovoltaic (PV) panels has been proposed to provide synergistic benefits as the panel is cooled by the presence of the vegetation, and thus produces more electricity, while the solar panel enhances growing conditions for vegetation, and increases abiotic heterogeneity, resulting in higher plant diversity. We tested these hypotheses in a non-irrigated green roof in a Mediterranean climate with replicated plots including green roofs only, green roofs with a PV panel, and a conventional roof surface with a PV panel. We found that presence of a panel resulted in higher heterogeneity in substrate moisture, but there was no effect on plant diversity. Plant species showed enhanced growth in plots with PV, including greater growth of Sedum sediforme and longer flowering time of annual species. On the other hand, arthropod diversity was lower during part of the year, and abundance of some arthropod taxa was lower in green roof plots with PV. The presence of the green roof also did not improve electricity production by the panels. We conclude that in a Mediterranean climate, it would be appropriate to examine the use of irrigation in green roofs with PV panels, including effects on the plant community and on electricity production., (Copyright © 2018 Elsevier Ltd. All rights reserved.) more...
- Published
- 2018
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22. Comparing grey water versus tap water and coal ash versus perlite on growth of two plant species on green roofs.
- Author
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Agra H, Solodar A, Bawab O, Levy S, Kadas GJ, Blaustein L, and Greenbaum N
- Subjects
- Aluminum Oxide chemistry, Coal Ash chemistry, Conservation of Natural Resources methods, Convolvulus growth & development, Drinking Water chemistry, Lamiales growth & development, Silicon Dioxide chemistry, Wastewater chemistry
- Abstract
Green roofs provide important ecosystem services in urban areas. In Mediterranean and other semi-arid climate regions, most perennial plants on green roofs need to be irrigated during the dry season. However, the use of freshwater in such regions is scarce. Therefore, the possibility of using grey water should be examined. Coal ash, produced primarily from the burning of coal in power plants, constitutes an environmental contaminant that should be disposed. One option is to use ash as a growing substrate for plants. Here, we compare the effects of irrigating with grey- versus tap-water and using ash versus perlite as growing substrates in green roofs. The study was conducted in northern Israel in a Mediterranean climate. The design was full factorial with three factors: water-type (grey or tap-water)×substrate-type (coal ash vs perlite)×plant species (Phyla nodiflora, Convolvulus mauritanicus or no-plant). The development of plants and the quality of drainage water along the season, as well as quality of the used substrates were monitored. Both plant species developed well under all the experimental conditions with no effect of water type or substrate type. Under all treatments, both plant species enhanced electrical conductivity (EC) and chemical oxygen demand (COD) of the drainage water. In the summer, EC and COD reached levels that are unacceptable in water and are intended to be reused for irrigation. We conclude that irrigating with grey water and using coal ash as a growth substrate can both be implemented in green roofs. The drainage from tap water as well as from grey water can be further used for irrigating the roof, but for that, COD and EC levels must be lowered by adding a sufficient amount of tap water before reusing., (Copyright © 2018 Elsevier B.V. All rights reserved.) more...
- Published
- 2018
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23. Inferring the shallow phylogeny of true salamanders (Salamandra) by multiple phylogenomic approaches.
- Author
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Rodríguez A, Burgon JD, Lyra M, Irisarri I, Baurain D, Blaustein L, Göçmen B, Künzel S, Mable BK, Nolte AW, Veith M, Steinfartz S, Elmer KR, Philippe H, and Vences M
- Subjects
- Animals, Bayes Theorem, Biological Evolution, Genome, Mitochondrial, High-Throughput Nucleotide Sequencing, Phylogeny, Polymorphism, Single Nucleotide, RNA chemistry, RNA isolation & purification, RNA metabolism, Salamandra genetics, Sequence Analysis, DNA, Transcriptome, Salamandra classification
- Abstract
The rise of high-throughput sequencing techniques provides the unprecedented opportunity to analyse controversial phylogenetic relationships in great depth, but also introduces a risk of being misinterpreted by high node support values influenced by unevenly distributed missing data or unrealistic model assumptions. Here, we use three largely independent phylogenomic data sets to reconstruct the controversial phylogeny of true salamanders of the genus Salamandra, a group of amphibians providing an intriguing model to study the evolution of aposematism and viviparity. For all six species of the genus Salamandra, and two outgroup species from its sister genus Lyciasalamandra, we used RNA sequencing (RNAseq) and restriction site associated DNA sequencing (RADseq) to obtain data for: (1) 3070 nuclear protein-coding genes from RNAseq; (2) 7440 loci obtained by RADseq; and (3) full mitochondrial genomes. The RNAseq and RADseq data sets retrieved fully congruent topologies when each of them was analyzed in a concatenation approach, with high support for: (1) S. infraimmaculata being sister group to all other Salamandra species; (2) S. algira being sister to S. salamandra; (3) these two species being the sister group to a clade containing S. atra, S. corsica and S. lanzai; and (4) the alpine species S. atra and S. lanzai being sister taxa. The phylogeny inferred from the mitochondrial genome sequences differed from these results, most notably by strongly supporting a clade containing S. atra and S. corsica as sister taxa. A different placement of S. corsica was also retrieved when analysing the RNAseq and RADseq data under species tree approaches. Closer examination of gene trees derived from RNAseq revealed that only a low number of them supported each of the alternative placements of S. atra. Furthermore, gene jackknife support for the S. atra - S. lanzai node stabilized only with very large concatenated data sets. The phylogeny of true salamanders thus provides a compelling example of how classical node support metrics such as bootstrap and Bayesian posterior probability can provide high confidence values in a phylogenomic topology even if the phylogenetic signal for some nodes is spurious, highlighting the importance of complementary approaches such as gene jackknifing. Yet, the general congruence among the topologies recovered from the RNAseq and RADseq data sets increases our confidence in the results, and validates the use of phylotranscriptomic approaches for reconstructing shallow relationships among closely related taxa. We hypothesize that the evolution of Salamandra has been characterized by episodes of introgressive hybridization, which would explain the difficulties of fully reconstructing their evolutionary relationships., (Copyright © 2017. Published by Elsevier Inc.) more...
- Published
- 2017
- Full Text
- View/download PDF
24. Sedum-dominated green-roofs in a semi-arid region increase CO 2 concentrations during the dry season.
- Author
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Agra H, Klein T, Vasl A, Shalom H, Kadas G, and Blaustein L
- Subjects
- Cities, Ecosystem, Israel, Carbon Dioxide analysis, Carbon Sequestration, Seasons, Sedum growth & development
- Abstract
Green roofs are expected to absorb and store carbon in plants and soils and thereby reduce the high CO
2 concentration levels in big cities. Sedum species, which are succulent perennials, are commonly used in extensive green roofs due to their shallow root system and ability to withstand long water deficiencies. Here we examined CO2 fixation and emission rates for Mediterranean Sedum sediforme on green-roof experimental plots. During late winter to early spring, we monitored CO2 concentrations inside transparent tents placed over 1m2 plots and followed gas exchange at the leaf level using a portable gas-exchange system. We found high rates of CO2 emission at daytime, which is when CO2 concentration in the city is the highest. Both plot- and leaf-scale measurements showed that these CO2 emissions were not fully compensated by the nighttime uptake. We conclude that although carbon sequestration may only be a secondary benefit of green roofs, for improving this ecosystem service, other plant species than Sedum should also be considered for use in green roofs, especially in Mediterranean and other semi-arid climates., (Copyright © 2017 Elsevier B.V. All rights reserved.) more...- Published
- 2017
- Full Text
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25. Intercohort size structure dynamics of fire salamander larvae in ephemeral habitats: a mesocosm experiment.
- Author
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Sadeh A, Polevikov A, Mangel M, and Blaustein L
- Subjects
- Animals, Body Size, Cannibalism, Larva anatomy & histology, Larva growth & development, Metamorphosis, Biological, Population Density, Population Dynamics, Salamandra growth & development, Ecosystem, Salamandra anatomy & histology
- Abstract
The size structure of a larval population facilitates interaction asymmetries that, in turn, influence the dynamics of size-structure. In species that exhibit conspicuous aggressive interactions, the competitive effects of the smaller individuals may be overlooked. We manipulated initial size differences between two larval cohorts and young-cohort density of Salamandra infraimmaculata in mesocosms to determine: (1) whether young individuals function primarily as prey or as competitors of older and larger individuals; (2) the resulting dynamics of size variation; and (3) recruitment to the postmetamorph population. Intercohort size differences generally remained constant over time at low young-cohort densities, but reduced over time at high densities due to retardation of the old-cohort growth rate. This suggests a competitive advantage to the young cohort that outweighs the interference advantage of older cohorts previously documented in this species. The increase in mortality from desiccation due to high young-cohort density was an order of magnitude greater in the old cohort than in the young-cohort, further indicating size-dependent vulnerability to competition. However, the conditions least favorable to most of the old-cohort larvae (large size difference and high young-cohort density) promoted cannibalism. Among cannibals, mortality and time to metamorphosis decreased and sizes at metamorphosis increased substantially. Thus, a balance between the competitive advantage to young cohorts, and the interference and cannibalism advantage to old cohorts shapes larval size-structure dynamics. Larval densities and individual expression of cannibalism can shift this balance in opposite directions and alter relative recruitment rates from different cohorts. more...
- Published
- 2015
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26. Correction: Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.
- Author
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Segev O, Polevikove A, Blank L, Goedbloed D, Küpfer E, Gershberg A, Koplovich A, and Blaustein L
- Published
- 2015
- Full Text
- View/download PDF
27. Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.
- Author
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Segev O, Polevikove A, Blank L, Goedbloed D, Küpfer E, Gershberg A, Koplovich A, and Blaustein L
- Subjects
- Animals, Body Size, Larva growth & development, Larva physiology, Metamorphosis, Biological, Regeneration, Salamandra growth & development, Tail physiology
- Abstract
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. more...
- Published
- 2015
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28. The taxonomic status of Dugesiabiblica from Israel and Turkey (Platyhelminthes, Tricladida, Dugesiidae).
- Author
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Solà E, Sluys R, Segev O, Blaustein L, and Riutort M
- Abstract
The taxonomic status of Dugesiabiblica (Platyhelminthes, Tricladida, Dugesiidae) from Israel and Turkey is problematic due to its morphological similarity with Dugesiasicula since these nominal species present overlapping characters. In this study we analyzed histological preparations of specimens of these two nominal species and also compared mitochondrial COI gene sequences from Israeli populations to the already known haplotype composition of Dugesiasicula. We concluded that these animals belong to the same species and therefore we consider Dugesiabiblica to be a junior synonym of Dugesiasicula. This implies that the distribution range of Dugesiasicula is even wider than previously thought, and that the species is present all around the Mediterranean Basin and on many of its islands. more...
- Published
- 2015
- Full Text
- View/download PDF
29. Landscape influences on dispersal behaviour: a theoretical model and empirical test using the fire salamander, Salamandra infraimmaculata.
- Author
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Kershenbaum A, Blank L, Sinai I, Merilä J, Blaustein L, and Templeton AR
- Subjects
- Animals, Gene Flow, Genetics, Population, Israel, Models, Theoretical, Caudata genetics, Animal Distribution, Environment, Salamandra genetics, Salamandra physiology
- Abstract
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. more...
- Published
- 2014
- Full Text
- View/download PDF
30. Interactive effects of salinity and a predator on mosquito oviposition and larval performance.
- Author
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Silberbush A, Tsurim I, Margalith Y, and Blaustein L
- Subjects
- Animal Distribution, Animals, Diptera, Ecosystem, Environment, Female, Hemiptera, Heteroptera, Larva growth & development, Predatory Behavior, Culicidae physiology, Oviposition, Salinity
- Abstract
Oviposition habitat selection (OHS) is increasingly being recognized as playing a large role in explaining mosquito distributions and community assemblages. Most studies have assessed the role of single factors affecting OHS, while in nature, oviposition patterns are most likely explained by multiple, interacting biotic and abiotic factors. Determining how various factors interact to affect OHS is important for understanding metapopulation and metacommunity dynamics. We investigated the individual and interactive effects of three water salinities (0, 15 and 30 p.p.t. NaCl added) and the aquatic predator Anisops debilis Perplexa (Hemiptera: Notonectidae) on OHS and larval performance of the mosquitoes Ochlerotatus caspius Pallas and Culiseta longiareolata Macquart (Diptera: Culicidae) in outdoor-artificial-pool and laboratory experiments. C. longiareolata inhabited only freshwater pools, strongly avoided pools containing A. debilis, and larvae experienced lower survival in the presence of A. debilis. Salinity concentration interacted strongly with the predator in affecting OHS and larval survival of O. caspius; oviposition increased with increasing salinity in the absence of the predator and decreased with increasing salinity in the presence of the predator. O. caspius larval survival in predator-free pools was lowest in freshwater and highest at intermediate salinity. In predator pools, survival was highest at high salinity, where predation rate was shown to be lowest in the laboratory. Our results highlight that assessing the role of single factors in affecting mosquito distributions can be misleading. Instead, multiple factors may interact to affect oviposition patterns and larval performance. more...
- Published
- 2014
- Full Text
- View/download PDF
31. Inter- and intra-specific density-dependent effects on life history and development strategies of larval mosquitoes.
- Author
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Tsurim I, Silberbush A, Ovadia O, Blaustein L, and Margalith Y
- Subjects
- Animals, Body Size, Ecosystem, Female, Male, Population Density, Population Dynamics, Sex Factors, Competitive Behavior physiology, Culicidae physiology, Genetic Fitness physiology, Larva physiology, Ochlerotatus physiology
- Abstract
We explored how inter- and intra-specific competition among larvae of two temporary-pool mosquito species, Culiseta longiareolata and Ochlerotatus caspius, affect larval developmental strategy and life history traits. Given that their larvae have similar feeding habits, we expected negative reciprocal inter-specific interactions. In a microcosm experiment, we found sex-specific responses of larval survival and development to both intra- and inter-specific larval competition. C. longiareolata was the superior competitor, reducing adult size and modifying larval developmental time of O. caspius. We observed two distinct waves of adult emergence in O. caspius, with clear sex-specific responses to its inter-specific competitor. In males, this pattern was not affected by C. longiareolata, but in females, the timing and average body size of the second wave strongly varied with C. longiareolata density. Specifically, in the absence of C. longiareolata, the second wave immediately followed the first wave. However, as C. longiareolata abundance increased, the second wave was progressively delayed and the resulting females tended to be larger. This study improves our understanding of the way intra- and inter-specific competition combine to influence the life histories of species making up temporary pond communities. It also provides strong evidence that not all individuals of a cohort employ the same strategies in response to competition. more...
- Published
- 2013
- Full Text
- View/download PDF
32. Syntactic structure and geographical dialects in the songs of male rock hyraxes.
- Author
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Kershenbaum A, Ilany A, Blaustein L, and Geffen E
- Subjects
- Algorithms, Animals, Israel, Male, Sound Spectrography methods, Animal Communication, Hyraxes physiology, Vocalization, Animal classification, Vocalization, Animal physiology
- Abstract
Few mammalian species produce vocalizations that are as richly structured as bird songs, and this greatly restricts the capacity for information transfer. Syntactically complex mammalian vocalizations have been previously studied only in primates, cetaceans and bats. We provide evidence of complex syntactic vocalizations in a small social mammal: the rock hyrax (Procavia capensis: Hyracoidea). We adopted three algorithms, commonly used in genetic sequence analysis and information theory, to examine the order of syllables in hyrax calls. Syntactic dialects exist, and the syntax of hyrax calls is significantly different between different regions in Israel. Call syntax difference is positively correlated to geographical distance over short distances. No correlation is found over long distances, which may reflect limited dispersal movement. These findings indicate that rich syntactic structure is more common in the vocalizations of mammalian taxa than previously thought and suggest the possibility of vocal production learning in the hyrax. more...
- Published
- 2012
- Full Text
- View/download PDF
33. Modelling transmission of vector-borne pathogens shows complex dynamics when vector feeding sites are limited.
- Author
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Kershenbaum A, Stone L, Ostfeld RS, and Blaustein L
- Subjects
- Animals, Humans, Population Dynamics, Disease Vectors, Host-Pathogen Interactions physiology, Models, Biological, Zoonoses transmission
- Abstract
The relationship between species richness and the prevalence of vector-borne disease has been widely studied with a range of outcomes. Increasing the number of host species for a pathogen may decrease infection prevalence (dilution effect), increase it (amplification), or have no effect. We derive a general model, and a specific implementation, which show that when the number of vector feeding sites on each host is limiting, the effects on pathogen dynamics of host population size are more complex than previously thought. The model examines vector-borne disease in the presence of different host species that are either competent or incompetent (i.e. that cannot transmit the pathogen to vectors) as reservoirs for the pathogen. With a single host species present, the basic reproduction ratio R(0) is a non-monotonic function of the population size of host individuals (H), i.e. a value [Formula: see text] exists that maximises R(0). Surprisingly, if [Formula: see text] a reduction in host population size may actually increase R(0). Extending this model to a two-host species system, incompetent individuals from the second host species can alter the value of [Formula: see text] which may reverse the effect on pathogen prevalence of host population reduction. We argue that when vector-feeding sites on hosts are limiting, the net effect of increasing host diversity might not be correctly predicted using simple frequency-dependent epidemiological models. more...
- Published
- 2012
- Full Text
- View/download PDF
34. Oviposition habitat selection by Anopheles gambiae in response to chemical cues by Notonecta maculata.
- Author
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Warburg A, Faiman R, Shtern A, Silberbush A, Markman S, Cohen JE, and Blaustein L
- Subjects
- Alkanes, Animals, Cues, Culicidae physiology, Ecosystem, Female, Predatory Behavior, Anopheles physiology, Behavior, Animal, Heteroptera physiology, Oviposition physiology, Pheromones chemistry
- Abstract
A number of mosquito species avoid predator-inhabited oviposition sites by detecting predator-released kairomones. In the laboratory, we found that when offered de-ionized water and de-ionized water conditioned with Notonecta maculata, gravid Anopheles gambiae females preferentially oviposited into the former. We then conducted further experiments using two chemical components found in Notonecta-conditioned water, chemically pure n-tricosane and/or n-heneicosane, that was previously shown to repel oviposition by Culiseta longiareolata. These hydrocarbons failed to deter oviposition by An. gambiae females. Thus, different mosquito species may rely on distinct chemical cues to avoid predators. Identification and chemical characterization of such kairomones could facilitate innovative, environmentally sound mosquito control., (© 2011 The Society for Vector Ecology.) more...
- Published
- 2011
- Full Text
- View/download PDF
35. Compensatory development and costs of plasticity: larval responses to desiccated conspecifics.
- Author
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Sadeh A, Truskanov N, Mangel M, and Blaustein L
- Subjects
- Animals, Desiccation, Larva growth & development, Phenotype, Selection, Genetic, Survival Rate, Caudata genetics, Adaptation, Physiological, Behavior, Animal physiology, Environment, Caudata growth & development
- Abstract
Understanding constraints on phenotypic plasticity is central to explaining its evolution and the evolution of phenotypes in general, yet there is an ongoing debate on the classification and relationships among types of constraints. Since plasticity is often a developmental process, studies that consider the ontogeny of traits and their developmental mechanisms are beneficial. We manipulated the timing and reliability of cues perceived by fire salamander larvae for the future desiccation of their ephemeral pools to determine whether flexibility in developmental rates is constrained to early ontogeny. We hypothesized that higher rates of development, and particularly compensation for contradictory cues, would incur greater endogenous costs. We found that larvae respond early in ontogeny to dried conspecifics as a cue for future desiccation, but can fully compensate for this response in case more reliable but contradictory cues are later perceived. Patterns of mortality suggested that endogenous costs may depend on instantaneous rates of development, and revealed asymmetrical costs of compensatory development between false positive and false negative early information. Based on the results, we suggest a simple model of costs of development that implies a tradeoff between production costs of plasticity and phenotype-environment mismatch costs, which may potentially underlie the phenomenon of ontogenetic windows constraining plasticity. more...
- Published
- 2011
- Full Text
- View/download PDF
36. Predator-released hydrocarbons repel oviposition by a mosquito.
- Author
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Silberbush A, Markman S, Lewinsohn E, Bar E, Cohen JE, and Blaustein L
- Subjects
- Alkanes chemistry, Alkanes metabolism, Animals, Culicidae physiology, Heteroptera physiology, Pheromones chemistry, Pheromones isolation & purification, Predatory Behavior, Alkanes pharmacology, Culicidae drug effects, Heteroptera chemistry, Oviposition drug effects, Pheromones pharmacology
- Abstract
Prey species commonly use predator-released kairomones (PRKs) to detect risk of predation, yet the chemical identity of PRKs remains elusive. Chemical identification of PRKs will facilitate the study of predator-prey interactions and the risk of predation, and when the prey are pests, will potentially provide environmentally friendly means of pest control. In temporary pools of the Mediterranean and Middle East, larvae of the mosquito Culiseta longiareolata Macquart are highly vulnerable to the common predatory backswimmer, Notonecta maculata Fabricius. We demonstrate that N. maculata releases two hydrocarbons, n-heneicosane and n-tricosane, which repel ovipositing females of C. longiareolata. In behavioural tests with environmentally relevant chemical concentrations in outdoor mesocosm experiments, the repellent effects of the two compounds were additive at the tested concentrations. more...
- Published
- 2010
- Full Text
- View/download PDF
37. Context-dependent reproductive habitat selection: the interactive roles of structural complexity and cannibalistic conspecifics.
- Author
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Sadeh A, Mangel M, and Blaustein L
- Subjects
- Animals, Feeding Behavior, Female, Larva physiology, Cannibalism, Ecosystem, Salamandra physiology, Sexual Behavior, Animal
- Abstract
Structural complexity generally reduces predation and cannibalism rates. Although the benefits from this effect vary among environmental contexts and through time, it has been the common explanation for high species abundance in complex habitats. We hypothesized that oviposition habitat selection for structural complexity depends on the expected trophic function of the progeny. In Salamandra infraimmaculata larvae, expected trophic function is dictated by their sequence of deposition. First cohorts cannibalize later-arriving cohorts, while all compete for shared prey resources. In a mesocosm experiment, we show that gravid salamanders facing conspecific-free pools preferred structurally simple habitats (no rocks), while females facing only pools with older conspecific larvae preferred complex habitats (with rocks). Context-dependent preference of habitat complexity for managing food/safety trade-offs may be extended from classic foraging patch decisions to breeding habitat selection. These trade-offs vary with dynamic larval processes such as priority effects and ontogenetic diet shifts, potentially leading to complex maternal parturition behaviours. more...
- Published
- 2009
- Full Text
- View/download PDF
38. Oviposition habitat selection by a mosquito in response to a predator: are predator-released kairomones air-borne cues?
- Author
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Silberbush A and Blaustein L
- Subjects
- Animals, Culicidae physiology, Female, Pheromones physiology, Predatory Behavior, Culicidae growth & development, Ecosystem, Oviposition physiology, Pheromones metabolism
- Published
- 2008
- Full Text
- View/download PDF
39. Interactions between mosquito larvae and species that share the same trophic level.
- Author
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Blaustein L and Chase JM
- Subjects
- Animals, Competitive Behavior, Cyprinodontiformes, Larva, Oryza, Oviposition, Population Dynamics, Predatory Behavior, Symbiosis, Culicidae, Ecosystem
- Abstract
Ecological theory predicts, and empirical research shows, that species sharing the same trophic level as a target species (hereafter controphic species) can have large direct and indirect effects on the target species by sharing resources and/or by serving as alternative prey to predators. Yet, the roles of controphic species of mosquito larvae in affecting mosquito populations have received little attention. Published empirical evidence, although scarce, suggests that controphic species such as zooplankton and anuran larvae compete with mosquito larvae, can positively affect mosquito larvae by consuming bacteria that are pathogenic to mosquito larvae, reduce predation on mosquito larvae by serving as alternative prey, and ultimately cause increased predation on mosquito larvae by causing a numerical response in the predator. We conclude that more extensive theoretical and empirical studies in elucidating the roles of controphic species will better allow us to predict mosquito population dynamics and allow for better management of mosquitoes. more...
- Published
- 2007
- Full Text
- View/download PDF
40. Effects of pool depth and risk of predation on oviposition habitat selection by temporary pool dipterans.
- Author
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Arav D and Blaustein L
- Subjects
- Animals, Behavior, Animal, Female, Chironomidae physiology, Culicidae physiology, Environment, Oviposition physiology, Predatory Behavior, Water
- Abstract
Natural selection should favor females that oviposit in sites providing the best available conditions for her progeny. In temporary pools, two important conditions include risk of desiccation and risk of predation to larvae. In an artificial pool experiment, we compared oviposition responses of two dipterans, Culiseta longiareolata Macquart (Culicidae) and Chironomus riparius Meigan (Chironomidae), in very shallow pools that, if left to dry, would not have had a long enough hydroperiod for larvae to complete development, versus deeper pools that would have a sufficiently long enough hydroperiod for development. Water depth was crossed with the presence or absence of the predatory backswimmer Notonecta maculata F. (Hemiptera: Notonectidae). Oviposition patterns were consistent with larval vulnerability of the two species to predation by N. maculata. C. longiareolata, whose larvae are highly vulnerable to predation, strongly avoided ovipositing in pools containing this predator, whereas C. riparius, whose larvae are considerably less vulnerable, did not display oviposition avoidance. Pool depth did not affect oviposition habitat selection in either dipteran. more...
- Published
- 2006
- Full Text
- View/download PDF
41. Chemical detection of the predator Notonecta irrorata by ovipositing Culex mosquitoes.
- Author
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Blaustein L, Blaustein J, and Chase J
- Subjects
- Animals, Female, Food Chain, Heteroptera metabolism, Mosquito Control, Pheromones physiology, Water Supply, Culex growth & development, Culex physiology, Heteroptera physiology, Oviposition, Predatory Behavior physiology
- Abstract
We tested the oviposition response of Culex mosquitoes to the predator Notonecta irrorata in an outdoor artificial pool experiment employing equal numbers of control and predator pools. There was a strong oviposition avoidance by Culex of Notonecta pools; 83% of egg rafts were found in control pools during the period in which Notonecta were present. After removing Notonecta, mosquitoes continued to avoid ovipositing in the former Notonecta pools for two additional days suggesting a predator-released kairomone as the cue used by the mosquitoes to detect the presence of this predator. more...
- Published
- 2005
42. First occurrence of Ochlerotatus japonicus in Missouri.
- Author
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Gallitano S, Blaustein L, and Vonesh J
- Subjects
- Animals, Demography, Missouri, Insect Vectors growth & development, Ochlerotatus growth & development
- Published
- 2005
43. Density and intercohort priority effects on larval Salamandra salamandra in temporary pools.
- Author
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Eitam A, Blaustein L, and Mangel M
- Subjects
- Animals, Cannibalism, Metamorphosis, Biological, Species Specificity, Larva, Salamandra growth & development
- Abstract
Priority effects, i.e., effects of an early cohort on the performance of a later cohort, are generally studied between, and not within, species. The paucity of intraspecific assessments does not reflect a lack of ecological importance, but the technical problem associated with differentiating between conspecific cohorts. Here, we examine priority and density-dependent effects on larval Salamandra salamandra infraimmaculata. Larvae deposited by their mother early in the season have increased risk of desiccation, as rains at the beginning of the season are less frequent and unpredictable. However, breeding later may incur a high cost through conspecific priority effects, including cannibalism and competition. In an outdoor artificial pool experiment, we established densities of 0, 1, 2, 4 or 6 newly born larvae per pool ( approximately 30 l), and 40 days later, added a second cohort of three newly born larvae to each pool. We differentiated between cohorts using natural individual-specific markings. For the early cohort, increasing density decreased survival and size at metamorphosis, and increased time to metamorphosis. For the late cohort, survival was 100% in pools without early-cohort larvae, but ranged between 13 and 33% in the presence of early-cohort larvae. Time to metamorphosis was significantly longer in the presence of low vs high densities of early-cohort larvae. Results suggest that early-cohort larvae are mainly subjected to exploitative competition and cannibalism mediated by food limitation, and that late-cohort larvae are subjected to cannibalism and interference due to size asymmetry between cohorts. The strong priority effects suggest that Salamandra females could increase their fitness by adjusting the number of larvae they deposit in specific pools to avoid cannibalism and intraspecific competition. more...
- Published
- 2005
- Full Text
- View/download PDF
44. Oviposition habitat selection in response to risk of predation in temporary pools: mode of detection and consistency across experimental venue.
- Author
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Blaustein L, Kiflawi M, Eitam A, Mangel M, and Cohen JE
- Subjects
- Animals, Female, Food Chain, Larva, Mosquito Control, Pheromones, Predatory Behavior, Water Supply, Culicidae physiology, Diptera physiology, Oviposition, Selection, Genetic
- Abstract
Natural selection should favor females that avoid ovipositing where risk of predation is high for their progeny. Despite the large consequences of such oviposition behavior for individual fitness, population dynamics, and community structure, relatively few studies have tested for this behavior. Moreover, these studies have rarely assessed the mode of detection of predators, compared responses in prey species that vary in vulnerability to predators, or tested for the behavior in natural habitats. In an outdoor artificial pool experiment, we tested the oviposition responses of two dipteran species, Culiseta longiareolata (mosquito) and Chironomus riparius (midge), to the hemipteran predator, Notonecta maculata. Both dipteran species have similar life history characteristics, but Culiseta longiareolata larvae are highly vulnerable to predation by Notonecta, while Chironomus riparius larvae are not. As their vulnerabilities would suggest, Culiseta longiareolata, but not Chironomus riparius, strongly avoided ovipositing in pools containing Notonecta. An experiment in natural rock pools assessing oviposition by Culiseta longiareolata in response to Notonecta maculata yielded an oviposition pattern highly consistent with that of the artificial pool experiment. We also demonstrated that the cue for oviposition avoidance by Culiseta longiareolata was a predator-released chemical: Notonecta water (without Notonecta replenishment) repelled oviposition for 8 days. Oviposition avoidance and mode of detection of the predator have important implications for how to assess the true impact of predators and for the use of commercially produced kairomones for mosquito control. more...
- Published
- 2004
- Full Text
- View/download PDF
45. Influence of nymphal Anax imperator (Odonata: Aeshnidae) on oviposition by the mosquito Culiseta longiareolata (Diptera: Culicidae) and community structure in temporary pools.
- Author
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Stav G, Blaustein L, and Margalit Y
- Subjects
- Animals, Nymph physiology, Risk Factors, Culicidae physiology, Insecta physiology, Oviposition, Predatory Behavior
- Abstract
We assessed the overall (consumptive plus non-consumptive) and non-consumptive effects of nymphal Anax imperator (Aeshnidae: Odonata) on experimental pool communities by comparing three treatments: (1) control (no Anax); (2) free Anax (Anax was not constrained); and (3) caged Anax (Anax, enclosed within a cage, could not consume prey outside the cages, but could possibly influence them via perceived risk of predation). Fewer egg rafts of the mosquito Culiseta longiareolata were found in the free Anax treatment compared to the other two treatments. There was no statistically significant difference in the number of egg rafts between control and caged Anax pools. Thus, while Culiseta females apparently oviposit fewer egg rafts in the presence of unconstrained Anax, they did not respond to predation risk from the caged Anax. Larval Culiseta densities were drastically reduced by free Anax; there was nearly a 100% reduction in the number reaching metamorphosis (pupae) and a 100% reduction in emergence (pupal exuviae). There were no significant treatment effects on densities of crustaceans, Daphnia magna and Heterocypris sp., or on chironomid pupal exuviae. Ceratopogonid pupal abundance was higher in free Anax pools than in the other two treatments toward the end of the experiment. Free Anax caused a trophic cascade, presumably by strongly reducing the dominant periphyton grazer, Culiseta larvae; periphyton mass was greater in the free Anax treatment than in the control. However, there was no behavioral trophic cascade, i.e., no difference in periphyton abundance between the control and caged Anax treatment. more...
- Published
- 2000
46. A new coccidian from Acomys cahirinus Desmarest, 1819, from Evolution Canyon, Lower Nahal Oren, Mount Carmel, Israel.
- Author
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Couch L, Blaustein L, Duszynski DW, Shenbrot G, and Nevo E
- Subjects
- Animals, Climate, Coccidiosis epidemiology, Coccidiosis parasitology, Eimeria ultrastructure, Feces parasitology, Israel epidemiology, Prevalence, Rodent Diseases epidemiology, Coccidiosis veterinary, Eimeria classification, Muridae parasitology, Rodent Diseases parasitology
- Abstract
In 1994, fresh fecal samples were collected and examined for coccidian parasites from 43 spiny mice (Acomys cahirinus) and from 60 wood mice (Apodemus mystacinus). The 2 genera of rodents inhabit an area in Lower Nahal Oren. Mount Carmel, Israel, known as Evolution Canyon, which consists of opposite-facing slopes that are geologically identical, but micro-climatically very different. Acomys cahirinus is found primarily on the warmer and drier south-facing slope (SFS), whereas A. mystacinus primarily inhabits the cooler and wetter north-facing slope (NFS). None of the samples from the A. mystacinus contained coccidia, but 6 of 43 (14%) A. cahirinus individuals were discharging eimerian oocysts that we describe herein as a new species. Five of the 6 positive samples were from the SFS. Sporulated oocysts are ovoidal to subspheroidal, 26.5 x 22.9 (21-29 x 19-26) microns, without a micropyle, but with an oocyst residuum of 1 to several large clear globules and a medium-sized refractile polar body; they contain lemon-shaped sporocysts, 10.4 x 8.1 (10 11 x 7-10) microns, with a sporocyst residuum and Stieda body, but no sub-/or parastieda body. Sporozoites lie side by side, completely filling oocysts; each contains a large posterior refractile body. more...
- Published
- 1997
47. Non-consumptive effects of larval Salamandra on crustacean prey: can eggs detect predators?
- Author
-
Blaustein L
- Abstract
Predators affect prey populations not only by prey consumption but also in nonconsumptive ways including modifying prey behavior. I tested the effects of fire salamander larvae (Salamandra infraimmaculata) on populations of co-occurring crustacean species in artificial outdoor pools. I also tested whether these effects were due entirely to prey consumption by Salamandra larvae or alternatively to some nonconsumptive effect. The soil (containing crustacean eggs) added to the artificial pools was collected from a dried-out temporary pool that is inhabited by Salamandra during the early part of the hydroperiod. I randomly assigned the pools to one of three treatments: control, free Salamandra, or caged Salamandra. Free salamander larvae could roam the entire pool and prey upon crustaceans. Caged salamander larvae were placed within a cage with having 250-μm mesh windows. They could not prey upon the crustaceans but could, for example, influence them by chemical cues. Densities of the three dominant crustacean species (Arctodiaptomus similis, Ceriodaphnia quadrangula and Cyzicus sp.) were drastically reduced in both salamander treatments compared to the control. Crustacean densities, however, were not significantly different between the two salamander treatments. One plausible explanation is that crustacean eggs can detect the presence of this predator via chemical cues and delay hatching. more...
- Published
- 1997
- Full Text
- View/download PDF
48. Predation by a cyprinodontid fish, Aphanius mento, on Culex pipiens: effects of alternative prey and vegetation.
- Author
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Blaustein L and Byard R
- Subjects
- Animals, Larva, Population Dynamics, Predatory Behavior, Culex, Cyprinodontiformes, Pest Control, Biological
- Abstract
We assessed the effects of an alternative prey species (Daphnia magna) and a submergent plant (Ceratophyllum demersum) on the efficiency of the fish, Aphanius mento, to prey on mosquito (Culex pipiens) larvae in the laboratory. Aphanius mento is an untested biological control candidate of mosquitoes. When D. magna was introduced with equal numbers of Cx. pipiens larvae, there was a 50.7% reduction in predation by A. mento on the mosquito larvae. However, the more D. magna a fish ate, the more Cx. pipiens it consumed. Ceratophyllum demersum did not affect predation rates on Cx. pipiens larvae. more...
- Published
- 1993
49. Spatial distributions of Anopheles freeborni, Gambusia affinis and Lepomis cyanellus in experimental rice plots.
- Author
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Blaustein L
- Subjects
- Animals, Demography, Ecology, Oryza, Anopheles, Cyprinodontiformes, Perciformes, Pest Control, Biological
- Published
- 1989
50. Effects of various factors on the efficiency of minnow traps to sample mosquitofish (Gambusia affinis) and green sunfish (Lepomis cyanellus) populations.
- Author
-
Blaustein L
- Subjects
- Animals, Environment, Female, Plants, Population Density, Water, Cyprinodontiformes anatomy & histology, Perciformes, Pest Control, Biological instrumentation
- Abstract
The effects of various factors on the efficiency of the Gee minnow trap to sample populations of mosquitofish, Gambusia affinis, in both rice field enclosures and a laboratory tank were assessed. Immature green sunfish, Lepomis cyanellus, were assessed in the laboratory tank only. Trap efficiency (percent catch) was greater for larger mosquitofish [greater than or equal to 35 mm total length (TL)] than for smaller mosquitofish. Immature green sunfish (25-40 mm TL) were caught at higher rates than either size class of mosquitofish. In the laboratory, trap efficiency increased with increasing mosquitofish density, but density had no effect in field enclosures. Vegetation did not affect trap efficiency. Minnow traps, lying on the substrate, caught a similar percent of available mosquitofish when water depths were 8 and 16 cm but a significantly smaller percent when 24 cm. In contrast, green sunfish, assessed at 8 and 24 cm, were trapped at a higher rate at 24 cm. These results demonstrate the importance of determining the effects of environmental factors on trap efficiency before using direct trap counts to assess effects of these factors on fish abundance. more...
- Published
- 1989
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