10 research outputs found

    Environmental effects of ozone depletion, UV radiation and interactions with climate change : UNEP Environmental Effects Assessment Panel, update 2017

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    Peer reviewe

    <i>Eucypris fontana</i> (Graf, 1931) (Crustacea, Ostracoda) in permanent environments of Patagonia Argentina: A geometric morphometric approach

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    Ostracods are microcrustaceans with a calcareous carapace, very useful as paleoenvironmental indicators. Eucypris fontana (Graf, 1931) is a non-marine ostracod species, distributed in southern Neotropics, commonly found in living bisexual populations as well as in quaternary sequences in Patagonia. Geometry morphometric analysis offers efficient and powerful techniques to quantify, describe and analyze shape and size variations. In this study, phenotypic changes in the carapace (size and shape) of E. fontana were analyzed using geometric morphometric methods. One hundred and two valves, including males and females from surface sediments of six permanent water bodies located in Patagonia, Argentina, were analyzed. Male and female valves are spread in the morphospace and sexual dimorphism in size and shape were no perceived. Valve size (centroid size) differed between environments; larger individual were correlated with higher Mg2+, Ca2+, K+ concentrations and temperature and lower pH (~9.1) of the host waters, whereas smaller specimens were associated with the opposite environmental extreme. The principal component analysis performed with Procrustes coordinates (shape) indicated a morphological gradient between elongated and rounded valves; major changes occurring on the dorsal margin, calcified inner lamella and in the position of the adductor muscles scars. Rounded carapaces were related whit higher Ca2+ and Mg2+ concentration and lower pH (~8.6) environments, whereas elongated valves were associated with the opposite environmental extreme. These results highlight the importance of morphometric studies of E. fontana in ecological research and their potential use in paleoenvironmental studies in Patagonia and other regions where this taxon is found.Facultad de Ciencias Naturales y Muse

    <i>Eucypris fontana</i> (Graf, 1931) (Crustacea, Ostracoda) in permanent environments of Patagonia Argentina: A geometric morphometric approach

    No full text
    Ostracods are microcrustaceans with a calcareous carapace, very useful as paleoenvironmental indicators. Eucypris fontana (Graf, 1931) is a non-marine ostracod species, distributed in southern Neotropics, commonly found in living bisexual populations as well as in quaternary sequences in Patagonia. Geometry morphometric analysis offers efficient and powerful techniques to quantify, describe and analyze shape and size variations. In this study, phenotypic changes in the carapace (size and shape) of E. fontana were analyzed using geometric morphometric methods. One hundred and two valves, including males and females from surface sediments of six permanent water bodies located in Patagonia, Argentina, were analyzed. Male and female valves are spread in the morphospace and sexual dimorphism in size and shape were no perceived. Valve size (centroid size) differed between environments; larger individual were correlated with higher Mg2+, Ca2+, K+ concentrations and temperature and lower pH (~9.1) of the host waters, whereas smaller specimens were associated with the opposite environmental extreme. The principal component analysis performed with Procrustes coordinates (shape) indicated a morphological gradient between elongated and rounded valves; major changes occurring on the dorsal margin, calcified inner lamella and in the position of the adductor muscles scars. Rounded carapaces were related whit higher Ca2+ and Mg2+ concentration and lower pH (~8.6) environments, whereas elongated valves were associated with the opposite environmental extreme. These results highlight the importance of morphometric studies of E. fontana in ecological research and their potential use in paleoenvironmental studies in Patagonia and other regions where this taxon is found.Facultad de Ciencias Naturales y Muse

    <i>Eucypris fontana</i> (Graf, 1931) (Crustacea, Ostracoda) in permanent environments of Patagonia Argentina: A geometric morphometric approach

    No full text
    Ostracods are microcrustaceans with a calcareous carapace, very useful as paleoenvironmental indicators. Eucypris fontana (Graf, 1931) is a non-marine ostracod species, distributed in southern Neotropics, commonly found in living bisexual populations as well as in quaternary sequences in Patagonia. Geometry morphometric analysis offers efficient and powerful techniques to quantify, describe and analyze shape and size variations. In this study, phenotypic changes in the carapace (size and shape) of E. fontana were analyzed using geometric morphometric methods. One hundred and two valves, including males and females from surface sediments of six permanent water bodies located in Patagonia, Argentina, were analyzed. Male and female valves are spread in the morphospace and sexual dimorphism in size and shape were no perceived. Valve size (centroid size) differed between environments; larger individual were correlated with higher Mg2+, Ca2+, K+ concentrations and temperature and lower pH (~9.1) of the host waters, whereas smaller specimens were associated with the opposite environmental extreme. The principal component analysis performed with Procrustes coordinates (shape) indicated a morphological gradient between elongated and rounded valves; major changes occurring on the dorsal margin, calcified inner lamella and in the position of the adductor muscles scars. Rounded carapaces were related whit higher Ca2+ and Mg2+ concentration and lower pH (~8.6) environments, whereas elongated valves were associated with the opposite environmental extreme. These results highlight the importance of morphometric studies of E. fontana in ecological research and their potential use in paleoenvironmental studies in Patagonia and other regions where this taxon is found.Facultad de Ciencias Naturales y Muse

    FIGURE 4. Cypridopsis silvestrii comb. nov. A. A1 in Taxonomic revision of Cypridopsis silvestrii comb. nov. (Ostracoda, Crustacea) from Patagonia, Argentina with morphometric analysis of their intraspecific shape variability and sexual dimorphism

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    FIGURE 4. Cypridopsis silvestrii comb. nov. A. A1 (UNC-PMIC 153 ES female). B. A2 (UNC-PMIC 155 ES female). C. A2 (UNC-PMIC 160 ET male). D. Md (UNC-PMIC 153 ES female). E. Md Palp (UNC-PMIC 153 ES female). Scale bar: 100 µm

    Morphological diversity and discrimination tools of the non-marine ostracod Cypridopsis silvestrii across temporal and spatial scales from Patagonia

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    Geometric morphometric methods are powerful tools to discriminate between closely related ostracods taxa as well as to study the relationship between their morphological variations, taxonomy and paleoecology. In this study, valve outline analysis allows the discrimination between the non-marine ostracod C. silvestrii and R. whatleyi juveniles, pointing out differences in the posterior valve area and surface ornamentation. Modern female specimens of C. silvestrii from 23 sites located in a spatial transect (41 to 51 °S) exhibited extensive morphological variability, on the basis of which three morphotypes (acuminated, transitional, subtruncated) were determined. Multivariate analyses showed that acuminated and transitional shapes are not arranged in groups but the subtruncated morphotype, previously described as E. cecryphalium, seems to be associated with low water conductivity (372 μS cm-1), dominant cold (5 ºC) and windy (8.6 m s-1) climatic conditions. The fossil cluster which included nine cores spanning the last 15.6 kyr, only covered acuminated and transitional shapes, which may indicate that these lineages might be older than the subtruncated morphotype. In addition, morphological differences between reproduction modes suggested that parthenogenetic females exhibit de posterior margin more acuminate than sexual females. These results set the ground for more precise ecological and paleoenvironmental studies in Patagonia

    Environmental effects of ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2017

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    From Naples 1963 to Rome 2013 — A brief review of how the International Research Group on Ostracoda (IRGO) developed as a social communication system

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