ISOTOPIC ECOLOGY OF THE MODERN LAND SNAIL CERION, SAN SALVADOR, BAHAMAS: PRELIMINARY ADVANCES TOWARD ESTABLISHING A LOW-LATITUDE ISLAND PALEOENVIRONMENTAL PROXY
ISOTOPIC ECOLOGY OF THE MODERN LAND SNAIL CERION, SAN SALVADOR, BAHAMAS: PRELIMINARY ADVANCES TOWARD ESTABLISHING A LOW-LATITUDE ISLAND PALEOENVIRONMENTAL PROXY
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DOI：
10.2110/palo.2005.p05.091r
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发表时间：
2007-03
期刊：
影响因子：
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通讯作者：
L. Baldini;S. Walker;L. B. Railsback;J. Baldini;D. Crowe
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文献类型：
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作者：
L. Baldini;S. Walker;L. B. Railsback;J. Baldini;D. Crowe
尽管这些数据集对古环境重建具有重要意义，但热带岛屿陆生蜗牛的同位素生态学尚不清楚。在这项研究中，通过对现代陆地蜗牛Cerion的全壳和序列肋骨分析，获得了碳（13C/ 12C）和氧（18O/16O）同位素比率的变化，揭示了巴哈马圣萨尔瓦多饮食和当地环境的记录。从C4植被中采集的成年Cerion贝壳的平均δ13C值比从C3植物中采集的蜗牛高1.0‰，表明壳碳酸盐中的碳同位素反映了饮食中的优势植物类型，尽管壳碳酸盐δ13C的广泛范围证实了该属的多样化饮食。在圣萨尔瓦多西海岸采集的成年Cerion贝壳的平均δ18O值比在圣萨尔瓦多东海岸采集的高0.8‰。这种差异可能反映了来自该岛西部内陆富含18o的高盐湖泊的水蒸气的掺入。对一个成年Cerion贝壳的序列-rib分析揭示了其δ13C和δ18O值的个体发生变化，可能分别反映了食物来源和降雨季节的变化。这项研究为未来的研究奠定了基础，将化石Cerion作为圣萨尔瓦多和巴哈马群岛有价值的古环境代表。
Abstract The isotopic ecology of terrestrial snails from tropical island settings is not known despite the importance of such data sets for paleoenvironmental reconstructions. In this study, variations in carbon (13C/ 12C) and oxygen (18O/16O) isotope ratios obtained during whole-shell and sequential-rib analyses of the modern land snail, Cerion, reveal a record of diet and local environment on San Salvador, Bahamas. The mean δ13C value of adult Cerion shells collected from C4 vegetation is higher by 1.0‰ relative to snails collected from C3 plants, suggesting that carbon isotopes in shell carbonate reflect the dominant plant type in the diet, though the broad range of shell carbonate δ13C confirms a varied diet for this genus. The mean δ18O values of adult Cerion shells collected from the west coast of San Salvador are 0.8‰ higher than those collected from the east coast of the island. This difference may reflect the incorporation of water vapor derived from 18O-rich hypersaline lakes located in the island's western interior. Sequential-rib analysis of one adult Cerion shell reveals variations in δ13C and δ18O values through ontogeny that may reflect changes in food source and rainfall seasonality, respectively. This study lays the groundwork for future studies to establish fossil Cerion as a valuable paleoenvironmental proxy for San Salvador and the Bahamas.