Past daily light cycle recorded in the strontium/calcium ratios of giant clam shells
| Autor: | Kohki Sowa, Sayumi Kobayashi, Tsuyoshi Watanabe, Kenji Iwai, Kotaro Shirai, Katsumi Matsumoto, Naoto Takahata, Yuji Sano |
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| Rok vydání: | 2012 |
| Předmět: |
Aquatic Organisms
Photoperiod Carbonates Spectrometry Mass Secondary Ion General Physics and Astronomy chemistry.chemical_element Environment General Biochemistry Genetics and Molecular Biology Algae Animal Shells Light Cycle Tropical climate medicine Animals Magnesium Shellfish Tropical Climate Strontium Multidisciplinary biology Giant clam Ctenidium General Chemistry Seasonality biology.organism_classification medicine.disease Bivalvia Circadian Rhythm Fluted giant clam Oceanography chemistry Barium Calcium Seasons |
| Zdroj: | Nature Communications. 3 |
| ISSN: | 2041-1723 |
| DOI: | 10.1038/ncomms1763 |
| Popis: | The historical record of daily light cycle in tropical and subtropical regions is short. Moreover, it remains difficult to extract this cycle in the past from natural archives such as biogenic marine carbonates. Here we describe the precise analysis of Sr/Ca, Mg/Ca, and Ba/Ca ratios in a cultivated giant clam shell, using a laterally high-resolution secondary ion mass spectrometer with 2 μm resolution. The Sr/Ca ratio exhibits striking diurnal variations, reflecting the daily light cycle. A clear seasonal variation in Sr/Ca is also observed in another longer set of measurements with 50 μm resolution. Light-enhanced calcification and elemental transportation processes, in giant clam and symbiotic algae, may explain these diurnal and annual variations. This opens the possibility to develop the Sr/Ca ratio from a giant clam shell as an effective proxy for parameters of the daily light cycle. A record of the daily light cycle in tropical regions is difficult to extract from biogenic marine carbonates such as shells. Here, the precise analysis of Sr/Ca ratios is shown in a cultivated giant clam shell, revealing variations that reflect the daily light cycle and the potential for future development of a proxy. |
| Databáze: | OpenAIRE |
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