CALCIFICATION IN MARINE MOLLUSKS - HOW COSTLY IS IT
CALCIFICATION IN MARINE MOLLUSKS - HOW COSTLY IS IT
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DOI：
10.1073/pnas.89.4.1379
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发表时间：
1992-02-15
影响因子：
11.1
通讯作者：
PALMER, AR
中科院分区：
文献类型：
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作者：
PALMER, AR
虽然对我们理解海洋无脊椎动物骨骼进化至关重要，但钙化的成本仍然难以捉摸，原因很简单：CaCO 3是一种无机材料。因此，它的成本仅来自积累、运输和沉淀CaCO 3的代谢费用，通常不能与其他代谢费用分开。传统上，钙化成本被忽略，总壳成本被假定为仅来自骨骼有机基质。这里的成本估计是允许的壳厚度在两个岩石海岸腹足类（Nucella lamellosa和Nucella lapillus）的大量自然变化。在野外和实验室中，来自三个独立实验的数据显示，在一组特定的实验条件下产生额外外壳材料的蜗牛群体也消耗了额外的食物。钙化的成本是通过计算以组织生长的共同速率产生的每单位额外壳吸收的额外能量，然后减去有机基质的成本来估计的。在1-2 J/mg CaCO 3时，这里报道的钙化成本大约是每克软体动物壳的主要蛋白质有机部分的5%。这可以解释为什么有机质含量高的钙质微结构在进化上变得不那么常见。
Although crucial to our understanding of skeletal evolution in marine invertebrates, the cost of calcification has remained elusive for a simple reason: CaCO3 is an inorganic material. Its cost thus derives solely from the metabolic expenses of accumulating, transporting, and precipitating CaCO3 and cannot normally be separated from other metabolic costs. Traditionally, calcification cost has been ignored and total shell cost has been assumed to derive solely from skeletal organic matrix. The cost estimated here was permitted by the substantial natural variation in shell thickness in two rocky-shore gastropods (Nucella lamellosa and Nucella lapillus). In both the field and laboratory, data from three separate experiments revealed that groups of snails producing extra shell material under a particular set of experimental conditions also consumed extra food. The cost of calcification was estimated by computing the extra energy assimilated per unit extra shell produced at a common rate of tissue growth and then subtracting the cost of the organic matrix. At 1-2 J/mg Of CaCO3, the calcification cost reported here is roughly 5% of that for the predominantly proteinaceous organic fraction of molluscan shells on a per-gram basis. This may explain why calcareous microstructures high in organic content have become less common evolutionarily.