Ocean acidification alters properties of the exoskeleton in adult Tanner crabs, Chionoecetes bairdi
Ocean acidification alters properties of the exoskeleton in adult Tanner crabs, Chionoecetes bairdi
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DOI：
10.1242/jeb.232819
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发表时间：
2021-02-01
影响因子：
2.8
通讯作者：
Aronson, Richard B.
中科院分区：
文献类型：
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作者：
Dickinson, Gary H.;Bejerano, Shai;Aronson, Richard B.
海洋酸化会影响钙化生物建立和维持矿化组织的能力。在十足类甲壳动物中，外骨骼是由几丁质、蛋白质和矿物质组成的多层结构，主要是镁方解石或无定形碳酸钙（ACC）。我们研究了酸化对成熟（终末蜕皮后）雌性南方坦纳蟹（Chionoeclumbairdi）外骨骼的影响。螃蟹暴露于三种pH值之一- 8.1，7.8或7.5 - 2年。pH值的降低导致了对外骨骼的一系列身体区域特异性影响。微硬度的爪是38%的蟹在pH值7.5相比，在pH值8.1，但甲壳微硬度不受pH值。相反，pH值降低改变甲壳中的元素含量（减少钙，增加镁），但不是爪。减少的结构完整性和变薄的外骨骼，观察在降低pH值在两个身体区域;内部腐蚀的甲壳存在于大多数螃蟹在pH值7.5，这些螃蟹的爪子表现出大量的外部侵蚀，与牙齿一样的denaphor几乎或完全磨损。使用红外光谱，我们观察到的相位的碳酸钙存在于甲壳的pH值为7.5的螃蟹：ACC和方解石的混合物被发现在甲壳的螃蟹在pH值为8.1，而大部分的碳酸钙已转化为方解石在pH值为7.5的螃蟹。由于修复能力有限，长寿螃蟹的外骨骼经历了最终的蜕皮，如C。bairdi可能特别容易受到海洋酸化的影响。
Ocean acidification can affect the ability of calcifying organisms to build and maintain mineralized tissue. In decapod crustaceans, the exoskeleton is a multilayered structure composed of chitin, protein and mineral, predominately magnesian calcite or amorphous calcium carbonate (ACC). We investigated the effects of acidification on the exoskeleton of mature (post-terminal-molt) female southern Tanner crabs, Chionoecetes bairdi. Crabs were exposed to one of three pH levels - 8.1, 7.8 or 7.5 -for 2 years. Reduced pH led to a suite of body region-specific effects on the exoskeleton. Microhardness of the claw was 38% lower in crabs at pH 7.5 compared with those at pH 8.1, but carapace microhardness was unaffected by pH. In contrast, reduced pH altered elemental content in the carapace (reduced calcium, increased magnesium), but not the claw. Diminished structural integrity and thinning of the exoskeleton were observed at reduced pH in both body regions; internal erosion of the carapace was present in most crabs at pH 7.5, and the claws of these crabs showed substantial external erosion, with tooth-like denticles nearly or completely worn away. Using infrared spectroscopy, we observed a shift in the phase of calcium carbonate present in the carapace of pH 7.5 crabs: a mix of ACC and calcite was found in the carapace of crabs at pH 8.1, whereas the bulk of calcium carbonate had transformed to calcite in pH 7.5 crabs. With limited capacity for repair, the exoskeleton of long-lived crabs that undergo a terminal molt, such as C. bairdi, may be especially susceptible to ocean acidification.