Mud blister worms bore into oyster shells; and oysters respond to shell penetration by secreting new layers of shell, resulting in mud blisters on inner surfaces of oyster shells. We conducted two experiments in off-bottom oyster farms along Alabama’s coast in summer 2017 to explore the dynamics of worm infestation, blister formation, and shell repair. Results support our hypothesis that only a small proportion of worms that bore into oysters cause blisters. Triploid oysters had fewer blisters than diploids, likely because of faster growth and shell repair. We treated oysters to remove mud blister worms, redeployed them at intertidal and subtidal sites for nine weeks, and found that reinfestation by worms occurred only in subtidal oysters. Intertidally deployed oysters showed no visible blister coverage, indicating recovery, whereas blister coverage increased in subtidal oysters. Reinfestation of subtidal oysters was correlated with previous burrow damage, visualized with X-ray images, thus supporting our hypothesis that worms preferentially settle in previously infested shells. Forces required to break blisters, measured with a custom-built shucking knife with an integrated force sensor, were low relative to forces required to shuck oysters, possibly because our experiment was conducted when worm infestation was increasing. Higher forces were required to break smaller, lighter-colored blisters, consistent with blister recovery; but results were highly variable and not consistent across sites and sampling times, suggesting that size and color of blisters alone did not explain shell strength. Our results indicate that oysters repair shells slowly relative to more dynamic patterns of worm infestation.

中文翻译：

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牡蛎对水疱蠕虫的侵染和壳修复的动力学

牡蛎壳中钻有泥状水泡蠕虫。牡蛎通过分泌新的壳层来响应壳的渗透，从而在牡蛎壳的内表面产生水泡。我们于2017年夏季在阿拉巴马州沿海海底牡蛎养殖场进行了两个实验，以探索蠕虫侵染，水疱形成和贝壳修复的动力学。结果支持了我们的假设，即只有一小部分钻入牡蛎的蠕虫会引起水泡。三倍体牡蛎的水泡少于二倍体，这可能是因为其生长和壳修复更快。我们对牡蛎进行了处理，以去除泥状水疱蠕虫，在潮间带和潮间带重新部署了9周，发现蠕虫仅在潮间带牡蛎中发生。散布的牡蛎没有可见的水疱覆盖，表明已恢复，而潮下牡蛎的水泡覆盖率增加。潮带下牡蛎的再侵染与先前的洞穴破坏相关联，并通过X射线图像进行可视化，因此支持了我们的假设，即蠕虫优先在先前受感染的壳中定居。用带有集成式力传感器的定制削皮刀测量的破坏水泡的力相对于削牡蛎所需的力低，这可能是因为我们的实验是在蠕虫感染增加时进行的。需要更大的力量才能使较小的浅色水泡破裂，这与水疱的恢复相一致。但是结果变化很大，并且在不同地点和采样时间之间不一致，这表明仅水泡的大小和颜色并不能解释壳的强度。