Growth and survival of larval fishes is highly variable and unpredictable. Our limited understanding of this variation constrains our ability to forecast population dynamics and effectively manage fisheries. Here we show that daily growth rates of a coral reef fish (the sixbar wrasse, Thalassoma hardwicke) are strongly lunar-periodic and predicted by the timing of nocturnal brightness: growth was maximized when the first half of the night was dark and the second half of the night was bright. Cloud cover that obscured moonlight facilitated a ‘natural experiment’, and confirmed the effect of moonlight on growth. We suggest that lunar-periodic growth may be attributable to light-mediated suppression of diel vertical migrations of predators and prey. Accounting for such effects will improve our capacity to predict the future dynamics of marine populations, especially in response to climate-driven changes in nocturnal cloud cover and intensification of artificial light, which could lead to population declines by reducing larval survival and growth.

中文翻译：

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幼鱼生长的月球节律

幼鱼的生长和生存变化很大且不可预测。我们对这种变化的了解有限，限制了我们预测种群动态和有效管理渔业的能力。在这里，我们展示了珊瑚礁鱼（六纹濑鱼、Thalassoma Hardwicke）的每日生长速度具有强烈的月球周期性，并通过夜间亮度的时间来预测：当前半夜黑暗和后半夜黑暗时，生长达到最大夜色明亮。遮挡月光的云层促进了“自然实验”，并证实了月光对生长的影响。我们认为月球周期的生长可能归因于光介导的对捕食者和猎物昼夜垂直迁移的抑制。考虑到这些影响将提高我们预测海洋种群未来动态的能力，特别是应对气候驱动的夜间云量变化和人造光强度的变化，这可能会减少幼虫的存活和生长，从而导致种群数量下降。