Abstract We tested the hypothesis that the coronate jellyfish Periphylla periphylla distributes vertically according to a preferential range of absolute light intensities. The study was carried out in Lurefjorden, Norway, a fjord characterized by mass occurrences of this jellyfish. We collected data on the vertical distribution of P. periphylla medusa during day, dusk and night periods from video observations by a remotely operated vehicle in relation to estimated ambient light levels. Our results suggest that large P. periphylla (average size in catches ~9 cm diameter) avoided total irradiance levels above 5×10−3 µmol quanta m−2 s−1. Nearly two-thirds of the population stayed above irradiance of 10−7 µmol quanta m−2 s−1 during daytime, while some individuals occupied much darker water. Thus, part of the population appeared to distribute vertically and undertake diel vertical migration (DVM) according to a preferential range of light intensities.

中文翻译：

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水母根据辐照度垂直分布


摘要 我们测试了冠状水母 Periphylla periphylla 根据绝对光强度优先范围垂直分布的假设。这项研究是在挪威的 Lurefjorden 进行的，该峡湾以大量出现这种水母为特征。我们通过远程操作车辆的视频观察，收集了与估计环境光水平相关的大叶水母在白天、黄昏和夜间的垂直分布数据。我们的结果表明，大型 P. periphylla（捕获物的平均尺寸约为直径 9 cm）避免了总辐照度水平高于 5×10−3 µmol 量子 m−2 s−1。近三分之二的人口在白天的辐照度保持在 10−7 µmol 量子 m−2 s−1 以上，而有些人则生活在颜色更深的水域中。因此，部分种群似乎垂直分布，并根据优先的光强度范围进行昼夜垂直迁移（DVM）。