Reduced Oxygen Impairs Photobehavior in Marine Invertebrate Larvae
Reduced Oxygen Impairs Photobehavior in Marine Invertebrate Larvae
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DOI：
10.1086/717565
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发表时间：
2022-01
期刊：
影响因子：
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通讯作者：
L. McCormick;L. Levin;Nicholas W. Oesch
中科院分区：
文献类型：
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作者：
L. McCormick;L. Levin;Nicholas W. Oesch
除了海洋脱氧外，沿海水域的生物还经历了天然的高氧变异性和随深度而陡峭的氧梯度。它们经常经历昼夜垂直迁移，包括辐照度的变化，从而引发视觉行为。视网膜功能已被证明对氧损失高度敏感；本文采用一种新的行为模式，评估了低氧条件下Doryteuthis opalescens鱿鱼和章鱼章鱼的视觉行为（光行为）是否受到影响。通过测量幼虫在室内垂直位置的变化，发现光照刺激消失后，幼虫表现出依赖于光照的下降光行为。随着氧气浓度的降低，光行为的大小逐渐减小，当氧气分压<6.4 kPa（15.3℃时<74.7 μmol kg−1）时，光行为完全消失。氧也会影响双斑梭鱼的光行为。暴露在缺氧环境下，幼虫的平均垂直速度不受影响，这表明缺氧在运动之前选择性地影响了视力。这些发现表明，在沿海上升流区和其他地方，氧气条件的变化和下降将损害光行为，并可能影响高视觉海洋物种的分布、迁徙行为和生存。
Organisms in coastal waters experience naturally high oxygen variability and steep oxygen gradients with depth, in addition to ocean deoxygenation. They often undergo diel vertical migration involving a change in irradiance that initiates a visual behavior. Retinal function has been shown to be highly sensitive to oxygen loss; here we assess whether visual behavior (photobehavior) in paralarvae of the squid Doryteuthis opalescens and the octopus Octopus bimaculatus is affected by low oxygen conditions, using a novel behavioral paradigm. Larvae showed an irradiance-dependent, descending photobehavior after extinction of the light stimulus, measured through the change in vertical position of larvae in the chamber. The magnitude of photobehavior was decreased as oxygen was reduced, and the response was entirely gone at <6.4 kPa partial pressure of oxygen (<74.7 μmol kg−1 at 15.3 °C) in D. opalescens paralarvae. Oxygen also affected photobehavior in O. bimaculatus paralarvae. The mean vertical velocity of paralarvae was unaffected by exposure to reduced oxygen, indicating that oxygen deficits selectively affect vision prior to locomotion. These findings suggest that variable and declining oxygen conditions in coastal upwelling areas and elsewhere will impair photobehavior and likely affect the distribution, migration behavior, and survival of highly visual marine species.