Ambient fluid motions influence swimming and feeding by the ctenophore Mnemiopsis leidyi
Ambient fluid motions influence swimming and feeding by the ctenophore Mnemiopsis leidyi
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环境流体运动影响栉水母 Mnemiopsis leidyi 的游泳和摄食
DOI：
10.1093/plankt/fbu051
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发表时间：
2014
影响因子：
2.1
通讯作者：
J. Dabiri
中科院分区：
文献类型：
--
作者：
K. Sutherland;J. Costello;S. Colin;J. Dabiri
浮游生物暴露在湍流的水运动中，影响着游泳和进食的基本活动。本研究的目的是测量实际湍流水平对(i)游泳行为和（ii）叶栉水母（一种非常成功的悬浮捕食者）进食过程中流体相互作用的影响。实验室湍流发生器产生的湍流(e = 0.5-1.4 × 10^（−6)W kg^(−1)）代表了美国MA Woods Hole的一个现场。与静水相比，m.l idyi通过提高游动速度和加速度，避开了实验船中湍流最大的区域(e = 1.1-1.4 × 10^（−6)W kg^(−1)）。实验室和现场颗粒图像测速数据均表明，M. leidyi的摄食电流受到环境流体运动的侵蚀。尽管如此，由于在湍流条件下较高的游泳速度，喂食结构的总体通量保持不变。背景湍流产生的瞬时剪切变形率高于栉水母摄食流产生的瞬时剪切变形率，并经常超过桡足类猎物的已知逃脱阈值。湍流中的食饵电流侵蚀和流体机械信号噪声影响了雷衣栉水母悬浮食饵过程中捕食者-猎物相互作用的机制。
Planktonic organisms are exposed to turbulent water motion that affects the fundamental activities of swimming and feeding. The goal of this study was to measure the influence of realistic turbulence levels on (i) swimming behavior and (ii) fluid interactions during feeding by the lobate ctenophore, Mnemiopsis leidyi, a highly successful suspension-feeding predator. A laboratory turbulence generator produced turbulence (e = 0.5–1.4 × 10^(−6) W kg^(−1)) representative of a field site in Woods Hole, MA, USA. Compared with still water, M. leidyi avoided regions in the experimental vessel where turbulence was greatest (e = 1.1–1.4 × 10^(−6) W kg^(−1)) by increasing its swimming speeds and accelerations. Both laboratory and in situ particle image velocimetry data demonstrated that feeding currents of M. leidyi were eroded by ambient fluid motions. Despite this, the overall flux to the feeding structures remained constant due to higher swimming speeds in turbulent conditions. Instantaneous shear deformation rates produced by background turbulence were higher than those produced by ctenophore feeding currents and frequently exceeded the published escape thresholds of copepod prey. Feeding current erosion and fluid mechanical signal noise within turbulent flows affect the mechanics of predator–prey interactions during suspension feeding by the ctenophore M. leidyi.