Prey capture by the cosmopolitan hydromedusae, Obelia spp., in the viscous regime: Obelia prey capture
Prey capture by the cosmopolitan hydromedusae, Obelia spp., in the viscous regime: Obelia prey capture
复制标题
世界性水螅科植物 Obelia spp. 在粘性状态下捕获猎物：Obelia 猎物捕获
DOI：
10.1002/lno.10390
复制
发表时间：
2016
影响因子：
4.5
通讯作者：
Costello, John H.
中科院分区：
文献类型：
--
作者：
Sutherland, Kelly R.;Gemmell, Brad J.;Colin, Sean P.;Costello, John H.
Obeliaspp.是刺胞动物水螅水母的世界性分布，但很少有人知道他们的饮食。Obelia的尺寸很小（钟直径为1毫米，触手宽度为0.05毫米），表明进食发生在以厚边界层为特征的粘性区域。在喂养观察与自然的猎物组合的大多数猎物被捕获的触角尖在收缩阶段。从高速摄像的游泳运动学证实游泳是一个低Re数（Re < 50）的过程，并显示最大的腱速度发生在钟状收缩的中间腱端。从粒子图像测速流动可视化表明，触手之间的流体运动是有限的，速度最高的触手尖端，导致在该地区的边界层变薄。在触手尖的同一区域观察到最高的包囊密度。两者合计，身体运动学，流动可视化和obelia的包囊分布解释了这些捕食者是如何能够摆脱粘性边界层，有效地捕捉microarsenotonic猎物。我们的研究结果有助于解释其他小型摄食流水母的摄食相互作用是由粘度决定的，它们是如何成功觅食的。
Obeliaspp. are cnidarian hydromedusae with a cosmopolitan distribution but very little is known about their feeding. The small size ofObelia(bell diameter ∼ 1 mm, tentacle width ∼ 0.05 mm) suggests that feeding occurs in a viscous regime characterized by thick boundary layers. During feeding observations with a natural prey assemblage the majority of prey were captured at the tentacle tips during the contraction phase. Swimming kinematics from high speed videography confirmed that swimming was a low Re number process (Re < 50) and showed that maximum tentacle velocities occurred at the tentacle tips midway through a bell contraction. Flow visualizations from particle image velocimetry demonstrated that fluid motion between the tentacles was limited and that velocities were highest at the tentacle tips, leading to a thinning of boundary layer in this region. The highest nematocyst densities were observed in this same region of the tentacle tips. Taken together, the body kinematics, flow visualizations and nematocyst distributions ofObeliaexplain how these predators are able to shed viscous boundary layers to effectively capture microplanktonic prey. Our findings help explain how other small feeding‐current medusae whose feeding interactions are governed by viscosity are able to successfully forage.