• Aquatic bladderworts (Utricularia gibba and U. australis) capture zooplankton in mechanically triggered underwater traps. With characteristic dimensions less than 1 mm, the trapping structures are among the smallest known to capture prey by suction, a mechanism that is not effective in the creeping‐flow regime where viscous forces prevent the generation of fast and energy‐efficient suction flows.
• To understand what makes suction feeding possible on the small scale of bladderwort traps, we characterised their suction flows experimentally (using particle image velocimetry) and mathematically (using computational fluid dynamics and analytical mathematical models).
• We show that bladderwort traps avoid the adverse effects of creeping flow by generating strong, fast‐onset suction pressures. Our findings suggest that traps use three morphological adaptations: the trap walls' fast release of elastic energy ensures strong and constant suction pressure; the trap door's fast opening ensures effectively instantaneous onset of suction; the short channel leading into the trap ensures undeveloped flow, which maintains a wide effective channel diameter.
• Bladderwort traps generate much stronger suction flows than larval fish with similar gape sizes because of the traps' considerably stronger suction pressures. However, bladderworts' ability to generate strong suction flows comes at considerable energetic expense.

中文翻译：

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膀胱草是已知最小的吸食器，产生惯性为主的流来捕获猎物。

• 水生狸藻（丝叶狸藻和U。 芦苇）捕获在浮游动物机械触发水下陷阱。捕集结构的特征尺寸小于1毫米，是已知的通过吸力捕获猎物的最小结构，这种机制在蠕变流态中无效，在这种蠕变流态中，粘性力阻止了快速高效的吸力流的产生。
• 为了了解在小规模的艾草捕虫器上实现吸食的原因，我们通过实验（使用颗粒图像测速仪）和数学（使用计算流体动力学和分析数学模型）对它们的吸流进行了表征。
• 我们表明，艾草捕集阱通过产生强大的，快速起效的抽吸压力，避免了蠕变流的不利影响。我们的发现表明，疏水阀具有三种形态学适应性：疏水阀壁的弹性能量快速释放可确保强劲而恒定的吸力；活板门的快速打开确保了有效的瞬时吸力。通往疏水阀的短通道确保了流量的畅通，从而保持了较大的有效通道直径。
• 与具有类似缝隙大小的幼鱼相比，Bladderwort诱集装置产生的吸力要强得多，因为诱集装置的吸力要大得多。然而，艾草产生强大吸力的能力要付出相当大的精力。