The Interuniversity Institute for Marine Sciences in Eilat, Eilat 88103, Israel
The Fredy and Nadine Hermann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
J Exp Biol. 2018 Aug 23;221(Pt 16):jeb179523. doi: 10.1242/jeb.179523.
A major challenge faced by sessile animals that feed in the flow is to maintain effective feeding postures while enduring hydrodynamic forces. Garden eels exhibit an exceptional lifestyle: feeding on drifting zooplankton while being 'anchored' in a burrow they dig in the sand. Using underwater observations, sampling and three-dimensional video recording, we measured the feeding rates and characterized feeding postures of garden eels under a wide range of current speeds. We show that the eels behaviorally resolve the trade-off between adverse biomechanical forces and beneficial fluxes of food by modulating their body postures according to current speeds. In doing so, the eels substantially reduce drag forces when currents are strong, yet keep their head well above bottom in order to effectively feed under conditions of high prey fluxes. These abilities have allowed garden eels to become one of the rare oceanic fishes that live in sandy, predation-rich habitats and feed on zooplankton while being attached to the bottom.
固着动物在流动中进食面临的一个主要挑战是，在承受水动力的同时保持有效的进食姿势。花园鳗鱼展现出一种特殊的生活方式：在它们挖掘的沙洞中“固定”自身的同时，以漂流的浮游动物为食。利用水下观察、采样和三维视频记录，我们在广泛的流速范围内测量了花园鳗鱼的进食率并描述了它们的进食姿势。我们表明，鳗鱼通过根据流速调节身体姿势来解决不利的生物力学力和有益的食物通量之间的权衡。这样，鳗鱼在水流较强时会大大减少阻力，但会让头部保持在底部上方，以便在高猎物通量的情况下有效地进食。这些能力使花园鳗鱼成为少数几种生活在沙质、捕食丰富的栖息地并以浮游动物为食的海洋鱼类之一，同时还能附着在底部。
