Data from: Hydrodynamic regime determines the feeding success of larval fish through the modulation of strike kinematics

Larval fishes experience extreme mortality rates, with 99% of a cohort perishing within days after starting to actively feed. While recent evidence suggests that hydrodynamic factors contribute to constraining larval feeding during early ontogeny, feeding is a complex process that involves numerous interacting behavioural and biomechanical components. How these components change throughout ontogeny and how they contribute to feeding remain unclear. Using 339 observations of larval feeding attempts, we quantified the effects of morphological and behavioural traits on feeding success of Sparus aurata larvae during early ontogeny. Feeding success was determined using high-speed videography, under both natural and increased water viscosity treatments. Successful strikes were characterized by Reynolds numbers that were an order of magnitude higher than those of failed strikes. The pattern of increasing strike success with increasing age was driven by the ontogeny of traits that facilitate the transition to higher Reynolds numbers. Hence, the physical growth of a larva plays an important role in its transition to a hydrodynamic regime of higher Reynolds numbers, in which suction feeding is more effective.鱼类幼体具有极高的死亡率：在开始主动摄食后的数天内，同批次种群中有99%的个体将会死亡。尽管已有研究表明，流体动力因素会限制早期个体发育阶段的幼体摄食行为，但摄食本身是一个复杂过程，涉及众多相互作用的行为学与生物力学组分。目前仍不清楚这些组分如何随个体发育进程发生变化，以及它们如何对摄食产生贡献。本研究通过对339次幼体摄食尝试的观测，量化了形态学与行为学性状对早期个体发育阶段金头鲷（Sparus aurata）幼体摄食成功率的影响。实验在自然水体与增粘水体两种处理条件下，通过高速摄像法确定摄食成功率。成功的摄食攻击行为，其雷诺数（Reynolds number）相较于失败攻击高出一个数量级。摄食攻击成功率随日龄增长而升高的模式，由有助于幼体向更高雷诺数环境过渡的性状的个体发育进程所驱动。因此，幼体的物理生长在其向更高雷诺数流体动力状态的过渡过程中发挥着关键作用，而在该状态下，吸吮式摄食的效率更高。