Longer development provides first‐feeding fish time to escape hydrodynamic constraints

What is the functional effect of prolonged development? By controlling for size, we quantify first‐feeding performance and hydrodynamics of zebrafish and guppy offspring (5 ± 0.5 mm in length), which differ fivefold in developmental time and twofold in ontogenetic state. By manipulating water viscosity, we control the hydrodynamic regime, measured as Reynolds number. We predicted that if feeding performance were strictly the result of hydrodynamics, and not development, feeding performance would scale with Reynolds number. We find that guppy offspring successfully feed at much greater distances to prey (1.0 vs. 0.2 mm) and with higher capture success (90 vs. 20%) compared with zebrafish larvae, and that feeding performance was not a result of Reynolds number alone. Flow visualization shows that zebrafish larvae produce a bow wave ~0.2 mm in length, and that the flow field produced during suction does not extend beyond this bow wave. Due to well‐developed oral jaw protrusion, the simil...

长期发育的功能效应是什么？通过控制体型大小，我们量化了斑马鱼和孔雀鱼后代（体长5 ± 0.5 mm）的初次摄食表现与流体动力学特征——两者的发育时间相差5倍，个体发育状态相差2倍。通过调控水体黏度，我们控制了流体动力学状态（以雷诺数（Reynolds number）衡量）。我们推测，若摄食表现完全由流体动力学而非发育过程决定，则其应与雷诺数呈比例关系。研究发现，孔雀鱼后代的成功摄食距离猎物更远（1.0 mm vs. 0.2 mm），且捕获成功率更高（90% vs. 20%），而摄食表现并非仅由雷诺数决定。流场可视化显示，斑马鱼幼体产生的弓形波长度约为0.2 mm，且suction过程中产生的流场未超出该弓形波范围。由于口腔颌部突出发育完善，simil...