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Longer development provides first‐feeding fish time to escape hydrodynamic constraints
Author(s) -
Dial Terry R.,
Lauder George V.
Publication year - 2020
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.21224
Subject(s) - biology , guppy , reynolds number , bow wave , zebrafish , offspring , flow visualization , suction , ontogeny , escape response , predation , flow (mathematics) , zoology , mechanics , fish <actinopterygii> , ecology , fishery , physics , pregnancy , biochemistry , genetics , quantum mechanics , meteorology , solar wind , magnetic field , turbulence , gene
Abstract 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 similar‐sized suction field generated by guppy offspring extends beyond the horizon of their bow wave, leading to successful prey capture from greater distances. These findings suggest that prolonged development and increased ontogenetic state provides first‐feeding fish time to escape the pervasive hydrodynamic constraints (bow wave) of being small.