游动的未成熟海胆幼虫的个体发育变化和湍流中的取向
Many marine organisms have complex life histories, having sessileadults and relying on the planktonic larvae for dispersal. Larvae swimand disperse in a complex fluid environment and the effect of ambientflow on larval behavior could in turn impact their survival and transport.However, to date, most studies on larvae–flow interactions havefocused on competent larvae near settlement. We examined theimportance of flow on early larval stages by studying how local flowandontogeny influence swimming behavior in pre-competent larval seaurchins, Arbacia punctulata. We exposed larval urchins to grid-stirredturbulence and recorded their behavior at two stages (4- and 6-armedplutei) in three turbulence regimes. Using particle image velocimetry toquantify and subtract local flow, we tested the hypothesis that larvaerespond to turbulence by increasing swimming speed, and that theincrease varies with ontogeny. Swimming speed increased withturbulence for both 4- and 6-armed larvae, but their responsesdiffered in terms of vertical swimming velocity.