Reply to: Boundary effects on currents around ciliated larvae
Authors: William Gilpin, Vivek Prakash, Manu Prakash
Link: https://www.nature.com/articles/nphys4166
DOI: https://doi.org/10.1038/nphys4166
Abstract: Gilpin et al. reply —
Whether confined with a slide or immobilized by a tether, microscopic swimmers produce currents that qualitatively differ from their freely swimming counterparts. Fortunately, this effect has been widely studied and modelled in previous literature1,2,3,4, and is explicitly considered in our recent Letter about swimming and feeding currents produced by larval starfish5. The slide-confined visualizations shown in Figs 1a and 4a of our Letter produce local particle recirculation, as von Dassow et al. describe. However, they fail to note that our data analysis and theoretical model explicitly include this effect. Moreover, their comparison of our confined organisms to their tethered animals remains incomplete because tethering introduces a new set of confounding far-field effects that von Dassow et al. fail to consider when discussing our observation of topological defects in the ciliary band. Thus, von Dassow and colleagues' broad statements regarding the relevance of their observations to our conclusions regarding ciliary bands and the feeding versus swimming trade-off are inconsistent with the content of our Letter.
