Modulation of Cilia Beat Kinematics Is a Key Determinant of Encounter Rate and Selectivity in Tintinnid Ciliates

Tintinnids are a group of ciliated microzooplankton, who spontaneously settle on marine snow and other aggregates. create feeding current that draws particles towards their mouth using crown continuously beating oral cilia. Similarly to not all encountered ingested. However, it is unclear what the mechanistic behavioral basis this selectivity. Here, we used particle tracking velocimetry quantify flow, prey fate, cilia beat frequency. We then asked (1) determines encounter rate with prey, (2) at which stages sequence does selectivity develop, (3) predator’s behaviors modify found speed tintinnids’ currents modulated by Individual tintinnids were observed frequency during foraging, resulting in ~3-fold acceleration or deceleration flow within seconds. Selectivity changed throughout as preferentially captured larger but subsequently ingested spherical over prolate prey. Short bouts reversal mitigated preference for both handling. Overall, show individual able modulate kinematics, affected rates, outcome, handling outcome. The ability kinematics major component behavior.