Adaptive flagella beats select phototaxis modes in Chlamydomonas reinhardtii

Many biological microswimmers modulate their flagella beats in response to environmental stimuli to exhibit complex navigation strategies. In this talk, we will discuss how Chlamydomonas reinhardtii adaptively switch their flagella beats in response to light to select different phototaxis modes (e.g., positive and negative phototaxis). We tracked individual cells and experimentally verified that the switching of flagella waveform and the modulation of flagella phase differences are the key mechanisms for phototaxis transitions. We will discuss a hydrodynamic model that connects photoreception and flagella beat modulation to capture the phototaxis transition.