Straight-line and turning locomotion of Paramecia

TL;DR

This study visualizes the flow fields around Paramecia during straight and turning swimming motions using micro-particle image velocimetry, revealing how ciliary control affects fluid velocities on either side of the organism.

Contribution

It provides the first detailed visualization of flow fields during Paramecia turning and straight swimming, linking ciliary activity to fluid dynamics.

Findings

Straight swimmers have similar velocities on both sides.

Turning Paramecia show asymmetric flow velocities.

Flow patterns differ significantly between straight and turning motions.

Abstract

In this fluid dynamics video we investigate the flow field around straight-line swimming and right and left turning Paramecia using micro- particle image velocimetry ({\mu}PIV). A Paramecium controls its ciliary beating to produce different fluid velocities on either side of its body. This phenomenon is visualized by applying {\mu}PIV to images in which Paramecia swim in a dilute suspension of 1 {\mu}m polystyrene spheres. Paramecia that swim straight exhibit similar magnitudes of velocity on either side of their bodies. In contrast, right-turning Paramecia exhibit greater magnitudes of velocity on their right sides, while left-turning organisms show the opposite.