In this video, I am showing the flow produced by a free-swimming Marsh grass shrimp (Palaemon vulgaris) during metachronal locomotion. Using bright-field particle image velocimetry (PIV), I am studying the flow produced around individual beating legs. To do so, I seed the water with microscopic particles that I can then use to compute fluid flow velocity fields. Using this data, I can then compute vorticity to highlight the presence of flow features such as vortices or shear layers forming along the bending pleopods. Using organismal studies, I provide a new framework to characterize the fundamental principles of metachronal swimming and contribute to the development of a unifying theory ...