The kinematics and particle image velocimet
The aim of this study was to examine the swimming locomotion of the green shore crab Carcinus maenas larvae (stage I zoeae), to investigate the role and mechanics of their swimming appendages. High speed video recordings of swimming and sinking zoeae revealed the kinematics of the whole zoea and its appendages. Analyses of these video recordings for swimming locomotion were performed using MATLAB software and ImageJ. From the body, maxilliped, and natatory setae kinematics and the zoea swimming gait, we found that swimming speed measurements were threefold higher than previously reported in green crab zoeae, and maximum and minimum maxilliped angles were greater than previously observed. We also quantified the flow generated by swimming zoeae using Particle Image Velocimetry (PIV). Analysis of recordings for flow fields was performed using the PIVlab-Digital PIV Tool for MATLAB. We obtained flow velocity and vorticity fields generated during free swimming and tethered zoeae. To our knowledge, this study is the first to report sinking speeds for green crab larvae, maxilliped and natatory setae speeds, and flow fields during routine free swimming and tethered escape responses.