Fig. 1. Peacock mantis shrimp use a pair of large raptorial appendages (A, white arrow) to strike hard objects with such high speeds that cavitation bubbles form between the appendage and striking surface (Patek et al., 2004). (B–I) The dactyl heel (h) of the raptorial appendage strikes a snail (s) that is loosely wired to a stick. Images recorded at 0.2 msintervals. Scale bar, 1 cm. Cavitation (yellow arrow) is visible between the dactyl heel and snail (D–G).