Fig. 2

Bottlenose dolphin caudal strikes on a nurse shark. The depth (shaded by vertical velocity), body pitch (black line), body roll (blue line) and lateral acceleration (sway; red line) over a 60-s period of the shark’s second descent during which it is struck twice by the dolphins as it follows them. Grey boxes indicate the moments of impact when the dolphins struck the shark with their caudal flukes. A dolphin can be seen descending from the surface (a), and the shark begins following it closely as they descend (b). This dolphin proceeds to strike the shark in the head with its caudal fluke. A dolphin moves into a head-down orientation and prepares to strike the shark (c) for the second time, and the shark continues to follow the dolphins (d) once it gets to the seafloor