Figure 2

Sailfish activity before, during and after the predation event. (a) Biologging float package attached to sailfish. (b) Depth, temperature, tailbeats (°sec⁻¹), speed (ms⁻¹), tailbeat frequency (TBF; Hz), vertical velocity (ms⁻¹) and body pitch angle (°) of the dive in which the event occurred. The timing and depth associated with each image (c–f) are identified by circles on the depth profile in (b). (c) The sailfish ascends from 60 m and encounters multiple potential prey items, outlined in red. (d) The available light is notably low at this depth and decreases rapidly with depth to almost zero light. (e) First observation of the prey. (f) Prey possibly attempting to ‘hide’ from the sailfish by swimming very close to it during the pursuit.