Speed or Agility?
A recent study published in the journal Integrative and Comparative Biology, titled “Not So Fast: Swimming Behavior of Sailfish during Predator-Prey Interactions Using High-Speed Video and Accelerometry,” evaluated swimming behavior of feeding billfish, largely considered some of the fastest swimmers in the oceans. A sailfish’s speed rarely exceeds 5 mph, but one would expect speeds to be far greater when hunting prey. Using high-frequency accelerometry and high-speed video observations during predator-prey interactions, the researchers found sailfish to burst at speeds of about 16 mph and not exceed 22 mph during these interactions.
These sailfish speeds are lower than previous estimates and further demonstrate that billfish benefit from their morphological adaptations and higher performances in turning and accelerating than their prey. The researchers also measured the oscillation of the bill during swimming, with and without extension of the dorsal fin — the sail of a sailfish. They suggest the extension of the dorsal fin might improve the control of the fish’s bill by minimizing yaw and increasing accuracy when hunting prey.