David Attenborough narrates amazing BBC underwater footage of the fastest fish in the sea using their 'swords' to 'disarm' their prey

Sailfish, the fastest fish in the sea, are top predators capable of swimming at over 90kmph, says Simon Blakeney.

One of the best places in the world to see them is off the coast of the Yucatán Peninsula in Mexico, where these incredible hunters gather in huge numbers to feed on sardines.

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It was once thought that the sailfish used their long, slender bills to chop and skewer their prey, but we now know that the reality is much more subtle. With amazing dexterity, they employ their weaponry to knock individual sardines off balance and out of the baitball, thereby isolating them.

Away from the protection of the shoal the sardines are vulnerable and the sailfish steer them into their mouths with their 'swords'.

AlL this can happen in less than second.

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