Cameras on the deep seafloor finally caught the defense in the act, and it works almost the instant a predator commits to the bite.
A hagfish looks like easy prey. It is a soft, eel-shaped, jawless fish with no scales, no bony armor, and no obvious way to fight back. Then a shark or a conger eel closes its mouth around one, and the water inside that mouth turns, almost instantly,... [6820 chars]