Thomas Holstein at the University of Frankfurt used a 1.4 million frame/second camera to capture, for the first time, the incredible explosive action of a jellyfish firing its stingers, fast as a speeding bullet:
The poisons are dissolved in a highly concentrated (2 molar) saline solution contained inside a vesicle within the nematocyst. The vesicle is held shut under the tension created by a rigid molecular collagen structure with a strength equivalent to that of steel, Holstein explains.
When the tentacle touches its prey the lid of the nematocyst flips open, triggering the folded collagen spring to release outwards. This ejects a sharp spine, known as a stylet. The stylet pierces the external barrier of the prey with a pressure of more than 7 billion Pascals – in the range of that generated by a bullet fired from a gun.
(via Digg)