Jellyfish: nature's quickest on the draw

Even faster than Rolf Harris

The sting of a jellyfish has been shown to be one of the fastest processes in the whole of biology. Using a super-fast camera technique German researchers have found it can fire off in just 700 nanoseconds.

The team, writing in Current Biology, calculates that the acceleration is equivalent to 5,410,000 times gravity. Its impact generates a pressure of seven Gigapascals, which is in the same range as a gunshot.

The stings arrive in the form of tiny capsules called nematocysts (pictured), which contain toxic compounds delivered through a spike. They are fired off for both defence and capturing prey by members of the Cnidaria phylum which includes jellyfish, anenomes and corals.

The elastic walls of nematocysts are key to the snap release. They are made of a stretchy collagen-based polymer and inflated to 15 Megapascals pressure by an ion-packed protein matrix.

The team says the spring from the potential energy stored in the wall is responsible for the incredible speed.

The new research rates the top speed of nematocyst release one hundred times faster than previously measured. In order to capture the process, the camera was run at a blistering 1,430,000 frames per second. ®