Carnivorous underwater plant sucks in prey

By Victoria Gill
Science and nature reporter, BBC News

High-speed cameras and computer simulations show how the trap works

Mechanical engineers could learn something from the carnivorous bladderwort it seems.

This underwater plant uses a suction trap to gobble up passing prey in an instant, which it slowly digests.

Using high-speed cameras and computer simulations, a team of scientists in France has shown exactly how this suction trap works.

They report their findings in the journal Proceedings of the Royal Society B.

It's an amazing piece of mechanics Philippe Marmottant University of Grenoble More on how predatory plants and animals trap their prey from BBC Wildlife Finder

The team, led by Philippe Marmottant from the University of Grenoble, says the plant could provide a template to design miniature medical devices, such as a "lab-on-a-chip", which samples tiny amounts of blood that could be used in diagnostic tests.

The plant's tiny suction trap was much faster and more efficient than the scientists had predicted. It took just a thousandth of a second to open and close.

"It features a remarkable door, that acts like a flexible valve," Dr Marmottant told BBC News.

This valve-based trap is set by glands in the plant that continually pump out water, creating a depression inside the tiny bladder.

When a passing creature stimulates microscopic, super-sensitive hairs, this trapdoor buckles inward and opens, allowing the bladderwort to suck in water and any unsuspecting creature it contains.

While its digestive enzymes get to work on whatever it gobbles up - dissolving its flesh and consuming its precious nutrients over a few hours - the water re-inflates the trap and closes the door.

"The same trap can fire hundreds of times," said Dr Marmottant. "It is an amazing piece of mechanics."