Closed cilia around the preyThe Venus Flytrap, Dionaea muscipula, is a carnivorous plant that catches and digests animal prey—mostly insects and arachnids. Its trapping structure is formed by the terminal portion of each of the plant's leaves and is triggered by tiny hairs on their inner surfaces. When an insect or spider crawling along the leaves contacts a hair, the trap closes if a different hair is contacted within twenty seconds of the first strike. The requirement of redundant triggering in this mechanism serves as a safeguard against a waste of energy in trapping objects with no nutritional value.
The carnivorous Venus flytrap plant can snap its clamshell leaves around an insect in less than a second. But how?
Unlike animals, plants have no muscles or brains. And plants are not known for their ability to move quickly, as a team of scientists and engineers point out in the Jan. 27 issue of the journal Nature.
The secret has been revealed: The flytrap's leaves snap from convex to concave the same way that a contact lens can flip inside out, the scientists say.
The team cut up leaves to study their natural curls, and also painted fluorescent dots on intact leaves to track their insect-devouring action with high-speed cameras.
Like most lenses, Venus flytrap leaves are doubly curved, that is, curved in two directions, which allows the leaves to store elastic energy.
With a contact lens, the two directions are perpendicular to one another. With a Venus flytrap leaf, they are not. That property creates an especially rapid elasticity that causes the leaf to snap even more quickly from convex to concave.
Source: http://www.livescience.com/