The Venus flytrap is well known for being carnivorous, but it’s far from the only plant that traps its prey. You’ve probably seen footage of a Venus flytrap snapping shut on an unsuspecting fly, cricket, or spider. Yet compared to the rootless carnivorous plants in the genus Utricularia, better known as the bladderworts, the Venus flytrap is definitely a slowpoke.
Bladderworts grow in bogs around the world. These freshwater aquatic plants don’t have roots, so they depend on trapping tiny organisms for sustenance. Bladderworts have small suction traps lining their stems that can snap shut around prey with around 600 Gs of force (600 times the force of gravity). It takes less than a millisecond for the traps to close around tiny organisms like protozoa, crustaceans, and insect larvae.
This motion is much too fast to be seen with the naked eye, though physicists at France's Université Grenoble Alpes filmed this mechanism with high-speed video cameras recording at up to 10,000 frames per second. The researchers discovered that bladderworts trap their prey faster than any other carnivorous plants. While a Venus flytrap can react and close around its prey in about a tenth of a second, a bladderwort can capture its prey in less than a millisecond, making it more than 100 times faster.
The traps work through spring-loaded suction by pumping out water over several hours in order to achieve a very low pressure, with the leaves of the trap bulging outwards and storing elastic energy. The “trap door” has sensitive hairs that are triggered by contact with prey, causing it to snap and collapse inwards, sucking in both the water and the prey. Almost immediately, the leaves of the trap door return to their initial shape, and the prey is digested with the help of enzymes, providing the plant with the nutrients it needs to survive. This process will repeat itself over and over throughout the plant’s life.
Caught in a trap:
- The acceleration of the bladderwort trap is incredibly powerful, at 600 Gs of force. By comparison, an astronaut feels around 3.5 Gs (3.5 times the force of gravity) during liftoff. At around 8 Gs, most people will black out.
- If they aren’t triggered by prey, the traps can also fire on their own, potentially sucking in phytoplankton and other microscopic plants.
- There are over 220 bladderwort species around the world, mostly living in bogs and saturated soil. Utricularia is the world’s largest genus of carnivorous plants.
