One Sundew's Amazing Catapulting Tentacles!
We've all -- at one time or another -- been amazed by the meat-eating Venus Flytrap. The plant's trapping structure, formed by its leaves, is a veritable weapon of death for unsuspecting insects.
But the Fly Trap has nothing on Drosera glanduligera, a species of sundew from Southern Australia. Its outstretched tentacles are elements of a sophisticated catapult system, which the plant utilizes to fling hapless insects into the ensnaring inner tentacles of its leaves, all in about 75 milliseconds!
The snappy process was just filmed and documented in its entirety by German researchers. After collaborating with private growers to cultivate their specimens, the researchers placed fruit flies in enclosed plant pots and sadistically waited for the plant predation to go down. They were not disappointed.
When the flies touched the snap-tentacles, they were rapidly lifted and thrown into the central part of the leaf, where, over about two minutes, glue-tentacles drew the prey into a depression, never to be seen again.
Scientists interpreted the catapulting action to result from hydraulic forces within the tentacle. Interestingly, this movement is not repeatable, they found. After being fired, the snap-tentacles fall off. But this obviously seems to suit the sundew, as the researchers posit that higher nutritional rewards resulting from larger and more consistent prey capture "could have acted as a selective advantage."
The study was published Sept. 26th in the online open-access journal PLoS ONE.
Check out the video of Drosera glanduligera's amazing catapulting tentacles over in the RCS Video Section.
Source: Poppinga S, Hartmeyer SRH, Seidel R, Masselter T, Hartmeyer I, et al. (2012) Catapulting Tentacles in a Sticky Carnivorous Plant. PLoS ONE 7(9): e45735. doi:10.1371/journal.pone.0045735