Video: Plant predators

The fastest known carnivorous plant is caught on tape

Mar 9, 2011
Jef Akst
Carnivorous plants are faced with the difficult task of catching animal prey that utilize high-speed nervous systems adept at avoiding such attacks. Aquatic bladderworts, plants that feast on insect larvae and nematodes swimming by, accomplish this feat using pressurized bladders equipped with a trigger-sensitive trapdoor to suck in prey faster than any other meat-eating plant.
Aquatic bladderwort (Utricularia stellaris)
Image: Amit Singh
Sensory neuroethologist Sanjay Sane of the National Centre for Biological Sciences in India and his student Amit Singh caught bladderworts in action for the first time on high speed video and describe the biomechanics that support the plant's unique hunting strategy in a paper published today (March 9) in Biology Letters."What we've been able to determine is that it's entirely determined by the pressure differences between the inside and outside [of the bladders]," Sane said. The closed bladders actively pumped water out to reduce the pressure inside, such that once the trapdoor opened, water rapidly gushed in, bringing the unsuspecting prey along for the ride. "It was stunning to see," Sane said. "It was amazing how fast it was."Within just 300-700 microseconds of stimulating their hair triggers, the trapdoors flew open, and water coursed into the bladder. If the prey were too large to fit in the bladder, the suction pressure was strong enough to tether them to the bladder's surface."What really excites me about this is it gives us a glimpse into how something without a nervous system can compete successfully with something with a nervous system," Sane said. "And what it does, essentially, is use physics."
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