for video of a bladderwort catching a crustacean,
visit www.sciencenews.org/bladderworts
Exposing secrets
of bladderworts
By Daniel Strain
Carnivorous bladderworts trap their
prey with speed that would make a Bond
villain shudder in gleeful envy.
Using high-speed cameras, researchers have gotten the first good look at how
these underwater plants spring their
ambushes. Bladderworts sport trapdoors that collapse inward with a tiny
nudge, creating a whirlpool that sucks
in wee critters — all in about half a millisecond. That’s some of the fastest plant
action on Earth, a French and German
team reports online February 16 in the
Proceedings of the Royal Society B.
Forget Venus flytraps. Bladderworts, of
the genus Utricularia, are cunning meat
eaters. “Utricularia are the smallest of
carnivorous plants and also, evidently,
the most sophisticated,” says Lubomír
Adamec, a plant physiologist at the Academy of Sciences of the Czech Republic.
Tiny traps, often no wider than an ant is
long, dot the surface of bladderworts.
The traps are masterpieces of suction.
Pumped nearly dry, the chambers set up
a pressure difference between the plant’s
innards and the water outside. When
small crustaceans and other swimmers
brush against hairs along the trapdoor, the
door bursts open and sucks in water and
prey at speeds up to 1. 5 meters per second.
The high-speed cameras show that,
at least in three bladderwort species,
the traps spring using an elastic buckle.
At just the right pressure, the domelike
trapdoor stays shut. But a tiny touch can
collapse the door like a popped bubble-
A cross-section of a bladderwort’s trap
reveals protruding hairs (right) that trig-
ger a door to pop open, sucking in prey.
1 mm
gum bubble, opening a small window
to the trap below. Unlike a gum bubble,
the doors are bouncy and spring back
to their original shape in fractions of a
second, says study coauthor Philippe
Marmottant, a physicist at Joseph
Fourier University in Grenoble, France.
Bladderworts move fluid so well, he says,
that they could inspire new lab tools.
www.sciencenews.org
march 12, 2011 | science news | 11
