Aldrovanda vesiculosa is a fully aquatic carnivorous plant (i guess you knew that) The plant is one of two Insectivorous plants that grow fully in water,the other being some aquatic Utricularia. All these plants have found a way to get their minerals from prey through their traps due to the need to do so,as the water is very low in minerals or has the wrong minerals the plants needs to grow.but they still use Photosynthesis by having chlorophyll in their cells,just like all other plants.
Aldrovanda vesiculosa is found in Africa, Australia, Europe, Japan and India,but sadly it's now become extinct in the wilds of Japan,In Europe the plant is dying out due to high pollution. The plant grows in water floating just below the water surface, like normal water weeds it grows amongst other water plants e.g. reeds. This plant has no roots unlike most other water plants. In places were Winters are cold the plant goes dormant, by forming a tightly rolled bud. Which some Utricularia ( bladderworts) do the same.
The plant grows to about six inches ( 15 cm ) long as one end grows the other dies,the plant has traps that look like Venus fly trap ( Dionaea muscipula ) .These trap move the same way too,there are about six to nine traps in a whorl around the stem, which grow at the end of a type of leaf which also has bristles, which allows them to survive out of water! When they are forced out of water, they abort forming traps, and their whorls collapse on top of each other forming a sheath around the center stem, and those bristles become loaded with tiny drops of dew every morning, which gets pulled into these hollow tubes (by capillary action) formed by the collapsed whorls, and stores enough moisture to sustain them an entire day out of free standing water
The plant flowers in the summer time which is white in colour,this grows above the water level,as i said before the trap has a look of the Venus fly trap but the trap is only about 10th of inch across and is a translucent green in colour and looks bit like a clamshell,each side of the trap is lined with with a big number of teeth,inside the trap there are digestive glands,unlike all other Carnivorous plants it has not been found what lures the prey to the trap.
The trap closes like the Venus Fly Trap with the teeth interlocking to stop the prey from getting out before the trap is fully closed,as the plant is under water the plant has a secretion which makes the trap water proof,this is done after it as forced the water out of the trap by squeezing the two lopes together,the plant is not that easy to grow in cultivation on a long term,though,when growing these plants you should keep the water free of Algae and have no tadpoles as both are enemies of the plant,authough it is helpful to keep water fleas in the water with the plant,to feed it.
Keep temperature relatively warm at 60F (16C) to 75F (24C) Under no circumstances let it freeze AT ALL!
As i have already stated,this is a fully aquatic plant and grows well in part rain water part pond water,with the bottom of you container lined with peat and gravel on top,you may also want to add other plants into the container,you may even go completely carnivorous with some aquatic utricularia!
As for containers,try a ten gallon container,or something around the same size
Give them as much light as you possibly can,they love light!
The joys of growing them
Aldrovanda are an amazing species of carnivorous plant,when grown properly they thrive And grow at amazing speeds and mutiply in large numbers,colonising whatever they grow in,soon from having a few turions you can have up to fifty growing,so,if you decide to grow them,give 'em the care they deserve