The paramecium is one of the poster children of the microscopic world. Widely distributed in freshwater environments, this slipper-shaped single-celled organism is easily located and often studied in schools because of its representative microscopic structures.
For example, it's rhythmically waving hairy coat of cilia, which propels the cell forward and backward in a corkscrew-fashion, can be seen even through a small microscope. The cell is also coated with spiky trichocytes, projectiles which provide a layer of porcupine-like protection.
Its contractile vacuoles – star-shaped bubbles which pump out the excess water constantly being absorbed by osmosis – work tirelessly to prevent the paramecium from exploding.
The creature's gaping mouth (or buccal cavity) is a fearsome prospect to the bacteria and other microorganisms that comprise the paramecium's prey; and its cytopharynx can be seen snaking like a throat down the length of its body, depositing nutrients into the food vacuoles which serve as its stomachs.
But the paramecium is not purely an epicurean. Its brain is readily apparent in the macronucleus that contains the DNA which governs the cell. And the micronucleus, activated during reproduction, shamelessly floats nearby within the gooey cytoplasm – assuring that paramecia will continue to delight and intrigue intrepid surveyors of the microscopic kingdom.
