What is an oral groove?

All forms of life need to take in nutrition to survive, even single-celled protozoans. Belonging to an overall grouping called Paramecium, these tiny organisms (make a dot with a pencil point and you've about covered their size) have no legs and arms to run around and grab food. So, they rely on hundreds of little hairlike structures (cilia) to move them toward their favorite diet — a healthy serving of bacteria. The cilia, which stick out from the Paramecium's outer coat of firm protein, known as the pellicle, don't settle for just locomotion in their job descriptions. As they sway like vibrating feathers all along the edge of the organism, the cilia sweep food particles into the paramecium's oral groove — a mouth of sorts. One Paramecium can take in as much as 5,000 bacteria a day, digesting meals in a miniature (to us) cavity and getting rid of waste from another compartment. These one-cell wonders, shaped like a shoe insert you might buy to manage foot odor, perform amazing feats for human water systems, cleaning up ground water that feeds wells and aquifers. Although these mini-creatures do their work out of our sight, they most definitely deserve our appreciation!