Paramecium or paramecia are single-celled protists that are naturally found in aquatic habitats. They are typically oblong or slipper-shaped and are covered with short hairy structures called cilia.

Paramecium bursaria, which forms a natural symbiosis with the alga Chlorella vulgaris in nature, serves as the host cell. The work is published in the journal Lab on a Chip.

The paramecium is an amazing organism. It survives and thrives using just one basic principle: If things are getting better, keep swimming in that direction, and if not, change course.