How Fast Is Paramecium?

Paramecia swim at about 1 mm per second using thousands of tiny cilia beating in coordination — corkscrewing through the water as they go. They cover roughly 10 body lengths per second, making them surprisingly athletic for single cells.

Paramecia have two kinds of nuclei — a small one for reproduction and a large one for everyday cellular function. Most other cells get by with just one.

• 10× faster than a sperm cell
• 1,400× slower than a walking human