This tiny organism can shrink to one quarter its size in milliseconds

A single-celled organism can shrink to one-quarter of its length in milliseconds using a remarkable calcium-powered protein “fishnet.” Scientists hope its unusual machinery could inspire artificial muscles capable of moving far faster than today’s designs. This tiny organism can shrink to one quarter its size in milliseconds. Scientists have now identified the unusual mechanism behind this remarkable movement.

The organism, Spirostomum ambiguum, relies on calcium ions and a specialized protein network arranged like a fishnet. This system allows it to contract far more quickly than human muscle, and researchers say the discovery could eventually help guide the development of faster artificial muscles and synthetic cellular machinery. A Single Cell With Extraordinary Speed Spirostomum ambiguum is a giant single-celled ciliate, named for the fringe of hairlike cilia it uses to swim.

Among ciliates, it stands out for its ability to contract at roughly 100 body lengths per second and then rapidly repeat the movement. Scientists think this behavior may help the organism escape predators or communicate with other ciliates. Human muscle fibers can shorten by comparable proportions, but the process takes about 10 times longer.