cirrus

Cirri are specialized structures found in some protozoans, particularly ciliates. These are essentially tufts of cilia that can function like limbs, aiding in locomotion or attachment. Cilia themselves are short, hairlike organelles used for movement and gathering food. In ciliates, these cilia are often arranged in rows called kineties, but they can also fuse to form more complex structures like membranelles, undulating membranes, or cirri. While most ciliates use cilia for movement, some, like the suctorian ciliates, lose their cilia in adulthood and develop tentacles instead. Cirri are a notable adaptation within the diverse world of ciliated protozoans.123