Floscularia ringens is a freshwater rotifer, a microscopic animal. In its first day of life, the rotifer permanently attaches to a substrate and begins building a protective tube where it will live.

The tube is made up of round pellets, a combination of detritus and secretions from the rotifer. An underlying membrane provides support. Pellets are constructed by the rotifer in a specialized organ on its corona called the modulus.

Cilia lining the outside of the coronal lobes beat rhythmically, creating currents that guide food into the rotifer’s mouth.