Vorticellidae is a family of ciliates belonging to the order Sessilida.
[1] They are colonial or unicellular organisms that are attached to a substrate via a stalk.
The distinguishing characteristic of the family is a helical spasmoneme within the stalk that is contractile.
[2] Members of this family are common in marine, freshwater, and terrestrial habitats around the world.
Genera:[1][3]