Spirostomum

Spirostomum is a member of the protist kingdom. It is an animal-like protist, or protozoan which feeds on bacteria. It is found in pond water. Spirostomum is a Ciliate, which use cilia to move through water.

Spirostomum is an unusual protozoan. It is large for a protist. It can grow up to .17 in (3 mm) which is large enough to be seen with the naked eye. Though a unicellular organism, it has multiple nuclei. Also, Spirostomum can contract it's body to 1/4 of it's length in 6-8 millisec which is the fastest contraction known in any living cell.