Vorticella (Protozoan) Videos

These bell-shaped ciliates live in fresh or salt water attached by a slender, unciliated stalk to aquatic plants, surface scum, submerged objects, or aquatic animals. Vorticella eat bacteria and small protozoans, using their cilia to sweep prey into their mouth-like openings.

Although vorticellas are often found in clusters, each stalk is individually attached to the surface. The stalk is made up of an external sheath that contains a fluid and a spirally arranged contractile fibril called a myoneme that contracts when stimulated. When disturbed, the vorticella contracts and the stalk thread is shortened, causing the sheath to coil tightly like a spring.

Vorticellas reproduce primarily by fission, dividing along the length of the organism. One of the two daughter cells retains the original stalk; the other grows temporary cilia at the bottom end and swims to another location. The migrant eventually grows a stalk, attaches to a substrate, and loses the temporary cilia. They also reproduce through conjugation. One small migrant finds an attached vorticella and fuses with it, forming a single organism, which will subsequently reproduce by fission.