The Carchesium is a smaller protozoan and belongs to the Phyllum Ciliophora. It lives in a colony with others and is from 100-150 um long.

The word Carchesium means a beaker or drinking cup which was used by the Greeks in very early times

The Carchesium is similar to the Vorticella. It has a stalk which contracts as well. Each one can contract individually without causing the colony to contract. It is quite a sight to see the individuals all bouncing about in the colony. These protozoans can be commonly seen in water samples taken from a fresh water aquarium filter.

Carchesium are available from science supply companies but because of their size are rarely used in the classroom.