A 'coenobium' (plural coenobia) is a
colony containing a fixed number of cells, with little or no specialization. They occur in several groups of
algae. The cells are often embedded in a
mucilaginous matrix and may be
motile or non-motile.
Examples include ''
Volvox'' and its relatives, ''
Scenedesmus'', ''
Pediastrum'', and ''
Hydrodictyon''.