Paramecium

Paramecium (/ˌpærəˈmiːʃ(i)əm/ PARR-ə-MEE-sh(ee-)əm, /-siəm/ -⁠see-əm, plural "paramecia" only when used as a vernacular name) is a genus of eukaryotic, unicellular ciliates, commonly studied as a model organism of the ciliate group. Paramecium are widespread in freshwater, brackish, and marine environments and are often abundant in stagnant basins and ponds. Because some species are readily cultivated and easily induced to conjugate and divide, they have been widely used in classrooms and laboratories to study biological processes. The usefulness of Paramecium as a model organism has caused one ciliate researcher to characterize it as the "white rat" of the phylum Ciliophora.