Paramecium is one of the best live foods for the smallest fry. Culturing Paramecium is relatively easy but your vessels need to be maintained on a rotational basis in order to keep the culture going. Paramecia multiply mostly by fission, with a little sex on the side from time to time. This flexible strategy helps them multiply very fast, so your culture will be mature in a matter of days.

Paramecium is a genus of unicellular ciliated protozoa, commonly studied as a representative of the ciliate group. Paramecia are widespread in freshwater, brackish and marine environments, and are often very abundant in stagnant basins and ponds.  Species of Paramecium range in size from 50 to 330 micrometres (0.0020 to 0.0130 in) in length. Cells are typically ovoid, elongate, foot- or cigar-shaped. Paramecia feed on microorganisms like bacteria, algae, and yeasts.