infusoria

/IH0 N F Y UW0 S AO1 R IY0 AH0/
noun
  1. 1

    Any of the many minute aquatic creatures, such as protozoa and unicellular algae, found in freshwater habitats.

Source: https://en.wiktionary.org/wiki/infusoria, https://en.wiktionary.org/wiki/infusorium