Foraminifera, informally called “forams,” are single-celled protists with shells. Most are benthic (or live on the seafloor) while some are planktonic (and float around). They produce their shells out of calcium carbonate and are tiny, generally millimeter-size.
Fun fact: Sea hares have shells, too, early in development because they’re technically mollusks.
~Adlysia
adlysia 