A live Marimo moss ball and black sea fan in a water-filled cylindar create a tiny aquarium that tops a working ink pen. A rubber stopper seals the aquarium cylinder, and is removable so that the water can be changed. Water changes are only necessary every 6-12 months! Are the Marimos alive? Yes! Do they grow? Yes! Are they hard to take care of? No! Your Marimo requires no regular maintenance. DO avoid leaving your Marimo in direct sunlight for extended periods of time. (You don't want to cook the little guy!) And..better not to leave it in a dark drawer for an extended period of time. Your Marimo can live for a year or more in your aquarium pen without even a water change. If you ever decide to add water, distilled water is best. Pen writes in blue ink and retracts with a twist of the tip of the pen. Your Marimo comes in an earth-tone gift box, well protected, with a care card and a pipette for water changes, if desired. Our wrapping is pictured, and includes a distressed leather bow. Ships in 1-3 days. * The moss balls used in my pens and jewelry are propagated by myself and are isolated from the current situation with zebra mussels being found in Marimos elsewhere. Mine have only been in distilled water in my own tanks for the past year.