Marimo are a unique growth form of lake algae and used to be found in cold lakes in Japan and Northern Europe. However, the only place where specimens larger than 20 cm in diameter can now be found is ...

In the winter months, at the bottom of Lake Akan in Hokkaido, Japan, harmless underwater algae balls that can grow to be bigger than basketballs are protected from death by an ice shield on top of the ...

Marimo moss balls now are rolling into stylish vases and even into tiny orbs and bottles as jewelry. Consider marimo the moss in your underwater terrarium. Or the floating plant in your aquarium.

Climate change could overexpose rare underwater "marimo" algae balls to sunlight, killing them off, according to a new study at the University of Tokyo. Marimo are living fluffy balls of green algae.