Scientific name - Cladophora Aegagropila

Common terms - Moss Ball, Marimo, Cladophora Ball, torasanpe, Lake ball

Geographic origin - Certain lakes in Japan, Iceland, Estonia

Type (stem, bulb, rhizome, floating etc.) - Free floating. Can be used as a carpet layer.

Max. size (height, width) - Up to 30cm in diameter in the wild. Generally smaller in home aquaria.

Lighting required - low to moderate - marimo will float due to pearling with higher light levels.

Temperature - <25C

Water chemistry requirements (pH, hardness) - Adaptable. Can tolerate some salinity.

Growth rates - slow (about 5mm per year)

Demands - undemanding

Additional info - An excellent and attractive addition to any freshwater tank. Being a form of algae (not moss), it tends to hinder the growth of other algaes by outcompeting them for the same nutrients (note: it won't 'cure' an algae infested tank). Requires regular turning to help keep it's spherical shape. Tends to pick up detritus, so may need rinsing occasionally -- just remove it from your aquarium and give it a few squeezes in some tank water. You may notice a few stray filaments floating about the bottom of your tank. This is normal - they'll eventually grow into a carpet or a baby moss ball. Amano shrimp seem especially fond of these plants.

Trivia - Marimo have been granted the status of "Special National Treasure" in Japan. In Iceland it's believed that taking good care of the plant will "make your wishes come true".