Marimo moss balls

Aegagropila linnaei, known as marimo (毬藻, literally "ball seaweed") in Japanese and as Cladophora ball, lake ball, mossimo or moss ball in English, is a species of filamentous green algae (Chlorophyta) found mostly in a number of lakes in the northern hemisphere. A marimo is a rare growth form of the species where the algae grow into large green balls with a velvety appearance. Colonies of such balls are known to form in Iceland, Scotland, Japan,...