Family: Unicellular or Colonial; cell body spherical, with one or more spiny projections;
a single cup-shaped chloroplast with a pyrenoid; asexual reproduction by zoospore or autospore;
sexual reproduction by fertilization between egg and sperm.
Genus: Colonial; cell body with 2 or more spiny hairs (Illustrations of The Japanese Fresh-water Algae, 1977).
Images of collecting locality:
Old Sugata river, Yasuzuka, Mibu town, Tochigi Pref., Japan, May 5, 2008 by Y. Tsukii