Scientific term for the phylum Rhodophyta; used in biology and marine contexts.
Red algae inhabit many shallow parts of the ocean.
緑藻類 refers to green algae (Chlorophyta), while 紅藻類 refers to red algae (Rhodophyta).
Compound of 紅 (こう, 'crimson, red') + 藻類 (そうるい, 'algae').