At present, there are about 30 thousand species of algae on the earth, most of which live in water, have chlorophyll and live by themselves.

Species distribution representative

Cyanobacteria are widely distributed, mainly in fresh water, such as auricularia auricula, Nostoc flagelliforme and Nostoc commune.

Primary green algae are epiphytic in the cloaca of sea squirts.

Euglena mostly lives in fresh water.

Diatoms are widely distributed in water and land.

Green algae accounts for about 80% in fresh water and 10% in seawater, including Chlamydomonas, Spirogyra, Chlorella and Ulva.

Red algae are common in seawater, such as laver and agar.

Brown algae are mostly attached to kelp, carrageenan and Undaria pinnatifida on shallow reefs.