Phylum Rhodophyta

Phylum Rhodophyta

Some of the oldest known fossils are red algae which appeared quite suddenly about two billion years ago and are not much like any other life forms. There are over 4,000 species mostly growing in the world's oceans. Nearly a third of them live as parasites on other organisms. Dulse and Porphyra are edible red seaweeds. Agar, used for culturing bacteria, is derived from red algae. The red or purplish colour is due to phycobiliprotein pigments. [CH] {EN}