Why are algae red?

Rhodophyceae:

1. The red-colored algae are known as Rhodophyceae.
2. They have red color due to the dominancy of red pigment, r-phycoerythrin in their body.
3. They are found in marine water.
4. Rhodophyceae can be found on the surface of water or in the depth of oceans.
5. Common examples of Rhodophyceae are Polysiphonia, Porphyra , Gracilaria, and Gelidium.