Rhodophyta (Red algae)
  
The division Rhodophyta is characterised by specific pigments (phycoerythrin and phycocyanin), combined with chlorophylls and xanthophylls, they bring about diferent colour of the algae, from pink to dark red and black,violet, bluish, green and yellow-greish-brown. Only multicellular complex forms are represented in the class. Red algae are typical marine organisms inhabiting the seas of all geographical zones. They predominating in the communities of sublitoral and forming the associations below the zone of brown algae.
Overwhelming majority of species are litophytes associated with rocky and stony grounds, although epiphytes and parasites occur among them as well. The range of depths where red algae live is wider than that for brown algae. The former grow from littoral down to the lower limit of development of algae, which is determinrd, especially in the northern seas, not only by light but the pattern of distribution of hard grounds.