In the rocky areas with little light in the Mediterranean there is an interesting community of chalky algae growing in adjacent horizontal plains to take advantage of the little light available. There are also large, colorful gorgonia.

In the Mediterranean, the so-called coralline area is characterized as colonized by a large number of chalky algae, among which other suspensive invertebrate organisms live: sponges, ascidia, and bryozoan and sea fans, in a large variety of colors: yellows, pinks and oranges. The fall in the amount of light is one of the key factors for the development of these algae, which are enhanced while other disappear that need more light and which would undoubtedly annul them. Furthermore, the calcification gives them the necessary strength not to be eaten by certain herbivores. Although they grow very slowly, they fight to obtain as much light as possible, which causes a singular growth in horizontal plains, with even some layers covering and superimposing over others.

Cardinal fish (Apogon imberbis)

Red Gorgonia (Paramuricea clavata)

Other common marine organisms that can be found in this community:

• Red sea anemone (Actinia equina)
• Red precious coral (Corallium rubrum)
• Common lobster (Palinurus elephas)