The transition towards the great Mediterranean reefs
When light becomes scarce, green plants are progressively replaced by colonies of encrusting animals, giving rise to a unique habitat where sponges, bryozoans, cnidarians and other substrate-attached organisms dominate.
This change marks the beginning of a very special community, adapted to conditions of low light and deeper waters.
The levels that lead into the coralligenous community are known as pre-coralligenous zones. This community is considered a transition zone between algae-dominated seabeds and the great coralligenous landscapes.
Despite being an intermediate stage, the pre-coralligenous zone is characterised by a great biological richness, with a high diversity of animal species and algae adapted to low light conditions.
As light penetrates the water, it is progressively absorbed, rapidly attenuating with depth. This phenomenon forces the various algae and organisms to undertake a selective occupation of space, establishing zones according to the intensity and quality of the light they receive.
Many of the organisms that inhabit these zones display reddish colouring, an adaptation that allows them to camouflage themselves in an environment where red light no longer reaches. This trait is characteristic of deep environments and contributes to the unique landscapes of the pre-coralligenous zone.