Aquascope Facts
Cliff and rocky beach ecology Besides the cnidarians, there are other colony building groups of specie such as sea-mats, sea squirts and fungi. Other groups of animals that are important on hard bottoms are molluscs, segmented worms, nematodes, arthropods, brachiopods and echinoderms - but with these individuals are almost always solitary. Many of these specie can reproduce asexually and build clones, but do not cooperate in large coherent colonies.
    Building colonies that consist of modules results in creatures that can grow larger without the need for the modules or organs to increase in size. This allows for a greater flexibility in construction, the ability to adjust their form after local conditions like the form of the substrate or after other organisms that they come in contact with.

Unite or kill

Within colonies there is usually some form of coordintion and a certain amount of work distribution between the different modules, but independence between them is usually greater than with solitary organisms. An injury does not necessarily have to be fatal for the colony. Colonies have a reasonable ability to survive without the injured parts and rebuild them. Many colonies can be rebuilt from small fragments or even single cells. Certain modules go through a process of breaking down and rejuvenation where older and worn out modules are replaced by newer and fresher.
Struggle between colonies
The sea-mats Membranipora membranacea and Electra pilosa that partly share the same area on laminaria. The largest colony is about 10 cm in diametre.

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Cliffs and rocks are fantastic!
Zoning and flecked occurrence
Animals that are attached
Modular construction
Variation and change
Variations in water level
Wave exposure
Both cliffs and rocks
Freshwater and saltwater
Geography, climate and history
Organisms life cycles
Organisms effect on each other
Energy and the flow of material

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Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson