Larvae distribution can complicate colonization
Occasionally, a fertilized female can drift into a new area and all of her young can be the new population. The problem is that if the larvae have to develope in the water over a period of several weeks, they run the risk of becaming dispersed and disappearing from the area. This is not the situation when the embryo develope within the mother until the time they are ready to start their own life on the beach. If for example a fertilized female periwinkle comes to an area where other periwinkles are absent, there is nevertheless a good chance that the periwinkle population will increase. She, the female periwinkle can have several hundred embryo within her shell and nearly all of the young she gives birth to will stay in the same area. Here, they can mate with each other and if the environment is favourable they can build a sizable population.
Many colony building animals can effectively spread over large areas by means of fragmentation.
Organisms effect on each other
|Cliffs and rocks are fantastic!|
|Zoning and flecked occurrence|
|Animals that are attached|
|Variation and change|
|Variations in water level|
|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|