Some tropical anemones cast off their tentacles which deve lop into entire polyps. Others just split down the middle of their polyps. If the anemone splits down the middle, the mouth is divided in half also. This is called longitudinal fission. An even rarer process is transverse fission, in which the anemone spl its across the middle of the column.
Little tentacles form around the middle of the column before the upper half is separated.
Many anemones leave little bits of their pedal discs behind when they move. These little pieces then develop into complete polyp s. These are just a few of the interesting ways in which sea anemones manage to populate the oceans. They outnumber most other attached or sessile marine animals. They may also have very long life spans, some living as long as one hundred years.