The lowtide crastrum split from its ancestor the suction crastrum. It has become amphibious and can stay out of the water for short periods. It now only grows on the ora koral crystal which only grows in the tidal zone where they are exposed during low tide. To cope with this it has developed a tougher skin to help keep in moisture when out of the water. While their skin is hard and protective it still can photosynthesize. Its suction has increased to prevent any predators from prying them off the crystals during low tide. They can only transfer from one crystal to another during high tide. Like their ancestors they reproduce by budding. This typically takes place during high tide as well.