The sand crastrum has split from its ancestor. It has adapted to live in the shallow waters and on the sands of the coast. Crastrum that were washed onto the beaches quickly dried out and the only ones to survive were the sand crastrum. During the day, the crastrum will either float on the surface of the water or sit on the surface of the sand. Thicker surfaces and a smaller surface area means they don’t lose too much water. The sand crastrum has enhanced it’s movement. Though its movement is slow, each tendril can be used to pull the crastrum along the sand or to swim through the water.
During the night when photosynthesis stops, the crastrum will move beneath the top layer of the sand to escape night herbivores. They still reproduce in the same way as their ancestor, except they only bud in water and not on land.