The name “sand dollar” mainly comes from their appearance. It is disc-shaped. After being washed ashore by the sea and died, it is white as a whole and looks like a silver coin in the sun, so it is named.
Sand dollar usually lives in groups. This is because they prefer to discharge sperm and eggs on the soft seabed to assist in the reproduction of larvae. Sand dollar larvae generally float in the sea and experience various metamorphosis. When the hard shells are formed, they will change from floating to perching on the seabed.
Sand dollar living in the sand is often exposed to the beach after the tide subsides. It will generally become the object of human collection and specimen. After the storm, the waves will wash the dead sand dollar onto the beach, which becomes a good opportunity to collect specimens.