Common name: Sand Dollar

Clypeaster, commonly known as sand dollars or sea biscuits, are a genus of sea urchins found in warm, sandy regions. They are characterized by their flat, disk-like shape and distinctive star pattern on their upper surface. These echinoderms are fascinating additions to a reef tank due to their unique appearance and behavior. They are detritivores, feeding on organic material in the sand, which helps to keep the substrate clean. However, they require a deep sand bed and stable water conditions to thrive. Hobbyists should note that they are sensitive to changes in water quality and may not be suitable for beginner tanks.

1. 
   Common name: Sand Dollar

   Scientific name: Clypeaster humilis
2. 
   Common name: Sand Dollar

   Scientific name: Clypeaster reticulatus
3. Common name: sea biscuit

   Scientific name: Clypeaster rosaceus
4. 
   Common name: sand dollar

   Scientific name: Clypeaster subdepressus