Supplier Availability: Common

This sea urchin will decorate itself with whatever is available in the aquarium. This could be for example Zoa Polyps but is typically algae, small stones, and shells.

This particular sea urchin is less willing to choose coral fragments and the like, than others. They come in multiple colors, red, blue, green, and black, among others.

Sea urchins are often used to keep various algae at bay. 

They are very effective algae eaters and will eat anything from coralline algae to green hair algae.
Sea urchins must not be kept in an aquarium with few algae, as they may starve to death. 

Sea urchins should be acclimatized slowly, due to sensitivity towards changes in salinity.