Sea urchins and starfish

For many saltwater aquarium enthusiasts, sea urchins and starfish are among the typical animals that make an aquarium a "sea at home." Sea urchins are particularly useful because they are excellent algae eaters and can combat large quantities of algae.

Popular algae eaters among sea urchins include the spherical sea urchin (Mespilia globulus), which is also well-suited for smaller tanks from about 100 liters, or sea urchins related to the spindle urchin (Tripneustes ssp.). Starfish, on the other hand, feed primarily on bacterial biofilms and therefore require a well-established, large aquarium (from 300 liters) that should not be too sterile.

Particularly interesting are sand-burrowing sea urchins and starfish such as the sand dollar or the sand-burrowing starfish, which loosen the substrate and remove dirt and algae. When placing them in the aquarium, care should be taken to ensure that sea urchins and starfish do not come into contact with air.