Pincushion Urchins (Lytechinus variegatus) can be one of the larger members of a saltwater aquarium Clean-Up Crew as they can grow to 8 inches in diameter in the wild. With their larger size they are able to cover more ground, quickly helping to rid your tanks of any unwanted algae, especially hair algae. In the wild, sea urchins help to keep coral reefs cleaned, allowing coral to grow without being hindered by algae growth and they apply that same behavior in home aquariums. While they are safe for reef tanks, make sure that all corals are glued down as the urchins will pick up and carry around any unattached frags. Their mouth is located on the bottom of their body and they use it to scrape along the rockwork which allows them to consume all parts of the algae. Oftentimes you can see where an urchin has been by the cleaned path it leaves behind. As they are fast eaters with big appetites, it may be necessary to supplement their diet with a mix of meats and veggies. Their body is covered with spines that they can manipulate to allow them to gain access to various places along the reef. If the water quality is poor, their spines will begin to fall out. Regular testing of calcium is important as they need calcium carbonate to help maintain their shells and spines. Similar to other invertebrates they are sensitive to copper so avoid any copper based medications. When adding them to an aquarium, drip acclimation is best done over the course of an hour.