Purple Pincushion Urchin (Lytechinus variegatus)
Max Size: 8 inches
Reef Compatible: Yes
Minimum Tank Size: 20 gallons
The Pincushion Urchin has a circular or oval-shaped body that is covered with uniform spines that can be red, purple, white or blue. To thrive in an aquarium, it requires enough space to forage and hide. During the day, it usually hides in caves or burrows in thick substrates, while at night, it grazes on algae, moving around with its suctorial podia, which are arranged in double rows of five. Large amounts of live rock should be provided in the aquarium, as it will help to graze the Urchin.
It can prey on some of the sessile invertebrates in the reef system, and the rock formations must be stable enough to withstand the Urchin's movement. The Pincushion Urchin is usually solitary but can tolerate others of its kind. Copper-based medications and high nitrate levels can harm it, and poor water quality can cause it to lose its spines. Breeding in an aquarium is very challenging, with no distinguishing characteristics to differentiate between males and females. If there is insufficient algae in the tank, dried seaweed can supplement its diet.