Pencil Urchin

The Pencil Urchin is distinguished by thick, blunt-looking spines and a habit of wedging into rocky shelter. It is mainly active after dark, when it searches hard surfaces for algae and animal material.

Provide sturdy rockwork with several caves and room to move between them. Offer dried seaweed together with suitable animal-based foods if natural forage is limited. The bulky spines can shift loose rock or unsecured fragments as the urchin squeezes through the aquascape.

A pencil urchin is a cautious choice around corals, sponges, and other attached invertebrates, which may be grazed or damaged. Never pull one forcefully from a crevice: the spines may break before its grip releases. Keep copper medication out of the system and check water quality if it begins losing spines.