Sea urchins are an often-overlooked but highly effective part of a reef tank’s cleanup crew, playing a vital role in algae control and overall tank health. Known for their powerful scraping mouthparts, urchins consume a wide range of nuisance algae, including coralline overgrowth, hair algae, and film algae that other invertebrates may ignore. By steadily grazing across live rock, glass, and hard surfaces, they help prevent algae from taking over and competing with corals for space and light.

Different types of urchins bring unique benefits: Tuxedo Urchins stay compact and are excellent for smaller reef tanks, often carrying bits of rubble or shells for camouflage. Pincushion Urchins are tireless grazers with strong appetites, perfect for tackling heavy algae outbreaks. Other varieties, such as long-spine urchins, provide wide-ranging coverage but also add striking visual interest to one's reef aquarium.

Together, sea urchins complement snails, crabs, and conchs, making them an integral part of a balanced reef cleanup crew that helps reduce manual maintenance while supporting a clean, thriving reef ecosystem.