Sea Urchins

Dive Deeper: Info & Tips for Sea Urchins in Aquariums

Sea urchins are echinoderms—related to starfish—and move using hundreds of tiny tube feet located on the underside of their bodies. Most urchins are herbivorous and rely on live rock and tank surfaces for grazing. Some species may pick up bits of shell, algae, or substrate to camouflage themselves, which is a normal and harmless behavior.

While they are generally reef safe, it’s important to secure corals and loose frags, as urchins may accidentally knock over items as they graze. They also require stable water conditions and plenty of live rock to graze on. If algae is sparse, supplemental feeding with nori or algae wafers may be needed to prevent starvation.

Sea urchins are unique, efficient algae grazers that serve both a functional and ornamental role in saltwater aquariums. Their slow, steady movement and spiny appearance make them a fascinating addition to reef tanks and fish-only systems alike. At Top Shelf Aquatics, we offer a curated selection of sea urchins for sale, chosen for their utility in algae control and their compatibility with a wide range of marine setups.

Whether you’re dealing with nuisance algae or just want to add more biodiversity to your tank, sea urchins are a great addition to any cleanup crew. They help maintain rockwork and glass surfaces, often accessing hard-to-reach areas that snails and other grazers can't. Many species are peaceful, reef safe, and long-lived with the right care.

Top Sea Urchins for Aquariums

Tuxedo Urchin – A small, colorful species perfect for nano and reef tanks. Known for picking up bits of substrate as camouflage.

Pincushion Urchin – Larger and very effective at cleaning live rock and glass. Peaceful and highly adaptable.

Longspine Urchin – Striking appearance with long, needle-like spines. Best suited for larger tanks with stable rockwork and moderate flow.

Halloween Urchin – A striking, deep purple urchin with vivid orange spines. Known for its effectiveness in algae control and its unique appearance, it's a reef-safe addition that stands out visually while performing essential cleanup duties.

Ideal Parameter Range

• Salinity: 1.023–1.026
• Temperature: 74–78°F
• pH: 8.1–8.4
• Ammonia/Nitrite: 0 ppm
• Nitrate: <15 ppm
• Calcium: 400–450 ppm
• Alkalinity: 8–12 dKH

Setting Up an Aquarium for Sea Urchins

Urchins thrive in established tanks with mature live rock, stable parameters, and minimal aggression from tankmates. They’re best suited for tanks that already have a good base of algae or biofilm for them to feed on. Avoid housing them with fish that nip at invertebrates, and ensure there are no sharp flow transitions that could dislodge them.

A secure lid is also advised, as urchins can sometimes climb glass and overflow boxes. Their spines are fragile, so handle them gently and avoid using metal tools around them to prevent injury.

Feeding Sea Urchins

Most urchins will graze continuously and do not require direct feeding if enough algae is present in the tank. However, in clean systems or newer setups, offer supplemental feedings of dried seaweed (nori) or algae-based sinking wafers.

Place food near their path or wedge it in the rockwork so it’s easy for them to access. Monitor their body size—shrinking or pale urchins may be signs of underfeeding.

Why Buy Sea Urchins from Top Shelf Aquatics?

Top Shelf Aquatics offers healthy, aquaria-ready sea urchins that are acclimated and monitored for activity and feeding before being listed for sale. Whether you’re adding to your cleanup crew or looking for a standout invert, our selection of sea urchins for aquariums is handpicked for reliability and long-term success.

Our team is here to help you select the right species for your setup, ensure compatibility, and provide tips on keeping your urchin healthy and active.