Longspine Urchin

Important Buyer Information:

At YoCamron’s Aquatics, all our invertebrates undergo a 76-day fishless quarantine with light medications to ensure there are no harmful parasitic, fungal, or bacterial pathogens on your new family member! Please contact us before purchasing to confirm availability and receive updates during the quarantine process. Our guarantee for live arrival applies only to shipments delivered through UPS early AM service. Livestock purchased directly from our wholesaler is ONLY covered by a 2-hour live arrival guarantee under our DOA (Dead On Arrival) terms. For more details, please reach out to us directly. We’re dedicated to ensuring the best for our customers and their aquatic environments.

Long Spine Urchin (Diadema setosum) – Striking Scavenger with a Sharp Defense

The Long Spine Urchin is one of the ocean’s most iconic invertebrates, instantly recognizable by its jet-black body and extremely long, needle-like spines that can easily exceed 12 inches in length. These elegant but cautious echinoderms are reef-safe algae grazers that provide critical tank maintenance by scraping diatoms, hair algae, and film algae from live rock and glass surfaces.

While stunning to behold, this urchin is not without caution. Its spines are venomous, capable of causing a painful sting if handled or brushed against. The venom is not typically dangerous to healthy adults but can result in localized pain, swelling, or skin irritation. In addition, the spines are very brittle and prone to snapping if stressed, mishandled, or exposed to poor water conditions. We strongly advise using care during acclimation and tank maintenance. Use a specimen container instead of nets, and avoid touching the spines directly.

Ideal for large reef tanks with ample rockwork and stable calcium/alkalinity levels, Long Spine Urchins are nocturnal and may hide in rockwork during the day before emerging at night to graze. They are known to bulldoze unsecured coral frags or small rocks, so secure any loose decor.

This species is also photosensitive, possessing an incredible ability to sense light through its entire body surface. Some specimens will even change position in response to sudden lighting changes, adding a fascinating dimension of behavior to your reef.

Whether you’re looking for a functional cleanup crew member or an otherworldly visual centerpiece, the Long Spine Urchin is a perfect choice for experienced hobbyists who respect its unique needs and potent defenses.