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Long Spine Urchin

$3499
Size

SKU: URCHINxLongSpReg

Long Spine Urchin (Diadema setosum)

The Long Spine Urchin (Diadema setosum) is a striking and highly effective reef tank cleaner known for its long, elegant spines and unique appearance. Commonly found across tropical reef environments, this urchin plays an important ecological role in controlling algae growth and maintaining balance within the system.

Behavior and Role in the Aquarium

This nocturnal invertebrate is most active at night, moving across rock surfaces and glass in search of algae and biofilm. During the day, it often hides in crevices or shaded areas with only its long spines visible. Despite their intimidating look, Long Spine Urchins are peaceful and excellent tank janitors—helping to keep nuisance algae under control naturally.

Feeding

Diadema setosum feeds primarily on film algae, coralline algae, and leftover detritus. If algae availability is limited, supplement their diet with dried seaweed (nori) or herbivore pellets to ensure they receive enough nutrition. Regular feeding helps prevent them from grazing too aggressively near coral bases or scraping encrusting organisms from rockwork.

Tank Requirements

  • Lighting: Not light-dependent

  • Water Flow: Moderate to strong

  • Reef Compatibility: Reef-safe with caution — may accidentally topple unsecured frags or small rock structures

  • Temperament: Peaceful and beneficial grazer

Quick Care Tips

  • Provide plenty of live rock for grazing and hiding spots.

  • Keep frags and loose corals secure to prevent accidental displacement.

  • Avoid copper-based medications when keeping invertebrates.

  • Use caution when handling—spines are sharp and can cause injury.