Shortspine Urchin

Short Spine Urchin
Echinometra viridis or Echinometra lucunter

The Short Spine Urchin is a small, reef-safe algae grazer that’s perfect for tight rockwork and lower-profile reef tanks. With its compact body and short purple, brown, or black spines, it quietly patrols the tank, feeding on film algae, coralline, and detritus.

Quick Stats:

• Care Level: Easy

• Temperament: Peaceful

• Color Form: Dark purple, black, or brown with short spines

• Diet: Herbivore – eats film algae, coralline, and detritus

• Reef Compatible: ✅ Yes

• Water Parameters:

  • Salinity: 1.023–1.025

  • Temperature: 72–78°F

  • pH: 8.1–8.4

  • Alkalinity: 8–12 dKH

• Max Size: 2–3 inches

• Minimum Tank Size: 20 gallons

Why We Like Them:

• Excellent algae grazer for smaller reef tanks

• Safer than large urchins in frag tanks and tight aquascapes

• Doesn’t bulldoze or dislodge coral as much as other species

• Hardy and long-lived when provided stable water and rockwork

🪸 Pro Tip:
Short Spine Urchins may hide in rock crevices during the day and come out at night. They can wear bits of shell, algae, or rubble for camouflage — a totally normal behavior that makes them fun to observe.