Summary: Small camouflaging crab that attaches macroalgae or sponges to its carapace. Reef safe with caution—may nip soft corals or zoanthids if underfed.

Key Facts

• Scientific name: Huenia grandidierii

• Common names: Decorator Crab, Leaf/Spider Decorator

• Origin: Indo-Pacific

• Adult size: ~3–5 cm carapace

• Minimum tank: 50+ L

• Temperament: Nocturnal, peaceful, opportunistic

• Difficulty: Easy–moderate

• Reef safety: With caution

Care

• Water: 24–26 °C, salinity 1.025, pH 8.0–8.4, dKH 7–10, NO3 2–15 ppm, PO4 0.02–0.1 ppm.

• Provide rockwork and hiding spots. Normal to “decorate” itself with algae or sponge pieces.

• Needs stable parameters for molting. Regular water changes supply trace elements; separate iodine dosing is usually unnecessary.

Feeding

• Omnivore. Offer 3–5×/week: nori/macroalgae, mysis, finely chopped seafood, quality algae/reef pellets.

• Adequate feeding reduces coral nipping.

Compatibility

• Good in mixed reef tanks with robust corals.

• Avoid tiny ornamental shrimp and very delicate polyps.

• Do not house with predatory fishes that eat crustaceans.