Spider Decorator Crab

Macroalgae Farms

Spider Decorator Crab

$39.99 $49.99
-20%

Key Features:
⭐ Active self-decorator that attaches sponges, algae, and rubble to its shell
• Long, spindly legs and slow, deliberate arachnid-like movement
• Hardy and beginner-friendly, adapts to most established reef systems
• Every specimen is visually unique because the costume is its own creation

Crab: Spider Decorator Crab
In stock

This product will be available for sale in 2 weeks, but you can pre-order now to receive 10% discount!

Estimated delivery between June 16 and June 18.

Spider Decorator Crab
$39.99 $49.99
$39.99 $49.99
Choose option
Crab: Spider Decorator Crab
  • Spider Decorator Crab
  • Blue Algae Decorator Crab
  • Red Algae Decorator Crab - Sold out
  • Green Algae Decorator Crab - Sold out
  • Soft Coral Decorator Crab

About this item

Spider Decorator Crab

The Spider Decorator Crab (Camposcia retusa) is one of the most charming and personality-driven invertebrates in the reef hobby. This crab actively decorates itself with whatever it can find in the aquarium — sponges, macroalgae, small bits of coral, even rubble — using tiny hooked hairs called setae to attach a custom camouflage costume directly to its shell. No two Decorator Crabs ever look the same, and the costume changes constantly as the crab swaps out pieces for new ones.

Beyond the novelty, the Spider Decorator Crab is a hardy, peaceful invertebrate that suits a wide range of reef and FOWLR systems. Its long, spindly legs and slow, deliberate movement give it a distinctly arachnid silhouette that adds an unexpected presence to live rock and sandbed alike. It is the kind of animal that turns a reef tank into a conversation piece, with hobbyists routinely spotting their crab and realizing it has redecorated itself overnight.

Available Options

Spider Decorator Crab

  • One healthy Spider Decorator Crab ready to begin decorating from day one
  • Active self-camouflaging behavior using whatever it finds in your tank
  • Generally reef-safe and well-suited to most established saltwater systems

Blue Algae Decorator Crab

  • Comes pre-decorated with vibrant blue macroalgae already attached — arrives as a living work of art
  • The blue algae decoration naturally pops under reef and actinic lighting, adding a splash of cool color to your display
  • Will continue to forage and redecorate over time, evolving its look as it explores your tank

Red Algae Decorator Crab

  • Comes pre-decorated with rich red macroalgae — a bold, warm-toned decoration that stands out against any rockscape
  • Red algae provides a striking contrast that makes this crab one of the most visually eye-catching invertebrates in the hobby
  • Will continue to redecorate naturally over time as it settles into your system

Green Algae Decorator Crab

  • Comes pre-decorated with lush green macroalgae — a natural, reef-blending look that makes it appear part of the aquascape itself
  • The green decoration creates a seamless camouflage effect that showcases exactly why this species is one of nature's most creative disguise artists
  • Will continue to add to and swap out its decoration as it explores your tank

Soft Coral Decorator Crab

  • Comes pre-decorated with soft coral fragments — the most visually stunning decorator variant available
  • Living soft coral pieces attached to its shell create a walking reef display that is genuinely unlike anything else in the hobby
  • A rare and collectible option for reef keepers who want a centerpiece invertebrate with maximum visual impact

Care Information

💡 Lighting
All lighting conditions		 🌊 Water Flow
Low to Moderate
📍 Placement
Rockwork and substrate — explores the entire system		 ⚙️ Care Level
Easy — beginner-friendly
🐠 Temperament
Peaceful — generally reef-safe with caution		 🍽️ Diet
Omnivore — algae, detritus, mysis, chopped seafood
🌡️ Temperature
72–78°F (22–26°C)		 🧂 Salinity
1.024–1.026 — drip acclimate carefully

Special Considerations

Spider Decorator Crabs are generally reef-safe but may occasionally clip small bits of soft coral, zoanthids, or mushrooms to use as camouflage. Most individuals favor sponges, macroalgae, and rubble over live coral, but behavior varies between specimens. Provide a varied diet of mysis, chopped seafood, and algae-based foods to discourage opportunistic clipping. Like all crabs, this species needs to molt as it grows — leave the empty exoskeleton in the tank for a few days afterward, as the crab may consume it for calcium. Cover powerhead intakes and ensure the tank is fully covered, as Decorator Crabs are surprisingly capable climbers. Drip acclimate slowly to match salinity precisely, and avoid copper-based medications.

🔍 Aquarium Insights

Spider Decorator Crabs are a hobby favorite for their behavior alone:

  • Active self-decorators that attach sponges, algae, and rubble to their shells using hooked setae
  • Hardy, long-lived invertebrates that adapt easily to most reef and FOWLR systems
  • One of the most personality-driven invertebrates in the saltwater hobby — every specimen is visually unique because the costume is its own creation

Learn More

For detailed species information, compatibility, and care tips, visit our Species Library.

Livestock Disclaimer

Due to natural variation, the Spider Decorator Crab you receive may vary in size, leg span, and base coloration. Each specimen develops its own unique camouflage costume based on what is available in your aquarium, so appearance will continue to change over time.

Photographs are representative examples. Decoration and visible coloration will differ between individuals and shift depending on tank inhabitants and available materials.

As with all live animals, proper acclimation and a suitable, established environment are essential for best results.

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