Blue Leg Hermit Crab.

About the Blue Leg Hermit Crab

The Blue Leg Hermit Crab (Clibanarius tricolor) is a marine invertebrate that occupies a defined ecological niche in a healthy aquarium. Inverts often carry more importance than their size suggests - cleanup crew species control algae and detritus, ornamental species add motion and color, and breeding species (especially shrimp) form the basis of self-sustaining secondary populations.

Marine inverts come into the trade through both wild collection (from Hawaii, Caribbean, and Indo-Pacific reefs) and an expanding aquaculture sector. Aquacultured specimens have lower mortality during shipping and acclimation, especially for sensitive species like Lysmata shrimp and starfish. Wild-caught inverts are generally inexpensive but more likely to arrive with parasites, missing limbs, or in starvation states from extended holding.

Tank requirements

The Blue Leg Hermit Crab requires a minimum tank size of 10 gallons for long-term keeping. Marine inverts demand stable specific gravity (1.024-1.026), tropical reef temperatures (76-80°F), and zero ammonia / nitrite at all times. Many inverts are extremely sensitive to copper - if the system has ever been treated with copper-based medications, copper will leach from the rockwork for years and kill any invert added to that system.

A mature tank with established live rock, sand bed, and microfauna is non-negotiable for sensitive inverts. Add inverts to the system 6-8 weeks AFTER the cycle has completed, and only after fish (which are typically more parasite-prone than inverts) have been quarantined and proven disease-free.

Diet and feeding

Marine inverts have varied diets. Cleaner shrimp (Lysmata amboinensis) eat parasites off fish and accept frozen mysis, brine, and pellet food. Hermit crabs scavenge - dropped food, algae, and detritus. Most snails graze film algae and detritus and need no supplemental feeding in a mature reef. Sand-sifting starfish (Archaster typicus) consume detritus and microfauna in the sand bed but starve in tanks under 100 gallons; consider tank size carefully before adding one.

Breeding and propagation

Marine invert breeding is genus-specific. Cleaner shrimp (Lysmata) hermaphroditic; pairs spawn regularly but larvae are difficult to raise (require dedicated culture). Peppermint shrimp (Lysmata wurdemanni) breed readily and are easier to raise. Most snails breed in display tanks but populations remain stable due to natural predation. Starfish (Asterina) often plague-breed and require manual removal.

Compatibility

Most marine ornamental fish will hunt and eat inverts. Wrasses, hawkfish, dottybacks, and triggers are major threats to small shrimp and crabs. Sand-sifting gobies prey on copepods. Coral-eating snails (heliacus) damage zoanthids. Add inverts BEFORE adding fish to give them territory and confidence; once predatory fish are in the system, new invert additions are usually quickly eaten.

Where to buy a Blue Leg Hermit Crab

Fast Aquatics connects you to vetted vendors of the Blue Leg Hermit Crab across all 50 US states. Every listing on Fast Aquatics ships overnight via FedEx Priority Overnight or UPS Next Day Air. Climate-aware shipping holds the order if forecasted temperatures at your ZIP exceed safe thresholds. The 4-hour DOA window starts at carrier-reported delivery, with photo-evidence-based claim filing and Fast Aquatics mediation when needed. An optional Tiered Living Guarantee (1mo / 3mo / 6mo / 12mo) extends coverage well beyond the standard arrival-state protection.

Frequently asked questions