Giant Hermit Crab

The Giant Hermit Crab (Petrochirus diogenes) is an impressive and highly effective member of any reef cleanup crew, known for its large size and voracious appetite for detritus, algae, and uneaten food.

Care Level & Requirements

• Care Level: Easy
• Temperament: Peaceful
• Minimum Tank Size: 30+ gallons
• Diet: Omnivore - scavenger
• Reef Safe: Yes

What to Expect

Living up to its name, the Giant Hermit Crab can grow significantly larger than standard hermit crabs, making it one of the most efficient cleanup crew members available. This hardy scavenger will patrol your sandbed and rockwork, consuming leftover food, detritus, hair algae, and cyanobacteria while leaving corals and other invertebrates undisturbed.

Behavior & Compatibility

Giant Hermit Crabs are generally peaceful and reef-safe, though they may occasionally show aggression toward other hermit crabs when competing for shells. They are active day and night, constantly foraging throughout the aquarium. Unlike some smaller hermit species, they are less likely to bother snails for their shells due to size differences.

Shell Availability

Important: Provide a variety of empty shells slightly larger than their current shell to prevent aggression and allow for healthy growth. As they grow, they will need to move into progressively larger shells.

Feeding

While excellent scavengers, supplement their diet in well-maintained aquariums with sinking pellets, algae wafers, or small pieces of meaty foods to ensure proper nutrition.

Acclimation

Use a slow drip acclimation method over 30-45 minutes to help your Giant Hermit Crab adjust to your aquarium's water parameters. Hermit crabs are sensitive to rapid changes in salinity and pH.

Our Live Arrival Guarantee

Every Giant Hermit Crab ships with our live arrival guarantee, carefully packed to ensure it arrives healthy and ready to work in your reef system.