Hermit Crab

Overview

Hermit Crabs are a frequently mis-housed pet - small crustaceans sold cheaply at beach souvenir shops without adequate care information. With proper care (large humid enclosure, group housing, shell collection) hermit crabs can live 10-30+ years. With typical pet-shop housing they usually die within months.

Natural History

Land hermit crabs (Coenobita species) live in coastal tropical regions worldwide. Most pet hermit crabs are wild-caught; captive breeding is rare and difficult.

Common pet species:

• Caribbean Hermit Crab (Coenobita clypeatus) - most common.
• Ecuadorian Hermit Crab (Coenobita compressus).

Appearance

Body 5-15 cm. Tucked into a borrowed snail shell - the crab grows and must move into progressively larger shells throughout life.

Temperament & Handling

Hermit crabs are social and active when properly housed. They are not handling pets - too much handling causes stress and shell drops. Pinches from large hermit crabs can be painful.

Enclosure (Crabitat)

The single biggest factor in hermit crab welfare:

Minimum: 75 L (20 gallon) for a colony of 3-5 small crabs. Larger preferred. Glass tank with secure lid.

Provide:

• 6+ inch (15+ cm) deep substrate - sand and coco fibre mix that holds tunnels (essential for moulting; hermit crabs bury for weeks).
• Two water dishes - fresh and saltwater (use marine salt, not table salt).
• Climbing structures.
• At least 5 spare shells per crab in graduated sizes.
• Hide caves.

Heating, Humidity, Lighting

• Temperature: 22-28°C.
• Humidity: 70-80% - essential. Crabs cannot breathe in dry air. Daily misting and proper substrate help.

Diet

Omnivore: commercial hermit crab food (no preservatives), fresh fruit and vegetables, raw fish and meat occasionally, calcium source (cuttlebone). Variety important.

Health & Lifespan

10-30+ years with proper care. Typical pet-shop crabs die within 1-6 months from inadequate housing.

Common concerns:

• PPS (post-purchase syndrome) - stress from wild-caught + retail conditions; many die soon after purchase.
• Moulting failure - from inadequate substrate or humidity.
• Shell evictions in stressed colonies.
• Mites.

Pros & Cons

Pros: long-lived (with proper care), social, fascinating moulting and shell-changing behaviour, low daily maintenance once set up. Cons: widely mis-housed, sold under false "easy pet" marketing, wild-caught populations declining, not for handling.