Crustaceans
Hermit crab
Coenobita sp.
Harmless🌊 0–10 m📏 up to 10 cm⏳ up to 30 yearsIUCN status: Not evaluated
Epipelagic zone
Unable to build its own shell, it spends its life squatting in abandoned ones, trading up for a bigger one as it grows — sometimes in genuine collective exchange chains.
🗺️ Geographic range
Tropical coastal and intertidal zones worldwide.
📊 Population
No global population estimate available; common on tropical coastlines, not evaluated by the IUCN.
Habitat
- Pacific Ocean · Coral reef · Epipelagic zone · Permanent
🥚 Reproduction
Females release their larvae into the ocean despite a sometimes terrestrial lifestyle.
Behaviour
- Diet
- Algae, decomposing organic matter, small invertebrates.
- Hunting
- More an opportunistic scavenger than an active hunter.
- Communication
- Tactile and chemical signals, notably during shell exchanges.
- Social life
- Can form organised queues to exchange shells of increasing size.
Physiology
- Anatomy
- A soft, spiralled, unprotected abdomen, adapted to fit inside a gastropod shell.
- Respiration
- Modified gills; some species can breathe out of water.
- Vision
- Good eyesight, with stalked eyes.
- Adaptations
- Regularly changes shells to accommodate its growth, carefully choosing the best size available.
🔗 Web of marine life
⚡ Its extraordinary abilities
- Can organise a shell-exchange chain among several individuals of different sizes
- Some species live almost entirely on land while still depending on the ocean to reproduce
If you cross paths with this animal…
Risk: None.
Behaviour: Timid, retracts instantly into its shell at the slightest danger.
Advice: Never forcibly remove a hermit crab from its shell.
💡 Did you know?
- Can form an orderly queue by size to swap shells among several individuals.
- Some land-dwelling species can live for several decades.
🧭 Continue exploring
Same ecosystem
Same ecosystem
Same ecosystem
Same ecosystem
Same ecosystem
Same ecosystem
