Where can you spot them? Populations of land hermit crabs are drastically reduced, but some specimens still exist in Hungry Bay nature reserve. They are a terrestrial crab, favouring mangrove habitats and sandy shorelines.
- Hermit crabs do not produce their own shell, so the invertebrates use discarded shells from other species in order to house their vulnerable bodies.
- The hermit crab can retreat completely into the shell when threatened, and has adapted a hook-shaped tail and strong forelegs to hold the shell securely on its back.
- Once a year, hermit crabs gather to spawn and to exchange shells, with the crabs lining up in height order, and with one crab climbing into the next largest shell, leaving their old shell empty for the crab next to them, and so on. Watch a BBC video of the curious behaviour here.
- Hermit crabs can grow up to four inches long, but appear larger because of their hefty shells.
- The West Indian Top Shell was the only animal producing a shell large enough to be suitable for adult hermit crabs. When populations of the marine snails were decimated by early settlers, the hermit crab population declined dramatically too. Hermit crabs were forced to use fossilized top shells, or human garbage for their homes.
- The female hermit crab reproduces once a year, releasing her eggs just before the full moon into the sea. The eggs hatch immediately and drift on the tides before returning to shore as crablets.
- Hermit crabs are scavengers, eating carrion like dead fish or rotting animals. They provide an important role in the ecosystem by cleaning up and recycling nutrients.
- Hermit crabs breathe through gills, and must keep them wet by storing water inside their shells. The biggest threat to hermit crabs today is human curiosity. When humans bring the crabs home, they don’t know how to care for them, resulting in the crab’s death.
**Featured image copyright Alison Copeland and Bermuda Department of Environment and Natural Resources
