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Marine Animal Encyclopedia

Reef Hermit Crab Dardanus megistos

Like other hermit crabs, the reef hermit crab uses a “borrowed” shell to protect its hindquarters, being unable to make its own carapace. When it grows too big for its current shell, it simply looks for an unused larger one. It is while switching from one shell to the next that the reef hermit crab is most vulnerable, as it risks exposing its soft, rather asymmetrical abdomen to predators. There are about 500 species of hermit crabs worldwide—the reef hermit crab lives in shallow-water tropical reef habitats, but some species live on land. The reef hermit crab is a scavenger rather than a hunter, and drags itself over the seafloor looking for bits of animal matter and algae, tearing apart any carcasses that it finds with its dextrous mouthparts. It may attach stinging anemones to its shell as protection from predators.

Reef Hermit Crabzoom image
  • Subphylum Crustacea
  • Width_leg_span Up to 12 in (30 cm)
  • Habitat Near-shore tropical reefs
  • Distribution Indian and Pacific oceans
Reef Hermit Crab habitat mapzoom image