Horseshoe Crab

Horseshoe Crab (Limulus polyphemus ) as seen in our Sea & Me exhibit.

These unusual-looking creatures have an ancient lineage. Fossils of prehistoric Horseshoe Crabs can be found dating back almost 500 million years – and the animal has changed relatively little during that vast time period. Despite their name, these are not true crabs as they have chelicerae (mouth parts that are more similar to that of spiders rather than mandibles like crabs.) Horseshoe crabs spend most of their lives living on the muddy sea bottom. From above, the hard, smooth carapace that covers their body may look like a rock to predators. Below this carapace, however, are five pairs of legs and a rigid tail that the animal uses to right itself if it is ever flipped onto its back.

Range & Habitat

Horseshoe Crabs can be found on muddy or sandy ocean bottom, migrating to shallow coastal waters or beaches when breeding. They have an extensive distribution from the Yucatan peninsula in Mexico to northern Maine.

Conservation Status

Common, but their numbers are in decline in the United States due to habitat destruction.