The Horseshoe Crab (Limulus polyphemus) is a striking marine species known for its distinctive appearance and dynamic presence in marine aquariums.

Distribution and Habitat

Found along the Atlantic coast of North America from Maine to the Yucatan Peninsula on sandy and muddy bottoms.

Physical Description

Not a true crab but a marine arthropod related to spiders, has a horseshoe-shaped carapace and a long tail spine, can reach 60 cm.

Diet and Feeding

Carnivorous, feeds on mollusks, worms and small invertebrates on the seafloor.

Behavior and Reproduction

Ancient species that has existed for over 450 million years, burrows in sand, migrates to beaches to spawn.

Aquarium Care

Requires 180+ gallons with deep sand bed, not reef-safe, needs cool water, not recommended for most home aquariums.

Conservation Status

Classified as Vulnerable by the IUCN Red List.