Horseshoe Crab

Horseshoe Crab

Scientific Name: Limulus polyphemus

Small Fish Safe: Yes

Invert Safe: No – will consume small inverts while foraging

Coral Safe: Yes – does not eat corals, but may disturb frags

Adult Size: Up to 60 cm (typically much smaller in captivity)

Diet: Carnivore – scavenges worms, detritus, and buried invertebrates

Why We Like It:

An ancient and alien-looking oddball, the Horseshoe Crab is a burrowing scavenger that constantly sifts through sand for food. While reef-safe in diet, it grows large and needs a deep, open sand bed to survive long-term. Often short-lived in home aquariums due to starvation or space constraints, it's best suited to large, mature systems with soft substrate and minimal competition. A fascinating talking point with serious care requirements.