Horseshoe Crab

Care Summary

Horseshoe Crabs are living fossils that have been around for over 400 million years, but their age does not make them easy to keep, as most aquacultured specimens sold in the trade are juveniles that will eventually outgrow any home aquarium. They need a large tank with a deep, fine sand bed to plow through in search of worms, mollusks, and organic detritus, and they do best in FOWLR or species tanks rather than reef setups where they can bulldoze corals and upset rockwork. The most common cause of death in captivity is starvation due to insufficient natural prey in the substrate, so target-feed with live blackworms, small clams, and meaty sinking foods regularly. Be prepared for the long term commitment, as horseshoe crabs can live for decades if their needs are met, so only purchase one if you have the tank size and food supply to support it for years to come.