Horseshoe SM

Horseshoe Crab — Limulus polyphemus

The Limulus polyphemus Horseshoe Crab is a hardy, prehistoric-looking invertebrate with a rounded, dome-shaped carapace, long spiked tail (telson), and jointed legs beneath. It is a peaceful scavenger that spends most of its time sifting through sandy substrate for detritus and small invertebrates, contributing to natural substrate maintenance. Its calm, slow-moving behavior and unique appearance make it a fascinating centerpiece for marine aquariums with suitable conditions.

Horseshoe Crabs thrive in established reef or marine tanks with stable water parameters, deep sandbeds, and moderate flow. Introduce them only once the system is mature to reduce stress and ensure proper foraging. A minimum tank size of 75 gallons is recommended to provide ample substrate for movement and burrowing.

Their diet can be supplemented with finely chopped or pellet foods from San Francisco Bay Brand, Hikari, PE, TDO, and New Life Spectrum, alongside natural detritus and microfauna consumption. Target feeding helps ensure proper nutrition and supports overall health.

Approximate product size: 6"–9" (varies by availability)