Horseshoe Crab

The Horseshoe Crab (Limulus polyphemus) is a peaceful species that is reef-safe with caution, admired for its unique prehistoric appearance, large, domed carapace, distinctive long tail spine (telson), and impressive size.

Males typically are smaller and often cling to females during mating, while females/juveniles are larger with a more rounded and broader carapace.

They reach about 12 to 15 inches in adult size and should be housed in aquariums of at least 75 gallons due to their size and need for movement.

Provide a deep sandbed for burrowing, ample open space for roaming, and some live rock for shelter. Maintain stable water parameters with salinity ~1.020-1.025, temperature ~72-79°F, and pH ~8.1-8.4. A secure lid is recommended as some crabs may attempt to escape.

Diet should consist of meaty foods such as brine shrimp, mysis shrimp, small mollusks, worms, and sinking pellets. With proper care, the Horseshoe Crab makes a fascinating and standout addition to a marine aquarium.

International Aquatics Quarantine & Guarantee: All fish are checked by marine vets, given a formalin bath, and held for 14 days in copper-treated systems. We feed Selcon-soaked food with Kanaplex and Metroplex during quarantine. Unless marked, all livestock comes with our 15-Day Guarantee. You will receive a video of your fish eating before shipment. On request, we also send photos/videos after arrival at IA. Some species are import-to-order (3-10 business days). Many common species are already cleared or near the end of QT.

Several species will be import-to-order and may take anywhere from 3-10 business days to secure. Once your fish is secured, you will be notified, and the quarantine process will then begin.