Horseshoe Crab (Adult)
An illustration of an adult horseshoe crab from the dorsal aspect. The horseshoe crab or Atlantic horseshoe crab (Limulus polyphemus) is a marine chelicerate arthropod. Despite its name, it is more closely related to spiders, ticks, and scorpions than to crabs. Horseshoe crabs are most commonly found in the Gulf of Mexico and along the northern Atlantic coast of North America. A main area of annual migration is the Delaware Bay, although stray individuals are occasionally found in Europe.