The Delaware Bay horseshoe crab is a marine arthropod found along the Atlantic coast of North America, particularly in the Delaware Bay area. This species is known for its distinctive hard shell and long, spiked tail, which is not a stinger but helps with movement and balance. Horseshoe crabs are ancient creatures, having existed for over 450 million years, and play a crucial role in the coastal ecosystem. These crabs are most famous for their spawning behavior, which occurs during the full moon in spring. During this time, they come ashore in large numbers to lay eggs, providing a vital food source for migratory birds. The blood of horseshoe crabs is also valuable in the medical field for testing the sterility of vaccines and medical equipment.