Horseshoe crab; photo by Amanda on Flickr (use permitted with attribution).
Official State Marine Animal of Delaware
The horseshoe crab (Limulus polyphemus) was designated as the official state marine animal of Delaware June 25, 2002 (Delaware also recognizes another marine-life symbol; a state shell). All State Fish & Aquatic Life
Horseshoe Crab Facts
Delaware Bay is the world's largest spawning ground for horseshoe crabs. Considered living fossils, these ancient creatures predate most species on the planet, including flying insects and dinosaurs.
Horseshoe crabs are an essential food source for migratory birds on the East coast and are also important to humankind - they are used in vision studies (their 10 eyes have a structure similar to the human eye); their blood protects them from infection and a compound it contains is used to detect bacterial poisons in some human medications; and a natural polymer found in the horseshoe crab’s shell (chitin) is used to make bandages.