Horseshoe Crab
Limulus polyphemus

This juvenile Atlantic horseshoe crab is more closely related to spiders, ticks and scorpions than to the crabs with which they share the bay. This is truly a living fossil, evolving over 365 million years ago in the Devonion Period of the Paleozoic Era. It has a very unique body shape, unlike any other organism. Its fearsome-looking tail, called a telson, is used mainly as a lever to right itself in the event it is upset. The smaller male is identified by its "boxing glove" first appendage. It uses this to assist in the mating process. Every spring during the full moons of May and June, the phenomenal spawn takes place along the beaches of the Chesapeake and especially Delaware Bays. The secret to the species' survival is its ability to reproduce in excessive numbers. The deposited eggs not feasted on by bird or crab will emerge from the sands to continue the species. The horseshoe crab's blood is often harvested to perform testing on toxins in humans.