Atlantic Horseshoe Crabs, Limulus polyphemus
Port Mahon, DE
Horseshoe crabs are not really crabs, but instead are more closely related to the spiders. They are often referred to as "living fossils" because they have remained virtually unchanged for 500 million years. Horseshoe crabs live on the ocean bottom, where they feed on worms and molluscs. Each spring they migrate into shallow water to lay their eggs on the beach in the intertidal zone. Shown are several males swarming around a single, much larger female (she is only partly visible at the center of the four males).
(Class Merostomata, Family Limulidae)