Natural History of Horseshoe Crabs
Around the new and full moons of May and June, keep an eye on the bay shoreline for some of the coolest creatures on Fire Island. Horseshoe crabs are marine invertebrates with large, horseshoe-shaped shells and a long, pointed tail, or “telson.” Fossils of horseshoe crab ancestors predate dinosaurs so these fascinating creatures are sometimes referred to as, “living fossils.”
Horseshoe Crab Ecology
Horseshoe crabs play an important role in the safety of many medicines used by people. Horseshoe crab blood cells (amoebocytes) attach to dangerous toxins produced by some types of bacteria (gram negative). When a crab is injured, the amoebocytes move to the wound and form a gel that surrounds and destroys the bacteria thus preventing an infection.
Native Americans used and taught early settlers to use the horseshoe crab as a fertilizer for crops. Native Americans also ate horseshoe crab meat, used the shell to bail water, and used the tail as a spear tip. In the United States, horseshoe crabs continued to be used as fertilizer through the 1960s.
Last updated: May 31, 2018