Horseshoe crabs, those mysterious ancient mariners, lured me into the sea as a child along the beaches of New Jersey. Drawn to their shiny domed shells and spiked tails, I could not resist picking them up, turning them over and watching the wondrous mechanical movement of their glistening legs, articulating with one another as smoothly as the inner working of a clock. What was it like to be a horseshoe crab, I wondered? What did they eat? Did they always move around together? Why were some so large and others much smaller? How old were they, anyway? What must it feel like to live underwater?...

Horseshoe crabs are "living fossils" that face growing threats. This book consists of papers presented at the 2007 International Symposium on the Science and Conservation of Horseshoe Crabs. It formulates plans for an international conservation program.