Horseshoe crabs, common along the Delaware coast, have evolved
little in the last 250 million years. Still, they have survived
because of their hard, curved shells, which have made it
difficult for predators to overturn them and expose their soft,
vulnerable underbellies. The horseshoe crab has also survived
because it can go a year without eating and endure extreme
temperatures and salinity. The Delaware Bay region is home to
the largest population of the American horseshoe crab (Limulus
polyphemus), which is found along the western shores of the
Atlantic Ocean from Maine to the Yucatan. Another three species
live in the coastal waters from Japan to Indonesia. Once called
"Horsefoot Crabs" because of the resemblance of its shell to a
horse hoof, the Horseshoe Crab isn't really a crab. Related to
scorpions, ticks and land spiders, horseshoe crabs have their
own classification (Class Merostomata). Horseshoe Crab Mating
Ritual Each spring during the high tides of the new and full
moons, thousands of horseshoe c