Horseshoe Crab
                                   Charadrius melodus

Habitat:  Along the east coast of North America from Maine through south Florida and the Gulf of
               Mexico to the Yucatan Peninsula.

Domain:  Eukarya
Kingdom:  Animalia
Phylum:  Arthopoda
Class:  Merostaomata
Order:  Xiphosura
Family:  Limulidae
Genus:  Limulus
Species:  polyphemus

     The horseshoe crab's symmetry is bilateral.  It is round with a brownish green exoskeleton and spike-like tail.  A structural adaptation is it's compound eyes.  This helps the crab have a sense of direction in murky waters.  A behavioral adaptation is that it lays eggs on land.  This helps them to develop quicker and protects them from prey.  A functional adaptation is that when they are injured the granulocytes in their body will immediately seal off the injured area.  An interesting fact about the horseshoe crab is that it is actually not a crab and is more closely related to arachnids.  Their prey are worms and clams.  Their predators are the shorebirds that eat their eggs.  They are heterotrophic and ectothermic.