Prehistoric

It was high tide today when we had Dunkin' at the beach and so we sat at the water's edge.  We saw this dead Horseshoe crab in the shallow water.  We watched it and it didn't move and it was moved by the small waves coming ashore.  I just remember learning that these are prehistoric animals.  So I looked up what "prehistoric" means and it just means before written history.  So I came home and looked up Horseshoe crabs.  The modern Horseshoe crab made its appearance 250 million years ago!  At that time on Earth, all land masses were grouped together in one continent, and the dinosaurs were just beginning to roam the Earth!  The Horseshoe crabs pre-date the dinosaurs! Wow, THAT'S OLD!  Horseshoe crabs in the modern era are only found on the eastern coasts of North America and South Asia.  So we are lucky to have them here, to remind us of what amazing creatures they are.  Unfortunately, they are caught for their blood which has a chemical in it useful in detecting endotoxins in medical applications.  They are used as fishing bait in the United States, and eaten as a delicacy in some parts of Asia.  Their population is in decline due to coastal habitat destruction and over harvesting.

As humans, our blood is based on iron-based hemoglobin, but horseshoe crabs transport oxygen with a copper-based protein, giving its blood a bright blue color!  Horseshoe crabs are found on the ocean floor searching for worms and mollusks which are their main food and foraging usually occurs at night.  Their breeding season is Spring and Summer.  Nesting happens at high tide around New or Full Moon.  They spawn on beaches and salt marshes.  The female digs a hole in the sediment and lays between 2,000 and 30,000 large eggs.  I am completely blown away by this information!  I was unable to find out how long Horseshoe crabs live, unfortunately.