By laelaps on June 2, 2008. Part of the head-shield of a horseshoe crab (Limulus polyphemus). Fragments of the carapaces of horseshoe crabs littered the entire length of the beach. Photographed May 17, 2008 at Prime Hook National Wildlife Refuge, Delaware. Tags Inverts Photography More like this The Scoop on the Red Knot and Horseshoe Crab Red knot, Calidris canutus rufus. Delaware Horseshoe Crab Harvest Moratorium Reversedtags: horseshoe crab, Limutus polyphemus, re Off to Delaware Horseshoe crabsSuch fascinating creatures! If you have missed it so far, don't miss it now - the two-part series by Mark H on DailyKos: