Fred Bavendam / Laughing Gull (Leucophaeus atricilla) group waiting right near the water's edge for the spawning Horseshoe Crabs (Limulus polyphemus), Cape May, New Jersey

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) pair overturned by the waves and will die in the sun, New Jersey

Fred Bavendam / Pattern of a wave written on the beach in Horseshoe Crab (Limulus polyphemus) eggs that have been uncovered by the diggings of others, New Jersey

Fred Bavendam / Migratory shorebirds stop at Delaware Bay to feed on Horseshoe Crab (Limulus polyphemus) eggs while flying from South America to their arctic nesting grounds, New Jersey

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) makes a loop in the sand while crawling back to the water after spawning, Cape May, New Jersey

Fred Bavendam / Horseshoe Crab (Mesolimulus walchi) fossil placed next to modern Horseshoe crab (Limulus polyphemus), species is 180 million year old, Bavaria, Germany

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) spawning and hungry shorebirds feeding on their eggs, New Jersey

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) group crawling ashore on the high tides of spring to lay their eggs in Delaware Bay's sandy beaches, New Jersey

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) group crawling ashore on the high tides of spring to lay their eggs in Delaware Bay's sandy beaches, New Jersey

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) group crawling ashore on the high tides of spring to lay their eggs in Delaware Bay's sandy beaches, New Jersey

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) freshly laid eggs uncovered by the digging of another female laying her eggs, Cape Anne, Massachusetts

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) male clinging to the telson of a larger female, photographed by diver, Cape Anne, Massachusetts

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) male clinging to the telson of a larger female, he will try to hold on until she goes ashore to lay her eggs, Cape Anne, Massachusetts

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) male clinging to the telson of a larger female, he will try to hold on until she goes ashore to lay her eggs, Cape Anne, Massachusetts

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) crawling across a sandy sea floor littered with many Sand Dollars (Echinarachnius parma), Cape Anne, Massachusetts

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) crawling across a sandy sea floor littered with many Sand Dollars (Echinarachnius parma), Cape Anne, Massachusetts

Doug Wechsler / Sand with Horseshoe crab eggs {Limulus polyphemus} NJ Delaware Bay USA

Jeff Rotman / Scientist bleeds Horseshoe crabs to extract blue, copper based blood, lysate used to test

Doug Wechsler / Tiny juvenile Horseshoe crabs {Limulus polyphemus} from Barnagat Bay USA

Mike Potts / Horseshoe crabs spawning on beach {Limulus polyphemus} Delaware bay, USA

Doug Wechsler / Horseshoe crabs (Limulus polyphemus) spawn on beach. Delaware Bay, New Jersey USA

Doug Wechsler / Male Horseshoe crabs mating with female. (L. polyphemus) NJ, USA. Limulus

Nigel Marven / Horseshoe (King) Crabs spawning in sand, Delaware Bay New Jersey, USA

Nigel Marven / Horseshoe (King) crabs laying eggs in sand. Delaware Bay New Jersey, USA. Happens at full moon

Doug Wechsler / Horseshoe (King) Crab goes back to sea, Delaware Bay New Jersey, USA. The tracks are being made through sand laden with horseshoe crab eggs.

Doug Wechsler / Horseshoe (King) Crabs on beach to lay eggs, Delaware Bay New Jersey, USA

Piotr Naskrecki / Horseshoe Crab (Limulus polyphemus) group crawling ashore during high tide to lay their eggs, Primehook Beach, Delaware

Piotr Naskrecki / Horseshoe Crab (Limulus polyphemus) pair returning to the ocean, Delaware

Piotr Naskrecki / Horseshoe Crab (Limulus polyphemus) group crawling ashore during high tide to lay their eggs, New Jersey

Piotr Naskrecki / Horseshoe Crab (Limulus polyphemus) group returning to the ocean after a night of spawning, Delaware

Piotr Naskrecki / Horseshoe Crab (Limulus polyphemus) eggs on beach, Delaware

Piotr Naskrecki / Horseshoe Crab (Limulus polyphemus) during high tide, New Jersey

Piotr Naskrecki / Horseshoe Crab (Limulus polyphemus) group crawling ashore during high tide to lay their eggs, New Jersey

Piotr Naskrecki / Horseshoe Crab (Limulus polyphemus) stranded upside-down on the beach trying to flip itself, Delaware

Doug Wechsler / Semipalmated sandpipers (Calidris pusilla) feed on horseshoe crab eggs (Limulus polyphemus) with other wading birds. Delaware Bay, NJ, USA. May

Doug Wechsler / Hand holding Horseshoe crab eggs (Limulus polyphemus) at spawning beach. Delaware Bay, NJ, USA. May

Angelo Giampiccolo / Horseshoe crab (Limulus sp) moving on sandy beach, Long Island, New York, USA.

Piotr Naskrecki / Horseshoe Crab (Limulus polyphemus) egg with a fully developed embryo inside, Slaughter Beach, Delaware

Fred Bavendam / Laughing Gull (Leucophaeus atricilla) group waiting near the water's edge for the spawning Horseshoe Crabs (Limulus polyphemus, Cape May, New Jersey

Doug Wechsler / Horseshoe crabs (Limulus polyphemus) spawning, and Turnstones on beach. NJ, USA

Doug Wechsler / Horseshoe crab crossing sand {Limulus polyphemus} Delaware Bay, New Jersey, USA

Doug Wechsler / Horseshoe / King crabs on shore {Limulus polyphemus} mass spawning New York, USA

Doug Wechsler / Tracks of coupled pair of Horseshoe crabs {Limulus polyphemus} New jersey USA

Juergen Freund / Naturalists examine underside of horseshoe crab {Limulus polyphemus} Florida USA

Juergen Freund / Naturalist examines underside of horseshoe crab {Limulus polyphemus) Florida USA

Nigel Marven / Horseshoe / King crabs spawning at full moon {Limulus polyphemus) New Jersey USA

Mike Potts / Horseshoe crabs massing to spawn {Limulus polyphemus} Delaware Bay USA May 1997

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) with American Slipper Limpet (Crepidula fornicata) clinging to its shell, Cape May, New Jersey

Fred Bavendam / Pattern of a wave written on the beach in Horseshoe Crab (Limulus polyphemus) eggs that have been uncovered by the diggings of others, New Jersey

Fred Bavendam / Photographer and migratory shorebirds which have stopped to feed on Horseshoe Crab (Limulus polyphemus) eggs while flying from South America to their arctic nesting grounds, New Jersey