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Horseshoe Crab

A Prehistoric Creature!

A photo of a small horseshoe crab
Although sharp, the tail of the horseshoe crab
is not poisonous

Interesting Facts

  • The horseshoe crab (Limulus polyphemus) is often referred to as a living fossil, and is thought to have evolved more than 200 million years ago!
  • Although the word "crab" is part of its name, the horseshoe crab is more closely related to spiders and scorpions than to true crabs.
  • Their blood is blue (caused by the presence of hemocyanin - human blood is red because of the presence of hemoglobin), and it has unique bacteria fighting ability which is used by pharmaceutical and biomedical industries for important medical research and testing.
  • Horseshoe crabs feed on a variety of marine worms, mollusks, and other small marine animals.
  • These prehistoric creatures can grow to about 20 inches (51cm) in width, that's almost 2 feet wide!
  • Their eggs are an essential food source for many migrating shorebirds, including red knots, semipalmated sandpipers, sanderlings and dowithers, and their eggs and larvae are consumed by many fish such as American eel, killifish, weakfish, silversides, summer flounder and winter flounder.

Where Are They Found?

Horseshoe crabs are found from Nova Scotia in Canada to the Yucatan Peninsula in Mexico. In New York they are found year-round in Long Island Sound, Great South Bay, and in other areas along the coast of New York.

When Can They be Spotted?

In the spring horseshoe crabs come to the shore to spawn. Thousands can be seen along the shorelines of Long Island making the shore quite a sight to see. The spawning season is usually in May and June, and tends to peak at night around the new and full moons.

Volunteer for Horseshoe Crab Research

Come out and help us track spawning horseshoe crabs! The horseshoe crab spawning survey is conducted annually during the spawning season (May-June) to monitor the relative abundance of horseshoe crabs in New York's coastal waters. NYSDEC and Cornell University Cooperative Extension's Marine Program work together to develop and organize this project, which helps in the management and conservation of this significant species. For more information on the survey and to find out how you can become a volunteer, visit (a direct link to this website can be found in the right hand column under Links Leaving DEC's Website).

Harvest Information

Horseshoe crabs are used as bait in fisheries, but are not typically eaten for a meal. Before harvesting horseshoe crabs be sure to contact the DEC Division of Marine Resources (contact information can be found in the right hand column) for current information on open seasons, permits and harvest regulations. Details of the regulations can be found in 6 NYCRR Part 44. A recreational limit of 5 horseshoe crabs per day may be taken but the crabs may not be offered for sale and must be for the harvester's own personal use.