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Horseshoe Crab

The horseshoe crab (Limulus polyphemus), is often referred to as a living fossil. This marine animal 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. 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. 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.

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

Horseshoe crab blood is blue, caused by the presence of hemocyanin (Remember human blood is red because of the presence of hemoglobin). An extract of horsehoe crab blood has unique bacteria fighting abilities and it is used by the pharmaceutical and biomedical industries for important medical research and testing.

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. Spawning tends to peak at night around the new and full moons. Horseshoe crabs eggs are an essential food source for many migrating shorebirds, including red knots, semipalmated sandpipers, sanderlings and dowithers. American eel, killifish, weakfish, silversides, summer flounder and winter flounder also eat horseshoe crab eggs and larvae. Horseshoe crabs are a very important component of the coastal ecosystem.

While many people do not eat horseshoe crabs, they are used as bait, or taken for use in pharmaceutical and biomedical research. Before harvesting horseshoe crabs, be sure to contact the DEC Bureau of Marine Resources 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.