When mating, the smaller male crab hooks himself to the top of the larger female’s shell by using his specialized front claws, and together they crawl to the beach. Horseshoe crabs are an important part of the ecology of coastal communities. Despite existing for hundreds of millions of years, horseshoe crabs are nearly identical to their ancient relatives. Are there any other interesting facts that you would like to share about Atlantic horseshoe crabs? These shorebirds have evolved to time their migrations to coincide with peak horseshoe crab spawning activity, especially in the Delaware and Chesapeake Bay areas. Horseshoe crabs do not bite or sting. The horseshoe crab is a merostomata because its legs surround the mouth. Copyright 1999 - 2020 State of Florida. Because they have no mandibles or teeth, they crush hard food between their legs before passing it to their mouth. No! Their tail also has the ability to detect light. Two eyes are on the side of their head, five are on top of … Threats to horseshoe crabs and research effortsHorseshoe crab numbers are declining throughout much of their range. Change ), Enter your email address if you want to learn more about animals, 5 Interesting Facts About Australasian Gannets, 5 Interesting Facts About Short-Beaked Echidnas, 5 Interesting Facts About Anatolian Newts, 5 Interesting Facts About Sydney Funnel-Web Spiders, 5 Interesting Facts About Luzon Bleeding-Hearts, 5 Interesting Facts About Dwarf Sperm Whales, 5 Interesting Facts About Egyptian Spiny-Tailed Lizards, 5 Interesting Facts About Golden Parakeets. In 1998, The Atlantic States Marine Fisheries Commission developed a Horseshoe Crab Fishery Management Plan that requires all Atlantic coastal states to identify horseshoe crab nesting beaches. The largest concentration of breeding horseshoe crabs anywhere in the world can be found around the Bay each spring. Read on to learn more about this valuable creature. Why do I see so many dead horseshoe crabs on the beach? Did you know that in late spring and early summer, you may spot two or more horseshoe crabs hooked together. Some males (called satellite males) do not attach to females but still have success in fertilizing the female's eggs by hanging around the attached pair. Expand/Collapse What do horseshoe crabs eat? This is an Atlantic horseshoe crab scuttling along the bottom of the ocean. Class: Merostomata. The crabs are especially sensitive to light. This species is found in the Gulf of Mexico and along the Atlantic coast of North America. This compound coagulates or clumps up in the presence of small amounts of bacterial toxins and is used to test for sterility of medical equipment and virtually all injectable drugs. Some people think horseshoe crabs are dangerous animals because they have sharp tails, but they are totally harmless. Subclass: Xiphosura. Protecting these amazing creatures would also help to save species that eat their eggs. They have been harvested in their millions over the years and may be threatened if they aren’t protected. The females come to the beach to lay their eggs. Like spiders, they have a pair of chelicerae (small appendages for moving food into the mouth). There are four species of horseshoe crabs still around today. The oldest known horseshoe crab … The horseshoe crab has a sword tail which the Xiphos- Greek prefix means sword. Despite their name, horseshoe crabs are more closely related to spiders, ticks, and scorpions than to crabs. Anyone who has had an injection, vaccination, or surgery has benefited from horseshoe crabs! Today I want to write about one of the strangest animals in the world, the Atlantic horseshoe crab. Other observers have mistaken horseshoe crab molts for dead crabs. The Bay is particularly ideal because of its relatively shallow depth, allowing the water to warm quickly after winter … These amazing animals aren’t actually crabs, but are more closely related to arachnids. Horseshoe crabs can nest year-round in Florida, with peak spawning occurring in the spring and fall. The Atlantic horseshoe crab (Limulus polyphemus), also known as the American horseshoe crab, is a species of marine and brackish chelicerate arthropod. Horseshoe crabs are also used in several fisheries. If you see horseshoe crabs mating and would like to report a sighting, please visit the Report Sightings page for more information. Despite their common name, horseshoe crabs are more closely related to spiders and scorpions than to “true crabs,” which are crustaceans. Their eggs are the major food source for shorebirds migrating north, including the federally-threatened red knot. Juvenile horseshoe crabs look a lot like adults except that their tails are smaller. ( Log Out /  They can be found all along the Atlantic Coast from Nova Scotia, Canada down to the Yucatan Peninsula in Mexico, but the majority live in Delaware Bay. Change ), You are commenting using your Facebook account. Really, horseshoe crabs are just clumsy and they use their tail to flip themselves back over if they get overturned by a wave.*. They can grow up to 60 cm long including their tail. ( Log Out /  No, horseshoe crabs are in a class by themselves; they are more closely related to spiders, scorpions, and ticks. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. Change ), You are commenting using your Twitter account. Female horseshoe crabs grow to around 2 feet long, while males are about 30% smaller. Florida Fish and Wildlife Conservation Commission • Farris Bryant Building The other three horseshoe crab species are found in Asia. ( Log Out /  They are different from true crabs because they have no antennae and no mandibles (mouth parts for grinding food). Most nesting activity takes place during high tides around the time of a new or full moon. Despite the ferocious look of the tail, it is not used as a weapon. They have 10 eyes, a pair of compound eyes on the prosoma, and "photo receptors" in other areas, primarily along the tail. Atlantic horseshoe crabs live in the Gulf of Mexico and along the northern Atlantic coast of North America. Learn more about Atlantic horseshoe crabs! Though the horseshoe crab's shell is hard, it is very sensitive to the world around it. Horseshoe crab larvae emerge from their nests several weeks after the eggs are laid. Florida Youth Conservation Centers Network. No, horseshoe crabs are in a class by themselves; they are more closely related to spiders, scorpions, and ticks. Two eyes are on the side of their head, five are on top of their shell and two are underneath. Expand/Collapse Why do I see so many dead horseshoe crabs on the beach? They do have spines along the edge of their carapace, so if you must handle them, be careful and pick them up by the sides of the shell, not the tail. Here are five interesting facts about them: I hope that you found these facts interesting and learned something new. Atlantic horseshoe crabs have nine eyes. The American horseshoe crab is a common sight on Florida's beaches. There are four species of horseshoe crab still alive, but only one (the Atlantic horseshoe crab) lives in the Western Hemisphere. 620 S. Meridian St. • Tallahassee, FL • (850) 488-4676 Unlike true crabs, which back out of their old exoskeletons, horseshoe crabs push forward, leaving their molts behind them, leaving a split in the front. Many fish species as well as birds feed on horseshoe crab eggs in Florida. They feed on small clams, crustaceans, and worms; however, they will also eat other animals and even algae. A horseshoe crab is part of the cheilcerata because it lacks jaws. Change ), You are commenting using your Google account. Horseshoe crabs are “living fossils” meaning they have existed nearly unchanged for at least 445 million years, well before even dinosaurs existed.