Horseshoe crab

Horseshoe crabs are bled at a facility in Charleston, S.C., in June 2014. Ariane Müeller Horseshoe crabs used to be everywhere. Millions of years before dinosaurs roamed the planet, each spring, the hard-shelled creatures gathered to mate in massive mounds along the beaches of the Atlantic coast. Later, migratory shorebirds like the robin-sized red knot learned to fly up from South America to join them for a feast. The crabs’ eggs gave the birds the energy they needed to keep flying north to breed in the Arctic. But humans began to want something from the crabs, too – their blood. In the 1960s, scientists discovered that the sky blue blood inside horseshoe crabs would clot when it detected bacterial toxins. Vaccines, drugs and medical devices have to be sterile before they're put inside people. A better toxin detection system meant less contamination risk for patients, so fishermen soon started collecting and selling the prehistoric animals to be bled. A synthetic alternative was later invented and has since been approved in Europe as an equivalent to the ingredient that requires horseshoe crabs. But in the U.S., the blood harvest isn't shrinking. It's growing. Five companies along the East Coast, with operations in South Carolina, New Jersey, Massachusetts, Virginia, and Maryland, drained over 700,000 crabs in 2021. That's more than any year since officials started keeping track in 2004. Since then, the number of crabs bled by the industry has more than doubled. At least ...

Horseshoe crabs used to be everywhere. Millions of years before dinosaurs roamed the planet, each spring, the hard-shelled creatures gathered to mate in massive mounds along the beaches of the Atlantic coast. Later, migratory shorebirds like the robin-sized red knot learned to fly up from South America to join them for a feast. The crabs' eggs gave the birds the energy they needed to keep flying north to breed in the Arctic. But humans began to want something from the crabs, too – their blood. In the 1960s, scientists discovered that the sky blue blood inside horseshoe crabs would clot when it detected bacterial toxins. Vaccines, drugs and medical devices have to be sterile before they're put inside people. A better toxin detection system meant less contamination risk for patients, so fishermen soon started collecting and selling the prehistoric animals to be bled. A synthetic alternative was later invented and has since been approved in Europe as an equivalent to the ingredient that requires horseshoe crabs. But in the U.S., the blood harvest isn't shrinking. It's growing. Five companies along the East Coast, with operations in South Carolina, New Jersey, Massachusetts, Virginia, and Maryland, drained over 700,000 crabs in 2021. That's more than any year since officials started keeping track in 2004. Since then, the number of crabs bled by the industry has more than doubled. At least 80 million tests are performed each year around the world using the blood-derived ingredi...

Kingdom Animalia Phylum Arthropoda Class Merostomata Order Xiphosura Family Limulidae Genus 3 Species 4 Niche Carnivorous Length Females: 8 – 19 in (46 – 48 cm), Males: 14 to 15 in (36 to 38 cm) Weight 2.2 to 9.9 pounds (1 – 4.5 kg) Lifespan 20+ years Social Structure Meet in large groups during breeding Status 1 endangered, 1 vulnerable, and 2 not listed yet Natural Habitat Ocean floor Average Litter Size Thousands Main food item Clams and marine worms Main threats Habitat loss and overharvesting The Basics The Horseshoe Crab is a prehistoric animal that belongs to a family of arthropods that have been around for more than 400 million years. This makes them even older than the dinosaurs! Their common name is misleading as horseshoe crabs are not true crabs nor are they crustaceans. While they look like prehistoric crabs, horseshoe crabs belong to the order Xiphosura and are more closely related to scorpions and spiders. They live in marine and brackish waters.Horseshoe crabs are carnivores that eat crustaceans, mollusks, and marine worms. There are four species of horseshoe crabs that can be divided into the Western horseshoe crabs, the American horseshoe crab ( Limulus polyphemus), and the Eastern horseshoe crabs, tri-spine horseshoe crab ( Tachypleus tridentatus), coastal horseshoe crab ( Tachypleus gigas), and the mangrove horseshoe crab ( Carcinoscorpius rotundicauda). Horseshoe crabs are only found in North America, Central America, and South-East Asia. Limulus polyp...

Horseshoe crabs are “living fossils”, the last survivors of a group of organisms that first appeared in the fossil record some 350 million years ago. Delaware Bay has the largest population of horseshoe crabs ( Limulus polyphemus) in the world. Besides their extraordinary antiquity, horseshoe crabs are also of paramount importance to human health. Their blood contains a clotting agent, LAL (Limulus Amoebocyte Lysate), which provides a fast, reliable test for the presence of infectious bacteria in drugs, as well as prosthetic devices such as heart valves and hip replacements. Since 1991, the Wetlands Institute has brought scientists and volunteer citizens together to conduct censuses of the ecologically vital horseshoe crab population on the New Jersey side of the Delaware Bay. These censuses take place during May and June and are central to our understanding and responsible management of this ancient marine creature. Horseshoe Crab Conservation The Horseshoe Crab, an important keystone species of the Delaware Bay, is an animal that is very much depended upon by many other species participating in the ecosystem. Shorebirds such as the Red Knot ( Calidris canutus), Ruddy Turnstone ( Arenaria interpres), and the Sanderling ( Calidris alba) depend upon Horseshoe Crab eggs deposited along the banks of the Delaware Bay for their own nutritional welfare. Some of these shorebirds make a 9,000 mile migration from their wintering grounds along the southern tip of South America to th...