As keepers of the environment, we have a responsibility to preserve, protect and live harmoniously with the animals that share our planet. As a source of critical proteins that detect the presence of endotoxins in products and instruments used by humans, the Atlantic horseshoe crab has long been treasured by the biopharmaceutical industry.


For this reason, it is critical that we serve as advocates for the humane treatment of these animals, and strive to achieve balance between our need for this valuable material and the livelihood of the animal that provides it. Charles River is proud to play a role in alleviating pressures on horseshoe crab populations through tireless conservation efforts, active animal welfare campaigns and decades of research and development.



Wading Deep

For a long-term view of how future generations
of horseshoe crabs will be able to cope and reproduce, one really needs to examine the
gene pool.

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Tracking the Atlantic's
Senior Citizen

Horseshoe crabs keep us healthy, but how are they doing? Tagging operations are one way to
find out.


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The Importance of Horseshoe Crab Habitats

These arthropods are found all along the Eastern seaboard, but their numbers are less abundant in New England and New York. Why?

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New England Aquarium and Charles River Presentation

Living Fossils and Blue Blood: The Story of the Horseshoe Crab and Human Health

Watch the Video

Tales of the Horseshoe Crab

Will the use of artificial bait help conserve American horseshoe crabs and stabilize their populations?


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Mystic Aquarium & Charles River’s Horseshoe Crab Count Walk

With a total of 88 horseshoe crabs counted, this year’s Mystic Aquarium Horseshoe Crab Counting Walk at Napatree Point in Westerly, RI was a huge success.

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The Most Noble Fishing There Is

Eureka guest blogger, Jerry Gault, a longtime South Carolina fisherman, talks about his moral duty and legal responsibility to handle horseshoe crabs with care.

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Preserving the role of
an ancient mariner

This podcast discusses some of the earliest work undertaken in South Carolina to conserve horseshoe crabs and how it benefits us all.


Listen to the Podcast

Crab Conservation in
South Carolina

Biomedical manufacturers and conservationists alike have a vested interest in making sure these invertebrates continue to thrive and flourish. Find out how the species is faring.

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Remarkable Success Story of the Horseshoe Crab

Learn about the horseshoe crabs’ remarkable story of survival and adaptability.

Watch the Video

Adventures of Protecting
the Horseshoe Crab

John Dubczak talks about the importance of endotoxin testing in drug development.

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An Ancient Animal's Blood is a Modern Medical Miracle

At night, during the full and new moon in late May and early June, the sands of East Coast beaches host a dance that is a half-billion years old.

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Horseshoe Crabs Mate in Massive Beach "Orgy"

Horseshoe crabs live in the ocean year-round, but they make one annual visit to the shoreline to lay eggs in sandy, wet beaches.

Watch the Video

Protecting an Ancient Mariner

The Atlantic horseshoe crab has found allies in the biotech community. Find out why.

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Ever Have an Injection? Thank a Horseshoe Crab

Dr. Norman Wainwright talks about the importance of bacterial endotoxin testing and the role horseshoe crabs have in it.

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Aquarium of the Pacific

Sponsorship of the Horseshoe Crab Exhibit at the Aquarium of the Pacific in Long Beach, CA.

Atlantic States Marine Fisheries Commission (ASMFC)

Active biomedical representation on the Fishery Management Plan for Horseshoe Crabs.

Ecological Research & Development Group (ERDG)
Horseshoe Crab Conservation Fund Corporate Sponsor and partner.

South Carolina Department of Natural Resources

Enacted legislation on hand-harvesting policies and that prohibits baiting of horseshoe crabs in South Carolina.

Mystic Aquarium
Corporate and conservation partner for the Mystic Aquarium, Mystic, CT.


Corporate and conservation partner for the New England Aquarium, Boston, MA.

South Carolina Aquarium

Sponsorship of the Horseshoe Crab Exhibit and Conservation program at the South Carolina Aquarium in Charleston, SC.

Though they look similar to crustaceans, they actually belong to the subphylum Chelicerata, relating them more closely to spiders and scorpions. Limulus polyphemus is found along the Atlantic and Gulf coasts from northern Maine to the Yucatán Peninsula, with the Delaware Bay as the center of the population. This interesting animal is important, not only for the pivotal role it plays in its ecosystems, but also for its valuable contribution
to biomedical research applications.

The true beauty of this remarkable creature, however, is seen in its primitive immune system. Instead of developing antibodies in response to infection, the immune system releases proteins that can bind and kill bacteria. In addition, other immune proteins clot when exposed to waterborne bacteria, a mechanism which forms the basis of the LAL test.


We are committed to employing only fishermen licensed by the Department of Natural Resources to hand-harvest horseshoe crabs from the coastal waters of South Carolina. Our highly controlled and monitored procedures enable us to collect enough raw material for 24 months of LAL production from a minimum number of donor animals. Once the crabs are brought into our lab, they are carefully inspected by trained employees who determine the animal’s health and maturity. After careful collection of a measured amount of blood, the crabs are returned unharmed to their natural habitat within the same day, and their blood volume rebounds quickly. These practices have allowed Charles River to achieve an industry-leading survival rate of donor animals.

Government Regulations

Much of the continued survival of the horseshoe crab can be attributed to its inherent adaptability, as well as modern-day government protection. Prior to 1991, there were no laws or regulations in South Carolina dealing with horseshoe crabs. Increased fishing industry demands for Limulus polyphemus made it necessary to develop a state-wide management plan to conserve this resource. In 1992, Dr. James Cooper (a pioneer in the research and development of the LAL assay) wrote draft legislation that called for the management and regulation of horseshoe crab fisheries.1 As a result, the South Carolina state legislature enacted laws to protect the indigenous horseshoe crab population. In South Carolina, horseshoe crabs must be harvested by hand and can only be used for biomedical applications (LAL production) and marine biological research, not as bait for the eel and whelk industries. The addition of six island sanctuaries makes the horseshoe crabs in South Carolina one of the most protected species on the East Coast of the United States.

The State of the Population

In 2013, the Atlantic States Marine Fisheries Commission (ASMFC) Stock Assessments emphasized that the horseshoe crab population in the Southeastern Atlantic Coast has increased.2 Additionally, the Southeast Area Monitoring & Assessment Program (SEAMAP) Coastal Trawl Survey, conducted by the South Carolina Department of Natural Resources, shows a population increase over the last several years.3 Results from a South Carolina tagging study also demonstrated that bled horseshoe crabs are able to return to spawning beaches in subsequent years.



1.   SC Code § 50-5-1330 (2012).

2.   Atlantic States Marine Fisheries Commission Stock Assessments.

3.   South Carolina Department of Natural Resources, Marine Resources Research Institute, “Southeast Area Monitoring & Assessment Program: South Atlantic.”


million years

Limulus polyphemus, known as the Atlantic horseshoe crab,
is an ancient mariner with a lineage that dates back

Our new video highlights our strong commitment to
the conservation of the horseshoe crab.


For more information about our commitment to the Atlantic horseshoe crab
or to request a copy of our conservation poster or brochure.

© 2016 Charles River Laboratories International, Inc. All rights reserved.