Have you heard of a horseshoe crab? Maybe you have. Maybe you’ve been lucky enough to witness these ancient-looking creatures that gather in great numbers on the shores of the US Atlantic coast and northeastern India.

Horseshoe crabs may not be on your top 10 list of favorite animals, but maybe they ought to be. Take the quiz to learn why!

Horseshoe crab quiz

Click check on each question or show solution at the end of the quiz to view the answers and learn cool horseshoe crab facts.

How to help horseshoe crabs

Horseshoe crabs have been in the ocean for over 400 million years. They are an established part of healthy marine ecosystems. And their eggs are fuel for migrating shorebirds. Beyond their important role in the environment, horseshoe crabs have helped save the lives of millions of humans.

You can help horseshoe crabs in return! Learn more about them using the links below. Participate in a local beach cleanup. Do horseshoe crab art. Celebrate, share what you learn, and support horseshoe crab conservation projects. Hooray for horseshoe crabs!

International Horseshoe Crab Day is held each year on the 20th of June.

Celebrate horseshoe crabs
horseshoe crabs

Learning resources on horseshoe crabs

NOAA educational video series: The Remarkable Horseshoe Crab

NOAA: Hooray for Horseshoe Crabs! Learning activity about American horseshoe crabs for grades 6-12. Activity pdf available here.

Horeshoecrab.org: A useful resource on horseshoe crab anatomy, ecology, conservation, and more

Video from TED-Ed: Why do we harvest horseshoe crab blood?

Maryland Department of Natural Resources: Resources on American horseshoe crab anatomy, evolution, fishery, medical uses, and conservation

Smithsonian’s National Zoo & Conservation Biology Institute: 10 Incredible Horseshoe Crab Facts

PBS News Hour article: Blue blood from horseshoe crabs is needed for medicine, but a declining bird species relies on the crabs to eat

IUCN SSC Horseshoe Crab Specialist Group: The scientific group in charge of evaluating horseshoe crab conservation status

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