Maryland: 5 Fascinating Facts About Horseshoe Crabs And Where To Find Them

CALIFORNIA, Md. — Living on the Chesapeake Bay is a treat because you’ll see some of the coolest animals that Maryland has to offer. Horseshoe crabs are abundant in the Old Line State, especially during the summer. Here are the best locations for spotting horseshoe crabs, along with a few fascinating facts that’ll make you fall in love with these hard-shelled wonders!

Fun Facts About Horseshoe Crabs

Horseshoe crabs, often called “living fossils,” are one of Maryland’s most fascinating animals. Between their impressive age as a species and their strange anatomy, there are a ton of fun facts that you should know about horseshoe crabs!

Horseshoe Crabs Have 10 Eyes

Though tiny, horseshoe crabs actually have 10 eyes in total. While their two primary eyes allow them to see, the other eight are mostly just to help them perceive light as these aquatic creatures explore the Earth.

Horseshoe crabs have eyes near their tail, sides, shell and mouth, so the eyes are scattered all over their bodies. It’s true that horseshoe crabs don’t have the most impressive vision in the animal kingdom, but their 10 eyes are incredibly helpful in navigating the world.

Horseshoe Crab Blood Has Historically Been Integral To Human Health

Like many other aquatic creatures, horseshoe crabs have blue blood instead of red. Their blood is useful to humans, allowing us to create LAL tests to detect bacterial contamination, keeping us safe from harmful health effects.

Biomedical workers often take about 30% of a horseshoe crab’s blood and then release it into the open water, though synthetic alternatives are now being explored. Horseshoe crabs aren’t just cool animals; they’ve also been integral to the health of humans for decades!

Horseshoe Crabs Are More Like Scorpions Than Crabs

Though they have “crab” in their name, horseshoe crabs aren’t actually crabs at all. Horseshoe crabs are classified within the subphylum Chelicerata and are closely related to arachnids like scorpions and spiders due to their anatomy, including their lack of antennae, a feature that most true crabs possess.

People who first came across these animals around the 1600s named them horseshoe crabs due to their horseshoe shape and crab-like appearance. Despite the lack of accuracy, the horseshoe crab title stuck all the way up until the present day.

Horseshoe Crabs Outlived The Dinosaurs

There are plenty of creatures alive today that existed in the prehistoric age, but horseshoe crabs are one of the oldest. Not only have horseshoe crabs existed for more than 440 million years, but they’re also older than the dinosaurs.

Furthermore, horseshoe crabs managed to persevere in the face of an extinction event that wiped the dinosaurs off the planet. Generally, horseshoe crabs live for around 20 years in the wild, so they can individually reach old ages as well!

There Are Four Distinct Species Of Horseshoe Crab

In total, there are four types of horseshoe crab that live in different regions. Atlantic horseshoe crabs live on the East Coast of North America and in the Gulf of Mexico, so they’re the species you’ll find in Maryland.

Indo-Pacific horseshoe crabs, mangrove horseshoe crabs and tri-spine horseshoe crabs are all native to Asia, leaving Atlantic horseshoe crabs as the only species that roam American waters. The four types in existence today aren’t the only ones that have ever lived, however, as there are plenty of extinct species of horseshoe crab, and some could even live in freshwater!

Where To Find Horseshoe Crabs In Maryland

Atlantic horseshoe crabs love to congregate on beaches surrounding the Chesapeake Bay during the evenings between May and July, especially during full moons. Between aquariums and local beaches, there are a few places in Maryland known to have regular horseshoe crab activity.

Southern Maryland is a top spot for sightings, including at popular locations like North Beach and Flag Ponds Nature Park. The following spots are great whether you want to visit horseshoe crabs in captivity or in the wild.

Note: If you encounter horseshoe crabs in the wild, make sure to look but not touch unless they’re in need of help. Click here for a quick look at how to interact with horseshoe crabs in the wild.

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