American Oceans
horseshoe crab limulidae appearance on the sand

Is a Horseshoe Crab a Crustacean?

If you’ve ever been to the Jersey shore, chances are you may have come across a horseshoe crab. These interesting creatures present many unique characteristics and surprising features, but what are they classified as?

two horseshoe crabs on the beachRead on to learn if a horseshoe crab is a crustacean or not.

What Qualifies as a Crustacean?

Crustaceans are part of a group, or taxon, known as arthropods. The main qualifying factor for crustaceans is their exoskeleton. This is a hard, external skeleton that helps protect these animals.

They can range greatly in size from .004 inches to 12.5 ft. Most crustaceans are water-bound animals, but some can live on land as well.

As you can imagine, there are many animals that fit the description of crustaceans. These can include lobsters, crabs, barnacles, woodlice, shrimp, crayfish, krill, and prawns.

american horseshoe crab

The exoskeleton of crustaceans is also molted. This means the animals shed their exoskeleton as it becomes too small for their body.

The molting process allows crustaceans to continue to grow. Some crustaceans molt several times before reaching their full size.

Horseshoe Crabs: Crustacean or Not?

Horseshoe crabs are not classified as crustaceans, though it may sound like they should be. Horseshoe crabs do not have two of the easily identifiable features that crabs do: antennae and mandibles.

Despite the fact that horseshoe crabs are classified as arthropods, the same species crustaceans are in, they are in a different class. There are four different species of horseshoe crabs and they are in fact more closely related to spiders and scorpions.

I know, really, spiders? But these creatures may surprise you with interesting facts.

Horseshoe Crab History:

Believe it or not, horseshoe crabs have quite a lengthy history. Shockingly, they’ve been around since before dinosaurs!

More specifically, the animals have been around for a whopping 350 million years! So the next time you’re looking for a wise animal, maybe skip the owl.

It’s clear that these animals must have some special characteristics to have survived for so many years. Let’s learn more about the anatomy and physical traits of horseshoe crabs.

Horseshoe Crab Physical Traits:

underneath a horseshoe crab

As you can imagine, horseshoe crabs have prehistoric physical traits due to their origin. Specifically, horseshoe crabs can be observed in three main sections: the head, the body, and the tail.

Though the “crab” part of their name doesn’t say much about their appearance, “horseshoe” certainly does. The head of the horseshoe crab is shaped similarly to that of a horseshoe.

The tail of the horseshoe crab serves its own purpose as it allows the animal to resituate itself if turned over. Though it may appear the tail is sharp, horseshoe crabs cannot hurt you and their tails serve no dangerous purpose.

In addition to their unique name, horseshoe crabs are also known for their blood. Guess what, it’s blue! However, they aren’t the only animal with this unique blood. Other sea creatures like squid also have blue running through their veins.

Final Thoughts

So, after learning about the countless eccentric characteristics of horseshoe crabs, you’re probably pretty amazed. Though they may not be the prettiest sea creature, horseshoe crabs will certainly grab your attention with their special abilities.

Despite the fact horseshoe crabs are not actual crustaceans, they have distinctive traits and have survived millions of years, so they must be doing something right.

They may not be very big, but the next time you hear horseshoe crab, you’re guaranteed to share some of these facts with your friends!

Add comment