The First Beach Chair Scientist post is about my favorite animal – The Atlantic Horseshoe Crab

Some might say that the horseshoe crab is quite possibly the scariest looking creature along the shoreline. However, I disagree. There’s actually a sweetheart of an animal underneath that tough, pointy, chitin exoskeleton. I am certain that the horseshoe crab has survived since before the time of the dinosaurs due to its ability to adapt and take in stride all conditions (Darwin’s theory of ‘only the strong survive’ should more aptly be taken as ‘the most adaptable species will prevail‘).

The shells that you may see washed up along the coast line are probably molts. Horseshoe crabs have to shed their exoskeleton just like crustaceans. They grow on average a quarter of their size each time they shed. Females grow to be approximately two feet across and males and a bit smaller (which helps for reproductive reasons).

Another reason that the horseshoe crab is a lot less intimidating than one might think is that the pointy ‘tail’ (telson) is not going to sting you at all. It is what helps the animal turn itself over when the ocean currents flip it a bit. For ten months out of the year horseshoe crabs live in the depths of the ocean floor. They are most often seen coming to the shore in May and June.

Image (c)

Please visit the Limulus Love page for more information about the Atlantic horseshoe crab.


  1. Bernard Sypniewski says:

    Scary-shmary. I think that they are kinds cute. Are they related to trilobites (or any other kind of bytes)?

  2. wow, ok I spent a REALLY long time last night trying to figure out what these things were. They’ve been washing up on our beach like crazy after the storm we had last week. Thanks for helping me ID them. 😀

  3. i know that horseshoe crab was belong in animal kingdom,But it already respawn into other place this animal who lived n250 million years ago….

  4. the hoseshoe crab loks devestating not fun to play with but it looks ugly but cool lokking.

  5. Alfredo Fregoso says:

    How cool is this animal you may ask?

    Well how about if we learn that it can be considered one of men’s best friend,
    their blood is used to ensure that drugs, vaccines, medical devices, blood tests
    etc. are free of bacterial toxins, it is by far the most reliable method to ensure
    there is no pathogens present.
    Horseshoe crab blood coagulates on instant around said pathogens, just think
    about the thousands if not millions of people saved by using their wonder blood!

  6. It’s hard to come by well-informed people for this topic, however, you seem like you know what you’re talking about! Thanks

  7. very scary when they come out and show there face, just a wild looking creature

  8. Hello to every , as I am truly eager of reading this website’s post to be updated regularly. It includes good stuff.


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