Polly surrounded by cast-off horseshoe crab shells





Horseshoe crabs, crabs, lobsters, spiders, scorpions, and insects belong to the group of animals called Arthropods. This means that they are invertebrates (no backbone) that have jointed appendages, segmented bodies, and an exoskeleton (external skeleton).






While visiting Cape Cod as a little girl, I used to find what I called, “horseshoe crab bodies” scattered by the dozens along the high tide mark on my Uncle Steve’s beach. I marveled over how many horseshoe crabs died each year, and I always felt a little saddened by this discovery. In response to that feeling, my cousin and I often hosted elaborate horseshoe crab funerals, complete with a proper burial in the sand and headstones made from flat, smooth stones. Out of deep respect, we often decorated the grave sites with seaweed and shells.

A molted shell that has faded to a light sandy tan from the hot summer sun




It wasn’t until years later when I learned that what I had been finding on the beach weren’t dead horseshoe crabs at all, but rather the exoskeletons from when they had recently grown and molted.


Horseshoe crabs shed (molt) their shells as they grow larger. When a new shell forms underneath, the old shell splits, the horseshoe crab crawls out and leaves the old shell behind. These molted shells are then swept to shore with the tide and left scattered about the beach.




This summer when I was visiting Cape Cod, I headed to the place where I spent so much time as a child, and was surprised by how many horseshoe crab exoskeletons were on the sandy beach—there were hundreds! I don’t remember ever seeing so many at one time. I couldn’t resist snapping a few pictures of Polly #3 sitting on the beach with a few of the cast-off shells. I didn’t host a funeral this time, but I did smile at a sweet childhood memory!

Uncle Steve's Beach--a beautiful view--and great memories!

If you’re interested in learning more about horseshoe crabs, check out these two videos:
Crash: A Tale of Two Species This is an excellent video–please take the time to view this one!
Horseshoe Crab Anatomy Video This informative site also has lots of interesting horseshoe crab pictures!



Great Children’s Books & Toys:

A wonderful book about horseshoe crabs!


Crab Moon (Read and Wonder)


This story is about a young boy named Daniel who witnesses the amazing sight of hundreds of horseshoe crabs spawning on the beach at night. He returns the next morning and finds a seemingly abandoned horseshoe crab stranded on its back. Danial flips the horseshoe crab over and helps it find its way back to the ocean. This book is beautifully illustrated and is interwoven with interesting facts about horseshoe crabs–the often misunderstood creatures that have occupied our planet since before the time of the dinosaur!



The Story of a Food Web

Horseshoe Crabs and Shorebirds: The Story of a Food Web


Unbeknownst to most people, horseshoe crabs play a vital role in the survival of many shorebirds. Horseshoe crabs lay billions of eggs every spring along the beaches of the Delaware Bay and shorebirds stop here for nourishment along their long migration from South America to the Arctic Circle. This is a “circle of life” story worth reading! This book would be the perfect partner for the video: Crash: A Tale of Two Species (link found above)


Great for classrooms!

Great learning tool!

Horseshoe Crab


This soft, true-to-life horseshoe crab is a must for classrooms! Educational information in five languages is included with each vinyl replica.


7 people like this post.


5 Responses to “Horseshoe Crabs on Cape Cod (Polly #3)”

  1. This is interesting. I can’t really say that I knew much about horseshoe crabs before reading this. I do have a question though: what did people call horseshoe crabs before mankind started shoeing horses?

  2. What nice childhood memories. Sounds like you had a wonderful place to spend your summers as a child.

  3. Polly #5: I couldn’t find an answer to your question, but I did find two very interesting videos about horseshoe crabs. The links are at the bottom of the post. Please check them out and let me know what you thought!
    Polly #3

  4. Polly, you rock!

  5. Great photos of horseshoe crabs and Cape beaches! Our family loves Martha’s Vineyard (and the Cape !)