The Clam Shrimp

In the early summer, my favorite hunting ground for new creatures to look at was the Brooklyn Botanical Garden. Although it is a constructed space, an artificial nature in the city, I found the creeks and the puddles, and even a knot in a tree, teeming with life. The usual bugs and ciliates and copepods, naturally abounded, but so did other things I never would have believed existed.

On an early expedition, I walked out of the gardens with a cup full of creek water and, once home, noticed that the sand seemed to be swimming around. I assumed I had caught some water beetles and was delighted to look at them.

This is what I saw:

Immediately I called to my partner and gleefully informed her I had caught some manner of predatory freshwater clam. To her great credit, she took this news in stride.

Since then, I’ve learned that what I found was not a clam, but a clam shrimp. Not a mollusc, but a crustacean. One whose carapace has spread to form a sort of bivalve shell around it.

Subsequent hunting revealed that often when I wasn’t sure what a speck moving around in a cup of water was, it was a clam shrimp. They were everywhere, and came in different forms. Here’s one I caught in an artificial pond at my dad’s house (you can see the shrimp body hovering there under the translucent shell):

The clam shrimp is an ancient creature. The fossil record has them existing in some form or other since the Devonian period. Which is to say they existed since before land plants as we know them. And here they stay, right under our noses. Swimming around in virtually every lake imaginable.

4 Comments Add yours

  1. laksiyer says:

    What always amazes me in these is the size range. you have microscopic crustaceans and giant ones like like the spider crab that can reach 4 meters or the giant horseshoe crabs.

  2. Matthew Rossi says:

    Whereas I’m fascinated by how many forms these creatures take. I’m about to post a bit on barnacles, which are, the more I learn about them, the weirdest things I’ve ever heard of. Connected to the ground by their foreheads, eating particles with their legs.

  3. laksiyer says:

    Yes I have read a great deal about them, but seen nothing :(.. One of the greatest monographs is by Charles Darwin himself, which makes for a fascinating reading as to how he documented his observations.
    http://darwin-online.org.uk/content/frameset?itemID=F339.1&viewtype=side&pageseq=1

  4. Manu Prakash says:

    One Foldscope community person who would get really excited right now – would be @Tom himself who did his PhD work on barnacles.

    @tom: you should keep an eye on what @Matt is about to share 🙂

    Cheers
    Manu

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