Ribbon worm – day 3 at Hopkins

I identified the ribbon worm as it was swimming on the air-water interface. Based on it swimming and sinking behavior, i am guessing it is negatively buoyant, but it is a mystery to me how it kept itself attached to the air-water interface.



Unfortunately, I did not take an image before, but on touching it to bring it to a glass slide, i found it to shrink approximately 250-350 % of its body size. You can confirm this yourself, by comparing the foldscope videos, with this final image, after releasing it back to the water.


Here are two videos:

It’s not clear what the flow inside the worm is – is it sucking the water and filter-feeding? Or is it particles inside its gut? The head darting around made it challenging to track.

Here’s another video.



3 Comments Add yours

  1. Manu Prakash says:

    Wow. Great find. Something to look for is the proboscis. Ribbon worms are supposed to have a really strange proboscis which “inverts” inside out and gets the prey. It’s the strangest animal. In the video; I do seem to see the inner proboscis which might be moving fast.

    For more images; and a simple schematic – this is a good place to start. http://lazy-lizard-tales.blogspot.com/2011/12/ribbons-terrestrial-nemerteans-of.html?m=1


  2. Saad Bhamla says:

    @Manu – awesome.

    I didnt know terrestrial nemerteans even existed!

    There are a few more aquatic nemerteans here – i have an idea to capture the projectile motion of the proboscis with the iPhone slow-mo camera.
    Will give it a shot this week.

    Awesome suggestions, as always :)))


  3. laksiyer says:

    What adventures @Saad. I’ve never seen one. Cant wait to read more about these…

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