Monday, January 28, 2013

Home is where your holdfast is

On Sunday, Eric wanted to go for a walk on the beach.  I was a little hesitant, as it was very windy in the late afternoon.  But we decided on Salmon Creek Beach, and in the end it was more than worth it!

The wind and waves had pushed large tangles of Bull Kelp (Nereocystis luetkeana) into the surfzone.  


We wanted to take a closer look at the kelp, but the waves were very strong.  Eric struggled to pull some kelp to shore by holding on to the holdfasts (the rootlike mounds that anchor the kelp to the substrate).


He finally succeeded, and we found a few large holdfasts to look at.  Here's a closer view of the top and bottom.  Note the complex three-dimensional structure and all of the nooks and crannies. 


Many small animals call holdfasts their home.  We started to search carefully and were rewarded for our efforts.

First Eric spotted this small chiton (Mopalia sp.).  (Photographed later under a microscope.)


Then he discovered quite a few crab megalopae.  These are very tiny crabs that are transitioning from a swimming, planktonic stage to a crawling, benthic stage.


Next he found one of my favorites, a beautiful little peanut worm (Phascolosoma agassizii).


And then we couldn't believe our eyes.  Something was reaching out between the branches of the holdfast.  We both leaned in and exclaimed, "Octopus!"


This is one of the smallest octopus we've seen. It's not much bigger than Eric's thumbnail!

It was very active and started to crawl across his hand.


Here's another image to emphasize just how small this little cephalopod is!

[If you focus on Eric's ring, you can see reflections of both of us — I'm at the bottom standing up to take the photo, and Eric is on the upper right (turn your head sideways) looking down at the octopus.]



I'll post some more pictures of these wonderful little animals and talk more about them in the days ahead.

4 comments:

  1. I love everything about this post. -AH

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  2. That would make an awesome bumper sticker - "Home is where your holdfast is"! :)

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  3. Holdfast "dissection" was one of my favorite lab class activities! Thanks for posting these pix :) CJBS

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  4. This puts a big smile on my face - thank you for sharing !

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