Pelagic barnacles attached to a...

Sometimes I'm asked what my favorite invertebrate is.  I can't answer that question, because I'm intrigued by so many of them.  However, pelagic barnacles (Lepas spp.) would definitely make it onto a list of candidate species.  We found some a few days ago washed up on Salmon Creek Beach.  

Pelagic barnacles are often attached to driftwood or floating seaweed, but this time Eric spotted some growing on a different object.  Can you tell what it is?

 

Here's a slightly different angle:

 

And another showing the opposite side with a larger cluster of barnacles:

 

Did you guess what the barnacles were attached to?  

Warning: The next picture will give it away.

  

Yes!  These pelagic barnacles were growing on a feather!

When examined closely, Eric noticed a newly settled barnacle larva, called a cyprid, attached to the feather, too (see below).  You can see it just off to the left of the large cluster of feeding barnacles.

 

Below is a close-up of the cyprid:

 

Although I haven't photographed a cyprid on a feather before, I shared some nice images and an explanation about pelagic barnacle cyprids in 2012.

After Eric spotted the first feather-with-barnacles, I wondered how many we had passed by.  Although we were near the end of our walk, I found one more:

 

After discovering them, we had lots of questions.  For example — Do the barnacles prefer a certain region of the feather?  If so, why?  Do some types of feathers make better floating rafts than others?  How many barnacles would it take to sink a feather?