Golden and groovy

 

This weekend we photographed some beautiful peanut worms (sipunculans).  This is Themiste pyroides, a local species that can be found in the low intertidal zone of rocky shores.  They nestle in crevices so they can be hard to see, but when their crown of tentacles is fully extended, they're pretty spectacular.

Eric photographed one individual with mostly golden-colored tentacles (above).  This individual also retracted its tentacles, revealing its introvert with dark hooks (see below; the hooks look like tiny chocolate chips).  (Peanut worms can withdraw their tentacles completely.)  We haven't been able to find any information about how these little hooks might be used in this species.  Do you have any ideas?

 

Then I photographed a different Themiste, this one with purple tips on many of its tentacles.  Here's a close-up:

 

Themiste uses this array of branched tentacles to capture food from the water.  In the next photo (below), look for the grooves in the center of the branches (especially on the right side of the image).  The tentacles are covered in cilia and mucous, and the grooves are probably involved in food gathering, but we haven't been able to locate a detailed description of the feeding behavior.

 

Branching out

 

Close-up of the beautiful tentacles of a local peanut worm (Themiste sp.).  

Here's a view of all of the tentacles:

 

I wrote about a similar peanut worm in 2014, so if you'd like to learn more about them, review the post called "Peanuts with chocolate chips" on 20 July 2014.

P.S.  Also — I have an update about the Bottlenose Dolphins photographed on 5 July 2018.  Bill wrote to say that he had identified one of them — an older female named "Sakura" that's been known to researchers since 1989!  For more information, you can read Bill's comment on that post (see link above).  Thanks, Bill!

The owner of the golden branches

And the answer to last night's mystery close-up is...

 

These are the tentacles of a peanut worm (Themiste sp.)!  The body of the peanut worm is buried below the sediment.  The tentacles are extended for feeding, but they can also be withdrawn when needed (e.g., for protection).

To watch a sequence of a peanut worm pulling in its tentacles, review the post from 20 July 2014.

And in case you were wondering — a sea cucumber's tentacles can look very similar.  But note that the peanut worm's tentacles lack the shiny ossicles of a sea cucumber.  This is especially apparent in the main tentacle branches.  To compare, check the photos in the sea cucumber post from 16 April 2013.

 

Peanuts with chocolate chips

For years I've been trying to photograph this intriguing peanut worm, Themiste pyroides:

 

I've discussed peanut worms on the blog before (see post from 31 January 2013), but I haven't shown this species yet.

Remember that peanut worm tentacles are located at the tip of a long "introvert" that can be withdrawn, or rolled in on itself.  Here's a series of pictures illustrating that process (below).  Watch the tentacles disappear!

 

 

 

 

 

Themiste pyroides has wonderful golden tentacles, a purple "neck", and fascinating hooked brown spines — see close-up below.  You'll laugh, but the shape of the spines reminds us of tiny chocolate chips!

 

Because peanut worms live in crevices, you often only get to see their tentacles.  Look closely for clusters of golden tentacles extending from low intertidal zone crevices along rocky shores, and you may be rewarded with a sighting of Themiste pyroides!

P.S.  In this species, the tentacles are used for suspension feeding — gathering small food particles from the water.