Sea star art

  

Close-up of the upper surface of a Bat Star (Patiria miniata).  Those are papulae (in purple) among clusters of spines (in pink).  (Papulae are finger-like projections for gas exchange). 

Like blackberry swirl

A mystery close-up for you.  Can you tell what type of organism this is?

 

The next image shows the entire animal:

 

 

Bat Star (Patiria miniata), photographed in Pacific Grove, CA.  In the first photo, the little bumpy curved purple and cream-colored pieces are spines.  Aren't they intriguing?

We were impressed with the diversity of Bat Star color morphs we saw this afternoon — red, orange, gray, brown, in various mottled combinations.

Five stars

 

Some nice examples of juvenile Bat Stars (Patiria miniata) raised in the lab.  Each one is less than 1 cm across.  Many thanks to Eric for sharing!

Up and down

Have you been looking up at the stars recently?

This morning we were looking down at some.  Here's a nicely patterned and textured juvenile Bat Star (Patiria miniata) to start your day:

 

First steps

 

Juvenile Bat Star (Patiria miniata), only a few days after metamorphosis.

I first wrote about beautiful little sea stars like this a few years ago, so you can review photos of Bat Star larvae and newly-metamorphosed juveniles in the post called "A new star(t)" from 2 August 2013.

Eric raised some Bat Star larvae in the lab again for his summer class, but this time he also recorded a short video.  

It's fun to watch these tiny sea stars (~0.5 mm across) exploring and learning to walk with their new tube feet:

 

Bat Star Settlers Sanford from Jackie Sones on Vimeo.

7 for the 7th

 

A seven-armed Bat Star (Patiria miniata) for 7 March 2017.

P.S.  Bat Stars typically have five arms.  We've encountered some six-armed individuals, but this is the first we've seen with seven arms! 

 

Star date: 26 July 2014

If you've been following this blog for a little while, you might remember a story about some Bat Stars (Patiria miniata) that Eric raised last summer and that we followed until they were tiny juvenile sea stars in the fall — review the post from 22 September 2013.

Well, the story didn't end there!  Although very little is known about what juvenile sea stars eat at that stage, Eric kept a few juveniles to observe how they developed.  If you're interested in seeing how they changed, I thought I'd show a few more time points.

The next two pictures were taken in April 2014.  The sea stars didn't grow very much over the winter, so they were still very small and didn't look too different than they did in September.

 

Here's a close-up of the plates on the upper surface (next image).  Note the overall number of plates, as well as the number of spines extending vertically from them.

 

By June, they had added a few more plates and a few more spines:

 

Remarkably, these juvenile Bat Stars really started growing in early summer.  The next series of photos was taken on 26 July 2014.

 

For comparison, here's a close-up of the plates and spines on the upper surface (below).  Look how many more there are!

 

And some of you will remember how, with the right lighting, you can see the stomach (pyloric caeca) of juvenile sea stars (for explanation, see post on 23 April 2014).  Two brown lobes extend into each arm of the sea star (for a total of ten lobes).

 

I know it's hard to visualize just how small these sea stars are.  So here's one more photo with a ruler for scale.  The Bat Stars photographed in July were about 4 mm across.

 

Star date: 14 September 2013

Are some of you wondering what happened to the little Bat Stars (Patiria miniata) that Eric raised in the lab?  (If you don't know about this story, you can read about it in the post on 12 August 2013.)  

Well, they've continued to do well, and they've grown quite a bit.  We photographed the Bat Stars again about one month after they went through metamorphosis from the larval stage.  Here are two pictures taken on 14 September 2013.

The first image shows the beautiful spines, giving the little sea star a snowflake-like appearance.  And notice the tubefeet reaching out from below.

 

The second image highlights the ossicles on the uppermost surface of the sea star.  The ossicles are calcified plates embedded within connective tissue.  They're the skeleton of the sea star.  In the picture below, the ossicles look like little floating puzzle pieces that are perforated.  (Although blurry, you may also be able to see that there are tall spines growing out of the ossicles.)

 

In these small Bat Stars, the ossicles look remarkably similar to those of a sea cucumber.  Review the post on 16 April 2013 to compare!