Guess who?

 

This is an extreme close-up.  Do you have any guesses about what type of animal it is?

The next photos show zoomed out views that might provide more clues. Hint: The phylum that this animal belongs to is known for being spiny.

 

Any ideas yet?  

You can see lots of small rounded spines.  Scattered among the spines are tiny claw-like pincers called pedicellariae.  The large white spot is a special structure called a madreporite (or sieve plate).

One more view before I show the entire organism:

 

Okay, here you go...and the answer is: 

 

It's a Six-armed Sea Star (Leptasterias sp.)!  It was fun to photograph close-ups of this species in the field.

I mentioned a few different structures above.  To learn more about the pincers or pedicellariae, check out these posts:

"Armed with pincers" on 5 March 2013

"A star from the depths" on 10 September 2014

"In a pinch" on 22 August 2013

And if you're interested in learning about madreporites or sieve plates, you can start with these posts:

"Spiny and groovy" on 14 June 2018

"Take five" on 7 May 2013

 

Spiny and groovy

 

Close-up of a very spiny Ochre Sea Star (Pisaster ochraceus).  The rounded white spines (or tubercles) are calcareous projections of the sea star's internal skeleton.

 

Close-up of the madreporite (or sieve plate) of an Ochre Sea Star (Pisaster ochraceus).  [I introduced madreporites back in 2013, so if you're interested in reviewing that post, check out "Take five" from 7 May 2013.]