Is this a Cushion Starfish?

[Bongo Shrimp]

Someone who usually gives me asterina stars for my Bongo Shrimp found this starfish and gave it to me. The color is about what asterina stars have but the shape is all wrong. It is about the size of a 50¢ piece. I think it's a cushion star but know nothing about it. And I could be wrong about what it is. Anyhow I put it in my tank and it is too big for my picky Bongo Shrimp as they are leaving it alone. So now I have a cool unusual starfish that I know nothing about.

Anyone know what it is and/or anything about it? Diet?

Here's some pics. I can get one of the mouth if you want. Sorry about the quality. I was a bit shaky with the underwater point and shoot today.

 

[LeslieH]

Take a look at this great column by Chris Mah on growth in Culcita, the best known cushion star.
http://echinoblog.blogspot.com/2009/02/cushion-star-culcita-novaeguineae.html
The juveniles are flat and have noticeably larger plates around the margins. Yours doesn't seem to have these plates so I think it's another member of the family Asterinidae.

 

[Bongo Shrimp]

Oooh I think I found it!

Patiriella dyscrita, a member of Asterinidae. http://www.marinespecies.org/Asteroidea/aphia.php?p=taxdetails&id=213146

What do you think? Is that it? If so, is it a cushion star? (it's cooler if I can say it's a cushion rather than just an asterina) And is it rather unusual to see these in the trade?

 

[Bongo Shrimp]

Well the Bongo Shrimp decided to eat it last night. They have almost eaten all the arms and the center is what's left.

 

[LeslieH]

Well, I was going to suggest that you take a better picture & send it to Chris Mah, the guy behind the Asteroid database & Smithsonian expert but I guess it's a bit too late :lol:

The color pattern of your soon-to-be dearly departed star does look like the one in the picture but the shape of the plates look different. It's really difficult to separate genera let alone species, that's why I don't even try.

 

[Bongo Shrimp]

Ahh well thanks for the help. It sure was different but the Bongo Shrimp sure enjoyed it.