Sand Dollar with red "bruises"?

I wondered if my sand dollar was alive or not so I went searching for it and found that it has the red "bruises" towards the edges. Not sure if it is because of the Emerald Crabs or not. I haven't found anything from searching about sand dollars, so anyone with any experience?

 

Pictures, pictures, pictures!!!!!

 

This is the best I can get with a phone camera, lights are out so I used a flashlight.. You can kind of see the red spot on the edge in the picture.

 

Yeah, I can see the red edges. But I don't know why that would be. I don't have any experience with keeping sand dollars. Sorry, bud.

 

Hmm I'm stumped as well. It's still moving around like normal. Just the red spots are concerning. Can't seem to find much on sand dollars, let alone health issues.

 

Haven't seen one of those since i was 7, on vacation in florida. From what I remember they are perfectly round. Just from it being red and indented. Looks like tissue is being picked away or he has a disease. How old is you sand bed? They are sand sifters and probably sub class of starfish. If you flip him over he has the same 5 piont skeleton on the bottom. I would look at their diseases also.

 

Unfortunately you can not keep a sand dollar alive in your average home aquarium. When you see them in the wild they are sitting at a vertical angle in the sand to catch the fine suspended particles in the water column. Without this constant supply of suspended particles to eat they starve.

 

The sandbed is pretty established I think, I would say close to a year or so. All I could find is stuff on urchins that have some kind of worm on them and that is the extent of what I found searching, but no sign of a worm or anything on the sand dollar.

 

That's interesting, that is the first time I've heard/read that anywhere. All I found is that they are sand sifters so that could be the problem there.

 

There are a few species of sand dollars. Look at arrow head sand dollars if yours isnt rounded. (For example...there are more) I want to say arrowhead sand dollars have two red spots on them too, or is that a heart urchin....it is too early for all this thinking.