sand dollars?

[shep]

One of my friends grabbed some when he was fishing and was just courious on how much of his tank they are going to screw up. I think he put 2 in a 55 reef tank and one in a fish only.

 

[nm reef]

I'm not positive but I don't believe a system can adaquately provide for them long term. They will likely die of starvation...or seriously deplete existing food sources.
Plus I would avoid directly adding any livestock from the ocean....no telling what kind of disease/parasite etc. could be introduced.

 

[ophiura]

They rarely live for any period of time. They require an extremely deep sand bed as the burrow at an angle. Some even require either silicious sand or calcareous sand to survive. They often require very particular particle sizes as well, and a healthy one will really never be seen. So, all in all, not a good choice for a tank. Best left in the wild for sure.