Can you tell me lots of stuff about sand dollars? if can, thanks!?

Answer 1

here's some basic info, including the difficulties of keeping live sand dollars in a home aquarium:
http://www.biomescenter.com/sanddollar_learn.htm

this one has a bunch of links at the bottom too...
http://www.wildsingapore.com/chekjawa/text/s620.htm

hope that helps!

Answer 2

sand dollars are in the echinoid family of marine animals. When living they are covered in movable spines that cover their entire shell. try the link below if it works.

Answer 3

sand dollars are not really easy to keep in reefs, im not even sure if i have seen them for sale, i used to order all the marine sh!+ for a pretty large shop and i dont ever recall seeing them, i think also that most of them are cold water
if you catch one and try to keep it in your tak it will probably die
good luck