I just started up a new saltwater tank for some marine hermit crabs and bought some live rock from a local aquarium store. Later on I realized one of the rocks is covered with tiny anemones. The big ones sold for $60 each at the pet store so they’re expensive to buy and cool to look at so I want to keep them alive. I think they’re filter feeders because they wouldn’t have survived the live rock aquarium at the pet store and they’re way too small to capture a fish. Any suggestions? If I buy fish (other than clownfish) will they hurt them?
One of them is red with white stripes and thick tentacles and big white spot in the middle like this: http://www.petsforum.com/personal/trevor-jones/Aiptasia2.jpg

Another type is red/brown with white stripes but no spot in the middle just a hole and thin tentacles similar to this: world.com/encyclo/reef/anemones/images/aiptasia.jpg

There’s black feathery ones with thin tentacles: http://tbn0.google.com/images?q=tbn:vXe0QMxty6wP9M:http://bp0.blogger.com/_60bWrbUN9iA/RmJ6MNpYOYI/AAAAAAAABBU/TCcvu6D9L_U/s400/6030057.jpg

And finally there’s one that magically apeared in 1 day that looks like the second picture but clear/colorless.

I hope this helps identify them, but needless to say I have several types. In just one day that have already moved around and multiplied.
That second link didn’t seem to work, here’s a similar one: http://saltaquarium.about.com/library/graphics/aiptasia2d_125.JPG