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guys can u please tell me what these small things are on the back of the turban snail is it a parasite or any type of coral!?

I am thinking of setting up an anemone tank. I might use a 10 gal I have or a cookie jar or maybe a wine bottle on its side. I understand the need for sump, skimmer & flow, I want to know what will happen when the anemone outgrows the tank? Will it be sad, die, or just stop growing? Can I frag...