Anemone hitch hiker

[lion king]

Just for fun, can someone tell me what this is and how it may have gotten in my tank, it's a fish only tank. The rocks where old stuff I had laying, my best guess is it came in some macro algae. Will it spread like aiptasia or is is fine to just let it be, thanks.

 

[tbrown]

That sure looks like it is aptasia, so it'll probably spread like aptasia.

 

[Bfragale]

Looks like a bleached aptasia to me. It will spread. I would kill it with a glob of kelkwasser or superglue or one of the many other ways- but yes it will spread in my experience. Could have came with macro algae- that’s very possible.