Any ideas what this hitchhiker is? My tank has been up about 4 months now and this appeared after 6 weeks. It has grown slightly, but not much and has not spread at all. It is soft to the touch and did not sting or stick to me. I did have some Aiptasia, which my Peppermint shrimp devoured, but they have not touched this. Any ideas what it is and what I should to with it?