What is this on my Trachy?

[thejtown]

Just brought this beauty home a few days ago. Drip acclimate, dip, all the usual steps and it pretty much immediately opened up. Full polyp extension, seems very happy. Today I notice this stringy substance coming off of it that's covered in bubbles and it seems to keep growing. Any idea what it is? Should I be concerned?

 

[Maho.B]

Hard to see but it looks like a little tiny string of slime, could be from something as simple as a shrimp or hermit crab crawling on it? But I'm not LPS expert at all. If conditions are stable and it stays open like that I wouldn't worry.