Yikes! What is this

[Dougal]

Hello, it's my first post here but I've been lurking for a while. Great forum and I've learned a lot from reading the posts here!

Hitchhiker Question: Have my first SW tank going, a 46 gallon which has been cycling for 3 weeks with live rock and live sand. Added another large piece of rock on Tuesday and then tonight (lights were off) I noticed the attached appendage poking out of a large hole in the rock. It's probably about an inch long. My son and I are pretty sure we saw at least two squirts of black ink appearing in the water beside the hole. Pic of appendage attached. Can you help me ID this and advise whether it is an undesirable resident of my tank Thanks in advance!

Phil

 

[mcentire1123]

Welcome to RS

 

[Luukosian]

Looks like a peanut worm to me, if it is they are harmless.

 

[Dougal]

Great, thanks Anthony! I was worried it was something I would have to get rid of pronto. And thank you for the welcome Mcentire

 

[Luukosian]

I have one that looks almost like that and its kind of neat how he sucks on the rocks and glass where he lives. Seems to stay pretty much in the same little hole.