Feather Duster?

This dark green thing at the edge of the plug grew out of nothing. It seems to be growing straight from the small hole in live rock.

Looks fuzzy and rather dense. Almost like furry spider/emerald crab legs.

No "worm" body visible and hole behind it is very shallow.

Is this some kind of feather duster?

 

If it does not withdrawal in response to movement I think it kind of looks like Byropsis.

 

I agree with Corailline on Bryopsis.

 

Unfortunately there are several types of Bryopsis, one of the main 2 types found in aquariums as hitchhikers can be eradicated by raising your Magnesium levels... but again, this is depending on the type.

Another thing you could try is scrubbing the hell out of that rock with a tooth brush if you can take it out. But since you posted that it's coming out of a hole in the rock, it may be quite hard to do, but definitely worth a try.

 

If the hole is deep, you might want to try a lettuce leaf sacoglossan

 

Darn it. I new it was a "mean, up to no good looking buncha feathery tentacles". I just had this gut feeling it was EVIL.

I guess I'll break off the plug, take the rock out, scrub area really well, rinse and put back.

Thanks for the help fellas.

 

Good luck, bud. Keep us posted.