Is this a good thing, poylp?

I have these polyps and wondering if they are a good thing? I would not worry about them but the ends look like stingers, but they are really pretty under the blue actinic light, very green.

Also a pic of my brand new sixline wrasse, must not be camera shy!

 

one more

 

last one!

 

those look cool were they hitchhikers?

 

yep, start with one a month ago and now there is about 15 of them. If harmless it is a nice addition. Free Polyps???

 

Do they suck into the rock if you touch them?

 

Sure look like aptasia to me. Is the base soft, I mean, is the skin soft or leathery?

 

I would say that those are most likely aptasia's.  I am no authority on them but I just got through getting rid of an infestation of them.  It sounds from what your are saying that they are invading the same way mine did.  It started out as one, then three to four then finally literally hundreds.  They carpeted every rock and the entire sand bottom.  My substrate is not fine sand but more like very small gravel and they were growing up out of the gravel.  I had approximately 2-3 per square inch of gravel.  They were also growing on the glass.  We were able to finally get rid of them by adding a Fox Face Rabbit fish and a Auriga Butterflyfish.  BOTH OF THEM ARE KNOWN TO EAT POYLPS/CORALS.  In our case we bought the foxface first and did not see a notable reduction.  We then decided to get the butterflyfish and soon after adding him saw a reduction.  All of the aptasia's were gone within about a month.  If you have corals in the tank you could try a couple of different methods.  One method is to inject hot water directly into the center of the aptasia with a syringe the other is a poison you can get from your LFS.  I did not like the idea of poison so tried the hot water and was unsuccessful.  The butterflyfish can be a picky eater so be sure that it is eating before purchasing.

 

don't aptasia have a long base (trunk)? These are flat against the rock.

 

I have 2 of those in my tank. Not aiptasia, I asked my LFS( very reliable) because they had a few on some liverock and he said they are little leathers of some sort. Mine dont move and they dont bother anything. Do they look like tiny little leathers but with longer tenacles?They are much thicker than aiptasia. Can someone post a picture of Aiptasia I dont have one?