What is this?

[jon150g]

alt="" width="518" height="863" />

 

[porpoiseaquatics]

What are you referring to?  The white thing toward the bottom of the picture?

 

[jon150g]

white thing in the middle of the screen. Ird like a circle with two tails coming off of it.

 

[FutureInterest]

Pineapple sponge.

 

[jon150g]

No its something that moves around on the glass. I will try to get a better picture tonight.

 

[ricky5415]

It is a snail I think

 

[FutureInterest]

Ahh, i thought it was on the rock.  In that case, it is some sort of flatworm, slug, nudi, snail... hard to tell from the pic.

 

[jon150g]

alt="" width="518" height="921" />

 

[jon150g]

The round part above the two tails is the mouth.

 

[FutureInterest]

Hmm... I have no idea.  It doesn't appear to be any of the well known pests so it's prolly safe but when in doubt... it's prolly best to just remove it imo.

 

[hiimsean]

looks like some sort of flatworm. I'd remove it either way.

 

[spike]

I have to agree with flatworm .  This type does not take over, usually the one or two you see will disappear.

 

[spike]

Look at Melves reef site under benign flatworm