Need ID - What kind of FLATWORMS are these?

[ReefGirlSara]

I found these tonight on two hairy mushrooms in my 90 gallon tank. They are both on a large (empty) mexican turbo snail shell. My 90 was my big reef tank, but I am setting up a 240 and have moved nearly everything over. I am keeping the 90 up as a QT for the time being for some new fish I got about 10 days ago.

I did have a lot of planaria flatworms in this same tank, but between my mandarin goby and my mckoskers flasher wrasse, I have not seen one for a while in there. Both of those fish were moved to the 240 though 10 days ago.

I searched all over everything in this 90 gallon tank, including another hairy mushroom (different kind though) and I have not seen one other flatworm. There was at least 80-100 on these two mushrooms though, on the base and all over the front of the mushrooms. On the shroom, they looked gray with a white stripe down the middle. On a white piece of paper they looked brown, almost a similar color as the planarias.

I put some Coral Cure in the cup and all of them look dead now. I may just pitch these 2 shrooms to be safe though.

Pics on a white sheet of paper:

http://i212.photobucket.com/albums/cc65/sararuder/IMG_0190.jpg

http://i212.photobucket.com/albums/cc65/sararuder/IMG_0175.jpg

http://i212.photobucket.com/albums/cc65/sararuder/IMG_0169.jpg

http://i212.photobucket.com/albums/cc65/sararuder/IMG_0198.jpg

After the Coral Cure:

http://i212.photobucket.com/albums/cc65/sararuder/IMG_0216.jpg

[greenbean36191]

They are one of the many commensal acoel flatworms that live on corals. They're especially common on mushrooms and are harmless. They usually don't spread beyond the coral they came in on.

[ReefGirlSara]

well that is good news! Thank you!