Help with Purple Spot ID on Corals

[maury]

The following pics are from a friend of mine's tank that has these purple/brownish spots for quite a while. These apparently were on some mushrooms that he bought over a year ago, and, from what it looks like, do not seem to damage/impair any coral growth or health. The spots have shown up on parts of other corals in the tank, some as recent as specimens like the elegant, which were only added 3 weeks ago. These spots are also known to attach to the class, and are not calcareous. Attached are the pics of a few corals with the spots. Any help is much appreciated. Is this something that is just a symbiont, or is this a parasite that we should be concerned about.
<a href="http://webpages.charter.net/maury/Elegant.jpg" target="_blank">Elegant</a>
<a href="http://webpages.charter.net/maury/Finger%20Leather.jpg" target="_blank">Finger Leather</a>
<a href="http://webpages.charter.net/maury/Yellow%20Leather.jpg" target="_blank">Yellow Leather</a>

 

[trompet3]

Looks to me like flatworms. I'm not sure what species, and since different ones are good and bad, I don't know if they'll hurt the corals. I have similar ones on some of my corals. Not as prominant as the ones in these pics though.

 

[maury]

Nope, they are not flatworms, or any type of mobile organism. They start as a small dot, and enlarge from there. It's more like a local change in color on the coral; it's not even noticeably raised at the site of discoloration. Almost like a spot of hyperpigmentation.

 

[trompet3]

I have seen the spots move sometimes. Well, not actually move, but they will have changed locations the next time I see them. I really don't know what they are, my guess of flatworms was because some of the shapes bear a resemblance.

 

[maury]

Trompet and Sammy, you are both right. Sorry about my reply trompet, saying you were wrong. After I had told my bud that you had said flatworms, he went and took a closer look, found some MOVING on the glass! So my apologies and thanks for the help!