Flashy Fins
New member
I have these on a rock from another person's tank, which I don't think are bad, but I'm wondering if they have spread to another rock in the tank, or if I have a lookalike pest?
The tiny polyp in the top right area of the pics looks just like the polyps in my first picture. However, the polyp in the bottom left corner of these pictures seems different; there is no green on it, just brown. Also, the stem doesn't seem quite the same. It's not as darkly colored and extends out from the rock a little further. Not the greatest pics, but a better look at the stem:
Anything to worry about?