fungia produces amazing mucus net!!!

[Boomer]

Some can creep along and some are sessile. I think yours, a "flatworm" like one, is a creeper.

Another pic of a flatworm type

This is a sessile type lobed type

 

[small alien]

Indeed. Mine is a creeper. Now that I know what I'm looking at, it's pretty clear. I can see the two little knobs from which the tentacles are deployed. Such a cool critter. I hope it lives.

 

[SweetCoralline1]

I have one of these too...are they good or bad around corals?

 

[Twwety]

I hade a few living in a toadstool, seemed harmless but it did manage to catch my peppermint pistol shrimp (about 1/2 long) when it was molting. But the toadstool never seemed to be bothered.

 

[small alien]

Checked with Dr. Ronald Shimek. This was a comb jelly. Its feeding structures were absolutely amazing. It came in on the bottom of a fungia. I believe a filefish took it out but I don't know. Truly an amazing animal.

 

[small alien]

Yeah, what Boomer said!

 

[Michigan Mike]

Harmless, tend to wax & wane as time goes, tank matures, food depletes etc.