Montipora digitata is being eaten

[mgreen18]

My montipora digitata has a bare spot on it and the spot is getting bigger every day.
Could this be from montipora eating nudibranch? I have another monti right next to it and it is doing fine.

[alton]

Do you have any fish in this tank, any wrasses? And welcome to MAAST. If you fear any bugs you may want to pull it dip and frag it. Isolate the base in a QT setup. Most eggs are safe from dips. Hopefully someone of the more knowledge will see this and have better answers.

[mgreen18]

I have fish, but not a wrass. Do I need to frag it? Or can I just dip and quarantine and try to save it?

[alton]

Isolation/ QT would be best until you find out what it is? Or you could dip and see if anything falls off as a minimum

[mgreen18]

I dipped all my montis in coral RX and went over them real good with a tooth brush. I have them in the QT. I also dipped a chalice coral that looked like it was receding. Does nudibranch go after chalice coral too? I guess I should dip every 3 days or so to get all the hatching eggs? If the bare spot on the monti is truly dead, should I frag it? Or will it be ok just to leave it like that?

[mgreen18]

Well if anything for documentation purposes. Here is a picture of the monti in the QT after dipping.

[Joshua]

Have you actually seen any nudi's or parasites? Did anything fall off or was left in the dip bowl after the dip?
I've seen that necrotic behavior plenty of times with various SPS in the past that wasn't due to any parasite.

[mgreen18]

I did not see anything significant. The coral plug it is attached to is a small piece of pukani and there were things living in that. I saw some copepods and some small feather duster worms in the dip bowl. But my eye sight is not that good.
Even with a magnifying glass. The skeleton of the monti seemed to be smooth and polished looking until I dipped it, but afterwards, it looks normal.
I do know that every day the spot seemed to get bigger until I dipped it. Now, the spot is not growing.

[Justin]

You should be able to see nudibranchs feeding at the edge of live tissue. What I have seen work on them for a dip but its a little harsh for sps at times is the following:

3x the Coral Rx dosage
2x the dip period

so roughly 1tsp for 20 mins, you will see the nudi's die from this.