Coral loses tissue in strange way! Please help!

[SimonMo]

Hello, my coral lost tissue in very strange way - about half of each polyp lost tissue. I don't know what could be the reason. I got this coral about 5 days ago and it looked very well. I have very good parameters.I keep sucesfully corals such as acropora, fungia, micromussa, euphyllia, chalice, duncan coral, birds nest, monti, zoas etc. In the same day i got it, i fed him with mysis. Do you know what went wrong? How to treat it?

The last photo shows how it looked like before.

 

[Stephen Glover]

Did you dip it before adding to the tank? It almost looks like something was eating it. What are your inhabitants?

 

[SimonMo]

Did you dip it before adding to the tank? It almost looks like something was eating it. What are your inhabitants?

Yes, I dipped it. I have only asterinas,turbo snails,cleaning shrimp, anthias, clownfish and hexataenia wrasse

 

[Stephen Glover]

Yes, I dipped it. I have only asterinas,turbo snails,cleaning shrimp, anthias, clownfish and hexataenia wrasse

If it happened during the night it could be an unknown inhabitant. An iodine dip wouldn’t hurt either in case it is a bacterial issue.

 

[SimonMo]

I found the photo which was taken 2 days before photos which i already posted, so now I can see that it wasn't very rapid lost of tissue. Maybe this photos will help..

 

[SimonMo]

Btw is this acanthastrea echinata?