What is causing this patch on acro ?

[christwendt]

Hello I’m having a weird patch on one acro only. I have a stocked sps system and this is the only one that has a dead patch. It’s been slowly expanding over the last month or two. Any ideas? Corral is overall healthy with PE and good colors.

 

[Doctorgori]

I have also noticed a frag or two with those marks…I would like to know also…..following

btw, I wonder if the urchin accidentally nipped it

 

[ReefStable Verified Sponsor]

Looks like something is eating the skin.
Possibly a fish/invert or a pest like acro eating flatworms.

 

[christwendt]

I have also noticed a frag or two with those marks…I would like to know also…..following

btw, I wonder if the urchin accidentally nipped it

Interesting seems similar. It’s very slow to progress. I also don’t have any urchins.

 

[christwendt]

Looks like something is eating the skin.
Possibly a fish/invert or a pest like acro eating flatworms.

I obviously wondered if I had pests but I don’t have flatworms I know. There are no bite marks on any corrals. This is a clear patch not a bite mark. I’ve watched it slowly expand from very small to this in about two months. I just don’t think it’s a bite mark of any kind as it’s the only spot and has slowly expanded. There is a very distinct border too. Here’s maybe a better pic.

 

[Charless]

I am not 100% sure from looking at your pics, but I can say from my own experience dealing AEFW, your pics show similar marks in my coral when I had AEFW. That is where the AEFW eat the flesh and deposit their eggs. To be certain, remove it, dip it and look at that area around the edges of the mark for tiny eggs, using a magnifying glass of some sort. Again, just stating facts from my own experience. Best of luck and I hope you find the true culprit.

 

[christwendt]

I am not 100% sure from looking at your pics, but I can say from my own experience dealing AEFW, your pics show similar marks in my coral when I had AEFW. That is where the AEFW eat the flesh and deposit their eggs. To be certain, remove it, dip it and look at that area around the edges of the mark for tiny eggs, using a magnifying glass of some sort. Again, just stating facts from my own experience. Best of luck and I hope you find the true culprit.

Thank you. Did you find marks on multiple corrals or just a single mark? When I look online it looks like most people have little marks all over.