What am I?

[PghReef]

So had this goniopora for about a month now, seems to have settled in ok and extends normally. There has always been this one area that looked like the coral but slightly different, never seemed to do harm or move.
The past few days I see some tissue recession snd skeleton at the site and it gets me thinking, maybe it's some kind anemone? But the more I look at it and it seems to be moving upward on the coral now I'm thinking a parasitic nudibach that's specific to gonis? Anyone seen such a thing? What do you guy think?
You can see it in the center of the 2 branches. Comes out mostly in morning under heavy blues and at nightbut seems to shrink real small and hide under the coral during the day. Pretty large maybe close to an inch.

 

[Highgrade]

Looks almost like Galaxea

 

[PghReef]

You see the photo from this morning vs tonight. Can it move that much? I agree and I do have a galaxea but it's about 18 inches away and had rock between it

 

[Highgrade]

You see the photo from this morning vs tonight. Can it move that much? I agree and I do have a galaxea but it's about 18 inches away and had rock between it

If its moving it sounds like some sort of anemone. Have you inspected it further to see if it has a foot?

 

[ScottR]

The goniopora isn’t extending its polyps and that spot would probably be polyp bailout. It’s not healthy looking. Usually they look that way as they slowly start to go.

 

[PghReef]

It's not extended because the photo is taken when lights first come on and at night. During the day the polyps extend enough that the area is mostly hidden

 

[C. Eymann]

Its bilateral-ish symmetry like morphology and small acrosphere tipped tentacles make me think it might be a small herpolithia, maybe H. limax
Could also be polyphyllia

 

[PghReef]

Not sure what it was but it continued to eat coral tissue from the spot it was on last night. Removed it with tweezers and it's like the back half fell apart into a million little pieces but the main body about half inch round just curled up. Definitely not an anemone as it didnt attach with a foot. Also not a coral as it moved around. Not sure if I should be concerned about eggs or spreading to other corals or if this with a goniopora specific pest.

 

[C. Eymann]

Didn't catch that it was motile,
Never seen anything like that before, very weird!

 

[WV Reefer]

Not sure what it was but it continued to eat coral tissue from the spot it was on last night. Removed it with tweezers and it's like the back half fell apart into a million little pieces but the main body about half inch round just curled up. Definitely not an anemone as it didnt attach with a foot. Also not a coral as it moved around. Not sure if I should be concerned about eggs or spreading to other corals or if this with a goniopora specific pest.

based on it falling apart like that I would say nudibranch of some kind. I’ve seen berghias fall apart in similar fashion when handled too rough.

Aquarium Invertebrates: Phestilla Nudibranchs: Cryptic Enemies of Porites, Goniopora, Tubastrea and Dendrophyllia Corals and an Identification of ‘Montipora-eating Nudibranchs’

Dana takes us on an in-depth look at the Phestilla and Embletonia nudibranchs that can wreak havoc on an unsuspecting coral in your tank.

www.advancedaquarist.com

 

[PghReef]

Never heard of a goniopora eating nudibach but I guess they probably exist. Thats my best guess as well. Cant find any information out there about them though.
I guess like other nudibachs goid worry it laid eggs to reproduce? Also probably an obligate goniopora eater since it mimics the short polyp purple goni so closely so no worries of it spreading to other corals?

 

[PghReef]

based on it falling apart like that I would say nudibranch of some kind. I’ve seen berghias fall apart in similar fashion when handled too rough.

Aquarium Invertebrates: Phestilla Nudibranchs: Cryptic Enemies of Porites, Goniopora, Tubastrea and Dendrophyllia Corals and an Identification of ‘Montipora-eating Nudibranchs’

Dana takes us on an in-depth look at the Phestilla and Embletonia nudibranchs that can wreak havoc on an unsuspecting coral in your tank.

www.advancedaquarist.com

Thanks for the article definitely looks like a phestilla of some sort.

 

[Samina]

Geeze, learn something new everyday sorry for your troubles. Glad you were able to extract it. Do you think dipping the Goni would help?

 

[Highgrade]

Wow, that’s crazy. I’d inspect the Goni for eggs. If you find any you should scrub/scrape them off in a dip.

 

[PghReef]

Wow, that’s crazy. I’d inspect the Goni for eggs. If you find any you should scrub/scrape them off in a dip.

I dont see anything that looks like egg sacs. Just a juicy amphipod for my wrasse and some small bristleworms thankfully but I'll be on the lookout.
I've had the coral about a month and noticed this same section from the begining. Looked slightly different but it didnt move and I didnt see any damaged coral tissue so didnt think much of it. Want until the past few days I noticed it creeping out further each night and seeing coral skeleton.
I purchased it from one of our trusted vendors, no fault to them coral looked great and healthy and i know you cant prevent every pest. Should I reach out to let them know so they're aware and can check out their stock?

 

[Highgrade]

I dont see anything that looks like egg sacs. Just a juicy amphipod for my wrasse and some small bristleworms thankfully but I'll be on the lookout.
I've had the coral about a month and noticed this same section from the begining. Looked slightly different but it didnt move and I didnt see any damaged coral tissue so didnt think much of it. Want until the past few days I noticed it creeping out further each night and seeing coral skeleton.
I purchased it from one of our trusted vendors, no fault to them coral looked great and healthy and i know you cant prevent every pest. Should I reach out to let them know so they're aware and can check out their stock?

Wondering if it grew over the last month and wasn't as noticeable at first. I would make them aware just incase.

 

[PghReef]

Seems to be specific to porites from what I read but some species able to also eat goniopora. I guess my euphyllia and elegance should be safe.