Acro Eating Pest?!

[AlaskaMatt]

I left my house around 2:00pm today and by the time I got home at 8pm and starting dipping and prepping a new frag to go into my display I noticed one of my new frags looked damaged.

This was before:

Now some of the tips were damaged on this coral when I got it but on the uppermost 3.

Between 2pm and 8pm something ate a whole chunk off of it and ground it flat:

If I saw some polyps missing or some flesh gone I would suspect one of my emerald crabs but this is pretty intense and I don’t know if an emerald grab would even be capable of eating the skeleton, I mean this looks like a rock fell on it and scrapped the tissue and broke off a piece but that’s definitely not the case.

I’m thinking maybe one of my turbo snails somehow bulldozed into it? Or perhaps my purple urchin is the culprit:

Anyone have any ideas what could have caused this?

 

[Dburr1014]

Fish in tank?

Bi-color blenny any chance?

Could be the urchin, if it's hungry.

 

[Battlecorals Verified Sponsor]

Fish in tank?

Bi-color blenny any chance?

Could be the urchin, if it's hungry.

yeah this was my first inclination as well I've seen bi-colors leave mouth shaped swaths on sps before that look similar for sure.

 

[AlaskaMatt]

I have:

1x Ocellaris Clownfish
1x Possum Wrasse
1x Royal Gramma
1x Firefish
1x Tailspot Benny (new addition — got him the same time as the frag)

I would have never conceived that the little tailspot could be the culprit. They can eat a branch off of an acro? Thats impressive, and a PITA because he’s not going to be easy to evict outta there haha.

 

[Mels_Reef]

I dont know what broke the branches off but tailspot blennies will definitely scrape on SPS. I actually just caught a blue hippo tang nipping on my acro tips!! And the only way to get tail spots out is to remove the rock that they will definitely dart to, and hide in lol. I love the little guys but they are definitely PITA’s

 

[AlaskaMatt]

Ah man that’s a bummer. Luckily the rock he likes to hide out on isn’t deep so I think I might be able to coax him out into a net but we will see. I might take the urchin out as well for good measure since my CUC has expanded over time and he’s getting pretty large now. Came as a hitchhiker on my TBS rock.

 

[Dburr1014]

1x Tailspot Benny (new addition — got him the same time as the frag)

My #1 suspect.
Urchin #2

 

[AlaskaMatt]

Well I’m almost positive this was the Urchin, this morning I woke up and checked on my tank — saw my urchin slowly slinking away from the frag, while he could have just been passing through I’d be shocked that my Benny could chow through an Acro skeleton from bottom up like an urchin could:

I had acros in here before and I’ve had the urchin a long time but I think the available algae has been greatly diminished and the CUC I’ve added has reduced his available supply — plus he’s gotten huge now so I went ahead and put him in the sump for now. I’ll keep my eyes peeled for additional damage from other critters but I’m pretty confident he was the culprit.