Newer to SPS, is this STN?

[CRABDADDY]

I'm looking at the exposed skeleton on the right side of the frag. It appeared with in the last week or so. I'm curious as to whether it looks like STN, or something maybe was eating it. It is in fairly direct flow, but I don't think the flow is overkill. The patch has gotten slightly bigger, but all other SPS are looking good. It's not flaking off or anything. I think the patch originally appeared overnight.

 

[Stephen Glover]

hard to tell. Please post parameters, age of tank, inhabitants

 

[CRABDADDY]

Tank is 2.5 years old. 40g AIO. No major parameters swings. Phosphates were near 0 about a month ago for a few weeks, but they've since been brought into normal range. Magnesium was also low (1175), but has since been corrected. I run my HOB skimmer 8 hours a night and when it's off some of the water flows back into my tank and my ATO won't top off until the skimmer kicks on, but I am dosing 400ml of kalk a day, so it's getting some fresh water, and then the ato kicks in when the skimmer turns on. These are the only parameters variations I have seen as of late.

Parameters are as follows:
Alk: 7.5
Calcium: haven't measured in awhile, but I'm dosing kalk, so I assumed it's ok, can test shortly.
Mag: 1300
Nitrate: 2.5
Phosphate: 0.05 ppm
Salinity: 1.026

Inhabitants:
Clownfish
Lawnmower blenny
Six line wrasse
Yellow assessor basslet
Yasha goby

Inverts:
Hermit crabs
Halloween hermit crab
Emerald crab
Tuxedo urchin
Conch
Cleaner shrimp
Pistol shrimp

 

[Stephen Glover]

my guess at this point would be the emerald crab. Shine a flashlight in your tank at night and see what he is up to.

 

[CRABDADDY]

Yeah, I did see him on an acro a few weeks ago, but there was no visible damage to it. Something got at the base of one of my leathers and cut it down. I'm wondering if that was him. I'm thinking about the urchin because I believe I saw him up there around the time this happened and I'm almost certain he ate some of my clove polyps.

There isn't much regular algae in the tank, but there's tons of coralline for the urchin. I should probably just remove the emerald crab just in case.

 

[Troylee]

looks like a sting almost from a neighboring coral… I wouldn’t call it stn as it’s not white and still melting away..!looks like it will recover just fine and I wouldn’t mess with it… any lps around it? They put long sweepers out at night..

 

[CRABDADDY]

There's no LPS or other corals near by. Just more acros. I don't think it could have been stung by anything, but that's a good thought.

 

[Troylee]

There's no LPS or other corals near by. Just more acros. I don't think it could have been stung by anything, but that's a good thought.

My next guess would be your urchin mowed over it… not on purpose but it happens.. the emerald will just eat polyps off the branches in my experience. Mine loved to naw on my torts rrrrrr… lol

 

[CRABDADDY]

That was my first thought too... I really like the urchin. I'll let him stay for now because he does good clean up, but I'll keep an eye on him. I didn't think this really looked like STN, but I'm not experienced enough to tell.

 

[Troylee]

That was my first thought too... I really like the urchin. I'll let him stay for now because he does good clean up, but I'll keep an eye on him. I didn't think this really looked like STN, but I'm not experienced enough to tell.

I really wouldn’t stress it… some times breaking tips off and scratches etc promote growing in stalled out corals..

 

[CRABDADDY]

Ok, cool. I've only had these acros in the tank for about 2 months, but they're coloring up and showing minor signs of growth so far. Mostly just pooling around the base. I'm excited to see them take off (hopefully) in the coming months!

 

[Charlie’s Frags]

This is your problem.

That’s a vermatid snail. They cast a stinging net that will necrosis tissue just like that. I bet your flow pushes the net on that area. That’s the first thing look for when one of my corals look irritated.You can crush them with some bone cutters.

 

[CRABDADDY]

Wow, that's a good catch and you're totally right about the flow. It definitely hits the coral from that angle. Going to go smash him to smithereens now. I forgot to list that I unfortunately have a few vermitids in the tank. I was only listing the inhabitants I purposely put in the tank.

 

[Charlie’s Frags]

Wow, that's a good catch and you're totally right about the flow. It definitely hits the coral from that angle. Going to go smash him to smithereens now. I forgot to list that I unfortunately have a few vermitids in the tank. I was only listing the inhabitants I purposely put in the tank.

 

[CRABDADDY]

It's been glued over because it was in a crevice and I couldn't reach it. I'm still amazed you found that. Big thanks to everyone that helped out!

 

[KrisReef]

I totally do not see a vermitid. Posts like this make me think I should give my coral back to the LFS, drain the tank, and take up Bingo and Horseshoes.

I had a pest awhile back that I never ID'd because I couldn't see anything except death. I let the tank fallow a couple of years and things are living again now after I rebooted with some frags since January.

Don't do things that will ruin your eyesite, and you all know what I mean. No squinting!

 

[Charlie’s Frags]

It's been glued over because it was in a crevice and I couldn't reach it. I'm still amazed you found that. Big thanks to everyone that helped out!

It was good timing for you bc I had to remove some corals yesterday that had the exact same thing. That’s one of the reason why I now mount frags on upside down plugs. The vermatids are easier to see.

 

[CRABDADDY]

I totally do not see a vermitid. Posts like this make me think I should give my coral back to the LFS, drain the tank, and take up Bingo and Horseshoes.

I had a pest awhile back that I never ID'd because I couldn't see anything except death. I let the tank fallow a couple of years and things are living again now after I rebooted with some frags since January.

Don't do things that will ruin your eyesite, and you all know what I mean. No squinting!

To be fair, I couldn't see it at all until I looked closely at the picture. I can only really recognize it because the color matches vermitids I've seen elsewhere in my tank. I STILL couldn't see it in person when I was trying to remove it. Sneaky little guy.

 

[KrisReef]

To be fair, I couldn't see it at all until I looked closely at the picture. I can only really recognize it because the color matches vermitids I've seen elsewhere in my tank. I STILL couldn't see it in person when I was trying to remove it. Sneaky little guy.

You are too kind, and I am glad the board figured out the mystery regarding the suffering coral. This certainly is a fun place to share the hobby around.

 

[dadnjesse]

I hope you figured it out. My long spine Urchin was taking chunks out of my Sps, now he lives in my sump