GARF Bonsai Issue

[msderganc]

Can anyone tell me what this is? I don't think it's AEFW, since it's not little bites. I was thinking it might be too much flow, but this is ~8 inches from a rotating 6095 at ~50% power. The coral is about 10 inches from the water line, or 16 inches below the light.

It's on the bottom side of the coral, shaded from the light, and the other side looks perfect. PE has been OK, although it's noticeably less than normal in this picture. I'm not sure if it's getting worse or has been there, but I just noticed it today. The coral has been in the tank for about a month and is encrusting.

pH - 8.15-8.3
Temp - 77-81F
Salinity - 35ppt
Calcium - 420 ppm
Alk - 8.3 dkH
N03 - 0
P04 - .03

I don't have any similar issues with any of the other coral in the tank.

Any idea?

 

[Tweaked]

Looks almost like a nem or mushroom sat against it for a bit. Any nearby corals that can sweep?

 

[rovster]

Looks like tissue necrosis to me. Why, we can only speculate. Could be a sting, but area is very broad.

 

[msderganc]

Thanks guys. There's nothing anywhere near it with sweepers. Closest is an anemone that's probably two feet away.

I just measured all of my parameters and it looks like my Calcium has dropped from 420 to 395 over the past 8 days, and my Alkalinity from 8.8 (not 8.3 as I thought) to 7.9 dkH over the same period. Doesn't seem severe enough to cause TN to me, but who knows?

I meant to bring up - I do run biopellets, and I had a little cyano near it recently. Could cyanobacteria have done that?

 

[triggreef]

Thats how a few of mine including a plum crazy looked after getting mauled by a black sailfin algae blenny. I guess not enough film algae so he decided to start going for zooxanthe.... Anyway relocated him to the sump after I figured out what he was up to. Saved the 3 acros he attacked one by one as I was relocating them to the frag tank to get them away from the beast. Who is now the sump monster.

 

[msderganc]

Hmm, the only fish in my tank that might have done it is a Foxface. Maybe my sexy shrimp as well, but they usually just harass a mille when they're mad I haven't fed them directly.

 

[polywise]

looks like something is eating its way up the first branch on the right...

 

[therman]

There are tube dwelling amphipods that will do this. Check around the base for a little "sleeve" of detritus stuck to the rock. It will have a small to medium sized fast amphipod that will stick out its antennae when you are close, and will shoot out when you tear at the tube. Be ready with very sharp forceps to grab it and kill it, or it will disappear into the rock and do the same thing again. They look similar to the standard amphipods, but with bigger blacker eyes and a bit more smooth and flattened.

I have also seen tanaid arthropods do this, but they tend to be smaller and more cigar shaped. Usually don't do that much damage. It seems their tubes usually just affect the encrusting edge of corals, they don't eat the tissue up the coral like the amphipods will.

The only info about them I've found was here:
http://reefkeeping.com/issues/2002-02/rs/index.php

Have not seen any info about the sps eating amphipods, but I have witnessed it myself several times. I think they are only an issue with smaller frags like yours.

Hope that helps, that is what it looks like to me from the photo.

Tim

 

[Kirkwood77]

I agree that it looks like a sting... any chance that a mojano anemone could be hiding in a crevice of the LR?

Your color and PE still look good so I'd try moving it to a different part of the tank to ensure its survival..

 

[msderganc]

Thanks guys - I'll looks for smaller potential predators. I haven't seen any majanos, but I do have a lot of pods around and I've seen some of those little tubes that might be amphipods.

I'll just clear everything around it and see what happens. I looked at it this morning and it didn't seem worse, though.

 

[msderganc]

Ok, so good news and bad news. I cleared the rocks around it, and I didn't see any possible predators.

Bad news is that I discovered my Hanna Alkalinity reagent was bad. So yeah, my Alk is more like 10.6 (double checked with RedSea). The Hanna has been reading between 8 and 8.8 for months. New reagent, immediately jumped 2 dkH.