Need Help - Something Killing/Eating My Duncans

[pdt7361]

Hello everyone,
I was looking at my tank this afternoon and found that something or someone in my tank has destroyed my duncans. Any thoughts? All other corals in the tank are fine and all other corals are soft corals. In the tank I have:

2 Fancy clowns
1 Tri-color wrasse
1 Diamond Goby
2 Peppermint shrimp (I am wondering if they are doing it)
1 Cleaner shrimp
1 Blue leg hermit
Numerous astrea & nassarius snails
2 Serpent stars

I have attached pics of what my duncans looked like 2 days ago and what they look like today.

 

[Tab28]

Your water perimeters? Some fish and shrimp pick, but the skeleton looks more like a water perimeter issue.

 

[pdt7361]

My current tank parameters are:
KH/Alk - 143.2ppm / 8 dKH
PH - somewhere 8 - 8.2
Ammonia - 0
Nitrite - 0
Phosphate - 0
Nitrate - 20ish (a little high tonight)
Calcium - 400
Magnesium - 1200
Salinity 1.026

All of the tests are API except the Mag which is a Nyos test. I test salinity using a refractometer.

 

[Tab28]

Calcium is a bit low, but that is not likely the problem. Your nitrate is pretty high and would slowly cause any coral to start to die, depending on water temps. More slowly for softies. You may want to do water change a few times a week to get nitrates between 5-10. If you are having ph swings, morning to evening .3 -.5 is common. More than that added to the nitrates maybe stressing polyp stonies.

 

[pdt7361]

No PH swings and I am guessing my nitrates are high today because of the torn up pieces of duncan coral laying in my sand bed.
I think one of my peppermint shrimp are actually a camel shrimp.

 

[pdt7361]

Here are a couple of pics of my "peppermint" shrimp. What are your thoughts? I'm pretty sure the first is a genuine peppermint, but the second looks more like a camel shrimp to me.

 

[Tab28]

Peppermint are red and clear or see through. Camel are red and white. Think a cleaner shrimp's contrast. The white is not see through. There are different shades of clearish areas of peppermint, depending on where they were collected or reared. Will not be white but kinda grayish. Kinda off since peppermint candy is red and white. But camels also do have a raised hump back, but this is not relative unless you have peppermint to compare the difference. Camels are less reef safe if not properly fed.

 

[rockskimmerflow]

Your tested water parameters don't look like anything that would present major concern for tissue necrosis on a duncan coral. I am very, very skeptical that nitrates in the 20ppm range would hurt a duncan. I've seen them thrive in systems with 0 ppm all the way up to 60+ppm nitrate. It looks like tissue loss due to a toxin or physical damage from a predator. If there are no other corals close enough to sting it then most likely some animal damaged it directly. Sometimes duncan can contract brown jelly infection like other LPS coral, but if you don't see any that's probably not the issue.

I have seen hungry peppermint shrimp eat away at just about any coral imaginable. And I'm talking about standard peppermint shrimp, not the camel shrimp that are known to pick at coral. Try feeding your shrimp or perhaps remove it if possible and see if the duncan gets better or worse. Good luck with the duncan!

 

[Bama fan]

The first pic was a blood shrimp and I have three of them and one cleaner shrimp and the same thing with my Duncan coral and it does have some kind of jelly stuff at the bottom how to get rid of it if that is what it is

 

[Bama fan]

The first pic was a blood shrimp and I have three of them and one cleaner shrimp and the same thing with my Duncan coral and it does have some kind of jelly stuff at the bottom how to get rid of it if that is what it is

 

[Bama fan]

The first pic was a blood shrimp and I have three of them and one cleaner shrimp and the same thing with my Duncan coral and it does have some kind of jelly stuff at the bottom how to get rid of it if that is what it is