Fish lose color and die

[pyroboy1der]

I've been fighting an unknown menace in my tank and am at my whits end.

I've had the exact same series of events happen several times now and I have no idea what I can do about it, if anything. Here's what happens.

Day 1: The fish looks healthy. It acts normally. Swims normally. Eats veraciously. Socializes just as it always has. In short. Day 1 the fish is 100% normal.

Day 2: The fish still acts normally, Swims Normally, Eats normally, Everything from top to bottom the same as day one EXCEPT the color on the fish looks washed out. It's as simple as that. No it doesn't look like spots from Ick. No it isn't a coating on the fish like velvet. It's just that the pigment on the fish has suddenly been diluted 50% with white. That is the one and only change.

Day 3: DEAD FISH.

So far I've had this process happen with: 2 Chromis, a Royal Gramma, a Blue Gugeon Goby, 2 Kole Tangs, and 2 Despar Anthias.


The kicker; I STILL HAVE OTHER FISH IN THE TANK THAT ARE TOTALLY FINE. Through the whole process I've had 2 O.Clowns, a Flame Angel, a PJ Cardinal, a Carpenter wrasse (TPM), and a green Mandarin.
The fish that have died have been in the tank on the short end 2-3 weeks and on the long end 2+ years.
The only fish I've added since the start of this that has survived is 1 Despar Anthia that survived when the group of 3 was added.
All corals are healthy and inverts (Anem, sea star, Shortspine Urchin and CUC) are all thriving.

After the first batch of deaths (5 all together including the fish that had been in the tank the longest) I waited 2 months before adding any livestock to see if the problem returned.
After 2 months with no Ill signs i replaced the Tang. The replacement died after about a month.
2 months following that I added 3 Anthias. 2 died in a week or two and the one has survived. I can't fully attribute these deaths to the same pattern as they hid much of the time but I thought it good to note them.
1.5 months after the Anthias were added I replaced the tang again. That was 10 days ago and today he might be looking a little white.

What I want:
What could this be? Why are some of my fish immune and not others? I have scoured for potential answers for what it could be but come up empty handed. Once I know what it is I can treat for it but right now I'm just sitting and hoping.

What I don't want:
Please don't just tell me to QT all my fish. I know how to QT. I made the decision 6 months ago when this started that it was already too late to try a mass quarantine to eliminate the problem. All of the fish in the tank have clearly already been exposed to whatever it is that is causing this. Unless you can give me a good, scientifically sound, explanations for what is causing this I'm not going to go through the trouble of QTing all my fish just to potentially have the problem occur again after they are re-introduced to the tank. Yes I do understand that some parasites and other fish diseases have either a dormant period or cystic period that require animals other than fish and removing them from the equation could clear up this problem. If you can prove to me with a high degree of confidence that would be part of a good, specific, treatment plan I will do it.

Yes I understand this may be harsh but I want real answers from people with good experience and backgrounds and not just wild speculation on what this"might" be. I AM willing to treat my fish in QT but I want a specific, targeted treatment instead of just dumping them in copper soup and hoping for the best.

Before you ask:
-Tank is 2.5 years old. 75 gallon with sump.
-Yes my water quality is good. Phosphate ~0.05 Nitrate ~5 Checked by Hanna checkers (yes I know how to use them) Nitrite and Ammonia at 0. Salt 35ppt checked with well calibrated refractometer (I have two sets of calibration fluid to check against and they both agree it is accurate.)
-Yes I use exclusively RODI water.
-Yes I have tried dipping the fish in both fresh water and Methane blue once they start showing symptoms, It doesn't keep them alive
-Yes I have tried QTing the fish that look sick. They still die in QT.
-Yes I purchase all my fish from reputable distributors (DFS) and they are healthy and well QT'd when I receive them.
-My fish are fed quality pellet food twice daily from an auto feeder and once daily a frozen food that includes both garlic and Selcon.

 

[Deinonych]

Frankly, the answers you receive here are going to be speculation at best, since none of us are able to observe your fish directly. I could venture a guess based on the timeframe and description, but you don't want that.

 

[pyroboy1der]

Frankly, the answers you receive here are going to be speculation at best, since none of us are able to observe your fish directly. I could venture a guess based on the timeframe and description, but you don't want that.

I said no WILD speculation.

I understand without actually witnessing the process one can't give a precise answer. I simply wanted to head off the answers of "yup QT for 9 years with copper because they're sick and that's what one does when fish are sick." If you have experience with a similar issue or are aware of something that could cause these specific symptoms that is what I'm looking for. Even if it's "Oh that sounds similar to this parasite and the treatment for that is..." it's more than I've already got.

I've done my best to give as much information as I can about the situation but if other answers would be useful I welcome questions.

 

[GroktheCube]

Have you tried examining mucous, skin, or gill tissue from any of the dead fish under a microscope?

I take it you didn't quarantine any fish before putting them into the tank?

Brooklynella can present with fading color (especially on/around the head) initially before it takes on the classic "peeling" appearance, and it can kill very quickly, but fish don't go from behaving normally to dead in 24 hours.

I'm not really aware of much of anything that takes a fish from normal behavior (including breathing) to dead in 24 hours, other than poisoning or hypoxia.

EDIT: Severe infestation with flukes can cause fading color and rapid death, but I don't think fish can develop any sort of immunity to them.

 

[pyroboy1der]

Have you tried examining mucous, skin, or gill tissue from any of the dead fish under a microscope?

I take it you didn't quarantine any fish before putting them into the tank?

Brooklynella can present with fading color (especially on/around the head) initially before it takes on the classic "peeling" appearance, and it can kill very quickly, but fish don't go from behaving normally to dead in 24 hours.

I'm not really aware of much of anything that takes a fish from normal behavior (including breathing) to dead in 24 hours, other than poisoning or hypoxia.

EDIT: Severe infestation with flukes can cause fading color and rapid death, but I don't think fish can develop any sort of immunity to them.

I actually thought it was brooklynella at first but ended up dismissing it because it DIDN'T kill everything. I haven't examined any dead fish tissue under a microscope because I wouldn't know what I would be looking for. I did do a small examination of the dead fish and didn't see anything out of the ordinary (other than the fish not being alive that is) on any of them. If i were to look at it what should I be looking for?

I dismissed flukes as well because whenever I've been able to capture a fish to dip nothing has ever come off of any of them. Is there something else I can do to check for them?

The normal behavior is the most frustrating part to me as well. The fish behave totally normally. They don't flash or gulp. They eat well and aren't breathing hard. If you have ever seen a Clown Tang change it's color when it gets upset you'll have an idea of what the color change looks like. There is no coating on the fish and their slime coat is normal the pigment within the skin simply looks washed out and pale.


As for my QT procedure. I do and and I don't. Any fish I get from a source I don't trust get 2 weeks in QT. However most of my fish come from DFS because their retail outlet is only 1.5 hours away from me and my work takes me in that direction at least once a month. All of their livestock comes from QM (all quarantined before shipping) and their large fish system is treated with copper as well. If I ever purchase anything not in their copper system or something that has been their less than a week I QT myself again but that hasn't happened in well over a year and a half. No, it isn't perfect but no QT procedure is.

I should also mention that about 6 weeks ago this tank underwent a move. I moved house and it took me about 6 hours total to move the system. I had no casualty and took that as a good sign that all of the inhabitants were able to undertake that level of stress without showing any adverse affects beyond being upset at me the next day.

 

[GroktheCube]

I actually thought it was brooklynella at first but ended up dismissing it because it DIDN'T kill everything. I haven't examined any dead fish tissue under a microscope because I wouldn't know what I would be looking for. I did do a small examination of the dead fish and didn't see anything out of the ordinary (other than the fish not being alive that is) on any of them. If i were to look at it what should I be looking for?

I dismissed flukes as well because whenever I've been able to capture a fish to dip nothing has ever come off of any of them. Is there something else I can do to check for them?

There's a photo of Brook here: http://www.chucksaddiction.com/brookynella.html

It's relatively large. You might even be able to see it moving around in the slide.

You hear reports here and there of fish developing some level of resistance to brook, but IDK how reliable and long lasting that resistance is.

Amyloodinium is smaller than brook, but would stand out reasonably well under a microscope because it is dark colored. This page has a photo of gill tissue infected by velvet:
http://www.merckmanuals.com/vet/exotic_and_laboratory_animals/fish/parasitic_diseases_of_fish.html

Sometimes gill flukes can be very small, about 1 mm. Easily visible under even low magnification, but can be tough to spot with the naked eye unless you have them against a black background.

I've never heard of fish developing any kind of immunity to gill flukes though, so they don't really seem as though they'd be a likely cause.

Given what's going on, if you have another fish kick the bucket, I'd be inclined to look at mucus and gill tissue under a microscope.

If you don't turn up anything there, I'd be inclined to cut them open to see if you see anything obviously wrong internally (gross organ damage, internal flukes, etc). I tend to be a bit like a dog with a bone with this kind of thing.

The normal behavior is the most frustrating part to me as well. The fish behave totally normally. They don't flash or gulp. They eat well and aren't breathing hard. If you have ever seen a Clown Tang change it's color when it gets upset you'll have an idea of what the color change looks like. There is no coating on the fish and their slime coat is normal the pigment within the skin simply looks washed out and pale.


As for my QT procedure. I do and and I don't. Any fish I get from a source I don't trust get 2 weeks in QT. However most of my fish come from DFS because their retail outlet is only 1.5 hours away from me and my work takes me in that direction at least once a month. All of their livestock comes from QM (all quarantined before shipping) and their large fish system is treated with copper as well. If I ever purchase anything not in their copper system or something that has been their less than a week I QT myself again but that hasn't happened in well over a year and a half. No, it isn't perfect but no QT procedure is.

FWIW, every DD fish I've gotten has pooped out parasites after I've fed it medicated food in QT, so there QT definitely isn't flawless either.

I should also mention that about 6 weeks ago this tank underwent a move. I moved house and it took me about 6 hours total to move the system. I had no casualty and took that as a good sign that all of the inhabitants were able to undertake that level of stress without showing any adverse affects beyond being upset at me the next day.

This is definitely a strange case. If it were a poison or hypoxia, you'd expect all the fish to be affected. If it were a "normal" disease, you'd expect to see some sort of progression over more than 24 hours. OTOH, if it happens a couple weeks after fish are introduced, that does suggest some sort of incubation period.

Hey, who knows, maybe you've found some sort of "new" disease. Something viral?

 

[Deinonych]

FWIW, every DD fish I've gotten has pooped out parasites after I've fed it medicated food in QT, so there QT definitely isn't flawless either.

I don't consider the procedures/protocols at DD to be thorough enough to call it quarantine. It's really more conditioning and acclimation of the fish for captive life. That's why they recommend QT for all new fish. QM doesn't QT their fish either, although they do run low levels of copper if memory serves (which presents its own set of problems).

 

[pyroboy1der]

This is definitely a strange case. If it were a poison or hypoxia, you'd expect all the fish to be affected. If it were a "normal" disease, you'd expect to see some sort of progression over more than 24 hours. OTOH, if it happens a couple weeks after fish are introduced, that does suggest some sort of incubation period.

Hey, who knows, maybe you've found some sort of "new" disease. Something viral?

Thanks for the info. It definitely didn't look like Brook but stranger things have happened than a disease showing abnormal symptoms. If I get another fish to examine I'll dig up my old microscope and see what there is to see on the gill tissue. Fingers crossed that won't be necessary. I sure hope it's not a new disease. figuring that out sounds like time and money I don't have. But maybe it would get named after me... that would be interesting.


FWIW the Tang I was concerned about is swimming around normally still and his coloration looks normal as well. Perhaps I was just being hyper sensitive to it after all the fist that were lost before.

 

[zland1]

Could it be where you are buying the fish? is it a new store maybe they buy fish collected with Cyanide?

 

[theoregonian]

Could be something is slightly off with the tank... the new fish are stressed from new environment so they die but the stronger established fish survive. Do you have a cobalt neotherm heater? Those are known to leak toxins into tank. Also a guy had a problems with a cheap uv sterilizer leaching plastics/chemicals into tank.

 

[Aliasger789]

I have had a same situation in my tanks, i have 2 x 4000 US gallons of marine aquarium and had this problem a year ago. Can i see the filtration you have ? if you could post few images?