Large Angelfish bacterial infection?

[Rossboss]

To preface this post, I study fish (BS and MS in fisheries science) and have a very good understanding of disease/ bacteria/fish anatomy, but this has me stumped.

In the past week, I've lost two large established angels. A masked swallowtail angel (G. semifasciatus) and a Regal Angel (P. diacanthus). Both of these fish I have had for 4+ years and were well established, healthy, active, and great eaters.

They have resided in a 100 gallon tank since I got them and did great. In January, I upgraded to a 200 gallon. It cycled for a month with preseeded live rock from another system, then I tore down the existing tank and moved fish, rocks, etc. They have been in this system since March 1. No evidence of a cycle nor did I expect one with using all the rocks from the existing tank.

Nitrates - 0
Nitrites - 0
Ammonia - 0
Po4 - 0
pH - 8.24
Temp - 76-78
Salinity - 35ppt

Inhabitants include:
Snails and hermits
2 clowns
A fairy wrasse
Only recent addition (2ish weeks ago) was a small royal gramma.

Everyone was doing great, eating, etc. adapting well to the new tank.
On Tuesday, my G. semifasciatus suddenly died. Watched it eat food less than 24 hours before and looked great no issues. No marks on the body, fins intact, no bloating, stringy poop, cloudy eyes, etc. Chalked it up to panic in the night and striking the glass.

At this same time, my Regal went on a hunger strike and got very lethargic, hiding in a back rock structure and would not come out for anything. He went 4 days refusing food and suddenly died overnight last night. Looking at his body, I see what looks like a slight bacterial infection - frayed fins and some discoloration on the caudal peduncle, but nothing overly alarming.

I am at a loss as to these two sudden deaths. The only new fish was the gramma, but it is perfectly healthy. All other fish are doing fine, eating, and acting as usual. No signs of disease or stress. Could a gram positive (or negative I suppose) bacteria taken hold of both angels so suddenly? Did the gramma introduce something? Were the deaths even related?
Pictures in the comments of both fish and overall tank - apologies I didn't get better picture of the semifasciatus.

 

[Rossboss]

 

[viceversabrd]

Was the gramma quarantined and treated? As you know a fish can look healthy but can still carry velvet or uronema, flukes etc. I’m assuming because you did not say that you did, that it was not quarantined, that would be my most likely suspect.

 

[vetteguy53081]

Sorry to see and regal angel's tail/fins shows sign of aggression. Swallowtail hard to see in pics being heavy in blue lighting.
Any new addition with fish?
Were fish last seen breathing normal or labored?
Will be hard to tell from dead carcasses but any info with abnormalities and as loss of appetite such possible gill issues but you would see labored breathing and lethargic behavior. Any signs of hiding, etc may offer clues. If coral and inverts doing good yet, eliminates possibility of water chemistry issue and then pints to disease of some sort
Looking at bodies, uronema out of question and often affects anthias, chromis/damsels and butterflies

 

[Rossboss]

Was the gramma quarantined and treated? As you know a fish can look healthy but can still carry velvet or uronema, flukes etc. I’m assuming because you did not say that you did, that it was not quarantined, that would be my most likely suspect.

That is correct, I did not quarantine him. I did a freshwater dip and inspected for flukes and found nothing. I cannot agree with velvet or uro however because neither fish that died (nor any of the living ones) show signs of outward disease. Velvet is very distinct when afflicting its host.

 

[Rossboss]

Sorry to see and regal angel's tail/fins shows sign of aggression. Swallowtail hard to see in pics being heavy in blue lighting.
Any new addition with fish?
Were fish last seen breathing normal or labored?
Will be hard to tell from dead carcasses but any info with abnormalities and as loss of appetite such possible gill issues but you would see labored breathing and lethargic behavior. Any signs of hiding, etc may offer clues. If coral and inverts doing good yet, eliminates possibility of water chemistry issue and then pints to disease of some sort
Looking at bodies, uronema out of question and often affects anthias, chromis/damsels and butterflies

A very small royal gramma two-ish weeks ago. Healthy as can be and eating normally currently.

No heavy breathing or gilling on the semifaciatus. Was alive and well the day before. The regal looked anxious but wasn't gilling excessively, just hiding. Sensitivity to light perhaps?

Also to add - the regal was the boss of the tank. Nothing else in there to be aggressive towards it. I thought the fins looked more like a bacterial infection eating away at them.

 

[vetteguy53081]

A very small royal gramma two-ish weeks ago. Healthy as can be and eating normally currently.

No heavy breathing or gilling on the semifaciatus. Was alive and well the day before. The regal looked anxious but wasn't gilling excessively, just hiding. Sensitivity to light perhaps?

Also to add - the regal was the boss of the tank. Nothing else in there to be aggressive towards it. I thought the fins looked more like a bacterial infection eating away at them.

The fins more than tail looked bitten, and not a sign of bacterial . The hiding can be disease related and the wrasse is prone to neurological issues but amount of time gone by may disqualify that.
My suggestion, place any fish, if any into a quarantine tank and change water in the display and let tank run fallow (with No fish present) to allow diseases to die off without a host fish for 6-8 weeks

 

[Jay Hemdal]

That is correct, I did not quarantine him. I did a freshwater dip and inspected for flukes and found nothing. I cannot agree with velvet or uro however because neither fish that died (nor any of the living ones) show signs of outward disease. Velvet is very distinct when afflicting its host.

Sorry to see....I always hate losing long term captives, so much invested in them.

Actually, Amyloodinium, velvet only has one primary symptom - rapid breathing. At the very end of the infection, in some fish, you'll see a sort of dusty haze to the fish. Most infections though, are centered in the gills and are not visible externally. Online, there are a slew of pictures of fish with "velvet" but most are just advanced cases of marine ich, Cryptocaryon. Velvet in FW fish is a different organism, and those DO cause dust-like spots on the fish, but don't cause rapid mortality.

Knowing the respiration rate of the fish is paramount - so much so that I built a database of fish respiration rates (fish size and water temperature are two variables that need to be controlled). Were your fish breathing faster than 100 gill beats per minute?

You're correct - in *most* cases when a new fish brings a disease into an established tank, they are also affected. That the gramma is still doing well is odd.

External bacterial diseases of marine fish are virtually always gram negative, and in most every case, they can be identified to a genus that's already living in the tank. The become infective due to some injury on the fish, allowing them to invade tissues that the fish's skin would otherwise keep them out of. Some internal bacteria are gram positive (such as Mycobacteria).

The only thing I can really see in the pictures is the damage to the angel's tail. Those sure look like bite marks, but none of your fish would really be contenders for causing that. I guess it could be a virulent bacterial infection....

As far as seeing flukes in a dip, without a microscope, you can only see capsalids like Neobenedenia. Other flukes are too small to see.

If this were velvet, your other fish would have perished. Flukes just don't kill the fish that fast, they generally look "tattered" and scratch a lot days before dying. That pretty much leaves a bacterial infection or a virus.

Jay

 

[W31Olds]

Do you run a UV system and for the fish Medics would that help suppress a potential bacterial infection or a virus?