Banggai Cardinal lethargic (and more)

[H4kimWibowo27]

Hello! So around two days ago, the fish in my 37gal tank started becoming lethargic one by one.
There's
4 Banggai cardinals,
1 firefish.
1 decorator crab
6-7 small hermits
2 urchins

On the first day, I noticed 2 of the cardinals have lost most of their fins, and were not accepting food. One became lethargic and had labored breathing on the first night, and died the next morning, same thing happened to the other one the next day. My firefish also became somewhat lethargic, was spending most of the time resting on the front glass looking all tired and such, instead of its lair. He vanished on the 2nd day.

Unfortunately it was Eid so I didn't pay as much attention to them. Today I just did a slow 50% wc, and now a third banggai got the curse as well.
Does anyone have any idea what might be causing this? It's a leather-dominated tank, everything else that isn't a fish is fine.

He tries to stand up every once in a while but ultimately falls back down. He struggles to float even against the low flow I have on. I will try to put him in a quarantine box with an airstone.
Thanks y'all

 

[Jay Hemdal]

Hello! So around two days ago, the fish in my 37gal tank started becoming lethargic one by one.
There's
4 Banggai cardinals,
1 firefish.
1 decorator crab
6-7 small hermits
2 urchins

On the first day, I noticed 2 of the cardinals have lost most of their fins, and were not accepting food. One became lethargic and had labored breathing on the first night, and died the next morning, same thing happened to the other one the next day. My firefish also became somewhat lethargic, was spending most of the time resting on the front glass looking all tired and such, instead of its lair. He vanished on the 2nd day.

Unfortunately it was Eid so I didn't pay as much attention to them. Today I just did a slow 50% wc, and now a third banggai got the curse as well.
Does anyone have any idea what might be causing this? It's a leather-dominated tank, everything else that isn't a fish is fine.

He tries to stand up every once in a while but ultimately falls back down. He struggles to float even against the low flow I have on. I will try to put him in a quarantine box with an airstone.
Thanks y'all

That's a tough one. I agree that with just the fish dying and the invertebrates being fine, that this is a fish disease. The most common cause of sudden fish loss like that is Amyloodinium/velvet. However, that causes rapid breathing and this cardinal isn't showing that. I'm not sure what this could be without having some other symptom to work with.....

You may end up losing the fourth cardinal as well (this one is moribund is going to die soon). If that happens, you'll want to leave the tank fishless for 60 days so that any fish parasites die out from lack of a host.

Jay

 

[vetteguy53081]

In addition, banghai cardinals fight especially with a dominant male, why I prefer single fish, however there has been an influx of poor quality banggai due to long shipping time and overbreeding but not ruling out disease