What's this on my cardinalfish?

[zaphod42]

And what should I do to treat it? Thanks for any help
Aquarium Parameters:
Aquarium type: was in reef, now in QT
Aquarium water volume: 40g breeder usually, now in 10g QT
Filtration type: HOB tidal on main tank, canister on QT
Lighting: popbloom 90
How long has the aquarium been established? 3 years
Digital image of the whole aquarium under white light

Water quality (be sure to indicate what measurement units you are using, as well as the test kit brand)
Temperature: 77-78
pH: 7.9-8.1 (salifert)
Salinity / specific gravity 1.0255-1.0258 (tropic marin hydometer)
Ammonia 0
Nitrite 0
Nitrate 0.2 (trying to raise it up with some ammonia dosing)
Phosphorus 0.08

 

[Jay Hemdal]

And what should I do to treat it? Thanks for any help
Aquarium Parameters:
Aquarium type: was in reef, now in QT
Aquarium water volume: 40g breeder usually, now in 10g QT
Filtration type: HOB tidal on main tank, canister on QT
Lighting: popbloom 90
How long has the aquarium been established? 3 years
Digital image of the whole aquarium under white light

Water quality (be sure to indicate what measurement units you are using, as well as the test kit brand)
Temperature: 77-78
pH: 7.9-8.1 (salifert)
Salinity / specific gravity 1.0255-1.0258 (tropic marin hydometer)
Ammonia 0
Nitrite 0
Nitrate 0.2 (trying to raise it up with some ammonia dosing)
Phosphorus 0.08

How long have you had this fish? It looks like a longer term captive.
Is it showing any other symptoms?
How long has it had this spot?

Most likely isn’t anything to be treated. If it happened suddenly, it’s probably an injury. If it grew in size over days to weeks, it could be a tumor.

 

[zaphod42]

How long have you had this fish? It looks like a longer term captive.
Is it showing any other symptoms?
How long has it had this spot?

Most likely isn’t anything to be treated. If it happened suddenly, it’s probably an injury. If it grew in size over days to weeks, it could be a tumor.

Have had it for about 2 years.
Seems to possibly have a bouyancy issue? It seems to need to swim down to stay in place.
I just saw the spot yesterday.

 

[vetteguy53081]

Have had it for about 2 years.
Seems to possibly have a bouyancy issue? It seems to need to swim down to stay in place.
I just saw the spot yesterday.

Im seeing possible bladder and these fish typically captive age . . . 3-4 years. Jay mentioned tumor, not ruled out. If this was gradual, may be the case as bladder would have a quicker onset

 

[wasabi bean]

Yeah i can say having an older cardinal myself that this fish does look bloated, might just be my one but it flattens out in the belly behind the pectoral fin so it does look like its a bladder issue