Fungus or Bacterial Infection?

[Khazmodain]

I've had a farily large blue tang in quarantine for about 5 weeks. He's been through four weeks of hypo, four rounds of CP, and two doses of General Cure (metro and prazi). The entire time he's had one relatively small spot on a dorsal spine which has been getting bigger. I would have thought that the metro in General Cure would have treated most bacterial infections.. is it possibly a fungal infection?

He's terribly difficult to photograph... but I circled the spot I'm referring to in the photos. For a frame of reference the blue tang is about 6.25" so the spot is probably larger than the picture makes it appear.

Since it has continued to grow I feel like I should take some kind of action. I have plenty of meds at my disposal but would be interested what some opinions are.

Thanks!

 

[zachfishman]

Looks like Lymphocystis, a viral infection. There is no treatment except clean water, a good, diverse diet, and reducing any potential stresses on the animal.

 

[Khazmodain]

Hrmm... I'll try raising the salinity back up over the next week and continue to watch the spot. I'm sure he'd be less stressed in my 400g display than in the 55g QT, but I don't want to transfer a fish to the display with a spot that I'm unsure about. Don't think a broad anti-bacterial and anti-fungal for good measure would be advisable?

 

[zachfishman]

Hrmm... I'll try raising the salinity back up over the next week and continue to watch the spot. I'm sure he'd be less stressed in my 400g display than in the 55g QT, but I don't want to transfer a fish to the display with a spot that I'm unsure about. Don't think a broad anti-bacterial and anti-fungal for good measure would be advisable?

It wouldn't be effective against lymphocystis. You'd also risk destroying your biofiltration with the broad antibiotic. Time and good care usually take care of lymph. New fish are susceptible to it due to the stress of capture and transport plus the close quarters often shared at wholesalers with other fish carrying the virus.

Some hobbyists will trim off persistent spots of lymph by cutting off the bit of fin its growing on. I'd wait a while before resorting to this.