Copperband Butterflyfish: Tailfin "thing" emerged

[allsite]

I noticed it a week ago and I think it's getting bigger. There's a black dot at the top of it's tailfin. Since it's hard to see in the picture I'll add its on both sides of the fin and is almost a ball shape. It's a black/dark-gray color.

Disclaimer: No, I'm not talking about the beautiful black circle on it's body.

 

[Jay Hemdal]

That is most likely Lymphocystis, a viral disease. It is very common in some species, including CBB. It could be another sort of tumor, but either way, there is no treatment. In most cases, Lymphocystis goes away on its own in 4 to 8 weeks.
If you can possibly get a clearer picture, closer up, I can likely confirm the diagnosis.

Jay

 

[allsite]

That is most likely Lymphocystis, a viral disease. It is very common in some species, including CBB. It could be another sort of tumor, but either way, there is no treatment. In most cases, Lymphocystis goes away on its own in 4 to 8 weeks.
If you can possibly get a clearer picture, closer up, I can likely confirm the diagnosis.

Jay

I found this image on google that highly resembles it. Same color, same "bulky" mass, different location. It's worth mentioning I recently improved my maintenance frequency and have corrected what were very high nitrates 100+ppm (now about 20ppm).

 

[Jay Hemdal]

I found this image on google that highly resembles it. Same color, same "bulky" mass, different location. It's worth mentioning I recently improved my maintenance frequency and have corrected what were very high nitrates 100+ppm (now about 20ppm).

Most likely Lymphocystis. It may get worse, but then it will get better. The only issue is if one of them grows on the mouth and impairs feeding.
Jay

 

[allsite]

Most likely Lymphocystis. It may get worse, but then it will get better. The only issue is if one of them grows on the mouth and impairs feeding.
Jay

Thanks for identifying it. I'll probably try soaking it's live black worms in selcon. Hopefully it goes away.

 

[ChaosAquaculture]

Lymphocytes is definitely a plausible explanation to the masses/marks on your fish. I’d keep an eye out for rotting on those spots of the fin though to make sure it’s nothing more. - kali

 

[Jay Hemdal]

Thanks for identifying it. I'll probably try soaking it's live black worms in selcon. Hopefully it goes away.

While that won’t hurt, it also won’t be of any real benefit for a viral issue like this. Kinda like chicken soup for a cold (grin).
Jay