Early sign of neon tetra disease?

Hello,
One of my neon tetras have a small yellow-white patch on its tail. In the picture it appears to be flat but it's actually a raised/bumpy mass on it's tail. Could this be neon tetra disease. It was hiding in the plants yesterday but it seems to be schooling today. In the tank there are 8 other neon tetras and 15 rummynose tetras.

On it's body there are also two small white streaks (just visible in the picture where the blue pigment ends). I've had these with cherry barbs before in my other tank but nothing came of it. Just wondering if this is something to be concerned about in this case.

The water is as clean as can be. 180L tank with just these fish in there and weekly 20% water change.

Thanks so much everybody!

 

Probably false NTD (Columnarus strain) but not the real NTD.

 

Thanks for the reply. Would you recommend me return this specimen to the pet store? They've a 30 day guarantee on live fish. My rummynose have given me enough trouble in the past, but they all managed to pull through various diseases from ich to columnaris. Would it be possible for them to be immune now and therefore do not require the neon tetra to be removed?

 

Some of mine have had similar symptoms for months with no obvious ill effects.

 

Hey guys, here's an update. So I've now separated this individual from the rest. As I don't have a quarantine tank available, I am just floating him inside a transparent Ferrero Rocher chocolate box lol. The box is still in the main tank so heating/light cycle are all unchanged. It is only half filled to prevent him from leaping out and to reduce pressure (if that helps him at all).

So far it's looking good for him. The symptoms are still there but have not spread to other parts of his body and have not gotten bigger. He is eating normally.

I did manage to get some better photos of him now that he doesn't have a lot of space to swim away from me haha. Here they are, see if you guys can diagnose anything from these:
- left side of body has two cloudy streaks where the blue pigment ends.
- bumpy white mass at base of tail
- Very small white spec on top half of tail (I'm certain it's not ich but don't know what else it could be).




Thanks for all the help!