Sick Serpae Tetras - Unidentified Contagious Disease?

[somecallmedaniel16]

Hello all!

I have 5 serpae (red minor) tetras, and they all seem to be getting sick. For several months now I have had fish with this visible illness in at least one of the serpaes at any time, and I have had to replace a couple. This sickness causes dark (grayish) slightly-raised bumps, marks, and scab-like tissue to appear on various parts of the fish. I have noticed that it slowly spreads, usually starting from the head/face of the fish only as dark marks. Eventually the fish's entire body becomes discolored to a significantly darker shade. The funny thing is, the serpae tetras are the only fish that have it; the neons and zebras are fine. I have no idea what this is! I have considered parasites, but I can't be sure. Does anyone have a possible diagnosis? Maybe a similar-sounding disease? Suggestions for treatment?

Thanks in advance!

 

[WhiteDevil]

Can you get a pic by chance, enable the macro setting and zoom in.

 

[somecallmedaniel16]

enable the macro setting and zoom in.

how do I do that?

 

[somecallmedaniel16]

Not very good pictures, sorry. Tried to zoom in as much as I could.
The resolution isn't the best when it's this zoomed in, and the glare makes it harder to see, but this is my worst-looking fish.

The fish is discolored (has a dark color, even maroon-ish), and the section of its body underneath the spine behind the main organs is more transparent than normal. The fish has marks right underneath the top fin and along the belly and tail area, as well as a few marks on random spots on the side and on the face and eyes.

The fish is actually swimming strangely too; it looks like the fish is always about to do a nosedive and has to continually reer or tilt backwards. The fish does this quite often, maybe a couple times a second. Also, you may notice that it seems like the tail of the fish unusually curves upwards, which may be the reason for its balance issues. I don't know if this symptom is inclusive or due to the disease, but it is the only fish that I have seen showing this strange balance problem.

The water is clear, and I do regular water changes. I have had these fish before without this problem but now it seems that it just won't go away.

The other fish have any combination of these symptoms, but all (except for one healthy-looking fish with no symptoms) have the dark marks on their faces.

 

[somecallmedaniel16]

bump.