What Is This Tail Disease / Injury?

[BigTallV]

Hi all.

I have a small tetra in a 5.5G tank that has what looks like some sort of nodule or polyp in its tail. See linked photo in my webshots album: Tetra Tail

Any ideas on what it is or how to treat it (if possible)? The fish is swimming fine and has been eating well. No odd behaviour at all. Fish is a couple years old and has been in this tank since it was started some 2 years ago. Tank mates are all healthy and no signs of them having any issues.

Thanks for any help.

 

[Mikaila31]

It doesn't look like a injury to me. What are your water stats: ammoina, nitrite, and nitrate? Also was the fish dyed when you originally got it?

 

[BigTallV]

It doesn't look like a injury to me. What are your water stats: ammoina, nitrite, and nitrate? Also was the fish dyed when you originally got it?

Haven't taken water tests recently. But will post that if I get the chance tomorrow.

Yes, this tetra was purchased from the LFS in the colour as you see it (light blue). Pick either of Blueberry Tetra or Fruit Loop Tetra. I'm well aware of how they got this way and wasn't enthused. I had to explain to my kids why I was reluctant to purchase any of them.

These 'polyps' or are a growth coming out of the tail. They are translucent, pinkish with a redish coloured spot at one end. There was one on the tail many months ago. It was very small for weeks on end, eventually growing slightly (filling out rather). Eventually it appeared to burst. Now more recently two have appeared.

 

[Tokis-Phoenix]

I think the fish probably has a bacterial infection, do the growths appear filled with fluid or are they very flat in appearance?

 

[BigTallV]

I think the fish probably has a bacterial infection, do the growths appear filled with fluid or are they very flat in appearance?

They appear filled with fluid. The initial one had filled with fluid over a period of weeks, it started within the tail close to the body as a small circular discolouration and grew eventually outward from the tail, finally it deflated (or perhaps burst). There are now two of them, on on either side of the tail. This time they grew a little quicker over two or three weeks.

I did water tests this morning:
Ammonia = 0, Nitrite = 0, Nitrate = 60~80ppm, KH = 4dKH, GH = 9dGH, Temp = 78F. *Note* source tap water is dechlorinated prior to water change, tap water has 5~10ppm Nitrates. Weekly water changes are performed routinely, 20% to 30% worth. Tank is 5.5G.

Tank is mature and has been running for well over 2 years. Water tests (today) are consistent with what I logged over the first year of operation. Filtration provided by Penguin-Mini Bio-Wheel. There is one live plant (not sure of sword variety). Again, this tetra is eating normally, swimming and behaviourally normal. Is *not* hiding or lethargic in any way. Attacks food per usual.

Total stocking: There are 2 tetras, 2 neons, 1 red wag sword and 1 otto.

If this is bacterial, the other fish do not appear to be suffering the same. What would I treat it with? I do have a 10G quarrantine that I could startup with waste water and mature filter cartridge from the 5.5G and treat in isolation.