so I see that this topic hasn't been updated for quite a while now. Still, I'd be very interested to know what happened to the hummingbird tetras. Did they make it or not? I have been searching for info about them in german forums, where two people had kept them, but in both cases the tetras died after some weeks. Probably, I will not dare to try to keep them myself. Especially not, if nobody else succeeded in keeping them alive...
All the best,
I ended up giving my remaining fish to a friend who breeds Apistos and Corydoras to see if his water parameters could save them but they all eventually died after displaying the white cloudiness. I asked the Wet Spot if they had any issues with theirs and they had this to say:
"When the fish first arrived, we noticed it on some of the larger ones, and kept them for 5-6 weeks before putting them up for sale. In that time period, we did not lose any, but the white patches did not seem to respond to anything either. We only noticed it on some of the fish, and we tried to avoid sending those out once orders were coming in. Unfortunately we did not notice any significant issues beyond being slightly more pale than normal in a few of the fish (out of 200+), so it is very frustrating to hear that the fish you received have not been doing well.
For a full run-down of what we’ve dealt with: We received the fish at the beginning of February. A few of the larger ones exhibited white patches. We tried treating them with antiparasitic meds at the start but quickly moved onto antibiotics. We have seen Glass Catfish exhibit similar symptoms in the past and the combination of meds we used usually clear them up, but it didn’t seem to affect the tetras in the same way. We also saw a similar thing happen with some Kubotai Rasboras this past week, and the meds seem to have worked instantly. Since they acclimated, we have only lost 5 fish (through 4 months). We have sold nearly 200 and have around 25 left which seem to be doing okay. There are still several with white patches that are much larger – likely the ones that initially had it that we have avoided catching.
I am wondering whether water parameters have an affect on the lethality of the problem, since that might explain why your fish have not done well and ours, at the very least, have not worsened any. We keep our tanks around 7.8 pH with very little hardness (I would guess lower than 150ppm). The room is 75-78° and they get fairly frequent, small water changes. How does your water compare? From the little I’ve read about them, they are likely softwater species that like lower pH.
I hope this helps in some way. We were not aware that the white patches were damaging the fishes as we have not heard from other customers, so I would like to see if we can narrow down our options for treatment and find something that works."
They're great fish and my favorite tetra species, but I personally won't buy them again until someone can definitively answer what causes the white patches and eventual death. Info on them is extremely limited as they're not commonly found in the hobby, but from what I've found several other people have had the same issues. Even in extremely soft, acidic water meant to replicate their supposed habitat they succumb to the condition. They are scaleless so I wonder if that makes them more susceptible to some other factor we haven't yet considered.
That said...the Wet Spot has some in stock right now if someone wants to see if they can figure it out!