Help, What's This?

[Flubberlump]

This is one of my parents' black widow tetras. It's developed this wound over the last few days. It looks open, and there's what looks like a red ulcer in the middle of the black bits. It also has it on the other side, and two of the other black widows have smaller patches on them, although not in the same place.

Does anyone know what it is and how to treat it?

Tank size: 125ltr
pH: 7.5
ammonia: 0
nitrite: 0
nitrate: 10
kH:
gH:
tank temp: 24C

Fish Symptoms:
black lesions, look like they're rotting, the worst one (in the photo) looks like it has a red ulcer and some white bumps. The fish in the photo has one on each side of it's head, and one on one side, another of the fish has a small one on it's tail, and the third one has one on one fin. All three fish are black widows, and seem to be behaving and feeding normally.

Volume and Frequency of water changes: 20-30% weekly

Chemical Additives or Media in your tank: none

Tank inhabitants: corydoras, kuhli loaches, 1 bristle nose plec, rummy nose, neon and black widow tetras.

Recent additions to your tank (living or decoration): live plants, but pretty sure this started before they went in.

Exposure to chemicals: none

Thanks in advance!

 

[Flubberlump]

Anyone have any ideas?

 

[Flubberlump]

No one? I don't know how to treat it.

 

[fluttermoth]

Sorry you haven't got any replies yet; it's a bit of a tricky one.

My best guesses would be; injury from scrapping between the tetras (I've always found them a very nippy fish), heater burn or a bacterial infection.

I would recommend a course of Myxazin, which I've always had good results with.

 

[Flubberlump]

Thanks Fluttermoth I thought it might be an injury that had ulcerated, then a secondary fungal thing where the white bits are. Where can I get myxazin from?

I did wonder about the heater, but as three of them have it I thought maybe it might be a bit less likely.

You're right about them being nippy! They're not as bad as a lot of barbs or other fish, but they're much more nippy than any other tetras I've kept.

Is myxazin safe to use with any fish? I could just about scrape together some bits for a quarantine tank though I think if I need to, just need to buy another heater. I think that's probably best.

 

[fluttermoth]

You can easily get Myxazin online, or most LFS stock it. I'm sure it is safe for scaleless fish, like the kuhlis, but if you can quarantine to treat it might be safest to do that.

 

[Flubberlump]

I've just found it on the pets at home website, that's close to me so I can get it from there. I'll get a little heater too. My sister has an old 30ltr or so tank that I can use, and I'll steal a bit of filter media from the main tank. They've just got a new filter for that tank so I can use the old filter.

Thanks a lot fluttermoth really appreciate your help!

 

[fluttermoth]

You're welcome, I hope they get better!

 

[Flubberlump]

Me too, I'll keep you updated.