Color Widow Tetra having blood on its scales | Urgent Help

[Mohanprasad]

Hello,
I have dozens of widow tetras in my 20ltr tank, which I bought a week ago. The fish were good night but when I saw them in the morning one of them got blood on its scales. I had already lost one fish a day ago. I don't know whether it is a coincidence or not but the died fish and the one now got blood on its scale both are blue color tetras. I don't know the reasons for this causing. Kindly give me the suggestions and solutions for this. And what are the things I need to know for avoiding this in the future?

 

[GaryE]

Sadly, you have bought fish with a severe bacterial infection. Without a laboratory to tell you what bacterium is doing the damage, you can't treat it effectively. Don't let the healthy looking fish feed on the dead ones - remove them quickly, or remove them before they die.

This is why many aquarists quarantine new fish before putting them in with their healthy older fish. Sometimes, they arrive with diseases.

 

[Essjay]

20 litres is a very small tank for these fish. If they don't all die from the disease Gary mentioned, you will need a much bigger tank for them going forward to keep them healthy.

 

[Mohanprasad]

Sadly, you have bought fish with a severe bacterial infection. Without a laboratory to tell you what bacterium is doing the damage, you can't treat it effectively. Don't let the healthy looking fish feed on the dead ones - remove them quickly, or remove them before they die.

This is why many aquarists quarantine new fish before putting them in with their healthy older fish. Sometimes, they arrive with diseases.

Thanks for your reply Gary, unfortunately it is died and I removed it immediately. Did I need to do anything for the other healthy fishs?

 

[Lcc86]

Thanks for your reply Gary, unfortunately it is died and I removed it immediately. Did I need to do anything for the other healthy fishs?

Move them to a larger tank, you will constantly be battling poor water quality and overstocking issues if you don't.

 

[CassCats]

These guys can reach 3 inches potentially, though most average 2.5 inches. That's a big tetra for any tank smaller than 100 liters imo. Dozen+ in a 20 liter? Yikes. You will definitely need to upgrade for these guys. Glofish unfortunately are marketed with small tanks, it's my only issue with glofish as a whole.

If water quality doesn't kill them in the small space, their aggressive behaviors will. These guys can get bossy and if crowded in a tiny space unable to establish territories, they will shred each other.