Neon tetras with black neons

[Catriona]

I have a tank with 4 neons and 5 black neons although last night one of my neons got killed by the other fish and then today I found a black neon with an alive neon in its mouth. I managed to distract the black neon with food and now the neon is still alive but weak is there anything I can do to help them and to stop this from happening again?

[Ric]

Are you sure the species have been identified correctly because they are usually a similar size?
If they have, then there is nothing you can do about it - a fish's instinct is to chase and feed. Can you separate the two species or perhaps put a divider in your tank (mesh, plexi glass with small holes in it) until the neons have grown up a bit?

[Catriona]

I've had the neons since November, so I think there fully grown there just quite small and there quite big black neons. I dont think I have something to separate the tank with

[Stephen]

Black neon tetra prefer the tank water (23-28C) a little warmer than the normal neon tetra (21-26C).
Some of my black neons grew quite big too.

Do you still have the platy?
If yes it may be better to re-home the black neon tetra and increase the numbers of the normal neon tetra and then keep the tank water at around 22/23C.
The LFS probably won't give credit for black neons but another 6 x neon tetra will only cost £10 (maybe less).

All the best


Stay safe & healthy everyone

ps
Are you in Scotland Catriona?
I have a cousin in Scotland with the same name.

[Catriona]

Unfortunately both the platies died and my lfs is currently shut.
And yes I am

[plankton]

Can you post pics of the tetras?
It would be highly unusual for small tetras to eat each other (except for small fry)......

[Catriona]

That's the best picture I could get

[Ric]

Penguin Tetras, not Black Neons. They would grow somewhat larger than the Black Neons. Never kept them myself but I have it in the back of my mind that they can be a lot more nippy than other tetras.

[black ghost]

Penguins are known for being a bit nippy.

[plankton]

Agreed, penguins can be nippy and get nearly twice the size of neons.