Neon Tetra Agression
 

Hi, I have five neon tetras in a 29 gallon tank with 10 other assorted small, non-agressive fish. The nitrates in the tank are always ten ppm or under. The tetras, on in particular, seem to exhibit extreme aggression towards each other. Most of the time they are biting each other's tails and two of the fish have no tail left! They have been together for about a month now...I don't really know what to do about them
Thanks
Christina

What you have my dear, is a rogue. 99% of all neon tetras are peaceful. but every once in a while a rouge pops up. Remove the rouge. Either exchange it to the store or get rid of it somehow.

Now about the tails, is it the total tail or just the fin of the tail gone.

hi
tetras need to be in a large group,
i echo the above,this one tetra is top of the pecking order
and will not stop,you could try to make the group larger
however i doubt this will stop him
take it back and presuming your tank can take it
add some more,it will give them more security.
only adding more when the other tetras are better .
:)

I had a feeling this was the answer...I can get more but can't take the fish back, either I feed him to Oscar, which makes me feel bad but I could do, or he stays.

Just the fin is gone, not the whole tail

Neon aggression
 

I was coming here to ask the very same question about fighting neon tetras. I've had a shoal of 10 for over a year in my 55 gallon tank. Just this past month I have noticed them fighting and can't figure out why this would suddenly start. It will be really tough to find the rouge and remove that one from the tank when they all look a like and catching them is NO EASY TASK. I think I'll just let mine bicker.