My Rainbowfish Are Fighting!

[Scrotius]

I've just set up a 30G planted tank and introduced 8 Dwarf Neon Rainbowfish (Melanotaenia praecox) into it yesterday,
Yesterday they seemed peaceful and happy but this morning the red finned ones are all beating the crap out of each other!
I'm guessing the red finned ones are males and the yellow finned ones are female - I've got 4 of each.
Basically they swim up to each other, head to tail and try to bat the other with their tails. I used to have male gouramis and they did the same.
The females are quite happy.

What can I do to calm them down!?

Any tips would be greatly appreciated.

 

[minxfishy]

Yes the red edged fins are male and they seem like they are displaying to each other in the hopes of attracting the females, its relatively normal behaviour when you have a group of males.

 

[Scrotius]

Ah great! Thanks for that.
They seem to have settled down a bit now actually, do I have a safe ratio of male / female in the tank?
I ask because when I kept gouramis in my more naive days, I only had 3 males and no females, they kept fighting until the 2 less dominant ones were dead!
I don't want this to happen to my rainbows, and I'm prepared to get more females if it's necessary.
thanks

 

[minxfishy]

4 on 4 isnt a bad ratio, it can be best to have 1m to 2f though

 

[trojannemo]

what you saw is normal rainbowfish behavior when they are happy.
they are continuous, egg-scattering spawning fish. so every morning they will do this!

the males will fight, usually harmlessly, to impress the females, in the morning, as that is when they prefer to breed. the females might fight back if she doesnt like the male.

after they've gotten it out of their system, they relax and school the rest of the day. and then it starts again in the morning...

if the males are fighting in the afternoon or at night after lights out, this is typically to establish dominance. this type of fighting can lead to nipped fins and body scars, but will heal with time and clean water

do you have java moss in your tank? rainbows love spawning over moss and if they're already doing the morning routine you should get eggs laid with the moss in...

 

[Scrotius]

cool, thanks, that's put me at ease
yeah I have java moss and cabomba - I heard they like fine leaved plants, I did set up the tank with spawning in mind