I suspect that in the right envrionment, many breed relatively easily too. I recently moved a large population of about 8 varieties of Rainbows out of my 180 gallon tank into a 55 gallon tank with the intention of completely redoing the 180 gallon tank.

I got busy and wasn't able to get around to tearing down the 180 gallon tank for about 4 weeks. Much to my suprise, when I turned on the lights, I spotted 8 fry.

Now, I have no clue what kind of rainbow these fry are <grin> ... I guess I am going to find out <grin> ... I believe that they are either Australian Rainbows or Turquoise Rainbows. Both of these groups had larger populations with fish that had frequently displayed the right characteristics <grin> ...

I have two huge 6 inch bright red Red Irian along with one female that remained totally silver. I also have numerous 5 inch Bosemani that just never did color up like I think they should have (of course others still thought they were beautiful!)

All of these schools were hunter seekers <grin> ... I used to drop baby black molies and baby swordtails into the tank ... even in a heavily planted tank, they could not survive long ... and no matter what people say about them having large mouths but small throats, anything that moved was considered food ...

Greg