[hyphen]

5-6 inch red bellies aren't sexually mature. they're still considered juvenile

 

[hyphen]

and to add, the rubbing and swimming in circles is most likely a territory dispute. they do that to basically arrange the pecking order and territories in the tank. my caribes did the same thing and it ended after a few days.

 

[hyphen]

5-6 inch red bellies aren't sexually mature. they're still considered juvenile

[snapback]884446[/snapback]​

I don't quite agree with this. The size of your piranha depends on the conditions that they live in and the nature of the fish. Not only on the maturity.

If you follow a shoal for a while you will notice that some of them are smaller than the others. In my shoal I have fish with almost a 2 inch difference aalthough they were the same size when they were small.

[snapback]884466[/snapback]​

good point. but stunting the growth of baby piranhas would be pretty tough. i mean, it takes about a year, on average, for a piranha to reach sexual maturity from birth [give or take]. and a piranha shoots up to the 5-6" mark in a very short time. usually around 4-5 months. and to stunt their growth at that young of an age would require someone to be holding the babies in a goldfish bowl and feed them nothing but cornflakes.

what i'm trying to get at is that stunting is usually seen past the 6-7" mark [in most cases i would think], unless they were put through some serious neglect.

either way, if they are breeding, then best of luck to you.