A little young to be breeding..?

[bettagurl]

I have a couple of tiny goldfish in my tank, I do not believe they are stunted, because they are growing very rapidly, but I noticed that Sharky, a tiny fantail, was pushing my little calico fancy around and harassing her like my adults do when breeding.
Definitely not fighting...
they are about 1.5 inches in body length without fins.

 

[Blueiz]

What size tank is it? There are lots of reason they one cold push the other arround, the other fish is weak, territory issues, fin nipping, to small a tank.

 

[bettagurl]

100+ gallon heavily planted.
I think the male could be stunted, he came form a bad situation, but the female is most certainly not, she came from a breeder and has been in a large tank since.

He is nosing her hind end when he sees her, he won't bother with the bigger goldfish though.

 

[Flaringshutter]

If he's housed with larger goldfish, he's likely just imitating the big fish. My young goldies will often chase each other, even though they're less than a year old. Just like other young creatures, they learn by imitation.