Another surprise in the filter

[Satanoperca]

I was cleaning out a home made large cannister filter that is on my 4 x 4 x 2 communal tank containing 7 Green Horseface and 2 Redhump horse face and lots of bristlenose

To my surprise, it was not baby bristlenose, but tiny fish fry about 8mm long, 40 in total.

The Redhumps are only jurveniles, about 9 months old, the greens are 4 years old. Both have been showing serious courting behaviour.

I rescued the fry from the filthy depths of the cannister filter and place them in a fin net back in the tank.

They are eating colored tetra bits.

Any idea on how to tell or when I will be able to tell who the parents are.

They are tiny small silvery fry with bluish eyes.

How long does it take the fry to get to about 3-4cm.

Any knowledge would be of great help.

Cheers

Benjamin