Found new fish in pond
 

Hi,

We inherited a pond when we bought our house 2 years ago. There were already 4 goldfish in it but we added two koi, one of which we never saw after a few weeks.

Today, my gf was cleaning a bit of weed out when she netted a small, green fish that had a silvery gold underside. One of the existing goldfish had been looking a bit chubby recently(!) so is it possible that it has spawned?

So, a few questions....
Are young goldfish green?
Is it likely that only one would have survived or should we expect more? (i.e. how many fish are expected from 'a spawn')
Is there anything in particular we need to do to assist it?
When should we expect it to change colour?

Ta,
Xeno