CanadianCowboy wrote:

As a longtime Tropical aquarium hobbyist I know of several species that
eat their young after birth, hence isolation is critical.

As a pond beginner I am not sure if Goldfish eat their babies.

Can anybody expand on the whole breeding process of goldfish ?
Do Goldfish multiply like rabbits ?

As an aquarium hobbyist, you probably know that terms like "herbivore" and
"piscivore" are completely relative with fish. Fish that can't live
without greens are generally happy to swallow anything that happens to slip
into their mouths, and even confirmed cannibals can be seen grazing on
algae. Goldfish will eat their young, but they don't seem to really go out
of their way for it. otoh, I've not seen them breed like rabbits either.

Some of the stories I've seen here have been utterly suprising - one person
saying she had 10 new goldfish last year, for instance - I'd say they
generally breed much faster than that. But in 8 years of essentially
unrestrained breeding in a 5000 gallon pond, I didn't ever see the goldfish
get to be more than a few dozen full grown adults and a few hundred young
of varying sizes.
--
derek