Hi in respect of the babies not saying you are wrong but I am trying to understand what has happened, about 10 of the baby fish are white with red/orange spots and growing very fast, the eggs were noticed after i moved 6 large Koi and one goldfish from the pond to their new home, i thought it takes two to tango is there any way a koi can fertilize goldfish or vice verse? if not then i have no idea what has happened here?
as for the large black fish in the other picture it is over a foot long closer to 14" are you saying that this is a goldfish too? it was mainly the large black fish I was interested in?
Also do goldfish change color from black when they are babies?
CB3100 wrote: Sadly the babies are not koi they are goldfish. They are not worth anything really but you may be able to offer them for rehome on Facebook pages and such.
If you are correct then it is a bit of a relief actually as they won?t grow as big as the other 2 foot Koi in the pond consuming and stretching tons of resources from the pond itself, I also have friends that would take goldfish on but not so much koi.
Two possibilities: the young are goldfish/koi hybrids (most likely as goldfish and koi interbreed very easily) or alternatively if you added any plants to the pond that came from a stocked pond elsewhere it's possible that there were fertile goldfish eggs on them. 99.9% likely that this is just a simple goldfish/koi spawning and the babies are hybrids.
Common goldfish can reach 18 inches/10lbs in the right environment. Koi/Goldfish hybrids anywhere up to the max for a pure Koi.