Koi and goldfish can be kept in the same pond, but there are a few things to keep in mind. Koi and goldfish
Both koi and goldfish can be beautiful and they come in a variety of colors. Koi will breed with the goldfish. Some of the baby fish (fry) will be born brown or grey and may turn orange as they get older. These fish will not be pure koi, something that doesn’t really matter unless you are really into koi!
Koi have whiskers called “barbels” while goldfish do not. Sometimes when they are kept together in the same pond, the fry come out brown. While some of them will turn a color as they get older, some will stay brown. Both koi and goldfish are a carp species and are originally from Asian descent.
What about having too many fish?
Fish will procreate like crazy in a healthy pond. Goldfish will eat koi eggs and fry (baby fish). While very few will make it, the population of the fish overall will stay at a manageable rate. Koi often nibble more at floating plants like water hyacinth and floating lettuce. Wondering how many fish your pond can sustain? Read How Many Fish Can I have? in our Ponds 101.