F. This is the coldest I've ever measured. It is too pretty to let something happen to it. Here is what I read in your email. You have two Calico Fantails, and one of them is being chased and annoyed part of the time by a Pond Comet. There are some Fantails in one of the pictures above, but none of them is a calico.
Fantails have two horizontal lobes on their tails.
When a Fantail swims one lobe of its tail is behind and to the left, and the other lobe is behind and to the right. Click here to see a picture of a Pond Comet. Pond Comets also have tails with two lobes, but one lobe is above and the other below. Maybe this sounds confusing, but when you look at the two kinds of tails, it is quite easy to see the difference. These two types of Goldfish are the same species and can interbreed, but they are not really compatible.