Some fish are aggressive when it comes to food. The fish may simply not have enough space, the fish they are chasing may be pregnant, and the others are chasing it in order to get her to "drop" (have the fish babies) or the fish they are chasing may be sick and dieing.
They could be mating or just trying to play with eachother.
The white dots mean the males are ready to spawn. The spawning procedure of goldfish is to chase one another.
They will chase eachother's tails.
Yes. My red ear slider turtles love to chase, catch and eat goldfish.
No. It is a territorial thing.
Take your goldfish. They will travel.
If they get hungry enough then they will resort to cannibalism. Meaning, yes the strongest will eat the weakest. I suggest you keep your fish fed!
Usually once the chase starts the breeding starts so both actions happen at the same time. The chase is a part of the breeding cycle.
Usually if your goldfish is a boy it will chase the girl around..also it will be more narrow if you look at it from the top and the girl will be fatter (due to pregnancy). Another way to tell is the fin. If the fin is more of a wave it is a girl; if the fin is more of a spike then your fish is a boy. Hope this helps!
I would name my black goldfish Fin
Goldfish are peacefull fish and do not normally fight with one another.
I have 8 goldfish and I believe you should not have a mix of those two fish breeds because they like different water temps., food, and other things. I believe you shouldn't get another goldfish.