Male goldfish will start chasing the females, displaying their fins, and nudging them with their noses. The males may also form a "T" shape with their bodies, with the female positioned in the middle.
Spawning:
When the female goldfish is ready, she will release a few eggs, and the male will immediately fertilize them. The female will then continue to release eggs, and the male will fertilize them until the female is done spawning.
Number of eggs:
The number of eggs released by a female goldfish can vary greatly, from a few hundred to several thousand.
Egg development:
The fertilized eggs will hatch in a few days, and the fry (baby goldfish) will emerge. The fry will then begin to swim around and feed on microorganisms in the water.
Caring for the fry:
The parents will not care for the fry, so they must fend for themselves. The fry will grow rapidly, and in a few months, they will be adults and ready to spawn themselves.