over a period of a few hours
It depends on how many eggs there are. One goldfish per egg.
Catfish eggs are fertilized by the male after being They must be goldfish eggs. It is nearly impossible to have catfish breed on their own in a tank or pond. Any fish female can have eggs, the eggs are fertilized after the female lays the eggs. So if the eggs hatch then most likely they be goldfish.
Thousands at one time.
Several thousand in one spawning.
Goldfish are not livebearers so they are never truly pregnant. If you think your goldfish is pregnant than she is just getting ready to spawn by becoming full of eggs. Unless there is a male goldfish present the eggs will be unfertilized and will not hatch into baby goldfish fry. Your female goldfish will soon lay her eggs, and if no further action is taken, she will then eat them. As for the small tank, I would really recommend moving her into a bigger one.
One lays eggs; the other fertilizes them.
Well, when goldfish spawn they lay thousands upon thousands of eggs. The male goldfish then sprays a cloud of milt which fertilises the eggs. For a goldfish to only lay one egg which, somehow triggers a male goldfish to release a cloud of milt, is highly unlikely. Truthfully, it is the person breeding the goldfish who chooses how many fish they are willing to raise. Technically, they could choose to only keep 1 goldfish fry but realistically they would not be willing to throw away the lives of so many baby goldfish fry.
If there is a male & female together in a tank, the male will chase the female poking his head against her side & belly to get her to release eggs. If she does, he will then release what is called milt in an attempt to fertilize the eggs.Then the breeder will remove the eggs from the tank into a shallow container and care for the eggs until fry are born which are cared for until they are big enough for a regular tank.
If you're talking about how many baby fish goldfish have, they can have up to 100 eggs(babies), but only about 20-30 will live. The way you can tell which ones are dead and which ones are not is that the ones that are alive are clear, and the ones that are dead are not clear like the live eggs. Hoped that helped.
You would need to put goldfish eggs in a separate tank, and yes, you may have to take the goldfish eggs out of the main tank where all the goldfish are, because the adult goldfish will eat the eggs. However, you can just cover the goldfish eggs in a plastic see-through box while being inside of the main tank if you don't want to take it out, just in case you may harm it, and the fish won't be able to eat it.
The female can produce a batch of 500-1000 eggs, but they need to be fertilized by the male for them to become viable. She releases the eggs, they stick to the plants, walls, rocks in the tank, and then the male has to come by and spray them.
Well, If it was me I would get a bigger tank because each goldfish that you have needs 10 gallons. So like if you had 3 goldfish you would need a 30 galloon fish tank. If you don't want them to die then you might want to get like a 100 galloon tank you can have a lot of goldfish. You can get a fish tank at petco.