drown it then flush it down the toilet
Take it to the vet
That is a disease cure it
yes, goldfish can get traumatized. if the are scared enough, they might get sick or even jump out of their tank if their isn't a lid on it.
Goldfish are naturally attracted to rotting fins, so if your goldfish has rotting fins get a cure for it or change your water. Or, in the other case, if that goldfish is bullying its tankmate, move the bully or victim to another tank or return the bully to the pet store.
That is what Ryunkin Goldfish look like. If however, the fishes scales are sticking out like a file or rasp, the fish is suffering from a fatal disease called Dropsy. There is no known reliable cure for Dropsy. There are expensive medications available at pet shops that make the claim to cure Dropsy but in my experience they do not work.
Huh? Come again? As far as I know, (sorry,) Goldfishes do not, um, become pregnant. Instead, they lay eggs. Your goldfish is most probably either down with dropsy (touch wood, okay? There is no cure for dropsy) or laden with eggs.
Long, stringy feces can be a clue in informing you that your goldfish has constipation. You can know this when the feces do not fall from the fish right away. To cure this, I suggest that you feed the goldfish the insides of boiled frozen peas for a few days. Eating too many fish food that are full of protein can be the result of constipation, like pellets.
Yes. It may have a hard time swimming for awhile until it gets used to it. Sorry, there is no cure.
This will depend on what is wrong with your fish. For the best health of your fish, you need to first make sure you have enough room for them, so for goldfish that means 20 gallons for one goldfish, plus 10 to 15 gallons per additional goldfish (that means at least 30 to 35 gallons for 2 goldfish). You must have good filtration on the tank, and do at minimum a 50% weekly water change in the tank as long as you are not overstocked.
Some common breeds of goldfish are: the Black Moor goldfish, the Ryunkin goldfish, the comet goldfish, the common goldfish, the Calico Fantail goldfish, the telescope eye goldfish, the bubble eye goldfish, the pearl scale goldfish and the Oranda goldfish.
If your goldfish is swimming upside down, that probably means it has swimbladder disease or something of the sort. To cure this, I suggest you feed your upside-down swimming goldfish the insides of boiled peas. I never tried it myself, but on the internet I saw the story of a person who fed his upside-down swimming goldfish some peas and the next day it was swimming normally! Try it! It will cure constipation too. But if your goldfish is floating upside down, there is a high possibility it is dead. Poke it or fish it up with a net. If it moves or thrashes around when you pick it up in a net, then it is alive.
No your goldfish did not "evolve" it "SURVIVED" being put in salt water. You don't say how much salt is/was in the water but placing a goldfish in water to which 1 teaspoon of salt has been added per gallon is a commonly used cure for fungus. Goldfish did not evolve they were selectively bred by Chinese aquarists from a species of wild Asian carp (Carassius gibelio) that had evolved over many millions of years.