If you honestly dont know the answer then you should not be keeping fish.
Poor water quality can eventually kill goldfish; this can be caused by a lack of regular maintenance, or even by overstocking your tank.
Why ask such a stupid question... NO.
no
No.
yes
Yes, goldfish can survive without food for two days.
No you mook
Goldfish
Goldfish are freshwater fish and can not survive in saltwater environments (oceans, etc) They can only survive in freshwater (non saltwater such as ponds, rivers, and lakes).
Goldfish need water to swim and breath in, not mud. There are some species of fish that have evolved to survive in mud but Goldfish are not one of those species.
It is possible that they may survive but not really likely.
It should be fine.
A swordtail is a tropical fish and a goldfish is not. The swordtail would need a higher temp. than the goldfish. Depending on where you live it probably wouldn't survive the winter.
No. Like all members of the carp family, goldfish can survive in a wide range of water temps.