No, however a goldfish will greatly benefit from having one. An air pump provides an added source of aeration which increases the levels of dissolved oxygen in the tank. This in-turn makes it easier for the fish to breath.
Change its water every day.
yes.
No, it means that there is not enough oxygen. Buy an air pump.
They definitely need a air pump, a filter, at least 20 gallons of water for one goldfish, a thermometer, and decorations to improve the goldfish's well-being/mood.
While it isn't required that goldfish have an air pump in their tank. It can help your tank life by providing valuable oxygen to the fish. This isn't specific to just goldfish, as all aquatic life can benefit from the presence of a air pump. If you notice your fish swimming with their lips on top of the water level most likely they are trying to get air. This is especially true for tanks that have canister or over flow filters where the water is pumped and filtered without making contact with air.
A goldfish does not need an airpump, it needs 3 stage filtration and good water movement from something such as a box filter and/or power heads. A goldfish, however, is not suited for a 5 gallon tank. 10 gallons per goldfish is the recommended minimum, as they grow very large and require more oxygen than almost any other fish. I would recommend something smaller such as rosy minnows, guppies, or if you get a heater, small tropical fish like tetras. ALL fish however, need filtration, not just an air pump.
Many things can live/survive for a while in terrible conditions.The goldfish you describe are living in spite of the terrible conditions and will inevitably become sick and then die eventually.
You need a lot of things, unless you are raising goldfish in a bowl. You need: (for a tank) A filter A tank (not recommended under 5 gal.) Goldfish food Gravel Live or fake plants (underwater plants) Air pump (not required) Choice of decorations These can be very expensive sometimes, but it will keep your goldfish living longer and happier than in a bowl
no that's ridiculous
Goldfish can survive in a pond without a pump, but it is important to ensure that the pond has enough oxygen and is properly maintained to support their health and well-being.
Yes. Every animal needs air.
An air pump is a pump which transmits air into or out of something.