"Nose up" is a warning sign of a lack of oxygen
Goldfish in external respiration, oxygen uptake in the body of water with water from a mouth-breathing, out out of the gills with water and carbon dioxide in the body.
The amount of oxygen in water is proportional to the temperature blend. At low temperatures, often at high temperatures is reduced.
Note that goldfish are breathing a larger amount than when hot. Sultry day before the rains begin to rain, at times less the amount of oxygen in the water even before dawn.
Consumes oxygen and can cause harmful substances remaining rotten food and fish waste also. When the oxygen in the water often has a spacious and up-up and water comes out the mouth are missing. This is the "nose up" is.
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