the fish tank is not saturated, the bigger the better, because the oxygen content is sufficient, the fish can breathe better, but if saturated, it may cause the fish to suffer from bubble disease. Although fish live in water, they also need to breathe oxygen. They mainly exchange gas through gill filaments in their gills. Water with sufficient dissolved oxygen is not only conducive to their breathing, but also helpful to the maintenance of water quality.

2. What kind of fish needs oxygen

? 1. Arowana: Arowana is a common large ornamental fish at present. Its body length is about 50-65 centimeters, and its life span is even decades. Their temperament is ferocious, while the requirements for dissolved oxygen are relatively high, artificial feeding is best equipped with oxygen pumps to ensure 24-hour oxygenation without stopping.

2. Map fish: Map fish originated in South America and was introduced into China in the last century. It can not only be used as an ornamental fish, but also has certain edible value. The size of this fish is relatively large, and the requirements for water quality are not strict, but it is also inseparable from sufficient oxygen, otherwise it will cause its head to float.

3. Siraitia grosvenorii: Siraitia grosvenorii is a kind of artificially cultivated ornamental fish. The big sarcoma on its head is its most ornamental place. It is beautiful in color, tall in stature, and has a high demand for oxygen, so it needs to be kept oxygenated.