guppy is a common small tropical fish, this fish because of the relatively small size, so the demand for oxygen is also very small, do not need oxygen can live. However, it should be noted that if the number of feeding is relatively large and the density is relatively large, insufficient oxygen will still be dangerous, so do not raise too much.
Mary fish is also a small fish, but it itself is resistant to low dissolved oxygen environment, so it does not need oxygen to live. This kind of fish in the wild habitat environment is also more raised, can live in fresh water, can also live in the sea, usually fed by algae and organic debris, pollution resistance is also relatively strong.
Fighting fish are generally divided into Chinese fighting fish and Thai fighting fish. Both kinds of fighting fish survive in places where the oxygen content is not high. Not only these two, but also fish of the same family as them all have an auxiliary respiratory organ that allows them to breathe oxygen on the surface of the water. Therefore, they are very resistant to low oxygen and do not have to worry about being suffocated to death.
Goldfish have a long history of cultivation in our country. In ancient times, they could be cultivated without oxygenation equipment, so there is no problem without oxygen. The species of this fish are divided into four categories, namely, grass species, culture species, dragon species and egg species, of which grass species are relatively easy to raise, and the other species still require oxygen.
