How often do fish tanks change water? Why can't fish leave the water? How long can it live without water? Which fish live without water?

Nowadays, many people like to raise fish at home. In addition to regular feeding, they also have to change water regularly. So, how often do fish tank culture change water? Why can't fish leave the water? How long can it live if there is no water? Which fish can live out of water?

How often do you change the water in the fish tank?

Generally speaking, when the weather is colder in winter, the water in the tank will not be changed so quickly, so it does not need to be changed as quickly as in summer. When we find that the fish begin to float to the surface to drink water, it shows that who in the fish tank has been deprived of oxygen, this is that we need to change the water. And we can also raise some useful aquatic plants in the fish tank, which can supply oxygen through photosynthesis. In addition, in the replacement of new water, we should also pay attention to the temperature difference of the water, the temperature difference can not be too large, otherwise the fish will not adapt and get sick.

Why can't fish leave the water?

The fish sucks the oxygen in the water by the four gills in the Gill cavity, and then the carbon dioxide in the body is discharged into the water through the operculum. As soon as it leaves the water, the water will not flow to the Gill cavity, and the gills will dry quickly, and the Gill pieces will adhere to each other. As a result, the fish can no longer breathe through their gills, and without breathing, the fish will die from lack of oxygen.

How long can it live if there is no water?

How long fish can live without water is related to the species of fish. Carp can live for 10 minutes without water, crucian carp can live for 20 minutes without water, and other fish can live for 10 minutes. However, some fish will live for a few days as long as they have a certain amount of humidity, and the black fish will have strong vitality. As long as there is a layer of water at the bottom of the container, there will be no problem to live for a day in a cooler place. If the environment is very dry and exposed to the sun, maybe half an hour. The koi can not die for about 10 minutes or even an hour after leaving the water, which has a lot to do with whether he has water and the size of the fish. If the koi less than 10 centimeters are directly put into the dry ground, they will be basically hopeless after 10 minutes. If you put ten kilograms of koi in a moist and dark environment, you may live for an hour.

Which fish can live out of water?

1. Catfish: it lives in swamps, estuaries and mudflats. It is famous for its ability to climb and bounce outside the water. It can breathe air and moisture in the Gill cavity outside the water. It can survive on land for a long time. If it does not swim out of the water periodically, it will die. Catfish have the habit of looking for food out of water. Whenever the tide goes out, they often rely on their pectoral fin muscle stalks to crawl on the mud to find food, or climb to rocks or mangrove bushes to prey on insects, or climb to rocks to bask in the sun. When it comes out of the water, the developed Gill chamber is filled with air and the tail is immersed in water as an aid to breathing. Living away from water has become an important habit of it.

2. Climbing perch: sea bass climbing is commonly known as walking fish, which is famous for living outside the water, crawling and climbing, breathing air, living in ponds and ditches, and sometimes jumping out of water or "walking" briefly with the help of hard spines on the tail and the lower edge of the Gill cover, so it is commonly called walking fish. The suprabranchial apparatus of the climbing perch is well developed, which can breathe air, support the body with pectoral fins, move forward like a seal, and can maintain life on land for hours, because some of the gills are wrinkled like rose petals and are covered with capillaries, which can directly absorb oxygen from the air and carbon dioxide from bleeding.

3. Eel: the eel can breathe through its skin and sometimes leaves the water. As long as the skin stays moist, it will not die.

4. Snakehead: Ophiocephalus Argus can survive for a long time after leaving the water.

5. Mackerel: a kind of fish that can live on trees for months, also called mangrove mackerel. The fish live in Latin American swamps, and whenever the swamp they live in dries up, they try to "climb" into the trees in the swamp, hiding in cracks or holes in branches or trunks for several months. This small creature can temporarily change its physiological structure so that it can breathe air, retain moisture and nutrition with its gills, discharge waste with its skin, and return to its original appearance after returning to the country.

6. Lungfish: lungfish use full cysts as lungs, hide in the substrate when the river is dry in the dry season, and wrap themselves in waterproof dry mucus sacs to survive. "Lung" is in fact derived from the specialization of well-developed animals, so some species can breathe air and survive even without water. In water, fins can support the body like feet.

However, it is worth noting that all fish need water, even if they can live without water, it is temporary, and water fish and crocodiles cannot live on land for a long time.