Water is the most important thing for fish to live. But did you ever wonder how long can a fish survive out of water? Are there any fish that can survive without water? If yes, for how long? Well, the short answer is yes. But, it varies from species to species. So, keep reading to know which fish can survive and which species of fish can’t!
How Long Can a Fish Survive Out of Water?
Fish can live outside of water but the duration varies from species to species. In general, fish breathe through their gills but there are several species that have evolved in such a way that they can stay out of water for some time.
For example, West African lungfish can stay outside of the water for years during drought. However, don’t keep your fish out of the water for a long time.
How Does a Fish Breathe Underwater?
Every fish needs oxygen as much as any animal in this world does. They have gills that are used in extracting oxygen from the water. Fish uses gills to allow water in and extract oxygen out of water.
The blood vessels on the surface of gills absorb oxygen into the body. So, basically, gills act as lungs.
Fish also use the water currents to be swept by water for a short distance to save energy and supply of oxygen in the water.
What Happens When You Place a Fish Out of Water?
When fish are taken outside water, the gills start collapsing. You can see that the fish tries very hard by flapping its fins and jumping to get back into the water.
But when the water is not available, the gills eventually collapse and the fish dies of suffocation. It is a debatable issue whether fish can feel any pain or not when they are dying.
Different Fish Species That Can Breathe Out of Water
There are several fish species that can survive without water. The duration, however, is different depending on the type of fish.
Some fish survives for a few minutes out of the water, some other fish can stay out of the water for a few hours to weeks, and there are some fish that can live for months or years.
Mudskipper: Mudskippers live most of their life on land as their skin is modified to absorb oxygen easily. These are amphibious fish that can live long out of the water. They usually live in shallow and muddy places where water is less available.
Walking Catfish: This fish has a unique organ that helps the gills to inhale oxygen directly from the air. This fish even wiggle and walk on land with the help of its pectoral fins!
Mangrove Killifish: It is also a type of amphibious fish that lives for over a month of time out of water. They can absorb oxygen through their skin and can even store it if they are staying months outside of water. When they get back in the water, they start using their gills.
Snakehead fish: They are usually found in Asia and Africa. They are amphibious fish and they can survive on land for around six days. Some fish go on living out of water for even months.
Climbing Perch: This type of fish can survive for about six to ten hours out of water. They are found in countries like India and China. They have both gills and lungs. They can be seen sometimes even in Australia and Papua New Guinea.
Eels: They look like a snake. They are found on rocky and sandy surfaces and in shallow waters deep in mud, sand, etc. They often lead a life out of water for several hours.
Pet fish: Pet fish like rainbowfish, betta fish, goldfish, etc. are all freshwater fish. They are weaker than saltwater fish. Along with that, these fish have small bodies and fragile gills.
These fish can’t survive even for a few minutes out of water. So, it is necessary that they must not be kept out of the water for a long period.
Note: We didn’t include large ocean fish like dolphins, sharks, etc. as they are not fish! They are mammals.
So, they don’t have gills and they come to the surface to inhale oxygen from the air and can stay underwater for several hours.
They can stay on land for several hours but their organs can get crushed under their weight. So, they live in water.
Why Some Fishes Leave the Water?
There are some reasons why they leave water.
- If the current environment has less oxygen, then they leave the water to get to a new place.
- To escape from predators.
- To move away from water that is getting warmed up.
- To search for food, mate, etc.
- If their ecosystem is changing or drying.
Aspects That Affect the Duration of Fish Survival Out of Water
How long a fish stays out of water depends on many factors. Some of them are listed below:
Metabolism: As mentioned earlier, fish require oxygen to stay alive. Metabolism plays a key role in determining the duration of how long a fish can live outside of water.
Warm water fishes require more oxygen and cold water fish requires less oxygen. The higher the oxygen requirement, the higher the metabolism.
So, a fish with a high metabolism (warm water fish) don’t survive for long without water. Whereas, the cold water species can easily survive for a long time.
Different fish species: The duration also heavily depends on the species of fish. Certain types of fish can live for hours to days to months outside water. Lungfish in general can live for up to 4 years without water. While some other species of fish likely will not survive if they are kept out of water for too long.
Oxygen: Some of the cold water fishes require very less oxygen than others to be able to survive without water. They are also resilient when they are out of water.