Ever visited an aquarium, seen the majestic species of fishes, and wondered ‘how long can a fish live out of water?’ Well, today is your lucky day. You do not have to be an Ichthyologist to know that water is crucial for the survival of fishes.
The phrase ‘fish out of water’ literally refers to one who is either out of place or in a new environment. Fishes need water as much as humans need air, they just get their oxygen from the water. Now, to answer the premise, there are a lot of factors that need considering. Yes, fishes need water to survive, but how long can they stay alive even as they are away from water bodies? To answer this, we will need to delve deep into some of these factors just to exhaust all possibilities.
Factors to consider where the lifespan of fish out of water is concerned
- The type of fish
There are over 28,000 different species of fishes, each one with its distinct physiology and anatomy. Hence to generalize the answer of the premise based on the observation of one or two species would be fallacious. Thus, it’s been researched that while some fishes can survive a few seconds fresh out of their major oxygen source, others can still be alive for several days or even a month after they’re displaced from their natural water-based habitat. National Geographic even claims that before evolution, while some fish species have developed the ability to breathe air or even cross dry roads, others are amphibious and hence can survive out of water. Even the whale as much as it’s classified as a mammal, cannot survive without frequently coming up to the surface for some ‘fresh air’. Some fishes have their tails dipped in both worlds and they are called amphibious. Let us look at some of these fishes which have adapted to staying out of the water.
- Amphibious fishes
These are species of fishes that have the anatomical features to store and absorb the diluted oxygen in the water into their skin which they channel when they are out of water.
- The snakehead fish: This fish can survive anywhere from 6 days to several months out of water. They are freshwater fishes and they can travel on land in search of new habitats.
- Lungfish: As its name implies, the lungfish has a sophisticated respiratory system which includes lungs and air sacs. These fishes can breathe air and while its Queensland specie can survive several days without water if kept moist, it’s West African counterpart can survive dormant for months or even years burrowing through the mud in its estivated state.
Other examples of amphibious fishes that can survive both on land and in water include and their survival durations.
- Mangrove Rivulus (1 month)
- The walking catfish (1 month)
- Eels (A few weeks)
- Climbing perch (several months)
- Mudskippers (most of their lives)
- Non-amphibious fishes
These are the species of fishes that cannot survive out of water or if the oxygen in their habitat is compromised. Non-amphibious fishes include pet fishes like the goldfish or the rainbow fish.
These fishes do not have the anatomical features that could sustain their survival out of the water and hence they will suffocate and die under 10 minutes.
- The Environment
As an amphibious fish like the mudskipper or the lungfish, the destination environment is also crucial for survival. Yes, these fishes may survive out of the water, but they certainly cannot survive in the desert or an arid environment. Thus, as much as amphibious fishes are out of the water, they still require a little moisture for survival. Therefore, such species of fishes can be found out of water in the mud (estivation), in swampy regions, on a wet rock, moist grounds, or by the riverbank.
With over 28,000 distinct species of the fish, one cannot generalize the premise of ‘how long can a fish live out of water’, especially with evolution and adaptation as crucial elements. As much as fishes require water for survival, the great range in species makes some more adaptable to conditions of water deprivation than others. This contributes to the difference in their survival duration when immersed from water between amphibious fishes and non-amphibious fishes.
Thus, to answer the question of how long can a fish live out of the water, the amount of time a fish can survive when taken out of their water habitat depends on the species of the fish as well as the destination environment. However, one thing is certain, any kind of fish whether amphibious or not cannot survive in completely arid locations. Hence, moisture is always involved.