How Long Can a Fish Live out of Water?

A fish that can survive for days on dry land is causing concern in Australia. The climbing perch, technically known as Anabas testudineus, is a fish species native to Southeast Asia that has an air-breathing organ that allows it to survive while traveling from one waterhole to another. The fish "walks" by using sharp spines on its extendable gill covers to drag itself along. Ecologists are concerned for birds and other fish, which can die from suffocation after eating the noxious perch.

Fearing a fish out of water:

• Climbing perch can flex their gill covers, causing them to become lodged in the throats of predators. It is believed that the fish are migrating to Australia aboard fishing boats.
• In late 2005, climbing perch were discovered on Saibai Island and another small Australian island in the Torres Strait, about four miles (6.4 km) south of Papua New Guinea.
• Despite being a freshwater fish, climbing perch can survive in briny water, and even bury themselves in mud to survive. The species grows to about 10 inches (25 cm) in length.

Frequently Asked Questions

How long can a fish typically survive outside of water?

Most fish species can only survive a few minutes outside of water, as they require water to breathe through their gills. However, some species, like the lungfish, have adaptations that allow them to live for extended periods out of water, sometimes for several months during drought conditions, by breathing air directly.

What happens to a fish's body when it is taken out of water?

When a fish is out of water, its gills often collapse and its body can no longer extract oxygen from the air. This leads to suffocation. Additionally, the fish's skin may begin to dry out, which can disrupt its protective mucus layer, leading to stress and potential infection.

Are there any fish that can naturally live on land for extended periods?

Yes, certain fish like the mudskipper and the mangrove rivulus have unique adaptations that allow them to spend considerable time on land. Mudskippers have modified gills to retain moisture and can absorb oxygen through their skin, while mangrove rivulus can breathe through their skin and even tolerate short periods of dryness.

How do fish adaptations for out-of-water survival benefit them?

Fish that can survive out of water often have adaptations like air-breathing organs or the ability to burrow into mud. These adaptations allow them to escape predators, find new habitats, or survive periods of drought. Such abilities provide significant evolutionary advantages in fluctuating environments.

Can a fish be revived after being out of water?

If a fish has been out of water for only a short time and hasn't dried out or suffered severe injury, it may be possible to revive it by gently placing it back into water. The fish must be handled carefully and allowed to reoxygenate its gills in clean, oxygen-rich water for the best chance of recovery.

What should you do if you catch a fish and want to release it unharmed?

To release a fish unharmed, minimize the time it spends out of water. Handle the fish with wet hands or gloves to protect its slime coat, remove the hook gently, and place the fish back in the water promptly. Support the fish in the water until it swims away on its own, ensuring it has recovered sufficiently.