Can Lobsters Live In Fresh Water?

These scary-looking crustaceans are a sought-after form of seafood. In most countries where they are available, they are considered a delicacy. Maine in the USA is famous for its abundance of lobster and delicious lobster dishes. But can they live in freshwater?

Lobsters cannot live in freshwater because they need the saltwater environment of the ocean to survive. When they are placed into tap water, lobsters will die very quickly. Lobsters absorb oxygen via osmosis, which can only occur in the sea’s salty water.

Have you ever wondered if these creepy crawlies could survive in freshwater? Maybe you have managed to catch one. You have heard that they must be kept alive just before cooking. Or perhaps you are an aquarium enthusiast, wanting to keep lobster in a tank as a pet! Whatever the reason for wondering if they live in freshwater, let’s find out the facts about lobsters and where they thrive.

Can Lobsters Survive In Fresh Water?

The most straightforward answer is no. Lobsters cannot live in freshwater. However, before we discuss the reason for this, I would like to clear up some confusion. Many folks consider crawfish to be lobster, but they are not.

Lobsters and crayfish are related. Lobsters and crayfish are both classified as arthropods. Lobsters have jointed legs, and a hard outer skeleton called an exoskeleton, as do crayfish. Crayfish, also called crawfish or crawdads, can be found in lakes and rivers.

Crayfish can live in freshwater, but actual lobsters can only live in the sea’s saltwater.  Lobsters are 10-legged crustaceans that are only found in the ocean. Because of their anatomy, they need a salty environment to extract oxygen from their surroundings via their gills.

Some folks will put a lobster in the bathtub after they have caught them, filling it with tap water. They think it will keep the lobster alive. Unfortunately, lobsters will only live two days in the tub and up to 36 hours out of the water if their gills are kept moist.  They cannot absorb the salt in their urine when placed in freshwater.

They start to lose the salt in their blood due to osmosis because tap water is a lower salinity than salt water. Lobsters will die very quickly if they are not in the right salty environment. Tap water is lethal to them. Besides the chlorine and chemicals in tap water, they cannot extract oxygen from it.

Their blood has lower salt levels than the seawater surrounding them. Because of this, osmosis occurs, and they will attain the correct amount of water and salt in their bloodstream. In freshwater, their cells will take in too much water. At the same time, they will be excreting salt in their urine. The delicate balance in their cells will be disturbed, and the cells will burst, killing the lobster within minutes.

How Do Lobsters Breathe?

Just like fish, lobsters have gills, not lungs, with which to breathe. They extract oxygen from the seawater around them. Water passes over the lobster’s gills, which are rich in blood. Oxygen is absorbed into the bloodstream as the water passes over the gills.

The water passes over their gills, from which oxygen is extracted. Just like our lungs circulate air, their gills circulate water. The blood in their gills has a lower salt level than the surrounding sea. The lobster cells allow salt water in, and oxygen is absorbed.

Some people believe lobsters can drown since they essentially “drown” when placed in freshwater because their bodies cannot absorb oxygen from the water. They also cannot retain salt, so their cells are overwhelmed and eventually burst.

Why Do Lobsters Need A Salty Environment To Live?

To understand why lobsters need a salty environment to live, you need to understand osmosis. Osmosis happens when the saltwater passes through the semi-permeable membrane of lobster cells.

It occurs because the blood circulating in a lobster’s body has a lower salt level than the surrounding seawater. Water will diffuse into the cells in their gills, and the lobster absorbs oxygen from it.

Because of the balance of salt found in the ocean and salt in the lobster’s bloodstream, they will only absorb just enough to live. Excess water and salt are excreted in the lobster’s urine, ensuring the correct ratio. Isn’t nature wonderful?

Just remember, if a lobster is placed in freshwater, it absorbs too much water, its cells burst, and they “drown.” Lobsters will survive longer on land than if they are in freshwater. It seems unlikely, yet they will live better out of fresh water.

Where Can You Find Lobsters?

Lobsters are scavengers living in the ocean on the seabed. They like to hide in rock crevices and among the seaweed. They have a high population from Newfoundland to North Carolina along America’s East coast. Maine, in particular, is famous for its lobster, offering visitors and locals many delicious lobster dishes.

Lobsters prefer cooler water rather than warmer seas. The reason is that cooler water is higher in oxygen than warmer water. The ideal temperatures that lobsters need are 61-64 degrees Fahrenheit.

They also do not like very deep or extremely cold water. You may also find lobster scurrying about on the shore. Lobsters can live on land for up to 48 hours if their gills are kept moist. If they need to be transported, they can be wrapped in a wet cloth or newspaper. Keeping their gills moist will help them to “breathe.”

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Can Lobsters Live In A Tank?

The answer is yes and no. It’s a no if the tank contains fresh water. Even if the tank is filled with seawater, it will still die after a while. The reason is that all the oxygen will be depleted.

Some folks will put a lobster in the bathtub after they have caught them, filling it with tap water. They think it will keep lobster alive. Unfortunately, lobsters will only live two days in the tub and up to 36 hours out of the water if their gills are kept moist. They cannot absorb the salt in their urine when placed in fresh water.

You would need to make sure the tank is aerated. It also requires just the right amount of salt in the water.

The other thing to consider is temperature. It would need to be a cold-water tank, not a warm-water one like most tropical fish aquariums. The water also must be at the correct pH level.

So theoretically, you could keep a lobster in a saltwater tank. However, not many folks have been successful, and the lobsters usually die.

Unless you have the right equipment and water that is the correct salinity, don’t try keeping lobster in a tank. Instead, stick with keeping fish!


To conclude, we now know lobsters cannot live in freshwater. They need to be in the salty water of the ocean. Their bodies are designed to take up oxygen from salt water, so placing them in freshwater will quickly kill them.