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How Long Can Crabs Live Out Of Water?

Although the popularity of keeping crabs in aquariums to eat algae and discarded fish food is increasing, we have noticed a number of people generally reaching out to ask how long crabs can live out of water recently.

As this can also help our regular readers who have a pet crab in their aquarium, we have decided to publish a dedicated article on how long crabs can live out of water as well as why some crabs are able to live out of water for much longer than others.

We hope that this will be able to help any of our readers who do have a pet crab in their aquarium as well as anyone who find our article via Google or social media.

The majority of people don’t realise that there are three main types of crabs and that you can seriously harm some of them by removing them from the water during your trip to the beach.

We will be covering a number of slightly different topics about crabs breathing and living outside of the water in this article so we have decided to add our table of contents below.

It should make the article as quick and easy to navigate as possible.

How Do Crabs Breathe On Land And Underwater?

Crabs are broken up into three main types aquatic, intertidal, and terrestrial with each type specializing in a certain type of breathing but all three types of crab can breathe in and out of the water for at least a short amount of time.

The three main types of crabs have taken different evolutionary paths giving some the ability to breathe well both on land or in water.

As the name suggests, aquatic crabs have evolved to live underwater for the vast majority of their lives and although they can come out of the water for very short periods of time, their internal organs will dry out quickly and they will start to die.

Terrestrial crabs are almost the exact opposite to aquatic crabs and they have evolved to live on land and although they can go underwater for short periods of time, they will actually drown if they stay in the water too long.

Intertidal crabs can live in water or on land but when on land they do need to stay as moist as possible. If they start to dry out then their gills and cuticles that they use to breathe start to suffer damage and may result in the death of the crab.

When you go to the beach, you will usually see intertidal crabs for the most part.

Aquatic Crabs

Aquatic crabs have gills similar to those of a fish that has evolved to allow the crab to live the majority of its life underwater.

The gills of an aquatic crab will start to dry out quickly and it will struggle to breathe due to its gills collapsing if you take it out of the water with survivable timeframes ranging from a couple of minutes to an hour or so depending on the specific species of crab.

Intertidal Crabs

Intertidal crabs have evolved to be able to breathe through their gills similar to that of an aquatic crab while underwater.

They have also evolved to have cuticles on their leg bases that allow them to breathe out of the water but their cuticles and gills have to be kept moist when out of the water.

Some intertidal crab species can stay out of the water for as long as three days without issue but most will need to return to the water in a day or less.

Terrestrial Crabs

Terrestrial crabs retain their gills for breathing but they have evolved to be much stiffer than normal gills and function more like lungs.

A terrestrial crab is able to stay out of the water indefinitely and it is common for some terrestrial crab species to never go into the water.

Due to the gills of a terrestrial crab having evolved to work when dry, they struggle to function when submerged in water and a terrestrial crab will drown surprisingly quickly if submerged in water.

How Long Can Crabs Live Out Of Water?

There is no generic time frame that a crab can live out of water. It will range from a couple of minutes to an hour for an aquatic crab to a day or two for an intertidal crab to being able to live out of the water indefinitely for a terrestrial crab.

Within the three main types of crab, there are also individual species of crab that have evolved in different ways so different species of intertidal crab can stay out of the water for very different time frames.

This is why there are often signs on beaches telling people not to remove the crabs from the water.

Many crabs look the same from the outside with most people not even knowing that aquatic, intertidal and terrestrial crabs exist. It can be common for children to accidentally cause irreversible damage to crabs when at the beach.

There are actually a small number of areas where aquatic, intertidal, and terrestrial crabs will all live in harmony with each other too.

Some of these areas are islands that are common tourist destinations causing more problems when they try to put a terrestrial crab into water or keep an aquatic crab out of water in a bucket.


That brings our article going over how long crabs can live out of water to an end. We hope that we have helped to explain why there is no generic term that is a standard answer for this question. Although we do often see people randomly throwing out time frames, the three different types of crab can live out of water for very different time periods. Within the three different types of cran, you also have different species of crab that also have very different time frames within the initial brackets too.