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Are Freshwater Blue Crabs Real Or Do They Need Salt Water?

Freshwater blue crabs are a species of crab that lives in both freshwater and saltwater. In the wild they are often found in brackish waters, which is water that is a mixture of fresh and salt.

Whilst blue crabs can thrive in freshwater, and tend to grow very quickly, the females need saltwater to lay their eggs. Mating and spawning can take place in different environments. 

The blue crab is very popular amongst both commercial and recreational fishermen and can be found along the Atlantic Coast of America.

The male crabs tend to gravitate towards the fresher waters, while the females enjoy the saltier water. Farmers have found that they are able to use their irrigation ponds with freshwater to raise the blue crabs. 

Some people who may be considering raising blue crabs in freshwater could be concerned about the quality of the meat and its flavor.

Apparently, the taste is just as good if they were raised in freshwater. Many say there is really no difference with blue crabs that have come straight from the sea or the coast. Blue crabs are considered a delicacy among some.

Can Blue Crabs Live In Freshwater Ponds?

Blue crabs can live in freshwater ponds and have been doing so in many places. As populations of blue crabs were declining in their natural environment, new methods were sort after for harvesting these delicious crustaceans.

Clean, freshwater ponds, that have sufficient oxygen levels are perfect for raising blue crabs.

If you want to raise blue crabs in a pond it is best to collect them from the wild when they are still young. Keep in mind that they don’t do well if it is too cold.

Blue crabs are relatively easy to catch, with warm estuary waters being a popular place to find them. You will also need to keep them well fed. It is recommended to give them a large amount of algae every day.

Blue crabs are not fussy eaters and are considered omnivores. They will eat worms, snails, oysters, algae and other plants, to name just a few.

Blue crabs are even known for eating their own species. Usually if they are sick, or maybe missing one of their legs, then they will end up us prey. They are known as bottom-dwellers and like a soft mud floor.

“Blue crab close up” by Romain Bochet is licensed under CC BY-NC-SA 2.0. To view a copy of this license, visit

Can You Keep A Blue Crab In A Freshwater Aquarium?

Blue Crabs can be kept in a freshwater aquarium. Just make sure it is large enough and that you follow a few simple steps.

Your tank will need to be at least 5 gallons, and even bigger if you have more than one crab, at least 20 gallons. Blue crabs may fight when kept in the same area, so try and separate them into different areas if possible.

Freshwater aquariums can be good for raising blue crabs as they are relatively easy to keep clean. You should change the water every week, although you don’t have to change it all, 20% should be enough.

Also check the pH level of your water, it is below 6 you may have to treat it. Make sure your blue crabs can’t escape, they are good climbers.

Provide your crabs with some places to hide. You want your aquarium to resemble as much of their natural habitat as possible.

Make sure you have a nice sandy/mud base. If you are cleaning the aquarium before you put the blue crabs in, make sure you don’t use any harsh chemicals, and if using a mild detergent wash the tank thoroughly afterwards. 

A few final things to consider. Choose some plants for the aquarium, but make sure they are non-toxic, just in case the crabs eat them. If you are going to put rocks (or similar) in there, give them a thorough clean first to remove any parasites or bacteria.

Blue crabs can also live out of the water for up to 24 hours, as long as the environment is cool and moist for them.

Can You Breed Blue Crabs In Freshwater?

Although blue crabs will live happily in your freshwater pond, they won’t reproduce. In the wild, the female may be living in freshwater, but will migrate to a saline environment when she becomes pregnant.

When pregnant, the female blue crab is referred to as a ‘sponge crab’ due to the sponge like orange sack of eggs she carries. 

When ready, the blue crab eggs will hatch in water that measures a salinity level of 23 – 33 ppt. Average sea water is 35 ppt, while freshwater is 0 – 0.5 ppt.

The female blue crab actually only mates once in her life. However, the spawning can occur twice and will happen at a much later time after mating. Male crabs can mate multiple times during their lifetime.

So, you can see that to raise blue crabs in freshwater you will first need to collect them from the wild and then stock your pond (or other habitat) with the young blue crabs.

When you collect the crabs, make sure you have a sufficient number of males and females. This can be seen by the different markings on the underside of the shell.


Freshwater Blue crabs are very resilient and adaptable creatures. People may have told you that they can’t live in freshwater because of where they are found in the wild; estuaries, salt lagoons and along the coastline. However, as long as there is enough calcium in the water then they will do fine in a freshwater environment. This is true for a number of crab species.

Raising them in freshwater ponds on farms could be a great solution to help the struggling population in the wild and as a profitable business. If stocking a pond with young blue crabs, you could expect them to be mature in approximately 105 days. You could probably expect to harvest about 20% of your stock. The females will sell for cheaper as they’re smaller.