Your Best Guide To Freshwater Fiddler Crab Care

Last Updated on March 28, 2022 by Marco C.

Do you want to learn more about freshwater fiddler crab care?  Use this article as your ultimate guide to becoming a fiddler crab care expert! 

There are many different varieties of crab out there.  Some of them are saltwater crustaceans.  This means they can only live in salinated water.

However, there are also freshwater crabs.  Many people like to raise freshwater crabs in their aquaponics system because they are very cute.  Many people consider this species a very fun one to raise because they have a lot of energy.

It is important to note that despite its names of freshwater crab, this variety needs both salt and fresh water to survive.  So if you want to know about Freshwater fiddler crab care, you will need to have an area where you can keep saltwater.  

These crabs are usually found in areas with brackish water like swamps and lagoons.  Brackish water is where salt mixes with fresh.  

As long as you can provide the proper habitat, you should have no problem raising these cute fellas!  They can go well with other fish as well.

Keep reading now to learn the best way to provide freshwater fiddler crab care!

Can Fiddler Crabs Live In A Fish Tank?

Fiddler crabs are a perfect pet to keep inside a fish tank.  However, you need to make sure that the fish live in similar brackish conditions.  

In general, though, you can use a fish tank to raise the crabs inside.  You will need to simulate a good environment for them.  To do this, we need to understand the behaviors of the fiddler crab.

First off, they like sand.  Fiddler crabs love to burrow and make their nests underneath the ground.  This is why you see them scurrying across the beach and dipping into holes.  

The sand is their home.  They live inside of it and get all of their nutrients from it.  It is a very important aspect of your freshwater fiddler crab care. 

You cannot just use any store-bought sand though!  Pay attention to the type of sand you use.  This will affect the overall wellbeing and happiness of the crab.  

Can Fiddler Crabs Live In A Fish Tank

Learn more about: How Long Does It Take For Brine Shrimp To Hatch? All Your Answers Now!

It is best to find something that is the most similar to their natural environment.  If you can take sand from the wild that is the top choice.  Sand from a beach contains all the necessary elements for a fiddler crab to survive.

Find a container and go to a beach or a swamp riverbank.  Keep in mind this sand should come from an area with saltwater or brackish water.  This will ensure the correct minerals will be inside.

Fill up enough sand to fill up at least ⅔ of your tank.  Every tank size will require different amounts of sand.  

This sand needs to be on a slope.  You can make this slope with your hand or a small garden shovel.  The whole point is to make a place above ground and underwater. 

Freshwater Fiddler Crabs Water Requirements

Once you have established your sand slope, it is time to add the water.  Please pay attention to this specific step.

Even though it is called a freshwater fiddler crab, you will need to add slightly salted water to the tank.   Remember, it has to be brackish.  

This means it is a mix of freshwater and saltwater.  It is not pure saltwater! If you put too much salt in the water, they will not survive. In order to know how much salt is in your water, you can measure the density.

There is a special tool called a hydrometer that is used to tell you the gravity of the water.  This is essentially measuring how many particles are in your water.

To create a perfect mix try to get a hydrometer reading of 1.005 to 1.08.  Anything exceeding this number will be too salty for the fiddler crabs.

Breeding Freshwater Fiddler Crabs

If you want to breed more fiddler crabs, you need to have a male and female in your tank.  

According to Arizona State University, Male fiddler crabs are famous for having complex signaling displays, waving the large claw in order to attract females and delimit territory. “

This is a pretty cool sight to see. Each male uses a different wave to try to impress a female.  

Another nice thing about fiddler crab care is that you do not need a lot of space.  They are very small creatures. On average they measure around 2 inches in length. You do not need a huge tank to raise these crabs.  You can raise 4 crabs in a 10-gallon tank.  

Be sure to have a secure lid on top of your tank.  Otherwise, they will climb out and can easily die.

You can use a screen to allow for some airflow in and out of the tank.  Aside from that, the only other important aspect of fiddler crab care is their diet.

In nature, fiddler crabs are scavengers.  This means they can eat a variety of things.  They are omnivores and enjoy eating whatever they can find amongst the sand.

They eat things like algae, small insects, fungus, and worms.  If you want to supplement what is in the sand, you can buy bloodworms, brine shrimp, or seaweed.

Now you know all about freshwater fiddler care.

Feel free to comment and ask questions below!

Read more about: Your Step By Step Guide On How To Raise Crawfish In A Tank!


Do freshwater fiddler crabs need air?

Fiddler crabs require both land and water because they need to leave the water to get air. So it is absolutely necessary to provide a space where they can come out from underwater to breathe. Do not skip this step.  There are some cases where the crabs survive without land, but they are very unhealthy and inactive.  

Do freshwater fiddler crabs need land?

Fiddler crabs like to be both on land and in the water. Your tank needs to provide both conditions.

This is very important because the crabs like to burrow in the sand, they cannot do this underwater.

How long can fiddler crabs live in freshwater?

Fiddler crabs don't need freshwater to survive, but they do need a little saltwater in their environment. If you maintain the water as freshwater, the crab will not survive very long.