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Why Your Crayfish Is Not Moving!

As the number of people who are keeping crayfish in their aquariums continues to increase, the number of questions that we see from crayfish keepers about caring for their pet also seems to steadily increase with each month that goes by.

Over the last month or so, we have noticed a number of people asking about their crayfish not moving so we have decided to publish this article to try and help our readers out who are within the crayfish keeping community.

The four most common reasons that a crayfish may not be moving while still being alive is due to the crayfish molting, poor water parameters, a small tank, and problems with their calcium intake in their diet with all three of these usually being easy to fix.

Less common but more serious reasons that a crayfish may not be moving is due to it being injured and unfortunately in some cases, dead.

Please note that a small number of crayfish just prefer to move as little as possible with their being their natural personality.

If you have had your pet crayfish for a number of months then you will know your crayfish well enough to know if the lack of movement may just be due to the personality of your crayfish.

Some crayfish will not move much in a new environment for around a week until they get used to their new surroundings too so keep that in mind.

Is It Normal For A Crayfish Not To Move?

In some situations, it can be totally normal and natural for a crayfish not to move much for extended periods of time.

The best case scenario is around the time your crayfish will molt as a lack of movement is normal with a crayfish usually laying on its side while not moving much as it prepares to start molting.

It is considered normal for a crayfish not to move much if it is in a new tank or its current tank is too small too but small tanks should be upgraded to a suitable size as soon as possible.

Keep in mind, that juvenile crayfish will molt far more frequently than an adult crayfish so if they are staying still and not moving much due to molting, this behavior will be far more common in a juvenile crayfish than an adult.

In addition to the age of the crayfish, the specific species of crayfish that you keep will also come into play as different species of crayfish molt more frequently than others too also playing an effect into how active they will be in their tank when it comes to movement.

Some crayfish may not move much directly after eating too but this doe tend to be rare. If you do notice that your pet crayfish stops moving much after it has been fed then this can be normal for your specific crayfish and just a natural response to eating.

Larger meals do seem to be more commonly associated with your crayfish not moving much after eating though so this may be an indication that you are actually overfeeding your pet crayfish.

Why Is My Crayfish Not Moving?

“Electric Blue Crayfish posing with-or for-the camera” by Capt Kodak is licensed under CC BY-NC 2.0. To view a copy of this license, visit

The most common reasons that your pet crayfish may not be moving much include molting, poor water parameters, a small tank, a lack of calcium in their diet, eating a large meal, and the crayfish being injured.

Unfortunately, at times it can be difficult to tell if your pet crayfish is not moving due to one of these reasons or if it is actually dead and some crayfish can remain still for days at a time depending on the situation.

Many people who are new to keeping a crayfish will have issues with maintaining optimal water conditions for their pet and this is totally normal as it is a skill that you have to build up over time.

You can use a aquarium test kit to check your water parameters to get a better idea if this could be your problem but a crayfish in an aquarium with poor water parameters will almost always not be eating much too helping you confirm the potential problem that way too.

Out of all of the possible reasons that your crayfish may not be moving much in its aquarium, the most common causes by far are due to issues with water parameters and the crayfish being about to molt.

Behind that you have issues with the size of your crayfish tank and keep in mind, as your crayfish grows you may have to upgrade your aquarium tank to maintain adequate size.

The rest of the potential reasons are less common than these three though so you should prioritize your initial efforts when investigating the problem towards water parameters, molting, and a small tank.

Why Is My Crayfish On Its Back And Not Moving?

A crayfish that is on its back and not moving much will often be very close to molting and you should be able to see the initial signs of the molt starting before your crayfish flips over onto its back.

If you are not able to see the signs of your crayfish molting and it is on its back and not moving much then stress or infection can also be responsible but they are far less common than molting, especially in juvenile crayfish.

If your tank has hiding spots where your crayfish is able to enter then it can be common for most species of crayfish to get into these hiding spots before they start their molt period too.

This is another indication that your crayfish may be on its back or side without moving due to it being ready to molt.

Stress can be a harder thing to confirm in your crayfish due to their being such a wide range of different things that can stress a crayfish out.

Often though, the cause of stress in a crayfish can be due to poor water parameters or being in a small aquarium tank anyway and in most cases of a crayfish not moving, you should be looking into these potential problems anyway.

How Can I Get My Crayfish Moving?

If your crayfish is not moving due to it getting ready to molt there is nothing you can do to speed the process up and you just have to wait for the molting process to end.

If your crayfish is not moving much due to water parameters, calcium issues in its diet, being in a small tank, or due to injury then you should investigate the problem and fix it as soon as possible.

Most species of crayfish are very responsive to issues with their water parameters being corrected and they should be moving around their tank again within days of the water quality improvement.

Issues with calcium can take around a week or in some cases two weeks to actually replenish the calcium stores in your crayfish and get it to start moving again.

Just keep in mind that a crayfish that is molting will require higher amounts of calcium and juvenile crayfish require even higher amounts of calcium in their diet due to their general growth rate resulting in them molting so frequently.

If your crayfish is in a small aquarium due to you accidentally purchasing a small tank or the crayfish outgrowing its current tank then upgrading to a larger tank should be able to correct the issue.

Just remember that it is totally normal for a crayfish in a new environment not to move much until it feels safe so even once your crayfish has been placed in a new aquarium it may take around a week or so before it will start to move around again anyway.


That brings our article going over why your pet crayfish is not moving much to an end and we hope that we have been able to help as many of our readers as possible. Unlike some of the other common problems that people can have with their pet crayfish, issues with a crayfish not moving much can be due to a number of different things so you may have to put some time and effort into correctly diagnosing the problem before you are able to treat it.