Why Is My Crayfish Not Moving?

Why Is My Crayfish Not Moving

This site does not constitute pet medical advice, please consult a licensed veterinarian in your area for pet medical advice.

If you are keeping crayfish for some time now, you might have experienced your crayfish not moving. Though ‘crayfish not moving’ is not very common, it can happen and you need to know why it is happening. Here’s everything I know about this issue:

Crayfishes stop moving or move very little during the molting process. They can also stop moving due to excessive stress, wrong water parameters, or unsuitable tank mates.

Though crayfishes generally stop moving during the molting process, many other reasons can be responsible for this type of behavior. Let’s discuss them in details.

3 Most Probable Reasons

It is very hard to exactly pinpoint the reason for your crayfish not moving. Many things can trigger this type of behavior in your crayfish. Here’s what I think the most common 3 reasons are:

1. The Crayfish Is Going Through Molting

This is the most common and most probable reason. When crayfishes go through molting, they get very vulnerable. At this time, other tank mates can attack them.

So, to keep themselves safe, the crayfishes lie still in a corner or inside the hiding place. You may find them moving very little, not interested to foods, etc. There is no need to worry and it is a natural defense mechanism of the crayfishes.

Generally crayfishes can take several hours to a day for the whole molting process. So, you might see your crayfish not moving for up to a day or two.

If it is longer than that, then some other thing is causing this type of behavior and you need to investigate.

2. The Crayfish Is Stressed

The crayfish might stop moving if it is stressed for some reason. Stress can happen for many reasons. Here are some of the most common ones:

Wrong Water Parameters

Every aquatic animal needs ideal water parameter ranges to live happily. When you ensure the idea water parameter ranges, you’ll replicate the ideal home for that animal. If the water parameters do not fall within that range or change drastically, it can seriously stress out the animal.

Here are the ideal water parameter ranges for crayfish:

Water ParameterIdeal Range
Ammonia, Nitrite, NitrateClose to 0 ppm
Temperature65 to 80 Degrees Fahrenheit (19 to 27 degrees Celcius)
pH6.5 to 7.5
GH4-10 ppm
KH3-10 ppm
TDS100-300 ppm
Important NoteConsistent water parameters are more important than trying to hit the correct number. If your tank water pH is 8.0, it’s not the end of the world for crayfish. Just make sure the parameters are consistent and do not change rapidly.

Need To Talk With A Vet Right Now?

Crayfishes are generally very hardy creatures. Even if your pH, KH, GH do not fall in the ideal range, it won’t be very fatal. Just try to keep the parameters consistent.

However, if there is ammonia or nitrite in the water, it can be very lethal for the crayfish. So, if the crayfish is not moving, check the water parameters. If you see any sign of ammonia, do a water change immediately and try to find out the source of the ammonia.

Generally overfeeding, dead organic matters, etc. give rise to ammonia spike. So, look for these carefully.

If you want to know more about water parameters for crayfish and how to check these, then I’ve written a detailed guide for you. You’ll know everything about water parameters for crayfish in that guide. Check it out!

Newly Bought

Your crayfishes can also show signs of stress if they are just bought from the fish store. This is normal and the stress should go away with a few days.

However, ensure that your tank has the proper setup for crayfish along with plenty of hiding places and substrate to dig. If you don’t know what substrate to choose so that the crayfish can dig, don’t worry.

I’ve written a detailed guide on that as well. Check out my substrate guide for crayfish to know what substrate to choose and how much should you use.

No Hiding Places

Crayfishes need hiding places. It is a must for them. In wild, crayfishes dig through the substrate or hide under rocks to save themselves from potential danger.

You’ll also need to replicate the wild environment for them. If there is no hiding places, the crayfish can easily get stressed out and cease to move.

Fortunately, providing hiding places is extremely easy & cheap. The easiest option is to cut some PVC pipes and throw them in the tank. The crayfish will use the PVC pipes as its hideout comfortably.

If you want something more naturally aesthetic, you can glue rocks together to form cave like shape. They look more natural and pleasing to the eyes.

There are also many hiding decorations you can buy from the fish store. Whatever you choose, make sure there is enough hiding places in the tank for your crayfish.

Unsuitable Tank Mates

If there are other predator fishes or creatures in the aquarium, they can stress out your crayfish. If the tank mates are not suitable, your crayfish might even get eaten.

So if your crayfish is stressed, check if the tank mates are suitable for crayfish or not.

Here are examples of some bad tank mate choices:

  • Cichlids: Cichlids are a very bad choice for crayfish tank. They are extremely aggressive and can eat your crayfish.
  • Other Crayfish: Generally crayfishes are very territorial themselves and can’t handle another one of their own in the same tank. So if you keep multiple crayfishes in a small tank, it is inevitable that they’ll fight to death and cause stress to each other. It is never recommended to keep multiple crayfishes in an under sized tank.
  • Monster Fishes: Other monster fishes like Arowana, Oscar, Giant Gourami, etc. are not suitable tank mates for crayfish. I don’t think I need to explain why they are unsuitable.

3. Crayfishes Are Nocturnal

Crayfishes get more active during the night and hide during the day. So, if your crayfish is not moving, check it again at the night. Chances are it will move to another place or look for food in the tank.

What Can You Do?

We’ve already talked about the most common reasons for your crayfish not moving. Now, let’s discuss what to do in such a situation:

Just Leave The Crayfish For 24-48 Hours

Crayfish generally takes several hours to a day for molting. It is a very long and tiresome process for the crayfish. During molting, it doesn’t move or go after foods.

So, if your crayfish is not moving, give it about 24-48 hours and check again. Your crayfish should complete the molting process by then and start moving again!

Check If You Are Looking At The Old Exoskeleton

As I’ve said, crayfish generally shows this type of behavior during molting. If your crayfish hasn’t moved even after a day or two, look closely. You might be looking at the old exoskeleton of the crayfish.

The exoskeleton of crayfish looks exactly like the crayfish. I have seen many crayfish keepers mistaking the exoskeleton as their crayfish and freaking out!

Just get a tweezer and gently touch the ‘thing’. You’ll understand if it is the exoskeleton or real crayfish!

Do A Water Change

if the crayfish is not moving due to bad water quality, a large water change will help a lot. Just do a 50% water change and check the water parameters. See if everything is in the right range.

If you see any of the parameters sticking out oddly, then you’ll know what’s causing the issue. Suppose if you’ve found out there is ammonia in the water.

So, you need to deal with this ammonia. Generally large water changes daily can help you out with it. Also, look for the reason what’s causing this ammonia spike in the tank. When you find out the source, try to get rid of it.

That’s how we should solve any issue with the tank water.

Do Crayfish Play Dead?

Generally, crayfish tend to show territorial behavior towards their tank mates. Due to their aggressive temperament, it’s pretty unusual to think of them playing dead.

But, crayfish can play dead. You shouldn’t get panicked by finding your crayfish motionless while these crustaceans may be just making you fool by playing dead.

On several crustacean forums, a few crayfish owners shared their experience of finding their crayfish playing dead. These crustaceans may show immobile behavior due to stress, improper water parameters, predatory attacks, etc.

If you notice your crayfish to lay on one side and motionless, your crayfish may be sleeping. The researchers found the slow electrical activity of crayfish brains during such postures. Your crayfish will stink, in case it becomes dead.

Gently Poke

If the crayfish doesn’t move even after a couple of days, gently poke it with something. See if there is any sign of movement.

If there isn’t any, then the crayfish is likely dead and you need to take it out before it gets rotten.

I am sorry. The hobby can get cruel sometimes! Just try to figure out what you did wrong, learn from your mistakes and next time prepare your tank better for the crayfish!

About Muntaseer Rahman

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