What Are the Signs Crayfish Dying? We’ve Got the Answer for You!

Crayfishes are commonly known to be very hardy species. So if one day you find out your crayfish is dying, there’s something wrong that you need to fix soon.

Today, we will cover all the elements that can cause crayfish and the ‘signs crayfish dying’. So let’s read on to see more!

What Are the Signs Crayfish Dying?

Young crayfish lobster

These common signs can tell if your crayfish are about to die.

  • Your crayfish will stay in a place most of the time, even at night. They are not interested in roaming around your aquarium for food.
  • Your crayfish shows no interest in the food you offer.
  • Their movement seems dull, and they move very slowly.

Sometimes, crayfish can show these signs as they molt. So your pets will be fine if showing the above signs while they are molting.

Why Might Crayfish Die?

You should know the most common signs that tell if your pets are dying. Now is the time to learn the causes of death in your crayfish.


Failing to molt

Failing to molt can also cause your crayfish to die

Molting is the process of removing the old shell from crayfish and most other animals, including humans. It can make your crayfish start displaying symptoms of dying, such as not moving or refusing to eat.

It can be one serious challenge to your pets and requires a lot of strength to get the job done. It can sometimes cause crayfish to die.

So, if your crayfish are displaying these above signs, find out if they want to molt by checking their skin to see if their shells are cracking. Give them several days, and do not interfere.

Un-Cycled Tank

One of the biggest mistakes various fish keepers make is to keep their pets in uncycled tanks. It can be hazardous as it might quickly kill your crayfish.

While crayfish are typically hardy, ensure your aquarium is cycled once it’s new so that it can avoid all possible problems that might happen.


Sickness can make your crayfish start as if they are about to die sooner. Various types of diseases can impact them and make them weak and sluggish.

We advise contacting your vet or doctor as you notice those signs and checking them out to know if they’re sick.

Poor Feeding

Your crayfish sometimes show a sign of weakness as they are starving, or your food is improper. When these fish starve and lack the needed nutrients, they can begin to lack enough strength to act and swim like before normally.

In this case, feeding them properly is essential. Aim for at least once per day. Also, feed your pets good quality and proper food that are rich in needed nutrients.

Improper Tank Mates

cichlid fish and blue lobster

Improper tank mates are another reason that can cause the death of your crayfish or make your fish show signs of death. It is dangerous to keep your pets with predators in the same tank.

Undesirable mates can harm crawfish in various ways, such as stressing them, killing them, or even robbing their food, making them die by starving.

So, whenever you see your pets showing signs of death, you should check their current tank mates and remove aggressive ones.

Also, it’s a good idea to create plenty of hiding places in your aquarium, like caves, if you’re unsure if your crayfish are kept with the right tank mates.

Unsuitable Water Parameters

Wrong water parameters can also be a death sentence for crayfish and any other fish.

If you notice that your fish displays signs of dying, it is a good idea to inspect the tank water parameters to know if anything is wrong. That’s why you should invest in water testing kits.

The three parameters you need to check first are the Nitrate level, the ammonia level, and the Chlorine level.

The following are ideal water conditions for your crayfish:

  • GH: From 4 to 10 ppm.
  • KH: From 3 to 10 ppm.
  • TDS: From 100 to 300 ppm.
  • pH level: From 6,5 to 7,5.
  • Water Temperature: From 65 to 80 degrees F (19 to 27 degrees C).
  • Water Temperature: From 65 to 80 °F (19 to 27 °C).
  • Ammonia, Nitrate, Nitrite: Aim to 0 ppm.

It is wise to put in a decent filter to keep your tank clean and fresh water. You should also add live plants to your aquarium to reduce nitrates by consuming them.

Old Age

Crayfish, like other animals, can die of old age. It happens when crayfish are very old and have reached their lifespan.

Although these crayfish might be normal, eating and moving very normally, once they are at the end of their lifespan, they might die via molting. The molting process always requires agility and strength, which old crayfish lack.

It’s natural to die from old age, and there’s nothing you can do about it.


What Are Suitable Tank Mates for Crayfish?

Here are some recommendations for proper tank mates for your crayfish:

  • Tetras
  • Barbs
  • Danios
  • Mollies
  • Platies
  • Betta fish
  • Swordtails
  • Corydoras
  • Big Shrimps
  • Other Crayfish
  • Red Tail Shark
  • Rosy Red Minnows
  • Rainbow Darters
  • Hatchetfish Plecostomus

Can Crayfish Die While Molting?

Yes. It is popular with old crayfish as the molting process always requires agility and strength, which old crayfish lack. Failure of the molting process will cause the old crayfish to die.

What Is a Crayfish’s Lifespan?

Crayfish usually live two to three years, with some species living even longer.

How Do Crayfish Sleep?

Sleep in crayfish is characterized by one stereotypical position: Lying on one side against the water’s surface.


The above are common signs and causes associated with death in Crayfish. We recommend getting your vet’s or doctor’s attention if you notice unusual behaviors from your crayfish.