Why Did My Crayfish Die?

Why Did My Crayfish Die

Crayfishes are generally very hardy creatures. If everything is right, they won’t die just out of the blue. So, if your crayfish has died, there is something wrong with your crayfish tank setup.

Crayfishes mainly die due to poor water parameters. They can also die because of larger & aggressive tank mates, uncycled tank, lack of oxygen and of course, too much age.

I have listed all the common reasons for crayfish death. Go through them one by one and check if you did anything wrong.

Bad Water Parameters

Any aquatic animal needs their ideal water parameters for living happily. It is extremely important. We humans need clean & fresh air for a healthy and sound body. Same goes for any aquatic animal. They need their ideal environment to thrive.

If you are keeping crayfish in a hostile environment with bad parameters, it can soon die. So, you need to make sure the water parameters fall into the acceptable range for crayfish.

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.

As you can see, crayfish can’t handle even a little bit of Ammonia. Ammonia is detrimental for any aquatic animal. So, check for Ammonia in your crayfish tank water. Even if there is a little bit of Ammonia, it can cause the death of your crayfish.

All the other water parameters are important too but not as crucial as keeping 0 ppm ammonia. If you can’t hit the ideal range exactly, that’s okay. However, try to be consistent with the water parameters.

If your tank water pH is 7.2 today and 6.4 the next day, then this rapid fluctuation can cause stress to the crayfish.

So, consistency is the key when it comes to water parameters.

Too Old / Unable To Handle The Molting Process

In a crayfish related facebook group, I have asked what are the most common reasons for crayfish death. Do you know what majority of the people answered?

Molting Failure!

Molting is a very delicate & sensitive process for crayfish. This can take even a whole day. During and after molting, a crayfish becomes very vulnerable. At this stage, other similar size fish or creatures can attack the crayfish.

Also, if the crayfish is old or stressed, then it might not recover from the stress of molting process. Molting requires a significant amount of energy. Unfortunately, most old crayfishes don’t have that type of strength left.

Another reason for molting failure can be improper diet. If the diet lacks nutrition like iodine, calcium, etc. then the crayfish can fail to molt. Iodine is extremely important for crayfish. It helps them to grow exoskeleton.

I know many crayfish owners who lost their crayfish due to bad diet. If you want to know what a proper crayfish diet looks like, read my guide on crayfish feeding.

Uncycled Tank

If you put your new crayfish into an uncycled tank, then most probably it will die within a week. Nitrogen cycle is one of the basics that you need to master for keeping aquatic animals. Without mastering this cycle, your aquatic pets will just keep dying.

I have written a detailed post on nitrogen cycle for shrimps. Though it is for shrimps, the basic concept is exactly same and you should read it before even buying the crayfish.

Let me share the basics briefly:

1st Stage: The Ammonia Rise

When we keep fish, crayfishes, etc. in a tank, they produce waste. There are also uneaten food particles in the tank. All these decaying organic matters produce Ammonia in the tank.

Ammonia is a chemical compound (NH3) that is very harmful for living creatures. A slight amount of it can cause the death of your pets. So, we need something to deal with this Ammonia.

That’s where beneficial bacterial colony comes in.

2nd Stage: Converting Ammonia Into Something Less Harmful

If your tank is properly cycled, then it will have a colony of beneficial bacteria in the filter media. The bacteria will use the Ammonia as a food source and convert it into Nitrite (NO2).

Nitrite is still very harmful for living creatures and need to be dealt with.

3rd Stage: Converting Nitrite Into Something Lesser Harmful

The bacterial colony will again use the Nitrite as food source and convert it into a chemical called Nitrate (NO3). Now, Nitrate is comparatively much less harmful than its predecessors. Even plants can absorb Nitrate as nutrient.

However, when too much Nitrate builds up, it can get harmful for the fish, crayfish, etc. That’s why we need to change the tank water regularly. By changing the tank water, we keep the Nitrate level in balance. So, it doesn’t harm our pets.

Unsuitable Tank Mates

Most of the time, you’ll hear hobbyists complaining about how their crayfish has killed other fishes. It is natural and will happen if you don’t maintain the compatibility.

Though crayfishes perform the role of hunter mostly, it can also be a prey to larger fishes and creatures. So, if you are keeping crayfish in a monster fish tank, then the other fish can certainly eat your crayfish. Unsuitable tank mates is another very common reason for losing your crayfish.

Here are the suitable tank mates for dwarf crayfish:

Good Tank MatesBad Tank Mates
TetrasBetta fish
Swordtails, Mollies, Platies, etc.Shrimp
Red Tail SharkCorydoras
Hatchet FishPlecostomus
Rosy Red Minnows, Rainbow Darters, etc.Any Bottom Dwellers
Barbs, Danios, etc.Other Crayfish
NB:Even the good tank mates can fall into the prey of crayfish. When it comes to crayfish, nothing is certain.

Lack Of Oxygen

Many people often wonder if crayfish can drown themselves. Though the question seems to be weird, but the answer is YES. Crayfishes can drown themselves.

Crayfishes need lot of oxygen in the water. In the wild they can get out of the water and comfortably live out of water for days. This is because crayfish has special gills that allows it to absorb oxygen from the air. However, for this to happen, the gills need to be moist. That’s why in a mushy & damp area, crayfishes can live out of water for days.

So, if your tank water doesn’t have enough oxygen in it, the crayfish will try to get out of the water. If it can’t, the inevitable result will be death.

Experienced crayfish keepers always recommend to keep an air pump ON in the crayfish tank 24/7. It will ensure enough oxygen in the water. You can also keep some large stones in such a way that their peaks breach the water level. That way, the crayfish can crawl out of the water whenever it needs.

What Are The Signs Of Crayfish Death?

These are some of the common signs of crayfish death that I can think of right now:

  • Your crayfish will seem very lethargic. It will stay in one place most of the time. Even at night, the crayfish will be uninterested to roam around the tank for food.
  • The crayfish will show no interest to foods.
  • It will move very slowly.
  • Sometimes after a bad molting, the crayfish might flip over.

Final Words

So, these are all the common reasons for the death of crayfish. As I’ve already said, crayfishes are generally very hardy creatures and they are not very demanding.

That being said, if the set up isn’t ideal or the water condition is poor, even a hardy creature like crayfish can die.

Muntaseer Rahman

I have been keeping shrimps as a pet for many years now. I’ve fallen in love with these cute pets from the moment I saw them. That’s why I am writing articles to share my shrimp keeping knowledge with you.

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