It is not uncommon to see a crayfish walking on land. You might wonder how long can a crayfish live out of water? Also, why do they get out of water? Well, I was curious too and here’s what I found:
A crayfish can live 5-7 days of out water. In a humid environment and marshy area, crayfish can live for several months out of water.
Why crayfish goes out of water? How do the breathe? I’ll try to answer all these questions in this article.
Why Crayfish Goes Out Of Water?
Crayfish goes out of water when there is lack of oxygen in the water. In the wild, crayfish often move from one place to another by walking out of water. It is not a problem for the crayfish, especially if the area is humid and marshy. Crayfishes can do this to explore other areas, find food or more suitable place to live.
In captivity, the crayfish will try to get out of the water if there is not enough oxygen in it. That’s why experienced crayfish keepers always recommend to leave a air pump ON 24/7 in a crayfish tank.
If you can’t get an air pump, just reduce the water height a few inches and place a stone or wood in the middle of the tank. Make sure the stone or the wood breaches the water surface. It’ll ensure the crayfish can get out of water if it wants without being able to escape from the tank.
How To Make Sure Enough Oxygen In The Crayfish Tank?
You already know why crayfish gets out of water. It is mainly because of lack of oxygen in the water. Now, you might ask, how to increase the amount of oxygen in the water.
That’s a very good question and extremely important for keeping crayfish.
There are mainly 2 ways to dissolve oxygen into aquarium water. Let me walk you through both of the ways:
1. Using An Air Pump
Every fish keeper knows how to setup an air pump. But do you know how to set it up safely?
You take an air pump, connect it to a air tube and connect the opposite end to an air stone. Then turn ON the pump and air will flow through the air stone.
There is nothing wrong with it, but I’ll recommend some safety options:
- Use a check valve between the air stone and the air pump. The check valve will ensure no water goes back to the air pump from the tank.
- It is recommend to use an air flow regulator. The regulator will let you control the air flow through the air stone. It’ll make sure there isn’t too much air pumping through the air pump.
- It is safe to place the air pump some place higher than the crayfish tank. It will further ensure nothing from the tank goes back to the air pump.
Now that you know how to setup an air pump safely, you might wonder how actually an air pump increases the amount of dissolved oxygen in the water? It is not as straightforward as you might think.
The air from the air pump doesn’t increase the oxygen level. It is just simple air, not oxygen. So, how an air pump increases the amount of oxygen?
When the air from the air stone hits the water surface, it agitates the surface. By agitating, I mean it disturbs the water surface and make it ripple.
This water surface agitation allows oxygen from the air to get dissolved into the water. This is how an air pump can help to increase the amount of oxygen in water.
2. Increasing The Surface Agitation
If you don’t have an air pump yet, don’t worry. If you understand the basic principle, there are many other ways to increase oxygen in the tank water.
Just remember this, for increasing the amount of dissolved oxygen, we need to agitate the surface of the water.
Now, there are many ways to agitate water surface. Here are a few ideas:
- You can use a powerhead. Make sure to setup the powerhead in such a way that it pumps out water along the surface. Or you can direct the face of the powerhead towards the surface. It will increase the surface agitation.
- Wavemakers are also a very good option to increase surface agitation. If you have the budget, go for it!
- If you are using a HOB (Hang On Back) filter, then reduce the water level about 1 inch below the HOB. The water fall from the HOB will create enough surface agitation for oxygen to get dissolved into the water.
Here’s What I Am Currently Doing
I am using a SOBO 320f filter. It is a very basic and simple internal power filter. I have detached the body from the filter and just using the powerhead.
This filter comes with a spraybar. I have attached the spraybar with the powerhead in such a way that the flow is directed along towards the surface of the water.
It creates enough surface agitation!
How Do Crayfishes Breathe?
I want to conclude the article with how crayfishes actually breathe. Their breathing mechanism is very special and I want to share it with you.
Crayfishes have very special gills that are different than fishes. With these gills, crayfish can breathe oxygen from the water. But what makes the gills special is, they can also absorb oxygen from the air.
To absorb oxygen from the air, the gills need to be moist. That’s why in a humid & mushy area, crayfishes can spend months out of water without any problem!