Oxygen..

[Muhammad Zuhail]

Do crayfish need oxygen...The pet store guy said that oxygen is not needed...
Can red and blue crayfish live together? will they kill each other...

[Northernguy]

You will have to change the water often!
The two will fight until one is dead.

[jaysee]

I have read that each crayfish needs 10G, but I had 2 in a 29G and had to seperate them. I think 20G per crayfish would work. Color is not important.

They take oxygen from the water like all fish, but are able to breath out of the water for some time - like lobsters and crabs.

[Muhammad Zuhail]

What i meant was i dont have a filter or a oxygen tube inside the tank..So will the crayfish survive..
They are mostly right at the top of the tank..they are lying side ways on top of the plant..some parts of their bodies are outside the water as well and sometimes a bit of the face as well..What does this mean..

What fish can u put along with crayfish..Anyfish which will not be attacked by the crays...recommend...

[jaysee]

Sounds like your crayfish are suffocating in the water, which is why they are at the top like that - They can breath air too. You don't need an oxygen tube, but a filter is a must or they will die. They will frequently climb everything in the tank, but should not be hanging out like that.

As far as fishy companions, I think the only fish to avoid keeping with crayfish are slow moving fish with long fins. They may not actually catch the fish, but will certainly destroy their fins trying. When I had one of mine in a 10G, I had to temporarily keep my betta in there. The bettas fins will never be the same...:scry:

I wouldn't keep them with Tiger Barbs either. Mine's not happy and has to be moved - I think they just harrass him everytime he leaves the cave.