Any information about crayfish?

Question
Hello, I'd like to set up a spare 10 gallon tank I have (with filter) and would like to know about cold water crayfish.  I'm in Southern Ontario and I've been reading that many can even be found under rocks in streams, etc.    I only want one for an aquarium but don't know if it's cruel taking one out of it's habitat.  Maybe I should purchase one from the petstore?  Are they bred in captivity?

Also, is a 10 gallon too small.  I keep reading people keeping one in a 10 gallon or in their community fish tanks which I'd never do (I like my fish alive).  

Are they easy to look after?  How long do they live?  Do you know of any type to buy that don't get very large so it would be comfortable in a small tank?

Thank you!
Paula

Answer
Hello,
The biggest one I've caught is about 6" long, but they almost never get that big even in the wild.

In terms of pet store vs. wild, check the legal aspects. Some places you are not allowed to do that, but you are where I live in the U.S., they can be very very expensive in pet stores.

They are often considered pests/ invasive species, and there are numerous extermination attempts that have failed.

I sent you care information on your other question. Feed it anything, they'll eat it.