Very cool looking crayfish! I'm not trying to hijack this thread but my 6 year old son has been wanting a fish tank of his own and I was looking at on of these online and the website said it would get up to 5" and would need at least a 20 gallon tank. Any idea why it would need a 20 gallon and if I could get away with keeping one in a 10 gallon as long as it was the only occupant in the tank?