if its a blue moon crayfish your talking about, then no. they're territorial and aggressive, and they would attack and eat any fish you put in there. however, if it was, say, a loach, then the loach would eat the crayfish. if you had Mexican dwarf orange crayfish though, they can be housed with any type of fish that will not eat them. they're very calm and docile.
The snapping turtle will eat the crayfish. So no they will not get along
another crayfish so when they grow up they can..... you know.... "stuff"
No. crayfish are invertebretes (so, crayfish are more related to bees than even a shark!!!)
Without much more information the question can not be answered accurately. Crayfish are scavengers and guppies are not their natural prey. If the crayfish is small enough and your guppies don't have long flowing fins then the guppies may well be too fast for the crayfish to catch. So the answer then would be none. Are you feeding the crays dead guppies? If so I would add one and see how long it takes the crayfish to eat it. Then I would add more and more dead guppies one at a time as the crayfish devours them. As the crayfish grows so it will eat more.
Yes, but only if the crayfish eggs are fertile which requires a male. So if you can see the crayfish eggs on the tail of the crayfish that means that the eggs are fertile and will hatch in about 30 days
Crayfish
Crayfish are very good at getting out, so it's best not to fill a tank to the top.
A crayfish has segments, which are sections of a body that are separated by a crease, so it might be determined as segmented because it has only two so it may be classified but it might not. Worms have many segments.
blue coloration for crayfish is an abnormality and i think only 1 in 100.000 are blue. so if you find one. good for you.
The answer is yes dogs can be aggressive, but some dogs when their puppy's can be trained not to be so aggressive.
Crayfish, Oscars and perhaps some of the more aggressive chiclids. If you do not want your betta any longer put it up on kijiji or return it do not just kill it.