I keep Dwarf Crayfish. They are less aggressive than other crayfish, but they will get into it with each other. I have Guppies in a tank with my crayfish and once in a while I will see one of the males fins a bit torn up. Large fish should have no problems with the crayfish. I have pictures at home. Here are some pictures.
This little guy pinched the fin of this CAE, but he is so big he didn't notice for a while.
This is how they mate. Sometimes one of the two loses a claw in the process.
This little guy pinched the fin of this CAE, but he is so big he didn't notice for a while.
This is how they mate. Sometimes one of the two loses a claw in the process.