I lost multiple fish to my crayfish. Actually caught him sawing through my blue gourami. I took the advice of several people on the board and removed part of the large claws. (I took off the "thumbs"
I'm am quite sure it didn't feel good - I don't think there is a gentle way to cut off part of a claw. ???
Losing his thumbs didn't appear to bother him. He ate his shrimp pellets just fine - he even molted several times after his claw removal, and had started regrowing the claws. He still climbed the plants and tried to catch fish! He continued to charge out of his log and wave his claws whenever someone approached the tank.
Alas, the little crawdad passed away. I believe it happened after the temperature jumped due to the weather. But he was a hoot.