@guppy and others who share his belief, anyone who clips their crayfish or do other sorts of "modifications" are just sick.... I am a huge exotic fish/invertebrate owner/collector, as i own over 400 unique species at the moment, and have had many more in the past. As it stands though, anyone who would clip or do other things of the sort, that would cause their owned species pain or declassify them from their original state should not be owning them... If you need to clip your crayfish to make sure it doesn't harm other fish, either A you don't understand the circle of life, B you just can't afford separate enclosures to own these unique species, or C you really are just sick or dimwitted and don't understand what it's like to have something ripped apart form you causing a dramatic change to you're natural instincts, habitat, feeding, and etc. Crayfish will use their claws/thumbs to hunt *PREY* it is in their instincts it is the way it was meant to be, if you can't handle that then just don't own one.