Cray's Anatomy: Episode 1. Here's how identify Montana's two most common crayfish. Signal crayfish are native west of the Continental Divide and Virile are native east of the Divide, but both species have been introduced around the state. It's also likely there are exotic species in MT. Crayfish are a popular food for people, and for 100's of species of animals ranging from owls, to spiders, to many fish. Stay tuned for Episode 2, and you'll learn how Montana FWP is teaming up with a world-renow