Advertisement Whether you call it a crayfish, crawfish, crawdad, mudbug or mountain lobster, this common freshwater crustacean is an important food source for Canadian gamefish. Yet crayfish are often a bit of an afterthought among fly anglers, even though many of our favourite species—including larger trout and bass—will readily chomp up these armoured crustaceans. Here’s how to get with the crayfish program.