Any decapod crustacean of the family Astacidae (genera Cambarus and Cambarus), resembling the lobster, but smaller, and found in fresh waters. Crawfishes are esteemed very delicate food both in Europe and America. The North American species are numerous and mostly belong to the genus Cambarus. The blind crawfish of the Mammoth Cave is Cambarus pellucidus. The common European species is Astacus fluviatilis.