Crayfish - crawfish
The words crayfish and crawfish are essentially the same. Both refer to species of aquatic crustaceans which resemble lobsters on a small scale. Classically, crayfish are small freshwater species. The term was originally applied only to European varieties. Later, it was extended to similar species found in the Americas, Africa, Australia and Asia, and also to marine relatives such as Spiny Lobster (Palinurus vulgaris, or Langouste).
- Crayfish is the more formal. It is also by far the more usual in British English, where 'crawfish' is mostly heard in conscious imitation of the American.
- Crawfish is more common in American English, where it is, however, still less usual in academic writing, where in biological sciences crayfish should always be used. Garner, 2000 observes: "With the rise in popularity of Cajun cuisine in the 1980s came a general awareness of such dishes as crawfish étouffée. And today, most people who buy the freshwater product for cooking call it crawfish."
- There is also a dialect variant in the southern USA: crawdad.
- Etymological note: Ecrevisse, the French name for a crayfish, does NOT mean etymologically 'a fish that lives in crevices', although a crayfish is one of a number of species of underwater crustaceans that do live in crevices in rivers or the sea. The name derives from the German krebs, from a common Germanic root krabb- 'to scratch', 'to claw'.