Crayfish, crawfish, or crawdads, are freshwater crustaceans resembling small lobsters, to which they are closely related. They breathe through feather-like gills and are found in bodies of water that do not freeze to the bottom; they are also mostly found in brooks and streams where there is fresh water running, and which have shelter against predators. Most crayfish cannot tolerate polluted water.
In Australia and New Zealand, the name crayfish (or cray) generally refers to a saltwater spiny lobster, of the type Jasus that is indigenous to much of southern Oceania, whilst the freshwater species are usually considered a yabby, or a koura, from the Aboriginal, and Māori, names for the animal respectively.
Crayfish are eaten in Europe, China, Africa, Australia, Canada, and the United States. 98% of the crayfish harvested in the United States come from Louisiana, where the standard culinary terms are crawfish or écrevisses.
Louisiana crawfish are usually boiled live in a large pot with heavy seasoning (salt, cayenne pepper, lemon, garlic, bay leaves, etc.) and other items such as potatoes, maize, onions, garlic, and sausage. They are generally served at a gathering known as a crawfish boil. Other popular dishes in the Cajun and Creole cuisines of Louisiana include crawfish étouffée, crawfish pie, crawfish dressing, crawfish bread, and crawfish beignets, and crayfish are an ingredient in Chicken Marengo.
Crayfish is a popular dish in Scandinavia, and is by tradition primarily consumed during the fishing season in August. The boil is typically flavoured with salt, sugar, ale, and large quantities of the flowers of the dill plant.
The Mexican crayfish is named locally as acocil and was a very important nutrition source of the ancient Mexican Aztec culture; now this kind of crayfish is consumed (mainly boiled) and prepared with typically Mexican sauces or condiments in central and southern Mexico.
In China, the culinary popularity of crayfish swept across Mainland China in the late 1990s. Crayfish is generally served with Mala flavour (a combined flavour of Sichuan pepper and hot chili) or otherwise plainly steamed whole, to be eaten with a preferred sauce.
Like other edible crustaceans, only a small portion of the body of a crayfish is edible. In most prepared dishes, such as soups, bisques and étouffées, only the tail portion is served. At crawfish boils or other meals where the entire body of the crayfish is presented, however, other portions may be eaten. Claws of larger boiled specimens are often pulled apart to access the meat inside. Another favourite is to suck the head of the crayfish, as seasoning and flavour can collect in the fat of the boiled interior. A popular phrase heard around crawfish season in Louisiana derives from this practice: "Suck the head, pinch the tail".