On this Wikipedia the language links are at the top of crawfish etouffee page across from the article title. Rearing white-clawed crayfish at Cynrig hatchery, Wales.

Establishing a breeding population from introduced captive-bred animals. Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. The term “crayfish” is applied to saltwater species in some countries. Some kinds of crayfish are known locally as lobsters, crawdads, mudbugs, and yabbies. The study of crayfish is called astacology. Crayfish are closely related to lobsters, and together they belong to the infraorder Astacidea. Northern Hemisphere and one in the Southern Hemisphere.

The greatest diversity of crayfish species is found in southeastern North America, with over 330 species in 15 genera, all in the family Cambaridae. A further genus of astacid crayfish is found in the Pacific Northwest and the headwaters of some rivers east of the Continental Divide. In 1983, Louisiana designated the crayfish, or crawfish as they are commonly called, as its official state crustacean. Australia has over 100 species in a dozen genera. Murray crayfish Euastacus armatus, which can reach 2.

It is found in much of the southern Murray-Darling basin. Australasian crayfish are threatened or endangered. Australian and Māori names for the animal, respectively, or by other names specific to each species. In Singapore, the term crayfish typically refers to Thenus orientalis, a seawater crustacean from the slipper lobster family. In England and Ireland, the terms crayfish or crawfish commonly refer to the European spiny lobster, a saltwater species found in much of the East Atlantic and Mediterranean.

Fossil records of crayfish older than 30 million years are rare, but fossilised burrows have been found from strata as old as the late Palaeozoic or early Mesozoic. Crayfish are susceptible to infections such as crayfish plague and to environmental stressors including acidification. In Europe, they are particularly threatened by crayfish plague, which is caused by the North American water mold Aphanomyces astaci. This water mold was transmitted to Europe when North American species of crayfish were introduced. Acid rain can cause problems for crayfish across the world.

Golden crayfish pendant, Chiriqui, Panama, c. Like other edible crustaceans, only a small portion of the body of a crayfish is eaten. In most prepared dishes, such as soups, bisques and étouffées, only the tail portion is served. Global crayfish production is centered in Asia, primarily China. Documentation of the consumption of crayfish dates to at least the 16th century.

Like all crustaceans, crayfish are not kosher because they are aquatic animals that do not have both fins and scales. They are therefore not eaten by observant Jews. Crayfish are preyed upon by a variety of ray-finned fishes, and are commonly used as bait, either live or with only the tail meat. When using crayfish as bait, it is important to fish in the same environment where they were caught. Crayfish are kept as pets in freshwater aquariums. They prefer foods like shrimp pellets or various vegetables, but will also eat tropical fish food, regular fish food, algae wafers, and small fish that can be captured with their claws. In some nations, such as the United Kingdom, United States, Australia, and New Zealand, imported alien crayfish are a danger to local rivers.