Crawfish

Crayfish, crawfish, or crawdads 160 members of the superfamilies Astacoidea and Parastacoidea 160 are freshwater crustaceans resembling small lobsters, to which they are 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, although some species such as the invasive Procambarus clarkii are more hardy. Crayfish feed on living and dead animals and plants.

In Australia, New Zealand and South Africa, the term crayfish or cray generally refers to a saltwater spiny lobster, of the genus Jasus that is indigenous to much of southern Oceania, 2 while the freshwater species are usually called yabby or koura, from the Indigenous Australian and M ori names for the animal respectively. An exception is the Murray Crayfish found on the Murray River.

The name "crayfish" comes from the Old French word escrevisse Modern French crevisse from Old Frankish krebitja cf. crab , from the same root as crawl. The word has been modified to "crayfish" by association with "fish" folk etymology . The largely American variant "crawfish" is similarly derived.

Some kinds of crayfish are known locally as lobsters, crawdads, 4 mudbugs, 4 and yabbies. In the Eastern United States, "crayfish" is more common in the north, while "crawdad" is heard more in central and western regions, and "crawfish" further south, although there are considerable overlaps.

The body of a decapod crustacean, such as a crab, lobster, or prawn, is made up of nineteen body segments grouped into two main body parts, the cephalothorax and the abdomen. Each segment may possess one pair of appendages, although in various groups these may be reduced or missing. On average, crayfish grow to 17.5 160 centimetres 6.9 in in length, but some grow larger.