Difference Between Crayfish and Crawfish

Crayfish vs Crawfish
 

Crayfish and crawfish are crustaceans living in freshwater with a great resemblance of the lobsters. However, their size is smaller compared to the lobsters. The two names crayfish and crawfish have reference to the same group of crustaceans of two superfamilies namely Astacoidea and Parastacoidea. However, the two names came in different times and those were coined by two different scientists. Crawdad is another referred name for these crustaceans.

These animals have been classified under three taxonomic families and two of which are distributed in the northern hemisphere with the highest diversity in the North America (more than 330 species in nine genera). There are seven species is two genera in Europe while the Japanese species is endemic to the region. The Madagascan species and Australian species are endemic to those regions, and it would be important to know that there are more than 100 species distributed in Australia. It would be interesting to notice that there is a pronounced difference between families of Southern and Northern hemisphere crawdads, which is the absence of the first pair of pleopods in the Southern hemisphere family.

Their anatomy is completely decapodan with two main body tagma cephalothorax and abdomen. The external appearance is much like a lobster with two large fore-appendages but only smaller. The whole body length of a crayfish or crawfish is about 17 – 18 centimetres. However, the Murray crayfish of Australia (Euastacus armatus) could grow up to a weight more than two kilograms, and the Tasmanian giant freshwater crayfish (Astacopsis gouldi) grows a body that easily weighs more than five kilograms. They mate in each winter and early spring and the females lay about 200 eggs in a clutch. The young are hatched after two months of incubation period, and they are carried in the back of the mother for another month before letting them go.

These are prehistoric animals, as their earliest fossils found from Australia could date back to 115 million years from today, but the other fossil records are only 30 million years old. People have been using crayfish as bait for fishing. They are a popular food source across the world including China, Australia, Spain, United States, and many other countries. They have been used as pets in many aquariums.

Crayfish

Crayfish has a French origin, it is the mostly referred name across the world, and an English scientist Thomas Huxley coined the name in late 1860s.

Crawfish

Thomas Say, an American zoologist, first introduced the name crawfish in 1817. This name is not very popular across the world but very commonly used among Americans, especially among the Southern states.