Crayfishes are tiny freshwater crustaceans resembling little lobsters and are placed in two superfamilies specifically Astacoidea and Parastacoidea. They have feather-like delicate gills that assist them in respiration. They are observed in brooks and streams of working water where they can get shelter from the predators. Most crayfishes are not able to tolerate very polluted drinking water but an invasive species Procambarus clarki can face up to hugely polluted waters. They are omnivores feeding on both residing as nicely as lifeless vegetation and animals.
In Australia, New Zealand and South Africa they are identified as spiny lobsters. Research of crayfishes is identified as astracology. The name crayfish has been derived from an Aged French phrase indicating to crawl. They are also decapods so their physique is strongly developed on the plan shared by crabs, lobsters and prawns. The system is ordinarily created up of nineteen physique segments grouped into two sections particularly the cephalothorax and stomach. Each and every segment bears a pair of appendages but in some they may well be lowered or absent. On an normal they are recognized to attain a size of 17.5 cm but several may mature even longer. There are a few family members of crayfishes identified out of which two dwell in northern hemisphere though a person lies in the southern hemisphere. The southern hemisphere relatives Parastacidae is recognised to arise in South The united states, Madagascar and Australasia and can be identified by absence of first pair of pleopods. The other two households namely Astacidae and Cambaridae are existing in western Eurasia and western North The us and japanese Asia and jap North The usa. Australasia possesses extra than 100 species.
The greatest variety of crayfishes has been isolated from North The usa all belonging to the loved ones Cambaridae and represented by 330 species in 9 genera. It is thought that they progressed both in the late Palaeozoic or Mesozoic about 30 million decades back. The oldest data have been attained from Australia. Some animals go through from a condition identified as crayfish plague. The illness is triggered by a water mold Aphanomyces astaci. The species of Astacus are at the greater hazard of acquiring infected with this mould. Lots of species dwelling in Europe get this infection pretty early. This disorder is not indigenous to Europe but has been unfold from North The united states when crayfishes were being launched in Europe.
They are predominantly marketed as bait as they are used to capture fishes although heading to fishing. They are extremely relished all over the globe as food. Like other crustaceans only a compact portion of their entire body is edible. They are boiled and utilized in soups. The claws of the larger species are boiled and then pulled aside to extract the meat. They are also utilized as pets in aquarium.