The common yabby, Cherax destructor, is an Australian freshwater crustacean in the Parastacidae family. It is listed as a vulnerable species of crayfish by the World Conservation Union (IUCN). Yabbies are between 10 cm (4 in) - 30 cm (12 in) in length. Colour is highly variable & depends on water clarity & habitat; yabbies can range from black, blue-black or dark brown in clear waters to light brown, green-brown or beige in turbid waters. Yabbies specifically bred to be a vibrant blue colour are now popular in the aquarium trade in Australia. Yabbies are active & thereby available to catch during the warmer months. In the cooler months, when temperature falls below 16 C (61 F), they enter a state of reduced metabolic activity, or partial hibernation. Catching yabbies, or yabbying, in rivers & farm dams is a popular summertime activity in Australia, particularly with children. The most popular method involves tying a piece of meat to a few metres of string or fishing line, which in turn is fastened to a stick in the bank, & throwing the meat into the water. The string is pulled tight when a determined yabby grasps the meat in its claws & tries to drag it off ther string or fishing line.. The line is then slowly pulled back to the bank, with the grasping yabby usually maintaining its hold on the meat. When the meat & the grasping yabby reaches the waters edge, a net is used to quickly scoop up both the meat & the grasping yabby in one movement. To sustain the species population, all females carrying eggs under their tails must be returned to the water. Yabbies make great pets. Information on yabby care & their dietary requirements are available from your local pet supplier.