Australian Yabby - Yabbie - Australia has over 100 species of crayfish. Crayfish are lobster-like freshwater crustaceans found in a variety of habitats such as rivers, streams, dams, lakes and swamps and include smooth-bodied species such as the Yabbie, Marron and Redclaw. Each of these have an enlarged pincer-like first pair of legs and their common name depends on the geographic area they inhabit. In New South Wales and Victoria they are called Yabbies (Cherax destructor); in Western Australia, the Marron (Cherax teniumanus); and in Queensland, the Redclaw (Cherax quadricarinatus). These Cherax species are the best known of the Australian species of crayfish and are the only species sold as pets in Australia. Pet crayfish are a relatively new phenomenon and they have actually been a native food for many thousands of years. Yabby and marron catching is still popular in country dams and they have become increasingly popular in the gourmet dining scene. Dam buster The yabby is the most hardy of crayfish. In its native habitat, it can tolerate poor water conditions and long periods of drought by burrowing deep into river beds or dam walls to stay moist. This is how it actually earned the name 'destructor' - because of the damage it can cause dam walls and levee banks after burrowing. Appearance Crustaceans are invertebrates, they are without a spine or bones and are protected by a hard outer casing, forming plates of calcified material which interlock to provide a shield-like structure around the animal's body. Yabbies vary widely in colour from dark greens, brilliant blues and near- white. Adults can grow to be over 25 cm (9.8 inches) and 300g but most commonly are 13cm (5 inches). Red Claw varies in body colour from bluish-green to brown whilst the claws have obvious red patches. Adults are the same size as the yabby. Marron usually vary in colour from brown to black but a striking blue form is now selectively bred and has become increasingly popular as a pet. This is the largest species of Cherax and has been recorded at up to 38 cm (15 inches) with weights of 2.5-2.7 kg. Pet adults are most frequently around 20 cm (7.8 inches). A crayfish's colour is in part influenced by the colour of the water. As the animal grows, it sheds its hard exoskeleton and produces a larger one. At each moult, the colour of the new exoskeleton will be influenced by the water colour. Muddied waters can produce darker crayfish, whilst blue and clear water can help produce the popular brilliant and iridescent blues and whites. Crustaceans also have the ability to regenerate lost limbs, a handy trick considering limbs and claws are often lost during fights with other crustaceans. The limb will start to grow back at the next moult, however total regeneration is not immediate and may take several moults to complete. Temperament Crayfish are very territorial and don't have those big claws just for looks. Overcrowding will cause continuous fighting, and any unsuspecting fish which also happen to get too close may end up between the large claws. Crayfish are opportunistic feeders and will sample anything within their reach.