Engaeus is a genus of freshwater crayfish found in Australia, the burrowing crayfishes. Fifteen of the 35 species in the genus occur in Tasmania, where they are known as the Tasmanian land crayfishes. The behaviour of these crayfish is notable as they live in burrows and construct large "chimneys" at the opening. The burrowing crayfish, in the genus Engaeus, are primarily found in Tasmania with 13 out of 15 species being endemic to the state with the other two species located in Victoria as well as Tasmania. The Engaeus genus is a highly specialized form of freshwater crayfish which is capable of living in tunnel systems in peaty, muddy or wetland environments with the burrows extending down to the water table (an underground level which defines the transition between water saturated ground and non-saturated ground such as the surface) where the water is generally constant. Description The burrowing crayfish spend their entire life cycle underground in tunnel systems, only coming to the surface during wet, overcast conditions and during the night. As the burrowing crayfish has evolved from a free-swimming organism to a terrestrial organism, many of the species have a reduced tail, a narrow body (which can grow up to 10cm long) and claws that open vertically allowing for enlarged claws in a confined space. This feature, the vertically opening claws, is distinctive of the Tasmanian species and will not be observed in the two species shared between Victoria and Tasmania. The burrowing crayfish can range in colour from orange, reddish-brown, grey-blue or purple. Breeding for the Engaeus genus takes place between spring and summer. During this period, females can be observed carrying large, orange coloured eggs or hatchlings under her tail which folds over to form a pocket structure for protection. The majority of the species in this genus consume rotting wood, detritus, root material and animal matter such as grubs and worms if they encounter them. Habitat Although burrowing crayfish do not typically live in open water, they still possess gills underneath their carapace (the hardened section of the dorsal exoskeleton observed in arthropods) concluding that the burrowing crayfish is still dependent on an aquatic environment to respire. Therefore, there are three different types of burrowing systems with different mechanisms to stay wet. A type 1 burrow is a burrow which is directly connected to a stream or lake, a type 2 burrow is a burrow which