Austropotamobius pallipes  Austropotamobius pallipes is an endangered European freshwater crayfish, and the only species of crayfish native to the British Isles. Its common names include white-clawed crayfish and Atlantic stream crayfish. It is found from the Balkan Peninsula to Spain and reaches its northerly limit in Great Britain and Ireland, where it also has its greatest population density. "A. pallipes" is the only species of crayfish found in Ireland, occurring over limestone areas inhabiting rivers, streams, canals, and lakes. It is absent from the more acidic waters of the west, and occurs in streams with a moderate flow alongside other freshwater invertebrates such as caddis fly, mayfly, and mollusc species. Trout and three-spined stickleback also occur in the same habitat. Tree roots and rocks in the banks provide shelter. Juveniles shelter in vegetation such as watercress and grass mats growing out of the bank. "A. pallipes" is an olive-brown colour, with pale-coloured undersides to the claws (whence the specific epithet "pallipes", meaning "pale-footed"). It may grow to long, although sizes below are more common. It typically lives in rivers and streams about 1 metre deep, where it hides among rocks and submerged logs, emerging to forage for food, and also in lakes. In France "A. pallipes" is found in streams such as the Mornante and Sellon, two small tributaries of the Dorlay in the Loire department. It is protected as a heritage species. The distribution of "A. pallipes" is rapidly shrinking and in Great Britain it is now more or less restricted to central and northern England, east Kent, and eastern Wales and a population has been discovered in Essex. There is also a population in Candover Brook, a tributary of the River Itchen in Hampshire. Until recently a population had existed in the River Frome in Bristol/South Gloucestershire, but Avon Wildlife Trust believe this was wiped out during 2007–2008. Populations of "A. pallipes" can also be found in the upper reaches of the River Thames, where it competes with the introduced noble crayfish. Dowdeswell Reservoir in Gloucestershire supports "A. pallipes" and during the engineering works undertaken in 1998, Severn Trent put in place a management programme for its protection.