White Clawed Crayfish
(Austropotanobius pallipes)

The White Clawed Crayfish, is the UK’s only native species of Crayfish. The crayfish favours clear relatively hard oxygenated water found in small streams, brooks, rivers and lakes. They can be found hiding in the crevices between rocks and under the tree roots along riverbanks. Populations of native crayfish have been dramatically affected in the South by the introduction of the crayfish plague carried by the non-native Signal Crayfish. The introduction of the larger Signal Crayfish has led to dramatic population declines on many of Britain’s rivers. Consequently the surviving populations of the native species found on the Western Rother are very important to the local biodiversity of this area.

Despite being protected under Schedule 5 of the Wildlife and Countryside Act 1981 and afforded protection under the European Habitats Directive it is important that remaining habitats are not allowed to deteriorate in quality as a result of pollution, dredging and sedimentation. Crayfish have many enemies including birds, trout, pike, eels, rats, mink, otters and the greatest of all, man. Habitat destruction and pollution may have also contributed to the species decline. The native crayfish has also been prone to a disease caused by a protozoan. This disease is also thought to be responsible for the decline of the species, which may have already begun before the introduction of the Signal Crayfish.

Issues affecting White Clawed Crayfish Populations.
• Introduction of the Signal Crayfish. These compete with the native species, occupying a similar habitat and carrying the crayfish plague which is so harmful to the native species.
• The Crayfish plague, responsible for the depletion of many of the White Clawed Crayfish populations.
• Loss of appropriate habitat through canalisation and sedimentation of waterways.
• Introduction of chemical pollutants and sewage may also have had a damaging effect on the Crayfish.

White Clawed Crayfish facts
Size: Adults can reach lengths of 12cm
Diet: Diverse range of plant and animal matter
Rostrum: Smooth sides, which converge towards the small triangular apex
Colour: Brown to olive colour on body, pink to dirty white on underside of claws
Claws: Top side rough. Underside dirty white.
Habitat: Streams, lakes, ponds, rivers, quarries.
Threats: Man, pollution, mink, fungus plague, pike, perch, chub, trout, alien crayfish
Lifespan 7 – 12 years
Habits Fairly docile, nocturnal.