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Identifying crayfish

Identifying crayfish in the UK

In the UK there are seven species of crayfish present in the wild, this includes our native White-clawed crayfish as well as an increasing number of non-native species. In order to facilitate effective management, conservation and control of crayfish they need to be identified correctly. This section guides you through materials and methods for identifying crayfish. Note that to catch and handle crayfish you need a licence without one you will be committing an offence. Click here for more information on licensing and the relevant legislation. Below is a section on identification resources.

Cray morph

Crayfish morphology © David Holditch

Identification resources

Outlined below are the best resources that are currently available on crayfish identification:

  • The most comprehensive key that is currently available is a paper by Holdich which is described in the 2009 Crayfish Conference proceedings, click here for a pdf of this paper.
  • Craynet identification booklet by Pockl, Holdich and Pennerstorfer (2006) identifies native and non-native crayfish species present in Europe.
  • The University of Nice is developing a database for field identification of crayfish in Europe which will be availble as an app to download. Link to crayfish key.
  • The Centre for Ecology and Hydrology, the Biological Records Centre and JNCC have recently completed an online recording form which can also be used to record sightings. If photos are uploaded, recorders will receive an email confirming the identification.