Crayfish
American signal crayfish
American crayfish in UK streams and rivers are threatening our indigenous crayfish. Where have they come from and how do they threaten their native cousins?
Native British crayfish
- breeds from the age of three to four years
- females produce up to 200 eggs
- young hatch from May to June
- adults smaller than signal crayfish
Invasive American signal crayfish
- breeds from the age of two (one in exceptional circumstances)
- females produce up to 500 eggs
- young hatch April to May
- more aggressive than native crayfish
- less fussy in what they eat – therefore more successful and rapidly colonise new areas
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The Crayfish Code: How Can You Help? (Acrobat, 65KB, 1 minute)
Help prevent the spread of crayfish and crayfish plague to other waters. - Crayfish plague
Find out more about crayfish plague - Native white-clawed crayfish
Find out more about native white-clawed crayfish - Trapping
Find out more about crayfish trapping
