title: The prevalence of Aphanomyces astaci in invasive signal crayfish from the UK and implications for native crayfish conservation.
abstract: The crayfish plague agent, Aphanomyces astaci, has spread throughout Europe, causing a significant decline in native European crayfish. The introduction and dissemination of this pathogen is attributed to the spread of invasive North American crayfish, which can act as carriers for A. astaci. As native European crayfish often succumb to infection with A. astaci, determining the prevalence of this pathogen in non-native crayfish is vital to prioritize native crayfish populations for managed translocation. In the current study, 23 populations of invasive signal crayfish (Pacifastacus leniusculus) from the UK were tested for A. astaci presence using quantitative PCR. Altogether, 13 out of 23 (56·5%) populations were found to be infected, and pathogen prevalence within infected sites varied from 3 to 80%. Microsatellite pathogen genotyping revealed that at least one UK signal crayfish population was infected with the A. astaci genotype group B, known to include virulent strains. Based on recent crayfish distribution records and the average rate of signal crayfish population dispersal, we identified one native white-clawed crayfish (Austropotamobius pallipes) population predicted to come into contact with infected signal crayfish within 5 years. This population should be considered as a priority for translocation.
authors.affiliation: School of Biosciences,Cardiff University,Cardiff CF10 3AX,UK.
authors.forename: J
authors.initials: J
authors.lastname: James
authors.affiliation: The Roslin Institute,University of Edinburgh,Easter Bush,Midlothian EH25 9RG,UK.
authors.forename: S
authors.initials: S
authors.lastname: Nutbeam-Tuffs
authors.affiliation: School of Biosciences,Cardiff University,Cardiff CF10 3AX,UK.
authors.forename: J
authors.initials: J
authors.lastname: Cable
authors.affiliation: Department of Ecology,Faculty of Science, Charles University,Viničná 7, CZ-12844 Prague 2,Czech Republic.
authors.forename: A
authors.initials: A
authors.lastname: Mrugała
authors.affiliation: Department of Ecology,Faculty of Science, Charles University,Viničná 7, CZ-12844 Prague 2,Czech Republic.
authors.forename: N
authors.initials: N
authors.lastname: Viñuela-Rodriguez
authors.affiliation: Department of Ecology,Faculty of Science, Charles University,Viničná 7, CZ-12844 Prague 2,Czech Republic.
authors.forename: A
authors.initials: A
authors.lastname: Petrusek
authors.affiliation: Centre for Environment,Fisheries and Aquaculture Science (Cefas),The Nothe,Weymouth,Dorset DT4 8UB,UK.
authors.forename: B
authors.initials: B
authors.lastname: Oidtmann
mesh_terms: D000818:Animals; D044744:Aphanomyces / Q000302:isolation & purification*; D003400:Astacoidea / Q000469:parasitology*; D003247:Conservation of Natural Resources; D006790:Host-Parasite Interactions; D058865:Introduced Species; D015995:Prevalence; D006113:United Kingdom
keywords: 
                 Austropotamobius pallipes
              ; 
                 Pacifastacus leniusculus
              ; Ark Sites; crayfish plague; white-clawed crayfish