TY - JOUR

T1 - Crayfish plague affects juvenile survival and adult behaviour of invasive signal crayfish

AU - Thomas, John Rhidian

AU - Robinson, Chloe

AU - Mrugała, Agata

AU - Ellison, Amy

AU - Matthews, Emily

AU - Griffiths, Sian

AU - Consuegra, Sofia

AU - Cable, Jo

PY - 2020/5

Y1 - 2020/5

N2 - The spread of invasive, non-native species is a key threat to biodiversity. Parasites can play a significant role by influencing their invasive host’s survival or behaviour, which can subsequently alter invasion dynamics. The North American signal crayfish (Pacifastacus leniusculus) is a known carrier of Aphanomyces astaci, an oomycete pathogen that is the causative agent of crayfish plague and fatal to European crayfish species, whereas North American species are considered to be largely resistant. There is some evidence, however, that North American species, can also succumb to crayfish plague, though how A. astaci affects such ‘reservoir hosts’ is rarely considered. Here, we tested the impact of A. astaci infection on signal crayfish, by assessing juvenile survival and adult behaviour following exposure to A. astaci zoospores. Juvenile signal crayfish suffered high mortality 4-weeks post-hatching, but not as older juveniles. Furthermore, adult signal crayfish with high infection levels displayed altered behaviours, being less likely to leave the water, explore terrestrial areas and exhibit escape responses. Overall, we reveal that A. astaci infection affects signal crayfish to a much greater extent than previously considered, which may not only have direct consequences for invasions, but could substantially affect commercially harvested signal crayfish stocks worldwide.

AB - The spread of invasive, non-native species is a key threat to biodiversity. Parasites can play a significant role by influencing their invasive host’s survival or behaviour, which can subsequently alter invasion dynamics. The North American signal crayfish (Pacifastacus leniusculus) is a known carrier of Aphanomyces astaci, an oomycete pathogen that is the causative agent of crayfish plague and fatal to European crayfish species, whereas North American species are considered to be largely resistant. There is some evidence, however, that North American species, can also succumb to crayfish plague, though how A. astaci affects such ‘reservoir hosts’ is rarely considered. Here, we tested the impact of A. astaci infection on signal crayfish, by assessing juvenile survival and adult behaviour following exposure to A. astaci zoospores. Juvenile signal crayfish suffered high mortality 4-weeks post-hatching, but not as older juveniles. Furthermore, adult signal crayfish with high infection levels displayed altered behaviours, being less likely to leave the water, explore terrestrial areas and exhibit escape responses. Overall, we reveal that A. astaci infection affects signal crayfish to a much greater extent than previously considered, which may not only have direct consequences for invasions, but could substantially affect commercially harvested signal crayfish stocks worldwide.

KW - Aphanomyces astaci

KW - behaviour

KW - crayfish plague

KW - invasive species

KW - reservoir hosts

KW - signal crayfish

U2 - 10.1017/S0031182020000165

DO - 10.1017/S0031182020000165

M3 - Article

VL - 147

SP - 706

EP - 714

JO - Parasitology

JF - Parasitology

SN - 0031-1820

IS - 6

ER -