Hosts and transmission of the crayfish plague pathogen Aphanomyces astaci: a review

Abstract

The crayfish plague pathogen, Aphanomyces astaci Schikora, has become one of the most well-studied pathogens of invertebrates. Since its introduction to Europe in the mid-19th century, it has caused mass crayfish mortalities, resulting in drastic declines of local populations. In contrast, North American crayfish usually serve as latent carriers, although they may also be negatively affected by A. astaci infections under some circumstances. Recent research benefiting from molecular tools has improved our knowledge about various aspects of A. astaci biology. In this review, we summarize these advances, particularly with respect to the host range and transmission. We highlight several aspects that have recently received particular attention, in particular newly confirmed or suspected A. astaci hosts, latent A. astaci infections in populations of European crayfish, and the relationship between A. astaci genotype groups and host taxa.

Risk assessment of pet-traded decapod crustaceans in the Republic of Kazakhstan, the leading country in Central Asia

“…This crayfish reproduces exclusively unisexually (parthenogenetically) and thus a single female can theoretically establish a viable population that might outcompete native crayfish (Scholtz et al, 2003). Moreover, both mentioned species were confirmed to serve as a host and vector of the crayfish plague, the disease caused by the oomycete Aphanomyces astaci, which is almost lethal for both Kazakhstan native crayfish species (Keller et al, 2014;Mrugała et al, 2015;Svoboda et al, 2017). The adaptability to environmental changes like precipitation together with the lowtemperature tolerance (Vesel y et al, 2015), and extremely fast growth and reproduction features (Vogt et al, 2004;SoutyGrosset et al, 2016) make these crayfish species to be "perfect invaders".…”

Observations of crayfish plague infections in commercially important narrow-clawed crayfish populations in Turkey

“…As those populations are still productive and have thus been commercially exploited, it seems that the Turkish narrowclawed crayfish could have considerably high resistance against both haplogroup A and B A. astaci infections, as has already been indicated (Unestam, 1969;Kokko et al, 2012;Svoboda et al, 2012Svoboda et al, , 2014Svoboda et al, , 2017, whilst there are also studies reporting significant susceptibility (Schikora, 1906;Alderman et al, 1987). This host-parasite co-evolution and adaptation possibility opens avenues for further studies on the relationship between A. astaci, other co-infecting pathogens and its native European crayfish hosts (e.g., Edgerton et al, 2004).…”

Experimental evaluation of the potential for crayfish plague transmission through the digestive system of warm‐blooded predators

“…Crayfish plague caused by the oomycete Aphanomyces astaci Schikora is undoubtedly the most serious disease of crayfish (Diéguez‐Uribeondo et al, ), which drastically reduced European populations of these crustaceans in the 19th and early 20th century (Alderman, ). Although latent infections with the crayfish plague pathogen have been recently reported from various populations of several European indigenous crayfish species (see review in Svoboda, Mrugała, Kozubíková‐Balcarová, & Petrusek, ), mass mortalities caused by the pathogen are still widespread across Europe (e.g., Caprioli et al, , ; Filipová, Petrusek, Matasová, Delaunay, & Grandjean, ; Kozubíková‐Balcarová et al, ; Strand et al, ; Viljamaa‐Dirks et al, ), and crayfish plague is considered responsible for recent steep declines of native crayfish in various countries (Holdich, Reynolds, Souty‐Grosset, & Sibley, ). Furthermore, the presence of A. astaci has also been recently reported from crayfish populations introduced to Japan, Brazil, Indonesia and Madagascar (Andriantsoa et al, ; Martín‐Torrijos et al, ; Mrugała, Kawai, Kozubíková‐Balcarová, & Petrusek, ; Peiró et al, ; Putra et al, ), indicating a potential threat to crayfish species native to those regions.…”