Persistent infection by crayfish plague Aphanomyces astaci in a noble crayfish population - a case report.

摘要

Crayfish plague infection, caused by the oomycete Aphanomyces astaci, is believed to lead to a total mortality of the populations of highly susceptible freshwater crayfish species like the noble crayfish Astacus astacus. It has therefore been customary in Finland to restock affected water bodies relatively soon after the population has been wiped out in an acute episode of crayfish plague. In many cases, these re-introductions have failed without any explanation. During a follow-up study of a small lake, no restocking was undertaken after an outbreak had struck the population in 2001. The crayfish plague agent was isolated three years after the outbreak and again a year later in 2005. This capability of A. astaci to survive supported by a weak noble crayfish population may explain the often recorded failures of repopulation attempts, and recurrent episodes of acute crayfish plague in certain lakes.