Crayfish plague is a disease that mainly affects European crayfish of the genus Astacus. It is caused by the crayfish oomycete Aphanomyces astaci. The disease is highly invasive. It originated in North America. It arrived in Europe in the 19th century, probably through shipping, and then spread rapidly, wiping out much of the original crayfish populations. However, crayfish plague is still an ongoing threat today, affecting native populations of river and stone crayfish in streams in the Czech Republic. The disease is almost 100% fatal for native crayfish species. It attacks their nervous system, causing paralysis and eventually death. The main carriers of the disease are the North American species of signal crayfish and striped crayfish that have been introduced into our conditions. These species are immune to the causative agent of the disease and act as symptomless vectors with which the disease spreads upstream.
SVÚ Prague is the only department in the Czech Republic that routinely diagnoses the causative agent of crayfish plague.
