The secondary zoospores have two flagella each and can repeatedly encyst before finally reaching a host, attaching and germinating.

[6] After its original introduction in Italy in 1860, it spread quickly through Europe and was discovered in Sweden in 1907, in Spain in 1972, in Norway in 1971, in Great Britain in 1981, in Turkey in 1984 and in Ireland in 1987.

[8] This species was studied and named by the German Mycologist Friedrich Schikora (1859–1932), from a type specimen in Germany in 1906.

[10] In the later stages, the muscles of the tail may appear whitened, or brownish-red where blood cells have encapsulated the hyphae.

The effects of the neurotoxins in the oomycete can include appearing in daytime (crayfish are typically nocturnal) and a lack of coordination.