Dermocystidium

Dermocystidium is a genus of cyst-forming, parasitic eukaryotes of fish, which are the causative agents of dermocystidiosis. The genus Dermocystidium was described in 1907. It was previously thought to be a genus of fungal parasites, related to the Thraustochytrida and Labyrinthulida (both those groups are now considered to be stramenopiles rather than fungi). Other biologists considered it to be a sporozoan protist. It was subsequently identified as one of a group of fish parasites (the 'DRIP clade') of previously uncertain affiliation, which were later identified as nonanimal, nonfungal opisthokonts, and renamed as Ichthyosporea, and after expansion as Mesomycetozoa. Parasites of crustacea (Dermocystidium daphniae) and molluscs (Dermocystidium marimum) placed in this genus have been found to be stramenopiles and reclassified as Lymphocystidium daphniae and Perkinsus marinus, respectively. The frog parasite Dermocystidium ranae has recently been segregated as Amphibiocystidium ranae.