See text Dermocystidium is a genus of cyst-forming, eukaryotic fish parasites,[2] the causative agents of dermocystidiosis.
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,[3] and renamed as Ichthyosporea, and after expansion as Mesomycetozoa.
Parasites of crustacea (Dermocystidium daphniae) and molluscs (Dermocystidium marinum) placed in this genus have been found to be likely a bacterium and an alveolate, respectively: Sayre, Gherna and Wergin (1983) concluded that Dermocystidium daphniae was likely identical to Pasteuria ramosa Metchnikoff, 1888,[4] while D. marinum has been reclassified as Perkinsus marinus.