Perkinsus marinus is a species of alveolate belonging to the phylum Perkinsozoa. It is similar to a dinoflagellate. It is known as a prevalent pathogen of oysters, causing massive mortality in oyster populations. The disease it causes is known as dermo or perkinsosis, and is characterized by the degradation of oyster tissues. The genome of this species has been sequenced.
The species originally was named Dermocystidium marinum by Mackin, Owen and Collier in 1950.<!-- It is responsible for the oyster disease perkinsosis, also known as dermo.
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Taxonomy
Perkinsus marinus is a protozoan of the protist superphylum Alveolata, the alveolates. Its phylum, Perkinsozoa, is a relatively new taxon positioned between the dinoflagellates and the Apicomplexa, and is probably more closely related to the former.
Description and life cycle
The protist is about 2 to 4 μm long. The zoospore has two flagella, which it uses to swim in its marine habitat. It is ingested by its mollusc host, which is often an oyster of the genus Crassostrea. It then becomes a trophozoite, which proliferates in the tissues of the host. P. marinus often infests the hemocytes, cells in the blood of the host, analogous to malaria in vertebrates. It is also often seen in the cells of the intestine, connective tissues, digestive glands, and gills. Warmer winter ocean temperatures also promote outbreaks.
While laboratory studies of certain antibiotics have been promising, no methods of eradication are effective, so prevention is important. Oysters from populations or farms that have experienced disease should not be moved to areas without infestations, because the protist is easily introduced and transmitted. In aquaculture, efforts to locate and breed more resistant strains of oysters are ongoing.