Virginia Institute of Marine Science
Journal of Parsitology
An apical complex comparable to that found in the Sporozoa is described from zoospores of Dermocystidium marinum Mackin, Owen, and Collier, a pathogen of the American oyster (Crassostrea virginica Gmelin). The complex consists of a conoid, polar ring, up to 39 subplasmalemmal microtubules, rhoptries, and micronemes. Micropores and a subpellicular membrane equivalent were also found. Acid phosphatase activity was found in cisternae of the endoplasmic reticulum, inclusion bodies, and vesicles within the conoid lumen. No polysaccharides were detected in the rhoptries and micronemes using the Thiéry method. Observations indicate that D. marinum is a protozoan in the subphylum Apicomplexa and is most closely related to the coccidian Sporozoasida Leuckart.
Perkins, Frank O., Zoospores of the Oyster Pathogen, Dermocystidium marinum. I. Fine Structure of the Conoid and Other Sporozoan-Like Organelles (1976). Journal of Parsitology, 62(6), 959-974.