Histopathology of Infection of Crassostrea virginica (Gmelin) by Dermocystidium marinum Mackin, Owen, and Collier

Although mass mortalities of oysters suspected or known to be caused by disease have been reported at widely separated points in the world, few studies have been made of the pathology of infection by a known organism. This paper describes a study of the histopathological effects of infection of oysters by Dermocystidium marinum, which shows that the early stages are characterized by inflammation followed in turn by fibrosis and extensive lysis of the tissues. Under conditions of high temperature and high salinity massive infections develop, involving all tissues but producing most extensive damage to connective tissues, adductor muscle, digestive epithelium and blood vessels. Attention is called to the resemblance of this type of infection to certain mycoses of man.