Lymphocystis tumours in the red mullet (Mullus surmuletus L.)

Abstract

A case of lymphocystis disease is descr. in M. surmuletus. The tumors showed typical lymphocystis cells in all stages of development from 9 to 430u in diam. The agglomerations of virus substance appear in young cells as several small granules which most probably merge into larger ones and form inclusions greatly resembling Guarnieri bodies. Their further development into a network follows the same lines as observed by other writers. There is no evidence in favor of the idea that these inclusion bodies may be derived from the nuclear substance of the cells. Various forms of degeneration of the lymphocystis cells have been descr. Special attention was given to the activity of the inclusion bodies in certain types of degenerating cells characterized by swelling of these bodies and rebuilding of their substance into more delicate networks exerting a lytic action on the cytoplasm of the host cell. At the end of this process the inclusion networks which up to that time stained readily with chromatin dyes become indistinguishable. It is suggested that these transformations may represent those stages in the life cycle of the virus agent during which it acquires the ability to transmit the infection to other cells of the same host or to other specimens.