The haemocytology and histology of the haemopoietic organs of South African freshwater fish. IV. Ultrastructure of some cells of Clarias gariepinus and Sarotherodon mossambicus.

This paper describes the ultrastructure of several cells found in the blood and haemopoietic tissues of the catfish (Clarias gariepinus) and the Mozambique bream (Sarotherodon mossambicus). The cells are haemocytoblasts, small lymphoid haemoblasts, thrombocytes, monocytes, lymphocytes, developing and mature neutrophilic granulocytes, plasma cells and macrophages. The various organelles normally found in mammalian haemocytes, plasma cells and macrophages were observed in those of fish. With the exception of the mature erythrocytes, which resemble the normoblasts of mammals, the various cells show distinct similarities to those of other fish species as well as of mammals.