The reticuloendothelial system (RES) was studied in vivo in Oreochromis
mossambicus by injecting colloidal carbon particles. Histological and cytological
examination of the organs from 2 hours to day 10 after injection revealed
that the major organs of particle localization in O. mossambicus were spleen,
kidney, atrium of heart and dermis. Among these organs, spleen showed high
antigen trapping ability in its ellipsoids followed by kidney. In the heart the
ventricular endocardial cells were more phagocytic than the atrial endocardial
cells
