Abstract
In the bulbus arteriosus of goldfish Carassius auratus a subendothelial ‘reticular space’ was comprised of reticular‐like cells, neutrophils, medium‐sized granular leucocytes, phagocytes, endothelial cells and reticulo‐endothelial cells; herein, rodlet cells (RCs) accumulated and probably matured. Four classes of RCs were identified: (1) Those occurring in the reticular space and contacting reticular‐like cells; (2) those present in the reticular space contacting reticular‐like and endothelial cells; here the RCs were discharging; (3) those occurring in the bulbar lumen anchored to lining endothelial cells or other RCs; (4) those free in the bulbar lumen. There was no significant difference in the number of RCs among control and saline‐ and dexamethasone‐treated fish, but significant differences were found in RCs' class partition and in their discharge modality. In dexamethasone‐treated goldfish class (3) RCs were almost absent (2% v. 10% of the other experimental groups), moreover 35% of the RCs developed a ‘bleb’ discharge modality rather than the most typical ‘koronenartigen konfiguration’ which developed in the vast majority (90%) of the other experimental groups.