Ultrastructure of the macrogamont ofGoussia cichlidarumLandsberg and Paperna, 1985, a Coccidian parasite in the swimbladder of Cichlid fish

Abstract

Ultrastructural features of the macrogamont of Goussia cichlidarum , a coccidian parasite of cichlid fish are described. Host cells derived from the swimbladder lining epithelium are reduced to membranous sacs in early gamogony. These are displaced to the surface of the epithelium, but maintain their attachment until an early stage of oogony. An elaborate junction zone between the host cell and the epithelial cells suggests a nutritive function. Immature macrogamonts are bound by a double unit membrane with only a few micropores. Intravacuolar tubules are absent. Mature macrogamonts are bound by a single unit membrane and are surrounded by an additional two envelopes. Round organelles resembling wall-forming bodies of other coccidia, reach their maximum number and differentiation in mature macrogamonts.