Sphaeromicola dudichi Klie, 1938, acommensal ostracod of the amphipod Chelura terebrans Philippi, 1839, is frequently found in the Mediterranean near Marseille. This ostracod proves to lay its eggs on the brood lamellae of the female, or on the gills of the male of Chelura, more frequently on the former. These eggs have been reared and the developmental stages are described and illustrated.