Ovisac secretion by the paired colleteric glands of Sacculina carcini and Heterosaccus dollfusi (Rhizocephala, Sacculinida) was documented and studied at the ultrastructural level. Preparatory to oviposition, the epithelium of each colleteric gland secretes one branched, elastic, transparent ovisac. The ovisac wall consists of a reticulated inner zone, secreted first, and a dense outer zone. After secretion, the ovisac detaches from most of the secretory epithelium but remains anchored proximally in the gland until oviposition ends. The exterior ovisac surface is predominantly smooth and impervious. Proximally, however, the surface is irregular and perforated. During oviposition the eggs enter the paired ovisacs, forcing the ovisacs through the ovipores... |