In vivo ion fluxes across the eggs of Armadillidium vulgare (Oniscidea: Isopoda): the role of the dorsal organ.

The thin-walled, lecithotrophic eggs of land isopods (suborder Oniscidea) are brooded in a fluid-filled maternal marsupium until a few days following the second embryonic molt. Eggs of Armadillidium vulgare possess a well-developed dorsal organ underlying a broad silver-staining saddle on the vitelline membrane. Based on its chloride permeability and known transport functions in planktotrophic crustaceans, we hypothesized that the dorsal organ …