Molecular Reproduction & Development Volume 79, Issue 7, July 2012 cover image

Planarians can exist in both innately sexual and asexual modes, and the latter can be sexualized by a feeding method. The Dugesia ryukyuensis pictured were experimentally sexualized via feeding. They develop hermaphroditic sexual organs, copulate, and lay crossfertilized eggs. Three spheres are cocoons that contain several fertilized eggs. More can be learned about the cellular basis for this switching process in Nodono and Matsumoto (this issue).