Oviparous Hermaphroditic Fish with Internal Self-Fertilization.

Adults of Rivulus marmoratus (Cyprinodontidae) contained eggs when dissected or laid eggs when kept alive. They invariably oviposited solo, emitting eggs in various developmental stages. Both juvenescent and senescent fish have functional ovotestes. Progeny (F3) were obtained via a selfed great grandparent, grandparent, and parent, the last two in isolation ab ovo.