Bau und Entstehung des Kopulationsorgans aus der Afterflosse. Kämpfe um Reviere und Rangordnung bei den Männchen: Bisse, Rammstöße, Maulkämpfe. Balz: Wiegen, Betupfen des Weibchens (Nippen), Rückwärtsschwimmen, Balztanz. Kopulation und Verankerung des männlichen Gonopodiums, "Gonopodialschwingen", Geburt (lebendgebärend). (Vgl. Film D 1178).

As an introduction, the male and female of the Green Swordtail are presented, the sexual differences, including the development of the gonopodium, is explained and the range of the species is shown. A high-ranking alpha-male drives a lover-ranking male away. Where only slight differences in rank occur, the males threaten each other frequently. If the rank-order is not yet decided, and two males are about the same size, aggression increases until an intensive fight begins. This will decide the future rank-order. The courtship patterns of the male, including possible variations, are first shown separately and then in sequence. During copulation the male inserts the tip of his gonopodium as an holdfast-mechanism into the female's genital opening. Finally, the birth of a number of young fish is shown. Very rapid sequences of motion are shown in slow motion (64 f/s).