Evidence for female heterogametic sex determination in paddlefish Polyodon spathula based on gynogenesis

A cohort of gynogenote paddlefish was stocked in a 26-ha lake and harvested nine years later. The sex ratio of these mature fish based on gonadal examination indicated that paddlefish female sex determination is heterogametic rather than the previously reported homogamety. Both sexually mature males and females were present (n=177). The observed sex ratio of 19.8% male: 80.2% female is consistent with the female heterogamety model and strengthens the emerging pattern in Acipenseriform fishes. (C) 2012 Elsevier B.V. All rights reserved.