Courtship and Tank Spawning Behavior of Temperate Basses (Genus Morone)

Abstract

Special arenas were used to observe and describe courtship and spawning behavior of captive striped bass Morone saxatilis, white bass Morone chrysops, and white perch Morone americana. To induce final gonadal maturation and spawning, fish were either implanted with gonadotropin-releasing hormone analog, injected with human chorionic gonadotropin, or both. Behaviors were videotaped and systematically quantified. Broodfish displayed courtship behavior for at least 5 h before spawning, characterized by one female and from one to five males releasing gametes at the water surface. Spawning lasted about 10 s for striped bass, 5 s for white bass, and less than 1 s for white perch. The best predictor of imminent spawning was a significant increase in male attending behavior, defined as extremely close and continuous following of the female, sometimes contacting her abdominal or vent area with the snout. Around the time of spawning, male striped bass attended females less intensely than did white bass or white perch. Just before and during spawning, male white perch and white bass displayed a stereotypical circling behavior whereas male striped bass did not. In volitional hybridization trials, white perch and white bass hybridized with one another, but striped bass and white bass did not. Electro-olfactogram recordings from juveniles of all three Morone species did not reveal sensitivity to any known teleost steroid or prostaglandin pheromone.