The determinants of male reproductive success in natural populations have not been measured for any fundulid species in North America. In this study, spawnings, courtship of females, and aggression toward other males, females, and heterospecifics were recorded during daylight hours in a natural population of bluefin killifish, Lucania goodei. Three main findings emerge. First, spawning success is correlated with male aggression toward other males and with male courtship of females, indicating that both male/male competition and female choice are likely to be operating. This result implies that both male/male competition and female choice must be considered in studies of sexual selection (as opposed to dichtomous choice tests, which preclude male/male competition). Second, males exhibited substantial levels of aggression toward both nonbreeding females and heterospecifics. Males may be guarding eggs, guarding food items, or trying to keep an open area around them so that they can be seen by gravid females. Third, a polymorphism is present where males had either yellow or red anal fins. Males of both morphs were in breeding condition and spawned with females. Potential mechanisms for the maintenance of the polymorphism are discussed.
|Original language||English (US)|
|Number of pages||6|
|State||Published - Aug 6 2001|
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science
- Animal Science and Zoology