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.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 2001 • No. 3