Differences in copulatory behavior as partial isolating mechanisms in the poeciliid fish Gambusia

Autor: Alex E. Peden
Rok vydání: 1975
Předmět:
Zdroj: Canadian Journal of Zoology. 53:1290-1296
ISSN: 1480-3283
0008-4301
DOI: 10.1139/z75-154
Popis: Differences between species were found in the direction of gonopodial thrust of male Gambusia during copulation. Males of species such as G. heterochir, G. marshi, and G. regani direct their gonopodia posteriorly in the same direction as the orientation of their female's urogenital sinus. Males of G. affinis and G. gaigei direct their gonopodia anteriorly, as would be expected from the morphology of their conspecific female's urogenital opening. G. vittata males adopt a precopulatory posture oriented at a much larger angle in relation to the female than is that of other species of Gambusia. This precopulatory angle probably allows male G. vittata to direct their gonopodia posteriorly rather than anteriorly during copulation.Because species of male Gambusia are known to court heterospecific females and produce hybrids in nature, ethological prefertilization mechanisms preventing this wasted effort are obviously inefficient. Since copulatory behavior and genital morphology are apparently adapted for efficient sperm transfer during conspecific copulation, the differences in copulatory behavior found in Gambusia could provide a partial prefertilization mechanism subject to reinforcement.
Databáze: OpenAIRE