Houde Anne E
Department of Zoology, University of Maryland, College Park, MD, 20742.
Evolution. 1987 Jan;41(1):1-10. doi: 10.1111/j.1558-5646.1987.tb05766.x.
This study tested the effect of differences in the extent of orange pigment in the color pattern of male guppies on the sexual responsiveness of females. Fish used in this study were descendants of a single natural population from the Paria River of Trinidad. Males from this population have unusually large, brilliant orange spots. I used three experimental approaches to test for discrimination by females among males based on the relative area of orange in color patterns: 1) the time to mating when a male was presented to a virgin female; 2) the frequency of sexual responses of females to passing, nondisplaying males; and 3) the proportion of a male's courtship displays that elicited a female sexual response. In all three experiments, females appeared to discriminate against males with less-than-average amounts of orange in their color patterns. In at least one experiment, however, the increase in female responsiveness with increasing amounts of orange leveled off and possibly decreased at high levels of orangeness. This suggests that there may be no advantage of increased amounts of orange above a certain level. These results suggest that female choice is a mechanism for the evolution of color patterns in guppies and may have contributed to the distinctive color pattern of the Paria population.
本研究测试了雄性孔雀鱼颜色图案中橙色色素含量差异对雌性性反应的影响。本研究中使用的鱼是特立尼达帕里亚河单一自然种群的后代。该种群的雄性有异常大且鲜艳的橙色斑点。我采用了三种实验方法来测试雌性是否会根据颜色图案中橙色的相对面积来区分雄性：1）将雄性展示给未交配过的雌性时的交配时间；2）雌性对路过且未展示的雄性的性反应频率；3）引发雌性性反应的雄性求偶展示的比例。在所有这三个实验中，雌性似乎会歧视颜色图案中橙色含量低于平均水平的雄性。然而，在至少一个实验中，随着橙色含量增加，雌性反应性的增加趋于平稳，并且在橙色含量较高时可能会下降。这表明橙色含量超过一定水平可能没有优势。这些结果表明，雌性选择是孔雀鱼颜色图案进化的一种机制，可能促成了帕里亚种群独特的颜色图案。
