McLennan Deborah A, Ryan Michael J
Department of Zoology, University of Texas, Austin, Texas, 78712.
Evolution. 1999 Jun;53(3):880-888. doi: 10.1111/j.1558-5646.1999.tb05382.x.
Female Xiphophorus montezumae were attracted to olfactory cues from conspecific and heterospecific (X. cortezi and X. nigrensis) males when given a choice between the stimulus and water. When given a choice between conspecific and heterospecific cues, females only demonstrated a strong preference for the conspecific stimulus when it was matched against X. nigrensis. Female X. nigrensis were attracted to olfactory cues from their close relative, X. cortezi, but did not respond to cues from the more distantly related X. montezumae. They preferred the scent of their own males to the olfactory cues of both heterospecific species. Our results indicate that X. cortezi and X. nigrensis share an apomorphic change in some aspect of their olfactory cue-receiver system that is not shared with X. montezumae. We also uncovered an asymmetry in response based on olfactory stimuli in these fishes: X. montezumae is moderately attracted to the cue from X. nigrensis, whereas X. nigrensis does not respond to the cue from X. montezumae at all.
当在刺激物和水之间进行选择时，雌性蒙特祖马剑尾鱼会被同种和异种（科尔特斯剑尾鱼和黑剑尾鱼）雄性的嗅觉线索所吸引。当在同种和异种线索之间进行选择时，只有当同种刺激物与黑剑尾鱼的刺激物相匹配时，雌性才表现出对同种刺激物的强烈偏好。黑剑尾鱼雌性被其近亲科尔特斯剑尾鱼的嗅觉线索所吸引，但对关系较远的蒙特祖马剑尾鱼的线索没有反应。与两种异种的嗅觉线索相比，它们更喜欢自己同种雄性的气味。我们的结果表明，科尔特斯剑尾鱼和黑剑尾鱼在嗅觉线索接收系统的某些方面存在共同的近裔性状变化，而蒙特祖马剑尾鱼则没有。我们还发现这些鱼类对嗅觉刺激的反应存在不对称性：蒙特祖马剑尾鱼会适度地被黑剑尾鱼的线索所吸引，而黑剑尾鱼对蒙特祖马剑尾鱼的线索则完全没有反应。
