想要征服一个女人的心，先要征服她的胃——至少对剑尾脂鲤来说是这样的。
这项日前在线发表于《当代生物学》（Current Biology)的发现，是第一个已知的所有物种中有雄性朝着类似食物的方向进化，以更好地赢取和异性交配机会的例子。
当这种热带淡水鱼的雄性想要交配时，它会在心仪的约会对象面前竖起来并摆动一种“装饰物”。这种类似旗帜的附属物，通常会隐藏在雄性剑尾脂鲤的身体附近。
这些装饰物的形状和大小各不相同。从上世纪60年代开始，研究人员就怀疑其形状能反映出雌性剑尾脂鲤所喜欢的食物。
现在，一个研究小组通过研究不同群落中雌性剑尾脂鲤的“食谱”和雄性鱼的装饰物变化情况，证实了上述推测。
研究发现，类似蚂蚁的装饰物，在主要以掉进溪流和河水中的蚂蚁为生的雌性剑尾脂鲤中深受欢迎；椭圆形的蛋状装饰物，则在偏好以甲虫和甲虫幼虫为食的雌性鱼中非常流行。
科学家们甚至能够在实验室中据此复制出以食物为基础的吸引物。这些生活在水族箱中的雌性剑尾脂鲤一生都以片状食品为食。但是，当研究人员将蚂蚁加进它们的“食谱”中并连续喂养十天之后，这些雌性鱼对类似蚂蚁的装饰物的喜爱程度超过了甲虫状装饰物。（生物谷Bioon.com）
doi:10.1016/j.cub.2012.05.050
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Diversification of a Food-Mimicking Male Ornament via Sensory Drive
Niclas Kolm, Mirjam Amcoff, Richard P. Mann, G?ran Arnqvist
The evolutionary divergence of sexual signals is often important during the formation of new animal species, but our understanding of the origin of signal diversity is limited [1,2]. Sensory drive, the optimization of communication signal efficiency through matching to the local environment, has been highlighted as a potential promoter of diversification and speciation [3]. The swordtail characin (Corynopoma riisei) is a tropical fish in which males display a flag-like ornament that elicits female foraging behavior during courtship. We show that the shape of the male ornament covaries with female diet across natural populations. More specifically, natural populations in which the female diet is more dominated by ants exhibit male ornaments more similar to the shape of an ant. Feeding experiments confirm that females habituated to a diet of ants prefer to bite at male ornaments from populations with a diet more dominated by ants. Our results show that the male ornament functions as a fishing lure that is diversifying in shape to match local variation in female search images employed during foraging. This direct link between variation in female feeding ecology and the evolutionary diversification of male sexual ornaments suggests that sensory drive may be a common engine of signal divergence.
