Puebla Oscar, Bermingham Eldredge, Guichard Frédéric, Whiteman Elizabeth
Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Republic of Panama.
Proc Biol Sci. 2007 May 22;274(1615):1265-71. doi: 10.1098/rspb.2006.0435.
Theory shows that speciation in the presence of gene flow occurs only under narrow conditions. One of the most favourable scenarios for speciation with gene flow is established when a single trait is both under disruptive natural selection and used to cue assortative mating. Here, we demonstrate the potential for a single trait, colour pattern, to drive incipient speciation in the genus Hypoplectrus (Serranidae), coral reef fishes known for their striking colour polymorphism. We provide data demonstrating that sympatric Hypoplectrus colour morphs mate assortatively and are genetically distinct. Furthermore, we identify ecological conditions conducive to disruptive selection on colour pattern by presenting behavioural evidence of aggressive mimicry, whereby predatory Hypoplectrus colour morphs mimic the colour patterns of non-predatory reef fish species to increase their success approaching and attacking prey. We propose that colour-based assortative mating, combined with disruptive selection on colour pattern, is driving speciation in Hypoplectrus coral reef fishes.
理论表明，在基因流存在的情况下，物种形成仅在狭窄的条件下发生。对于有基因流的物种形成而言，最有利的情形之一是，单一性状既受到分裂性自然选择，又被用于引导选型交配。在此，我们证明了单一性状——体色模式，有可能推动 Hypoplectrus 属（锯鳃石鲈科）的初始物种形成，该属是珊瑚礁鱼类，以其显著的颜色多态性而闻名。我们提供的数据表明，同域分布的 Hypoplectrus 体色形态进行选型交配，且在基因上是有区别的。此外，我们通过呈现攻击性拟态的行为证据，确定了有利于对体色模式进行分裂性选择的生态条件，即掠食性 Hypoplectrus 体色形态模仿非掠食性珊瑚礁鱼类的体色模式，以提高其接近和攻击猎物的成功率。我们提出，基于颜色的选型交配，再加上对体色模式的分裂性选择，正在推动 Hypoplectrus 珊瑚礁鱼类的物种形成。
