Department of Biology, Brigham Young University, Provo, UT 84602, USA.
Mol Phylogenet Evol. 2013 Apr;67(1):15-27. doi: 10.1016/j.ympev.2012.12.019. Epub 2013 Jan 8.
The family Melanotaeniidae (rainbowfishes) represents the largest monophyletic group of freshwater fishes found in Australia and New Guinea. The family consists of seven genera and a total of 81 species, which are broadly distributed throughout the region. We conducted a phylogenetic analysis of Melanotaeniidae based on nearly complete taxonomic sampling of all species. We sequenced seven protein coding mitochondrial genes and the first two introns of the nuclear S7 gene, for a total of 6827 base pairs. Our goal was to use the phylogeny to infer the biogeographic history of rainbowfishes in this region, to provide a framework for the timing of divergence within the family, and to test for possible introgression between species. We found strong support for the monophyly of Melanotaeniidae. Three species-poor genera-Cairnsichthys, Rhadinocentrus and Iriatherina-were all resolved as early branching lineages within the family. The three species-rich genera-Melanotaenia, Chilatherina and Glossolepis-did not form a single monophyletic group, but instead formed three monophyletic groups endemic to discrete geographic regions: western New Guinea, northern New Guinea, and southern New Guinea plus Australia, respectively. All three geographic regions also contained three to four additional lineages that were separated by large genetic divergences and were frequently sympatric (except in western New Guinea). Our molecular clock results provide much older estimates of divergence than some aspects of the present geological setting. For instance, the formation of the present day Central Highlands, the integration of the Birds Head region with the rest of New Guinea, and the present proximate position of Waigeo and Batanta islands relative to the Birds Head, are all younger than the rainbowfishes living there based on our molecular clock estimates. We also identified ten species that have likely experienced historical introgression. Most introgression events were between different groups within the northern New Guinea lineage and the Southern New Guinea/Australian lineages. Finally, we identified nearly 20 undescribed species within Melanotaeniidae, demonstrating that much work remains in describing freshwater fish diversity in this region.
虹鳉科（彩虹鱼）代表了澳大利亚和新几内亚发现的最大的淡水鱼类单系群。该科由七个属和总共 81 个种组成，广泛分布于该地区。我们对虹鳉科进行了基于几乎所有物种的完整分类采样的系统发育分析。我们对七个蛋白质编码的线粒体基因和核 S7 基因的前两个内含子进行了测序，总共 6827 个碱基对。我们的目标是利用系统发育推断该地区彩虹鱼的生物地理历史，为家族内的分歧时间提供框架，并测试物种间可能的基因渗入。我们强烈支持虹鳉科的单系性。三个物种贫乏的属-Cairnsichthys、Rhadinocentrus 和 Iriatherina-在家族内均被解析为早期分支谱系。三个物种丰富的属-Melanotaenia、Chilatherina 和 Glossolepis-没有形成一个单系群，而是形成了三个特有的单系群，分别位于离散的地理区域：西新几内亚、北新几内亚和南新几内亚加上澳大利亚。这三个地理区域还包含了三到四个额外的谱系，它们之间存在着较大的遗传分歧，并且经常是同域的（西新几内亚除外）。我们的分子钟结果提供了比目前地质背景更古老的分歧估计。例如，中央高地的形成、鸟头地区与新几内亚其余地区的融合，以及 Waigeo 和 Batanta 岛屿相对于鸟头的当前位置，都比根据我们的分子钟估计生活在那里的彩虹鱼年轻。我们还确定了十个可能经历过历史基因渗入的物种。大多数基因渗入事件发生在北新几内亚谱系内的不同群体之间，以及南新几内亚/澳大利亚谱系之间。最后，我们在虹鳉科中鉴定出近 20 个未描述的物种，这表明在该地区描述淡水鱼类多样性仍有大量工作要做。
