Abstract：
Three nominal species of the killifish genus Aplocheilus are reported from the lowlands of Sri Lanka. Two of these, Aplocheilus dayi and Aplocheilus werneri, are considered endemic to the island, whereas Aplocheilus parvus is reported from both Sri Lanka and Peninsular India. Here, based on a collection from 28 locations in Sri Lanka, also including a dataset of Asian Aplocheilus downloaded from GenBank, we present a phylogeny constructed from the mitochondrial cytochrome b (cytb), mitochondrial cytochrome c oxidase subunit 1 (cox1), and nuclear recombination activating protein 1 (rag1), and investigate the interrelationships of the species of Aplocheilus in Sri Lanka. The endemic Sri Lankan aplocheilid clade comprising A. dayi and A. werneri is recovered as the sister group to the clade comprising A. parvus from Sri Lanka and Aplocheilus blockii from Peninsular India. The reciprocal monophyly of A. dayi and A. werneri is not supported in our molecular phylogeny. A. dayi and A. werneri display strong sexual dimorphism, but species-level differences are subtle, explained mostly by pigmentation patterns. Their phenotypes exhibit a parapatric distribution and may represent locally adapted forms of a single species. Alternatively, the present study does not rule out the possibility that A. dayi and A. werneri may represent an incipient species pair or that they have undergone introgression or hybridization in their contact zones. We provide evidence that the Nilwala-Gin region of southwestern Sri Lanka may have acted as a drought refugium for these fishes.
摘要：
据报道，斯里兰卡低地的killifish属Aplocheilus属的三种名义物种。其中两个，AplocheilusDayi和Aplocheiluswerneri,被认为是岛上的地方病，而Aplocheilusparvus则来自斯里兰卡和印度半岛。这里,根据斯里兰卡28个地点的收集，还包括从GenBank下载的亚洲Aplocheilus数据集，我们提出了由线粒体细胞色素b（cytb）构建的系统发育，线粒体细胞色素c氧化酶亚基1（cox1），和核重组激活蛋白1（rag1），并研究斯里兰卡Aplocheilus物种之间的相互关系。由A.dayi和A.werneri组成的特有的斯里兰卡aplocheilid进化枝被回收为来自斯里兰卡的A.parvus和来自印度半岛的Aplocheilusblockii的进化枝的姊妹组。在我们的分子系统发育中不支持A.dayi和A.werneri的互惠单生。A.Dayi和A.Werneri表现出强烈的性二态，但是物种水平的差异是微妙的，主要由色素沉着模式解释。它们的表型表现出超儿科分布，可能代表单个物种的局部适应形式。或者，本研究不排除A.dayi和A.werneri可能代表一个早期物种对，或者它们在其接触区经历了渗入或杂交的可能性。我们提供的证据表明，斯里兰卡西南部的Nilwala-Gin地区可能是这些鱼类的干旱避难所。
