Guangxi Botanical Garden of Medicinal Plants Nanning, 530023, Guangxi, China.
Nanning Zoo Nanning, 530003, Guangxi, China.
Ecol Evol. 2014 Sep;4(17):3383-94. doi: 10.1002/ece3.1183. Epub 2014 Aug 18.
The black-spotted tokay and the red-spotted tokay are morphologically distinct and have largely allopatric distributions. The black-spotted tokay is characterized by a small body size and dark skin with sundry spots, while the red-spotted tokay has a relatively large body size and red spots. Based on morphological, karyotypic, genetic, and distribution differences, recent studies suggested their species status; however, their classifications remain controversial, and additional data such as ecological niches are necessary to establish firm hypotheses regarding their taxonomic status. We reconstructed their ecological niches models using climatic and geographic data. We then performed niche similarity tests (niche identity and background tests) and point-based analyses to explore whether ecological differentiation has occurred, and whether such differences are sufficient to explain the maintenance of their separate segments of environmental ranges. We found that both niche models of the black- and the red-spotted tokay had a good fit and a robust performance, as indicated by the high area under the curve (AUC) values ("black" = 0.982, SD = ± 0.002, "red" = 0.966 ± 0.02). Significant ecological differentiation across the entire geographic range was found, indicating that the involvement of ecological differentiation is important for species differentiation. Divergence along the environmental axes is highly associated with climatic conditions, with isothermality being important for the "black" form, while temperature seasonality, precipitation of warmest quarter, and annual temperature range together being important for the "red" form. These factors are likely important factors in niche differentiation between the two forms, which result in morphological replacement. Overall, beside morphological and genetic differentiation information, our results contribute to additional insights into taxonomic distinction and niche differentiation between the black- and the red-spotted tokay.
黑纹带肛棘蜥和红纹带肛棘蜥在形态上有明显的区别，且分布范围基本不同。黑纹带肛棘蜥体型较小，皮肤呈暗黑色，有各种斑点，而红纹带肛棘蜥体型相对较大，有红色斑点。基于形态学、染色体型、遗传学和分布差异，最近的研究表明它们具有物种地位；然而，它们的分类仍然存在争议，需要更多的数据，如生态位，来建立关于它们分类地位的可靠假设。我们使用气候和地理数据重建了它们的生态位模型。然后，我们进行了生态位相似性测试（生态位同质性和背景测试）和基于点的分析，以探索是否发生了生态分化，以及这种差异是否足以解释它们各自环境范围的维持。我们发现，黑纹带肛棘蜥和红纹带肛棘蜥的生态位模型拟合度都很好，表现稳健，曲线下面积（AUC）值较高（“黑”= 0.982，SD = ± 0.002，“红”= 0.966 ± 0.02）。在整个地理范围内发现了显著的生态分化，表明生态分化的参与对物种分化很重要。沿着环境轴的分歧与气候条件高度相关，等温性对“黑”型很重要，而最暖季度的降水量和年温差对“红”型很重要。这些因素很可能是两种形态之间生态位分化的重要因素，导致形态替代。总的来说，除了形态学和遗传学分化信息外，我们的结果有助于进一步了解黑纹带肛棘蜥和红纹带肛棘蜥之间的分类区别和生态位分化。
