Kanyakumari Parakkai Centre for Sustainable Aquaculture, Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Tamil Nadu, India.
Department of Zoology, Manipur University, Imphal, India.
Mol Biol Rep. 2023 Nov;50(11):9707-9714. doi: 10.1007/s11033-023-08802-w. Epub 2023 Oct 6.
Horadandia brittani is a small cyprinid fish species initially discovered in the coastal floodplains of southern India. For almost 50 years, the genus Horadandia was monotypic with a single species confined to Sri Lanka. In 1992, a new species H. brittani was described from south-western India. Despite being described as a separate species, H. brittani was later considered a synonym of H. atukorali, but in 2013, researchers recognized it as a distinct species based on morphological differences. Despite this clarification, there was still a need to validate the identity of H. brittani and determine its evolutionary relationship with its closely related species using DNA sequences.
To address the uncertainties surrounding the identity of H. brittani, the present study utilized molecular techniques to generate DNA sequences. Sample collection involved obtaining specimens of H. brittani from their natural habitats. Subsequently, DNA was extracted from the collected samples, and the mitochondrial cytochrome C oxidase (COI) gene was amplified using appropriate methods.
The analysis of DNA sequences obtained from the COI gene revealed significant genetic distinctions between H. brittani and H. atukorali. The genetic distance values between these two species ranged from 3.21 to 3.63%, clearly indicating that these two species are genetically separate entities. The study successfully established the phylogenetic relationships between H. brittani and H. atukorali based on the COI gene sequences, further confirming the validity of H. brittani as a distinct and separate species.
The findings of this study conclusively demonstrate that H. brittani is a valid and separate species, distinct from H. atukorali. The genetic analysis based on mitochondrial COI gene sequences provided strong evidence for the differentiation between these two species. The molecular data generated in this research can be used to identify H. brittani quickly and accurately in the future.
霍拉丹迪亚 Brittani 是一种小型鲤科鱼类，最初在印度南部沿海洪泛区发现。近 50 年来，霍拉丹迪亚属一直是单种属，仅有一种物种局限于斯里兰卡。1992 年，一种新物种 H. brittani 从印度西南部被描述。尽管被描述为一个单独的物种，但后来认为 H. brittani 是 H. atukorali 的同义词，但在 2013 年，研究人员根据形态差异将其视为一个独特的物种。尽管如此，仍有必要利用 DNA 序列验证 H. brittani 的身份，并确定其与近亲物种的进化关系。
为了解决 H. brittani 身份的不确定性，本研究利用分子技术生成 DNA 序列。样本采集涉及从其自然栖息地获取 H. brittani 的标本。随后，从收集的样本中提取 DNA，并使用适当的方法扩增线粒体细胞色素 C 氧化酶（COI）基因。
从 COI 基因获得的 DNA 序列分析显示，H. brittani 和 H. atukorali 之间存在显著的遗传差异。这两个物种之间的遗传距离值在 3.21%至 3.63%之间，清楚地表明这两个物种在遗传上是独立的实体。该研究成功地根据 COI 基因序列建立了 H. brittani 和 H. atukorali 之间的系统发育关系，进一步证实了 H. brittani 作为一个独特和独立的物种的有效性。
本研究的结果明确表明，H. brittani 是一个有效的独立物种，与 H. atukorali 不同。基于线粒体 COI 基因序列的遗传分析为这两个物种的分化提供了有力证据。本研究中生成的分子数据可用于未来快速准确地识别 H. brittani。
