Abstract

Morphological identification of the commonest Indian freshwater calanoid copepod Heliodiaptomus viduus has been facing a lot of controversies. To solve this problem, additional molecular support is needed. Hence, molecular analysis, along with morphological identification of the species using scanning electron microscopy (SEM) and optical microscopy, was carried out. The genetic distance between the intraspecific sequences in the 18SrRNA observed to be 0.000, while the interspecific distance within genus sequences varied from 0.000 to 0.002. Besides, it was noted that both the sequences (intraspecific) were present within a single clade of the phylogenetic trees with 100% bootstrap value. The genetic distance between the intraspecific sequences in the mtCOI observed to be 0.000, while the interspecific distance within genus sequences varied from 0.000 to 0.267 and lay in a separate clade in the phylogenetic tree from the within genus clade. Besides, it was noted that both the sequences (intraspecific) were present within a single clade of the phylogenetic tree with above 75% bootstrap value. Hence, the 18S rRNA (MH145356, MK457456) and mtCOI (MK621900) gene sequences of the present study are well supported the identification of H. viduus and it serves as the first molecular database besides providing morphological authentication (SEM images) of H.viduus. This combined analysis is envisioned to be helpful in selecting the ecologically and nutritionally important species for practical aquaculture

摘要

最常见的印度淡水calanoid桡足类Heliodiaptomus viduus的形态鉴定一直面临很多争议。为了解决这个问题，需要额外的分子支持。因此，进行了分子分析以及使用扫描电子显微镜 (SEM) 和光学显微镜对物种进行形态鉴定。观察到的 18SrRNA 中种内序列之间的遗传距离为 0.000，而属序列内的种间距离从 0.000 到 0.002 不等。此外，注意到两个序列（种内）都存在于系统发育树的一个进化枝中，具有 100% 的引导值。观察到的 mtCOI 中种内序列之间的遗传距离为 0.000，而属序列内的种间距离从 0.000 到 0.267 不等，并且位于系统发育树中与属内进化枝不同的进化枝中。此外，注意到两个序列（种内）都存在于系统发育树的单个进化枝中，具有超过 75% 的引导值。因此，本研究的 18S rRNA (MH145356, MK457456) 和 mtCOI (MK621900) 基因序列很好地支持了H. viduus，它作为第一个分子数据库，除了提供H.viduus的形态鉴定（SEM 图像） 。预计这种综合分析有助于为实际水产养殖选择具有生态和营养价值的重要物种