Department of Zoology, Faculty of Science, Kasetsart University, Bangkok, Thailand.
Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Palermo, Italy.
Sci Rep. 2022 Feb 9;12(1):2218. doi: 10.1038/s41598-022-06295-4.
Tropodiaptomus is one of the most specious genera in the family Diaptomidae, but it is often rare in terms of distribution and abundance. Moreover, Tropodiaptomus species show a noteworthy variability in some of the morphological characters considered of prime importance in diaptomid taxonomy, and the presence of cryptic or pseudocryptic species is likely. Thus, through a geographically-wide sampling in Thailand, we aimed to investigate the local diversity of the genus and to compare the morphological and molecular diversity pattern based on mitochondrial and nuclear genes sequences. DNA taxonomy was also implemented in order to check whether the Tropodiaptomus lineages were independent species according to the "evolutionary genetic species concept". Six Tropodiaptomus morphospecies were found, three of which are putative species new to Science pending a formal description. The finding of such a high incidence of undescribed species stresses the existence of a significant "Linnean shortfall" affecting Thai diaptomids. The molecular results showed that most of the studied species could be identified consistently with their morphology-based taxonomy. However, Tropodiaptomus vicinus and T. cf. lanaonus showed a high level of genetic diversity, suggesting that traditional morphological techniques might be inadequate for correctly assessing their taxonomical status.
粗钩镖水蚤属是镖水蚤科中最具多态性的属之一，但在分布和丰度方面通常较为稀少。此外，粗钩镖水蚤种在一些被认为是镖水蚤分类学中最重要的形态特征上表现出显著的可变性，而且可能存在隐种或拟隐种。因此，通过在泰国进行广泛的地理采样，我们旨在调查该属的本地多样性，并比较基于线粒体和核基因序列的形态和分子多样性模式。还实施了 DNA 分类学，以检查根据“进化遗传物种概念”，粗钩镖水蚤的谱系是否为独立的物种。发现了六种粗钩镖水蚤形态种，其中三种是根据正式描述有待公布的科学新种。如此高比例的未描述物种的发现强调了存在着影响泰国镖水蚤的显著“林奈氏短差”。分子结果表明，大多数研究的物种可以与其基于形态的分类学一致地识别。然而，近缘粗钩镖水蚤和 T. cf. lanaonus 表现出高度的遗传多样性，这表明传统的形态学技术可能不足以正确评估它们的分类地位。
