Math and Science Program, Soka University of America, 1 University Drive, Aliso Viejo, CA, 92656, USA.
Department of Scientific Computing, Florida State University, 400 Dirac Science Library, Tallahassee, FL, 32306, USA.
Sci Rep. 2021 Apr 16;11(1):8351. doi: 10.1038/s41598-021-87255-2.
Ascidians (Phylum Chordata, Class Ascidiacea) are a large group of invertebrates which occupy a central role in the ecology of marine benthic communities. Many ascidian species have become successfully introduced around the world via anthropogenic vectors. The botryllid ascidians (Order Stolidobranchia, Family Styelidae) are a group of 53 colonial species, several of which are widespread throughout temperate or tropical and subtropical waters. However, the systematics and biology of this group of ascidians is not well-understood. To provide a systematic framework for this group, we have constructed a well-resolved phylogenomic tree using 200 novel loci and 55 specimens. A Principal Components Analysis of all species described in the literature using 31 taxonomic characteristics revealed that some species occupy a unique morphological space and can be easily identified using characteristics of adult colonies. For other species, additional information such as larval or life history characteristics may be required for taxonomic discrimination. Molecular barcodes are critical for guiding the delineation of morphologically similar species in this group.
海鞘（脊索动物门，尾索动物亚门）是一个大型的无脊椎动物群体，在海洋底栖生物群落的生态中占据核心地位。许多海鞘物种通过人为载体成功地在世界各地传播。瓶海鞘（头索动物亚门，海鞘科）是一个拥有 53 个群体物种的群体，其中一些物种广泛分布于温带或热带及亚热带水域。然而，该群体海鞘的系统发育和生物学还没有得到很好的理解。为了为这个群体提供一个系统的框架，我们使用 200 个新的基因座和 55 个标本构建了一个分辨率很高的系统发育基因组树。使用 31 个分类特征对文献中描述的所有物种进行主成分分析表明，一些物种占据独特的形态空间，可以通过成年群体的特征轻松识别。对于其他物种，可能需要幼虫或生活史特征等附加信息来进行分类鉴别。分子条形码对于指导该群体中形态相似物种的划分至关重要。
