Abstract：
Chaetonotidae is the most diversified family of the entire phylum Gastrotricha; it comprises ~430 species distributed across 16 genera. The current classification, established mainly on morphological traits, has been challenged in recent years by phylogenetic studies, indicating that the cuticular ornamentations used to discriminate among species may be misleading when used to identify groupings, which has been the practice until now. Therefore, a consensus is developing toward implementing novel approaches to better define species identity and affiliation at a higher taxonomic ranking. Using an integrative morphological and molecular approach, including annotation of the mitogenome, we report on some freshwater gastrotrichs characterised by a mixture of two types of cuticular scales diagnostic of the genera Aspidiophorus and Heterolepidoderma . Our specimens\' overall anatomical characteristics find no correspondence in the taxa of these two genera, calling for their affiliation to a new species. Phylogenetic analyses based on the sequence of the ribosomal RNA genes of 96 taxa consistently found the new species unrelated to Aspidiophorus or Heterolepidoderma but allied with Chaetonotus aff. subtilis, as a subset of a larger clade, including mostly planktonic species. Morphological uniqueness and position along the non-monophyletic Chaetonotidae branch advocate erecting a new genus to accommodate the current specimens; consequently, the name Litigonotus ghinii gen. nov., sp. nov. is proposed. The complete mitochondrial genome of the new taxon resulted in a single circular molecule 14,384 bp long, including 13 protein-coding genes, 17 tRNA genes and 2 rRNAs genes, showing a perfect synteny and collinearity with the only other gastrotrich mitogenome available, a possible hint of a high level of conservation in the mitochondria of Chaetonotidae. ZooBank: urn:lsid:zoobank.org:pub:9803F659-306F-4EC3-A73B-8C704069F24A.
摘要：
Chaetontidae是整个胃门中最多样化的家族；它包括分布在16个属中的约430种。目前的分类,主要建立在形态性状上，近年来受到系统发育研究的挑战，表明用于区分物种的角质层装饰在用于识别分组时可能会产生误导，这一直是迄今为止的做法。因此,达成共识的方向是实施新的方法，以更好地定义更高的分类学排名的物种身份和隶属关系。使用综合形态学和分子方法，包括有丝分裂体的注释，我们报道了一些淡水胃病，其特征是两种类型的角质层鳞片的混合物，这些角质层鳞片可诊断为蛇形和异形皮。我们的标本的整体解剖特征在这两个属的分类群中找不到对应关系，呼吁他们加入一个新物种。基于96个分类单元的核糖体RNA基因序列的系统发育分析一致发现了新物种，该新物种与蛇形藻或杂皮藻无关，但与Chaetonotusaff相关。subtilis,作为一个更大进化枝的子集，主要包括浮游物种。沿非单系Chaetonotidae分支的形态独特性和位置主张建立新的属以适应当前的标本；因此，Litigonotusghiniigen的名字。11月。,sp.11月。是提议的。新分类单元的完整线粒体基因组产生了一个长度为14,384bp的单个环状分子，包括13个蛋白质编码基因，17个tRNA基因和2个rRNA基因，与其他唯一可用的胃分裂细胞有丝分裂体表现出完美的同质性和共线性，可能暗示了Chaetonotidae线粒体的高度保守性。ZooBank:urn:lsid:zoobank.org:pub:9803F659-306F-4EC3-A73B-8C704069F24A。
