GĄsiorek Piotr, Stec Daniel, Morek Witold, Michalczyk Łukasz
Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland.
Zootaxa. 2018 Apr 27;4415(1):45-75. doi: 10.11646/zootaxa.4415.1.2.
A laboratory strain identified as "Hypsibius dujardini" is one of the best studied tardigrade strains: it is widely used as a model organism in a variety of research projects, ranging from developmental and evolutionary biology through physiology and anatomy to astrobiology. Hypsibius dujardini, originally described from the Île-de-France by Doyère in the first half of the 19th century, is now the nominal species for the superfamily Hypsibioidea. The species was traditionally considered cosmopolitan despite the fact that insufficient, old and sometimes contradictory descriptions and records prevented adequate delineations of similar Hypsibius species. As a consequence, H. dujardini appeared to occur globally, from Norway to Samoa. In this paper, we provide the first integrated taxonomic redescription of H. dujardini. In addition to classic imaging by light microscopy and a comprehensive morphometric dataset, we present scanning electron photomicrographs, and DNA sequences for three nuclear markers (18S rRNA, 28S rRNA, ITS-2) and one mitochondrial marker (COI) that are characterised by various mutation rates. The results of our study reveal that a commercially available strain that is maintained in many laboratories throughout the world, and assumed to represent H. dujardini sensu stricto, represents, in fact, a new species: H. exemplaris sp. nov. Redescribing the nominal taxon for Hypsibiidae, we also redefine the family and amend the definitions of the subfamily Hypsibiinae and the genus Hypsibius. Moreover, we transfer H. arcticus (Murray, 1907) and Hypsibius conifer Mihelčič, 1938 to the genus Ramazzottius since the species exhibit claws and eggs of the Ramazzottius type. Finally, we designate H. fuhrmanni as subjectively invalid because the extremely poor description precludes identifying neotype material.
一种被鉴定为“杜氏高生熊虫（Hypsibius dujardini）”的实验室菌株是研究得最为透彻的缓步动物菌株之一：它在从发育生物学、进化生物学到生理学、解剖学乃至天体生物学等各种研究项目中被广泛用作模式生物。杜氏高生熊虫最初由多耶尔于19世纪上半叶在法兰西岛描述，现在是高生熊虫总科（Hypsibioidea）的模式种。尽管存在描述不足、年代久远且有时相互矛盾的情况，以及类似高生熊虫物种的划分不够充分，但该物种传统上被认为是世界性的。因此，杜氏高生熊虫似乎在全球都有出现，从挪威到萨摩亚。在本文中，我们首次对杜氏高生熊虫进行了综合分类学重新描述。除了通过光学显微镜进行经典成像以及提供全面的形态测量数据集外，我们还展示了扫描电子显微镜照片，以及三种核标记（18S rRNA、28S rRNA、ITS - 2）和一种线粒体标记（COI）的DNA序列，这些标记具有不同的突变率。我们的研究结果表明，一种在世界各地许多实验室中保存的、被认为代表狭义杜氏高生熊虫的市售菌株，实际上代表了一个新物种：典范高生熊虫（Hypsibius exemplaris sp. nov.）。在重新描述高生熊虫科的模式分类单元时，我们还重新定义了该科，并修订了高生熊虫亚科和高生熊虫属的定义。此外，由于北极高生熊虫（Hypsibius arcticus，默里，1907）和针叶高生熊虫（Hypsibius conifer，米海尔契奇，1938）表现出拉马佐蒂熊虫属（Ramazzottius）类型的爪和卵，我们将它们转移到拉马佐蒂熊虫属。最后，我们主观判定富氏高生熊虫（Hypsibius fuhrmanni）无效，因为其描述极其简略，无法确定新模材料。
