Bartylak Tomasz, Kulpa Adam, Grobys Daria, Kepel Marta, Kepel Andrzej, Kmita Hanna, Gawlak Magdalena, Grabiński Wojciech, Roszkowska Milena, Kaczmarek Łukasz
Department of Animal Taxonomy and Ecology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland..
Zootaxa. 2019 Nov 26;4701(1):zootaxa.4701.1.1. doi: 10.11646/zootaxa.4701.1.1.
The majority of species in the genus Echiniscus (Heterotardigrada) have been described based on differences in the chaetotaxy or dorsal sculpture. Dorsal sculpture is, in general, considered to be species-specific and not very variable; however, many problems have arisen due to various interpretations of microscope images, which has led to taxonomic confusion in the genus Echiniscus. Conversely, chaetotaxy is generally much easier to interpret, even using low-quality microscope optics. In this study, we emended the description of Madagascan population of Echiniscus tristis Gąsiorek & Kristensen, 2018 that exhibits several different types of chaetotaxy and dorsal sculpture. The analysed specimens were characterised by two types of chaetotaxy, A-C-Dd-E and A-Dd-E, but we also found a wide range of variation in appendage number, shape and length. The observed differences are partly correlated with life stages. Additionally, we analysed DNA sequences of 28S rRNA, ITS-2 and COI of the two main morphotypes, and did not find significant genetic differentiation of the two morphotypes. This highlights the importance of analysing the morphology of both immature stages and adults, as well as of DNA markers in tardigrade species identification.
棘影熊虫属（异缓步纲）的大多数物种是根据刚毛序或背部体表特征的差异来描述的。一般来说，背部体表特征被认为具有物种特异性且变化不大；然而，由于对显微镜图像的各种解读，出现了许多问题，这导致了棘影熊虫属的分类混乱。相反，即使使用低质量的显微镜光学设备，刚毛序通常也更容易解读。在本研究中，我们修订了2018年加斯奥雷克和克里斯滕森描述的马达加斯加棘影熊虫种群，该种群呈现出几种不同类型的刚毛序和背部体表特征。分析的标本具有两种刚毛序类型，即A - C - Dd - E和A - Dd - E，但我们也发现附肢数量、形状和长度存在广泛的变异。观察到的差异部分与生命阶段相关。此外，我们分析了两种主要形态型的28S rRNA、ITS - 2和COI的DNA序列，未发现这两种形态型之间存在显著的遗传分化。这凸显了在缓步动物物种鉴定中分析未成熟阶段和成虫形态以及DNA标记的重要性。
