Nelson Diane R, Adkins Fletcher Rebecca, Guidetti Roberto, Roszkowska Milena, Grobys Daria, Kaczmarek Łukasz
Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States of America.
Department of Appalachian Studies, East Tennessee State University, Johnson City, TN, United States of America.
PeerJ. 2020 Nov 23;8:e10251. doi: 10.7717/peerj.10251. eCollection 2020.
The phylum Tardigrada consists of over 1,300 species that inhabit terrestrial, freshwater and marine environments throughout the world. In terrestrial habitats they live primarily in mosses, lichens, leaf litter and soil, whereas tardigrades in freshwater and marine environments are mainly found in sediments and on aquatic plants. More than 65 species have been previously reported in the state of Tennessee, USA.
Tardigrades present in moss cushions ( sp.) collected from a xerothermic habitat on the East Tennessee State University campus, Johnson City, TN, USA, were extracted, mounted on slides, identified, and counted. Additional samples of fresh dried moss were used for integrative analyses, including morphological analysis with phase contrast (PCM) and scanning electron microscopy (SEM), as well as molecular analyses of COI, 18S rRNA, 28S rRNA, and ITS-2 of the and species.
Five species were found, including two species new to science: sp. nov. and sp. nov. sp. nov. differs from other members of the genus mainly by having a different type of dorsal cuticle and some other, more subtle, morphometric characters. In addition to the two new species, and were present, and males of were found for the first time, the first record of males in the genus . sp. nov. is most similar to , but it differs from mainly by the stylet supports being situated in a more anterior position, shorter and narrower egg processes, and a smaller number of areoles around the egg processes. Moreover, the identification of was confirmed as the first record for the USA by analysis of COI.
缓步动物门由1300多种物种组成，它们栖息于世界各地的陆地、淡水和海洋环境中。在陆地栖息地，它们主要生活在苔藓、地衣、落叶层和土壤中，而淡水和海洋环境中的缓步动物主要存在于沉积物和水生植物上。此前在美国田纳西州已报道过65多种。
从美国田纳西州约翰逊市东田纳西州立大学校园的一个干热栖息地采集的苔藓垫层（苔藓属）中的缓步动物被提取出来，安装在载玻片上，进行鉴定和计数。新鲜干燥苔藓的其他样本用于综合分析，包括相差显微镜（PCM）和扫描电子显微镜（SEM）的形态分析，以及苔藓属和苔藓属物种的细胞色素氧化酶亚基I（COI）、18S核糖体RNA、28S核糖体RNA和内转录间隔区2（ITS-2）的分子分析。
发现了5个物种，包括两个新物种：苔藓属新物种1和苔藓属新物种2。苔藓属新物种1与该属的其他成员不同，主要在于具有不同类型的背角质层和一些其他更细微的形态特征。除了这两个新物种外，还发现了苔藓属和苔藓属，并且首次发现了苔藓属的雄性个体，这是该属中雄性个体的首次记录。苔藓属新物种2与苔藓属最相似，但它与苔藓属的不同之处主要在于口针支撑位于更靠前的位置、卵突更短更窄，以及卵突周围的小区数量更少。此外，通过对COI的分析，确认苔藓属为美国首次记录。
