Species of the genus Mesobiotus are some of the most often recorded eutardigrades throughout the world. The majority of Mesobiotus species have been described based on morphology of the eggs, which is the most important character in this genus, from the taxonomic point of view. In this paper, we analysed in detail the morphology of eggs, oral cavity armature and claws in all known Mesobiotus species. Precise analysis of eggs allowed the recognition of their huge diversity and the division of Mesobiotus egg types based morphological characters of egg shell (general shape of processes, sculpture of processes, morphology of process bases and structure of egg shell). Similarly, we distinguished five different types of oral cavity armature based on number of rows of teeth that are visible under the light microscopy. We also noted the taxonomic value of claw modifications observed in some Mesobiotus species. Furthermore, we analysed other morphological traits (e.g. placoids, lunules, cuticle granulation) of adult specimens, which are often used for species differentiation in classical tardigrade taxonomy. Additionally, here we provide a diagnostic key to the currently known species of the genus and discuss, in detail, some problems with the species identifications. Finally, alongside with the comprehensive revision, we provide an integrative description of a new Mesobiotus species found in a moss sample collected from Madagascar – Mesobiotus fiedleri sp. nov.

Mesobiotus属的物种是世界上最常被记录的eugraddigrades。从生物分类学的角度，大多数中观虾属物种已经根据卵的形态进行了描述，这是该属中最重要的特征。在本文中，我们详细分析了所有已知的Mesobiotus物种的卵，口腔电枢和爪的形态。鸡蛋的精确分析使人们认识到它们的巨大多样性和中生虾的分裂蛋的类型基于蛋壳的形态特征（工艺的一般形状，工艺的雕刻，工艺基础的形态和蛋壳的结构）。同样，我们根据在光学显微镜下可见的牙齿排数区分了五种不同类型的口腔电枢。我们还注意到在某些中生鞭毛虫中观察到的爪修饰的分类学价值种类。此外，我们分析了成年标本的其他形态特征（例如泥lac，钩针，角质层颗粒化），这些特征通常用于经典的缓坡分类学中的物种分化。此外，在这里，我们提供了当前已知属的诊断钥匙，并详细讨论了物种鉴定中的一些问题。最后，在进行全面修订的同时，我们对从马达加斯加采集的苔藓样本中发现的一种新的Mesobiotus物种进行了综合描述– fisolerus sp。十一月