Integrative Description of a New Freshwater Tardigrade Species, <i>Dactylobiotus taiwanensis</i> (Tardigrada: Eutardigrada: Murrayidae), Discovered Through Social Media.

Two freshwater tardigrade populations belonging to the genus <i>Dactylobiotus</i> were investigated using phase contrast microscopy, scanning electron microscopy, and molecular markers commonly employed in tardigrade phylogenetic studies (18S rRNA, 28S rRNA, ITS2, and <i>COI</i>). The population from Taiwan, discovered through social media, represents a new species, described here as <i>Dactylobiotus taiwanensis</i> sp. nov. This species is most similar to <i>Dactylobiotus parthenogeneticus</i> but differs in the presence of singular rings of pores surrounding the egg processes and specific morphometric traits. The second population, from Greenland, was provisionally identified as <i>D.</i> cf. <i>octavi</i>, and its morphological discrepancies are discussed in detail. A revision of the type material for <i>Dactylobiotus caldarellai</i> and <i>Dactylobiotus lombardoi</i> raises questions about their validity due to insufficient data. Finally, a phylogenetic analysis incorporating taxa from the family Murrayidae, along with the newly sequenced populations, is presented. An updated dichotomous key for the genus <i>Dactylobiotus</i> is also provided.