Phylogenetic position and redescription of Dastychius improvisus Dastych, 1984 – the first tardigrade species with molecular evidence of endosymbiotic Wolbachia infection

In present study we examined paratypes (from Zoologisches Museum of Hamburg, Germany) of D. improvisus and fresh material of this species from Vechernia Mt Base. Based on paratypes and new material we prepared a full set of measurements and microphotographs of this species and described some new morphological structures not reported in original description and later partial re-description. On the basis of molecular analyses of COI, 18S rRNA and 28S rRNA sequences we confirmed phylogenetical position of this genus in the family Isohypsibiidae. Moreover, we analysed also microbiome of D. improvisus to test the hypothesis that putative endosymbiont infections, i.e. intracellular Wolbachia, occur in tardigrade and can be identified in its microbiome community.