The discovery of Scutovertex ianus sp. nov. (Acari, Oribatida) – a combined approach of comparative morphology, morphometry and molecular data

Based on morphological, morphometric and genetic data Scutovertex ianus sp. nov. is described as a new oribatid mite species. The traditional comparison with the morphologically most similar congeneric S. minutus and S. sculptus demonstrated that the new species shares certain characters with both species, but can be clearly identified by indistinct cuticular notogastral foveae in combination with short spiniform notogastral setae. Furthermore the eggs of S. ianus exhibit a different fine structure of the exochorion. The morphometric analysis of 16 continuous morphological variables separated the three species, S. minutus, S. sculptus and S. ianus with a certain overlap indicating minor size and shape differences in overall morphology. The molecular phylogenetic analysis of mitochondrial COI gene sequences supported the monophyly of all three investigated species and confirmed S. ianus as separate species with high bootstrap values. Each performed analysis approves the discreteness of S. ianus and the results contradict the formerly supposed large intraspecific variability of the representatives of the genus Scutovertex. The records of S. ianus are as yet restricted to the Eastern part of Austria and to one location in Germany, but findings of intermediary Scutovertex specimens from other European countries may refer to this new species.