A revision of the Macrobiotus hufelandi group (Tardigrada, Macrobiotidae), with some observations on the taxonomic characters of eutardigrades.

This study considers specimens of Macrobiotus hufelandi C. A. S. Schultze, 1834 collected from Italy and Germany, including the type locality. In addition to a qualitative analysis of the animals and eggs, statistics were performed on the measurements of the sclerified parts of the animals. The data illustrate low intra-species variability in the morphology of both the animals and the eggs. Differences in egg shell morphology, previously attributed to the variability of M. hufelandi, were found to fall into distinct types, related to different animal morphotypes. The data also indicate that M. hufelandi contains several new species: M. macrocalix sp.n., M. sandrae sp.n. and M. terminalis sp.n.; M. hufelandi is redescribed, and a neotype is assigned.