New cases of parthenogenesis and polyploidy in the genus Ramazzottius (Tardigrada, Hypsibiidae) and a hypothesis concerning their origin.

Specimens of the genus Ramazzottius Binda and Pilato 1986; were obtained from 2 moss and one lichen sample(s) collected in the Emilian Apennine Mountians. R. tribulosus was only found in one sample, whereas R. oberhaeuseri wa sfound in all three. The first species had only diploid specimens, with 6 bivalents during the first meiotic division; the second had only females showing various polyploid cytotypes in addition to the diploid bisexual cytotype cited for this area. One of the triploid and the tetraploid cytotyoes were charactetized by the presence of univalents at oocyte metaphase, Though the large number of cytotypes found in a single sample may be attributed to chance, it is better explained by an in loco origin, at least in soem cases.