The karyotype of Apteranabropsis tonkinensis, described for the first time, is characterized by 2n_= 19 (XO) and 2n_=20 (XX). Successive stage of spermatogenesis were analysed.
E. Warchalowska-Sliwa, Department of Experimental Zoology, Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Slawkowska 17, 31-016 Krakow, Poland