The karyotype of milnesium tardigradum doyère, 1840 (Eutardigrada: Apochela)

Abstract

The karyotype of the eutardigrade Milnesium tardigradum Doyère, 1840 from a parthenogenetic population is described for the first time. Mitotic cells prepared from early developmental stages revealed ten more or less rod-shaped telocentric chromosomes. Chromosomes are not uniform in size, and differ in length depending on the developmental stage and in compactness, i.e. namely the chromosomes in metaphase exhibit a polymorphic appearance in size and staining intensity. One pair of chromosomes is characteristic in most metaphases. Here, each chromosome is either nearly twice as long as the others or both can be observed as the densest chromatin. The diploid chromosome number of 2 n = 10 corresponds very well to that known from many other eutardigrades. © 2005 Taylor and Francis Group, LLC.