Karyotype analysis of two oribatid mite species (Acari: Oribatida)

Abstract

The chromosomal parameters and karyotypic relationships may provide very valuable information about speciation and karyotype evolution. In the order Oribatida, the chromosomal data are limited to a few reports. In the present study, the chromosomal data of two species are provided for the first time. The diploid chromosome numbers are 2n = 14 in Oribotritia hermanni Grandjean, 1967 (Oribatida: Oribotritiidae) and 2n = 22 in Hermanniella gibber Kulijev, 1979 (Oribatida: Hermanniellidae) and chromosomes are small holocentric chromosomes. The smallest and largest chromosome sizes are 0.38 μm and 1.08 μm in O. hermanni, respectively. The total haploid chromosome length is 4.88 μm, in O. hermanni, and a higher value of 6.98 μm is recorded in H. gibber. The sex chromosomes could not be identified, because the oribatid mites show weak sexual dimorphism. In this respect, the results of the study provide important contributions to the cytotaxonomy of oribatid mites.