CHROMOSOMAL EVOLUTION IN DIPLOPODA (MYRIAPODA, ARTHROPODA)

A check-list of diplopod chromosomes of 60 species, so far investigated, with the chromosome numbers and sex-determining mechanism is presented. Chromosome numbers in diplopods range from 2n = 12 to 2n = 30, with the XY type of sex-mechanism in the male sex of majority of species. The main principles underlying the evolution of karyotypes, based on the numerical relationships of the chromosomes, are discussed. The major chromosomal rearrangements including Robertsonian changes and pericentric inversions, in addition to polyploidy, appear to have played some significant role in the chromosomal evolution of diplopods. A "Modal Hypothesis" for the karyotype evolution of Diplopoda has been suggested.