Karyotype characteristics of Chironomus fraternus Wülker and Ch. beljaninae Wülker (Diptera, Chironomidae) from Northern Russia

Abstract

Karyotypes of Chironomus fraternus Wülker (2n = 8) (cytocomplex thummi) and Ch. beljaninae Wülker (2n = 6) (cytocomplex modified thummi) from the aberratus group are described. Both species are recorded for the first time for the Russian fauna. Their karyotypes are similar in the banding sequences of chromosome arms A, C, D, E, and F, which suggests that Ch. fraternus and Ch. beljaninae are sister species. Besides the chromosome number, the two species differ in some karyotype markers, the amount of heterochromatin in the centromeres, and the chromosome arm combinations (AB, CD, EF, G in Ch. fraternus and GAB, CD, EF in Ch. beljaninae).