Markers in the polytene chromosomes of freshwater Chironomus Meigen (Diptera, Chironomidae) species Author Michailova, Paraskeva text Zootaxa 2024 2024-05-22 5453 4 511 537 http://dx.doi.org/10.11646/zootaxa.5360.3.8 journal article 10.11646/zootaxa.5453.4.3 1175-5326 11239735 B535A3FF-151C-4070-9BE7-2FE6E3238847 Chironomus muratensis Ryser, Scholl & Wülker The chromosome set is 2n = 8. Chromosomes AB, CD are metacentric, EF—submetacentric and G—telocentric ( Fig. 8 ). The centromere regions of the chromosomes are characterized by distinct dark bands. The G chromosome is partially unconjugated. The NOR is next to the centromeric region of the chromosome. It has two BRs. Arm B has very well-developed BR. Two dark bands of the chromosome G are centrally located, separated by several lighter disks—species markers ( Fig. 8 ). The species is highly polymorphous—25 band sequences have been reported by Kiknadze et al (2016) . The material from Bulgaria has an inverted sequence in arm B ( Fig. 8 ). The arm C has an active NOR—a marker of the species. Forty-four individuals were studied. Collection sites : Plovdiv : fish pool.