Karyotype characteristics, larval morphology and chromosomal polymorphism peculiarities of Glyptotendipes salinus Michailova, 1983 (Diptera, Chironomidae) from Tambukan Lake, Central Caucasus

Abstract. Data on the karyotype characteristics, larval morphology and features of chromosomal polymorphism of a population of Glyptotendipes salinus Michailova, 1983 (Diptera, Chironomidae) from Tambukan Lake (on the northern macroslope of the central Caucasus) are presented. It was found that diagnostic larval characters of Glyptotendipes salinus from Caucasus in general are similar to those described in previous studies, but with some significant differences. By some morphological characteristics Caucasian larvae appeared to be closer to Glyptotendipes barbipes than to ones provided for European larvae of Glyptotendipes salinus by Contreras-Lichtenberg (1999). Obtained morphological data make possible to conclude that Caucasian population of Glyptotendipes salinus can be a markedly diverged population of the species, probably even subspecies. In the Caucasian population 12 banding sequences were found: two in arms A, B, C, E, and G, and one in arms D and F. Eight of these are already known for this species, and four, salA2, salB2, salEX, and salG3, are described for the first time. Genetic distances between all the previously studied populations of Glyptotendipes salinus were measured using Nei criteria (1972). The population of the central Caucasus occupies a distinct position on the dendrogram compared with populations from Altai and Kazakhstan. All the obtained morphological and cytogenetic data can indicate the plausible relative isolation and complexity of the Caucasus from the viewpoint of microevolution. More researches are required in other parts of Caucasus and other geographically distant regions for more specific allegations.