FIGURE 1 in Redescription of Bythotrephes arcticus Lilljeborg, 1901 (Crustacea: Cladocera: Onychopoda) and confirmation of an independent species status of the distant Transcaucasian populations of the genus Bythotrephes Leydig

FIGURE 1. Bythotrephes arcticus Lilljeborg, adult parthenogenetic females and juveniles. A–G, I, K–M: lake 1 (basin of River Tchernaya, Bol'shezemelskaya tundra, Arkhangel'skaya region, North-Eastern European Russia). H: Lake Yan (basin of the River Pur, Western Siberia), J: Forelenmägen (Norway). A, general lateral view. B, antennule. C, upper lip (labrum) with anterior process. D, apical end of lower antennal branch, outer side. E, apical end of upper antennal branch, inner side. F, seta on apical end of upper antennal branch, outer side. G, distal part of caudal process. H, terminal setae of caudal process (juvenile specimen). I, thoracic limb of first pair (tl I) (C, anterior setae, see Fig. 2). J, armament of first segment and second segment of endopodite of tl I. K, distal setae of first segment of endopodite of tl I. L, distal end of second segment of endopodite of tl I. M, the same (juvenile specimen).