FIGURE 6. Acroperus angustatus Sars, 1863. A–H in Discrimination between two sibling species of Acroperus (Baird, 1843) from the Palearctic (Cladocera: Anomopoda: Chydoridae)

FIGURE 6. Acroperus angustatus Sars, 1863. A–H—specimens from Germany, Berlin Area, Petersdorfersee Lake: A–B—juvenile females of instar I–II, C—parthenogenetic female, D–E—ephippial female, F–G—juvenile males of instar I–II, H—adult male; I–K—parthenogenetic females: I—from Norway, Oslo, Lake Ostensjovand (specimen from G.O.Sars collection, slide F9012), J—from Belarus, Vitebsk Area, Miorskii district, Lake Obsterno, K - from Russia, Chita Area, Chita town, Lake Kenon. Scale bar 0.2 mm.