New species of Alona from South-East Russia and Mongolia related to Alona salina Alonso, 1996 (Cladocera: Anomopoda: Chydoridae)

Two new species of genus Alona Baird, 1843 were found in regions along the south-east border of Asian Russia. Alona irinae sp. nov. was found in a lake in the plain of the Zeya River, a north tributary of the Amur River, and in a lake in the steppe region along the West coast of Baikal. Alona floessneri sp. nov. inhabits saline lake Uvs-Nuur on the border of Russia and West Mongolia, and several other saline lakes of Mongolia. Both species share numerous affinities with each other and with the Iberian species Alona salina Alonso, 1996, but differ in the shape and armament of postabdomen, sculpture of carapace, and size. Detailed morphology of Alona salina, including that of juveniles, was studied for the first time. Studied species belong to the elegans-group of species, likely of generic rank, which include also A. elegans Kurz, 1875 and A. orellanai Alonso, 1996.